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Stanowisko: Profesor Telefon: +48 32 603 4167 Email:Marian.Nowak@polsl.pl Adres: ul. Krasińskiego 8, p.161 PL-40-019 Katowice |
Zainteresowania naukowe:
- Sonochemiczne wytwarzanie nanomateriałów (np. SbSI, SbSeI, SbSxSe1-x).
- Produkcja monokryształów, polikryształów i nanokryształów fotoferroelektryków (np. SbSI, SbSeI, SbSxSe1-xI, SbI3),
- Wytwarzanie materiałów optycznie nieliniowych (np. SbI3.3S8).
- Wytwarzanie opali, opali wypełniony fotoferroelektrykami oraz odwrotnych opali fotoferroelektrycznych (np. odwrotnych opali SbSI).
- Laserowa obróbka półprzewodników (np. laserowe wytwarzanie heterostruktur SbSI/Sb2S3 i podwójnych heterostruktur SbSI/Sb2S3/SbSI).
- Obliczanie rozkładu natężenia światła oraz koncentracji fotogenerowanych nośników ładunku elektrycznego w układach z wnęka optyczną.
- Wyznaczanie parametrów półprzewodników w różnych temperaturach, różnych polach elektrycznych i magnetycznych, przy różnym oświetleniu oraz w różnych atmosferach z wykorzystaniem zjawisk:
- optycznych (transmisja i odbicie zwierciadlane oraz dyfuzyjne, fotoodbicie),
- elektrycznych (stałoprądowe przewodnictwo elektryczne oraz spektroskopia impedancji),
- fotoelektrycznych (stałoprądowe i zmiennoprądowe fotoprzewodnictwo elektryczne, efekt fotowoltaiczny),
- magnetoelektrycznych (magnetoopór, efekt Halla oraz fotohalla),
- fotomagnetoelektrycznych (metody kontaktowe i bezkontaktowe).
- Badania fotoferroelektryków (np. SbSI),
- Badania elektryczne i optyczne nanomateriałów:
- półprzewodnikowych i ferroelektrycznych nanodrutów (e.g. SbSI, SbSeI,
SbSxSe1-xI), - nanorurek węglowych wypełnionych fotoferroelektrycznymi nanodrutami (np. SbSI@CNT, SbSeI@CNT),
- grafenu.
- półprzewodnikowych i ferroelektrycznych nanodrutów (e.g. SbSI, SbSeI,
- Nanosensory gazów i nanofotodetektory.
- Produkcja materiałów optycznie nieliniowych (np. SbI3.3S8).
- Wytwarzanie i badanie własności brązu o dużej zawartości cyny.
Publikacje:
2005 |
Nowak, M; Starczewska, A Steady-state photocarrier grating method of determining electronic states parameters in amorphous semiconductors Journal Article Journal of Non-Crystalline Solids, 351 (16–17), pp. 1383 - 1392, 2005, ISSN: 0022-3093. @article{Nowak20051383, title = {Steady-state photocarrier grating method of determining electronic states parameters in amorphous semiconductors}, author = {M. Nowak and A. Starczewska}, url = {http://www.sciencedirect.com/science/article/pii/S0022309305001705}, doi = {http://dx.doi.org/10.1016/j.jnoncrysol.2005.03.004}, issn = {0022-3093}, year = {2005}, date = {2005-01-01}, journal = {Journal of Non-Crystalline Solids}, volume = {351}, number = {16–17}, pages = {1383 - 1392}, abstract = {The steady-state photocarrier grating (SSPG) technique is usually used for determining the diffusion length of carriers in amorphous semiconductors. This technique uses the interference pattern obtained over an illuminated sample surface when two coherent radiation beams hit the sample at different angles of incidence. A figure of merit of these materials is a continuous distribution of electronic states over a so-called mobility gap. In the present paper the influence of an energetic distribution of electronic states on results of SSPG measurements is analyzed. Simultaneously, the influence of a spatial distribution of photogenerated carriers over semiconductor thickness is taken into account. Fitting of the angular dependence of the results of SSPG measurements with appropriate theoretical formulae allows the determination of energy levels and densities of acceptor and donor-like states in the investigated a-Si:H.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The steady-state photocarrier grating (SSPG) technique is usually used for determining the diffusion length of carriers in amorphous semiconductors. This technique uses the interference pattern obtained over an illuminated sample surface when two coherent radiation beams hit the sample at different angles of incidence. A figure of merit of these materials is a continuous distribution of electronic states over a so-called mobility gap. In the present paper the influence of an energetic distribution of electronic states on results of SSPG measurements is analyzed. Simultaneously, the influence of a spatial distribution of photogenerated carriers over semiconductor thickness is taken into account. Fitting of the angular dependence of the results of SSPG measurements with appropriate theoretical formulae allows the determination of energy levels and densities of acceptor and donor-like states in the investigated a-Si:H. |
Grabowski, A; Nowak, M; Śleziona, J Optical and conductive properties of AlSi-alloy/SiCp composites: application in modelling CO2 laser processing of composites Journal Article Optics and Lasers in Engineering, 43 (2), pp. 233 - 246, 2005, ISSN: 0143-8166. @article{Grabowski2005233, title = {Optical and conductive properties of AlSi-alloy/SiCp composites: application in modelling CO2 laser processing of composites}, author = {A. Grabowski and M. Nowak and J. Śleziona}, url = {http://www.sciencedirect.com/science/article/pii/S0143816604001319}, doi = {http://dx.doi.org/10.1016/j.optlaseng.2004.06.010}, issn = {0143-8166}, year = {2005}, date = {2005-01-01}, journal = {Optics and Lasers in Engineering}, volume = {43}, number = {2}, pages = {233 - 246}, abstract = {The optical properties—reflectivity, real part of the refractive index, absorption coefficient as well as the thermal and electrical conductivity of AlSi-alloy/SiCp composite were measured. The optical parameters and both conductivities decreased with the increase of SiCp particles volume in AlSi-alloy matrix. This decrease was almost linear for the volume fraction of SiCp particle up to 10 vol% of the total mass of the composite. For the 15 vol% of SiCp particles, the departure from linearity is connected with the presence of additional phases in AlSi-alloy/SiCp composite materials. The measured temperature dependencies of optical reflectivity and electrical conductivity for AlSi-alloy/SiCp 15 vol% are of metallic character. Modelling of the interaction of the CO2 laser radiation with AlSi-alloy/SiCp 15 vol% composite should allow to estimate the initiation time at which the surface composite reaches melting temperature.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The optical properties—reflectivity, real part of the refractive index, absorption coefficient as well as the thermal and electrical conductivity of AlSi-alloy/SiCp composite were measured. The optical parameters and both conductivities decreased with the increase of SiCp particles volume in AlSi-alloy matrix. This decrease was almost linear for the volume fraction of SiCp particle up to 10 vol% of the total mass of the composite. For the 15 vol% of SiCp particles, the departure from linearity is connected with the presence of additional phases in AlSi-alloy/SiCp composite materials. The measured temperature dependencies of optical reflectivity and electrical conductivity for AlSi-alloy/SiCp 15 vol% are of metallic character. Modelling of the interaction of the CO2 laser radiation with AlSi-alloy/SiCp 15 vol% composite should allow to estimate the initiation time at which the surface composite reaches melting temperature. |
2003 |
Duka, P; Nowak, M; Solecka, B Influence of acousto-optical modulation of laser radiation on the results of contactless photoelectromagnetic investigations Journal Article Proc. SPIE, 5229 , pp. 329-333, 2003. @article{doi:10.1117/12.520772, title = {Influence of acousto-optical modulation of laser radiation on the results of contactless photoelectromagnetic investigations}, author = {P. Duka and M. Nowak and B. Solecka}, url = {http://dx.doi.org/10.1117/12.520772}, doi = {10.1117/12.520772}, year = {2003}, date = {2003-01-01}, journal = {Proc. SPIE}, volume = {5229}, pages = {329-333}, abstract = {The contactless photoelectromagnetic (PEM) method of determining carrier lifetimes in semiconductors needs high frequency modulation of laser light. Recently the acoustooptical modulation technique was used for this purpose. In this paper the influence of frequency of acoustooptical modulation on time dependence of intensity of laser light was examined. One can recognize the importance of taking into account in contactless PEM investigations of carrier lifetime the dependence of amplitude of illumination on frequency of laser beam acoustooptical modulation.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The contactless photoelectromagnetic (PEM) method of determining carrier lifetimes in semiconductors needs high frequency modulation of laser light. Recently the acoustooptical modulation technique was used for this purpose. In this paper the influence of frequency of acoustooptical modulation on time dependence of intensity of laser light was examined. One can recognize the importance of taking into account in contactless PEM investigations of carrier lifetime the dependence of amplitude of illumination on frequency of laser beam acoustooptical modulation. |
Nowak, M; Szperlich, P; Kidawa, A; Kêpiñska, M; p. Gorczycki,; Kauch, B Optical and photoelectrical properties of SbSI 2003. @proceeding{doi:10.1117/12.518846, title = {Optical and photoelectrical properties of SbSI}, author = {M. Nowak and P. Szperlich and A. Kidawa and M. Kêpiñska and p. Gorczycki and B. Kauch}, url = {http://dx.doi.org/10.1117/12.518846}, doi = {10.1117/12.518846}, year = {2003}, date = {2003-01-01}, journal = {Proc. SPIE}, volume = {5136}, pages = {172-177}, abstract = {The optical transmittance and reflectance of SbSI single crystals had been measured for photon energies from 1.5 to 2.6 eV in temperature range from 77 K to 343 K. The experimental data had been evaluated to determine anisotropic, spectral and temperature dependences of real part of refractive index and absorption coefficient of SbSI. The temperature dependence of the energy gap had been evaluated from the spectral characteristics of absorption of light with electric field parallel and perpendicular to the c axis of the SbSI. The phase transition had been determined from the temperature dependences of optical parameters as well as from the temperature dependence of the energy gap. The photoconductivity of the investigated crystals had been measured as a function of photon energy, illumination intensity and temperature.}, keywords = {}, pubstate = {published}, tppubtype = {proceeding} } The optical transmittance and reflectance of SbSI single crystals had been measured for photon energies from 1.5 to 2.6 eV in temperature range from 77 K to 343 K. The experimental data had been evaluated to determine anisotropic, spectral and temperature dependences of real part of refractive index and absorption coefficient of SbSI. The temperature dependence of the energy gap had been evaluated from the spectral characteristics of absorption of light with electric field parallel and perpendicular to the c axis of the SbSI. The phase transition had been determined from the temperature dependences of optical parameters as well as from the temperature dependence of the energy gap. The photoconductivity of the investigated crystals had been measured as a function of photon energy, illumination intensity and temperature. |
2001 |
Jarząbek, B; Jurusik, J; Cisowski, J; Nowak, M Roughness of amorphous Zn-P thin films Journal Article Optica Applicata, 31 (1), pp. 93-101, 2001. @article{jarzkabek2001roughness, title = {Roughness of amorphous Zn-P thin films}, author = {B. Jarząbek and J. Jurusik and J. Cisowski and M. Nowak}, url = {http://yadda.icm.edu.pl/yadda/element/bwmeta1.element.baztech-article-BPW3-0009-0061}, year = {2001}, date = {2001-01-01}, journal = {Optica Applicata}, volume = {31}, number = {1}, pages = {93-101}, abstract = {The effect of thickness variation and the surface roughness of amorphous Zn/sub 32/P/sub 68/ thin films has been investigated by the interference spectroscopy of the optical transmittance and reflectance, as well as by the atomic force microscopy (AFM). The analysis of the optical data allowed determination of the standard deviation of the thin film thickness by taking into account the Gaussian distribution of the change in phase of radiation traversing a thin film. It appears that the value of the standard deviation of the film thickness determined from the optical interference spectroscopy ( sigma /sub w/ approximately=26 nm) is comparable with the value of the mean surface roughness (R/sub a/ approximately=19 nm) evaluated from the AFM studies.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The effect of thickness variation and the surface roughness of amorphous Zn/sub 32/P/sub 68/ thin films has been investigated by the interference spectroscopy of the optical transmittance and reflectance, as well as by the atomic force microscopy (AFM). The analysis of the optical data allowed determination of the standard deviation of the thin film thickness by taking into account the Gaussian distribution of the change in phase of radiation traversing a thin film. It appears that the value of the standard deviation of the film thickness determined from the optical interference spectroscopy ( sigma /sub w/ approximately=26 nm) is comparable with the value of the mean surface roughness (R/sub a/ approximately=19 nm) evaluated from the AFM studies. |
2000 |
Grabowski, A; Nowak, M Modification of the optical and electronics parameters in a-Si:H as a result of annealing with CO2 laser radiation Journal Article Proc. SPIE, 4238 , pp. 174-179, 2000. @article{doi:10.1117/12.405973, title = {Modification of the optical and electronics parameters in a-Si:H as a result of annealing with CO2 laser radiation}, author = {A. Grabowski and M. Nowak}, url = {http://dx.doi.org/10.1117/12.405973}, doi = {10.1117/12.405973}, year = {2000}, date = {2000-01-01}, journal = {Proc. SPIE}, volume = {4238}, pages = {174-179}, abstract = {Thin film of hydrogenated amorphous silicon (a-Si:H) were annealed using CO2 laser radiation ((lambda) equals10,6 micrometers ). The influence of this laser treatment on spectral dependencies of real part of refractive index and absorption coefficient of light in a-Si:H are presented. The values of energy gap have decreased while the Urbach energy increased after CO2 laser annealing of a-Si:H. The conductivity and photoconductivity of the annealed material have decreased. The power coefficient of the light intensity dependence of photoconductivity has also changed. The influence of CO2 laser irradiation on the energetic distribution of electron states of a a-Si:H is reported.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Thin film of hydrogenated amorphous silicon (a-Si:H) were annealed using CO2 laser radiation ((lambda) equals10,6 micrometers ). The influence of this laser treatment on spectral dependencies of real part of refractive index and absorption coefficient of light in a-Si:H are presented. The values of energy gap have decreased while the Urbach energy increased after CO2 laser annealing of a-Si:H. The conductivity and photoconductivity of the annealed material have decreased. The power coefficient of the light intensity dependence of photoconductivity has also changed. The influence of CO2 laser irradiation on the energetic distribution of electron states of a a-Si:H is reported. |
Nowak, M; Solecka, B Application of high-frequency contactless method of PEM investigations to examine near-surface layer of Si and GaAs Journal Article Vacuum, 57 (2), pp. 237 - 242, 2000, ISSN: 0042-207X. @article{Nowak2000237, title = {Application of high-frequency contactless method of PEM investigations to examine near-surface layer of Si and GaAs}, author = {M. Nowak and B. Solecka}, url = {http://www.sciencedirect.com/science/article/pii/S0042207X00001184}, doi = {http://dx.doi.org/10.1016/S0042-207X(00)00118-4}, issn = {0042-207X}, year = {2000}, date = {2000-01-01}, journal = {Vacuum}, volume = {57}, number = {2}, pages = {237 - 242}, abstract = {The recently reported contactless photoelectromagnetic (PEM) method of determining carrier lifetimes was used to investigate Ga : AS : Te and Si : B samples with polished and grinded surfaces. In the presented experiments the samples were illuminated with radiation of different wavelengths (and different absorption coefficients) emitted by diode lasers, argon and HeNe lasers acoustooptically modulated up to 100 kHz. The frequency dependence of PEM magnetic flux registered for cases of excess carriers photogeneration at different depths in a sample are presented and fitted with theoretical dependencies. It allows an evaluation of the bulk and near-surface region electron and hole lifetimes.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The recently reported contactless photoelectromagnetic (PEM) method of determining carrier lifetimes was used to investigate Ga : AS : Te and Si : B samples with polished and grinded surfaces. In the presented experiments the samples were illuminated with radiation of different wavelengths (and different absorption coefficients) emitted by diode lasers, argon and HeNe lasers acoustooptically modulated up to 100 kHz. The frequency dependence of PEM magnetic flux registered for cases of excess carriers photogeneration at different depths in a sample are presented and fitted with theoretical dependencies. It allows an evaluation of the bulk and near-surface region electron and hole lifetimes. |
1999 |
Nowak, M; Starczewska, A Influence of spatial distribution of radiation on steady-state photocarrier grating measurement Journal Article Journal of Non-Crystalline Solids, 260 (1–2), pp. 41 - 53, 1999, ISSN: 0022-3093. @article{Nowak199941, title = {Influence of spatial distribution of radiation on steady-state photocarrier grating measurement}, author = {M. Nowak and A. Starczewska}, url = {http://www.sciencedirect.com/science/article/pii/S0022309399005591}, doi = {http://dx.doi.org/10.1016/S0022-3093(99)00559-1}, issn = {0022-3093}, year = {1999}, date = {1999-01-01}, journal = {Journal of Non-Crystalline Solids}, volume = {260}, number = {1–2}, pages = {41 - 53}, abstract = {The influence of spatial distribution of radiation intensity on results of steady-state photocarrier grating (SSPG) measurements is analyzed. This technique uses the interference pattern obtained over an illuminated sample surface when two coherent radiation beams hit the sample at different angles of incidence. The sample usually consists of a thin semiconductor film on a thick, parallel-sided substrate. In this paper, the interference of radiation internally reflected in the thin film as well as internally reflected in the substrate are taken into consideration. These phenomena evoke complicated spatial distributions of radiation in a sample, and consequently they affect the magnitude of photoconductivity. The value of SSPG response can be even a few times greater than the predicted one for a homogeneous distribution of light over the thickness of a semiconductor film. If one does not take this effect into account, the carrier diffusion lengths estimated with the SSPG technique may vary from those suggested by the measurement.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The influence of spatial distribution of radiation intensity on results of steady-state photocarrier grating (SSPG) measurements is analyzed. This technique uses the interference pattern obtained over an illuminated sample surface when two coherent radiation beams hit the sample at different angles of incidence. The sample usually consists of a thin semiconductor film on a thick, parallel-sided substrate. In this paper, the interference of radiation internally reflected in the thin film as well as internally reflected in the substrate are taken into consideration. These phenomena evoke complicated spatial distributions of radiation in a sample, and consequently they affect the magnitude of photoconductivity. The value of SSPG response can be even a few times greater than the predicted one for a homogeneous distribution of light over the thickness of a semiconductor film. If one does not take this effect into account, the carrier diffusion lengths estimated with the SSPG technique may vary from those suggested by the measurement. |
Kochowski, S; Nowak, M An analysis of small-signal response of the SiO2–(n) GaAs interface based on a surface disorder model Journal Article Vacuum, 54 (1–4), pp. 183 - 188, 1999, ISSN: 0042-207X. @article{Kochowski1999183, title = {An analysis of small-signal response of the SiO2–(n) GaAs interface based on a surface disorder model}, author = {S. Kochowski and M. Nowak}, url = {http://www.sciencedirect.com/science/article/pii/S0042207X98004576}, doi = {http://dx.doi.org/10.1016/S0042-207X(98)00457-6}, issn = {0042-207X}, year = {1999}, date = {1999-01-01}, journal = {Vacuum}, volume = {54}, number = {1–4}, pages = {183 - 188}, abstract = {An attempt to clarify the frequency behaviour of the (n) GaAs–SiO2 interface has been presented. Metal–SiO2–GaAs structures with a PECVD-deposited insulator layer have been investigated. The measurements of capacitance–voltage characteristics at different frequencies as well as the frequency dependence of MIS capacitance and conductance at fixed gate voltages have been performed. A large frequency dispersion of MIS admittance has been revealed. The model of an insulator–semiconductor interface as a disordered system with localized electron states distributed in energy and in space can be used to explain the experimentally observed broad spectrum of time constants. The method of analysis of measured characteristics is based on a least-squares fitting of experimental data with theoretical dependencies allowed to determine the parameters of the interface states as well as some parameters of MIS structures.}, keywords = {}, pubstate = {published}, tppubtype = {article} } An attempt to clarify the frequency behaviour of the (n) GaAs–SiO2 interface has been presented. Metal–SiO2–GaAs structures with a PECVD-deposited insulator layer have been investigated. The measurements of capacitance–voltage characteristics at different frequencies as well as the frequency dependence of MIS capacitance and conductance at fixed gate voltages have been performed. A large frequency dispersion of MIS admittance has been revealed. The model of an insulator–semiconductor interface as a disordered system with localized electron states distributed in energy and in space can be used to explain the experimentally observed broad spectrum of time constants. The method of analysis of measured characteristics is based on a least-squares fitting of experimental data with theoretical dependencies allowed to determine the parameters of the interface states as well as some parameters of MIS structures. |
Augelli, V; Nowak, M Distribution of radiation intensity in a thin semiconductor film on a thick substrate Journal Article Thin Solid Films, 338 (1–2), pp. 188 - 196, 1999, ISSN: 0040-6090. @article{Augelli1999188, title = {Distribution of radiation intensity in a thin semiconductor film on a thick substrate}, author = {V. Augelli and M. Nowak}, url = {http://www.sciencedirect.com/science/article/pii/S0040609098009493}, doi = {http://dx.doi.org/10.1016/S0040-6090(98)00949-3}, issn = {0040-6090}, year = {1999}, date = {1999-01-01}, journal = {Thin Solid Films}, volume = {338}, number = {1–2}, pages = {188 - 196}, abstract = {Formulae describing the spatial distribution of radiation intensity in a thin semiconductor film on a relatively thick, transparent, parallel-sided substrate are given for the case of non-normal incidence of radiation. Internal reflection and interference of radiation in the film makes the radiation intensity very sensitive to geometrical and material parameters of the structure as well as to the wavelength, angle of incidence, and polarization of radiation. The influence of radiation wavelength range and uncertainties of film thickness and refractive index on the spatial distribution of radiation intensity is discussed. The presented formulae are useful in photoelectric and photoelectromagnetic investigations on thin-film semiconductors. They make the calculations about fifty times faster than those using the general equations.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Formulae describing the spatial distribution of radiation intensity in a thin semiconductor film on a relatively thick, transparent, parallel-sided substrate are given for the case of non-normal incidence of radiation. Internal reflection and interference of radiation in the film makes the radiation intensity very sensitive to geometrical and material parameters of the structure as well as to the wavelength, angle of incidence, and polarization of radiation. The influence of radiation wavelength range and uncertainties of film thickness and refractive index on the spatial distribution of radiation intensity is discussed. The presented formulae are useful in photoelectric and photoelectromagnetic investigations on thin-film semiconductors. They make the calculations about fifty times faster than those using the general equations. |
1998 |
Grabowski, A; Jaglarz, J; Nowak, M Optics & Laser Technology, 30 (3–4), pp. 183 - 187, 1998, ISSN: 0030-3992. @article{Grabowski1998183, title = {Angular distribution of intensity of reflected radiation investigations of the influence of CO2 laser treatment on optical properties of hydrogenated amorphous silicon}, author = {A. Grabowski and J. Jaglarz and M. Nowak}, url = {http://www.sciencedirect.com/science/article/pii/S0030399298000310}, doi = {http://dx.doi.org/10.1016/S0030-3992(98)00031-0}, issn = {0030-3992}, year = {1998}, date = {1998-01-01}, journal = {Optics & Laser Technology}, volume = {30}, number = {3–4}, pages = {183 - 187}, abstract = {Thin films of hydrogenated amorphous silicon (a-Si:H) were annealed using CO2 laser radiation (λ=10.6 μm). Changes of optical properties of the treated a-Si:H were investigated using optical transmittance spectroscopy and the angular distribution of intensity of reflected radiation (ADIRR). The CO2 laser annealing influences the spectral characteristics of the real part of refractive index n and absorption coefficient α of light in a-Si:H. This treatment increases the n and α values as well as the Urbach energy of a-Si:H. Simultaneously it decreases the optical energy gap of this material. The changes of optical parameters at the interfaces of a-Si:H–glass substrate and a-Si:H–air were established.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Thin films of hydrogenated amorphous silicon (a-Si:H) were annealed using CO2 laser radiation (λ=10.6 μm). Changes of optical properties of the treated a-Si:H were investigated using optical transmittance spectroscopy and the angular distribution of intensity of reflected radiation (ADIRR). The CO2 laser annealing influences the spectral characteristics of the real part of refractive index n and absorption coefficient α of light in a-Si:H. This treatment increases the n and α values as well as the Urbach energy of a-Si:H. Simultaneously it decreases the optical energy gap of this material. The changes of optical parameters at the interfaces of a-Si:H–glass substrate and a-Si:H–air were established. |
Jaglarz, J; Nowak, M Investigations of spatial distributions of intensity of radiation reflected from thin films which are inhomogeneous over thickness Journal Article Journal of Modern Optics, 45 (12), pp. 2451-2460, 1998. @article{doi:10.1080/09500349808230498, title = {Investigations of spatial distributions of intensity of radiation reflected from thin films which are inhomogeneous over thickness}, author = {J. Jaglarz and M. Nowak}, url = {http://dx.doi.org/10.1080/09500349808230498}, doi = {10.1080/09500349808230498}, year = {1998}, date = {1998-01-01}, journal = {Journal of Modern Optics}, volume = {45}, number = {12}, pages = {2451-2460}, abstract = {Abstract The angular distributions of the intensity of reflected radiation of thin films of amorphous silicon (a-Si) on thick transparent parallel-sided substrates illuminated with a light beam of finite diameter were fitted with theoretical dependences taking into account the optical inhomogeneity over the film thickness. This inhomogeneity was described by the values n f, αf, n b and αb of the real part of refractive index and absorption coefficient at the surface of the film. The investigated film was also characterized by the values of the real part of the refractive index and the absorption coefficient averaged over its thickness namely ñ and α respectively. Values of the parameters determined in different experiments (both side sample illumination and different polarities of light) are consistent. For the investigated a-Si, n b, < n f < ñ and α > α > αf.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Abstract The angular distributions of the intensity of reflected radiation of thin films of amorphous silicon (a-Si) on thick transparent parallel-sided substrates illuminated with a light beam of finite diameter were fitted with theoretical dependences taking into account the optical inhomogeneity over the film thickness. This inhomogeneity was described by the values n f, αf, n b and αb of the real part of refractive index and absorption coefficient at the surface of the film. The investigated film was also characterized by the values of the real part of the refractive index and the absorption coefficient averaged over its thickness namely ñ and α respectively. Values of the parameters determined in different experiments (both side sample illumination and different polarities of light) are consistent. For the investigated a-Si, n b, < n f < ñ and α > α > αf. |
Jaglarz, J; Nowak, M New technique of VAR investigations of thin films on thick substrates Journal Article NDT & E International, 31 (5), pp. 341 - 347, 1998, ISSN: 0963-8695. @article{Jaglarz1998341, title = {New technique of VAR investigations of thin films on thick substrates}, author = {J. Jaglarz and M. Nowak}, url = {http://www.sciencedirect.com/science/article/pii/S0963869598000176}, doi = {http://dx.doi.org/10.1016/S0963-8695(98)00017-6}, issn = {0963-8695}, year = {1998}, date = {1998-01-01}, journal = {NDT & E International}, volume = {31}, number = {5}, pages = {341 - 347}, abstract = {A new technique of variable angle reflectometry (VAR) investigations of thin films on thick, transparent, parallel-sided substrates is presented. This technique uses spatial distribution of intensity of reflected radiation of a sample illuminated with a light beam of finite diameter. The experimental results obtained for amorphous silicon (a-Si) were fitted with theoretical dependencies taking into account the optical inhomogeneity over the film thickness. This inhomogeneity was described by values nf, αf, nb and αb of the real part of the refractive index and absorption coefficient at the surfaces of the film. The investigated film was also characterized by the average over its thickness values of the real part of the refractive index and absorption coefficient . For the investigated a-Si . It can be suggested that the presented investigations of optical inhomogeneity of thin films of a-Si should be taken into serious consideration for optimized technological conditions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A new technique of variable angle reflectometry (VAR) investigations of thin films on thick, transparent, parallel-sided substrates is presented. This technique uses spatial distribution of intensity of reflected radiation of a sample illuminated with a light beam of finite diameter. The experimental results obtained for amorphous silicon (a-Si) were fitted with theoretical dependencies taking into account the optical inhomogeneity over the film thickness. This inhomogeneity was described by values nf, αf, nb and αb of the real part of the refractive index and absorption coefficient at the surfaces of the film. The investigated film was also characterized by the average over its thickness values of the real part of the refractive index and absorption coefficient . For the investigated a-Si . It can be suggested that the presented investigations of optical inhomogeneity of thin films of a-Si should be taken into serious consideration for optimized technological conditions. |
Kępińska, M; Nowak, M NDT & E International, 31 (2), pp. 105 - 110, 1998, ISSN: 0963-8695. @article{Kȩpińska1998105, title = {Comparison of optical constants and average thickness of inhomogeneous rough thin films obtained from special dependences of optical transmittance and reflectance}, author = {M. Kępińska and M. Nowak}, url = {http://www.sciencedirect.com/science/article/pii/S0963869597000169}, doi = {http://dx.doi.org/10.1016/S0963-8695(97)00016-9}, issn = {0963-8695}, year = {1998}, date = {1998-01-01}, journal = {NDT & E International}, volume = {31}, number = {2}, pages = {105 - 110}, abstract = {The knowledge of the optical and geometrical parameters of thin films is important for optics and optoelectronics. The comparison of spectral dependences of real part of refractive index and absorption coefficient of radiation in a-Si:H as well as thin film thickness and its standard deviation obtained from spectral dependences of optical transmittance T(λ) and/or R(λ) is presented. Taking into account the Gaussian distribution of the change in phase Γ of radiation traversing a thin film on the spectral characteristic T(λ) and R(λ) is the novelty of the used method of investigations. The consequences of linear and Gaussian distributions of Γ for R(λ) are shown the first time. It is shown that the values of optical parameters obtained from T(λ) and R(λ) simultaneously are more reliable, although the simpler investigations of T(hp) or R(hv) separately can give results comparable with them.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The knowledge of the optical and geometrical parameters of thin films is important for optics and optoelectronics. The comparison of spectral dependences of real part of refractive index and absorption coefficient of radiation in a-Si:H as well as thin film thickness and its standard deviation obtained from spectral dependences of optical transmittance T(λ) and/or R(λ) is presented. Taking into account the Gaussian distribution of the change in phase Γ of radiation traversing a thin film on the spectral characteristic T(λ) and R(λ) is the novelty of the used method of investigations. The consequences of linear and Gaussian distributions of Γ for R(λ) are shown the first time. It is shown that the values of optical parameters obtained from T(λ) and R(λ) simultaneously are more reliable, although the simpler investigations of T(hp) or R(hv) separately can give results comparable with them. |
1997 |
Loncierz, B; Nowak, M 1997. @proceeding{doi:10.1117/12.276215, title = {Determining carrier lifetime using frequency dependence in contactless photoelectromagnetic investigations of GaAs:Te, GaAs:Si, and MQW on GaAs}, author = {B. Loncierz and M. Nowak}, url = {http://dx.doi.org/10.1117/12.276215}, doi = {10.1117/12.276215}, year = {1997}, date = {1997-01-01}, journal = {Proc. SPIE}, volume = {3179}, pages = {151-157}, abstract = {Recently reported contactless photoelectromagnetic (PEM) method of determining carrier lifetime was used for the first time to measure carrier lifetimes in variously doped GaAs:Te, GaAs:Si as well as in multiquantum well structure grown on GaAs substrate. This method uses the dependence of PEM magnetic flux evoked in AC illuminated sample on frequency of chopping of the illumination intensity. In the presented experiments the samples were illuminated with radiation of different intensities and wavelengths emitted by diode lasers. The simple inspection of semiconductor wafer for laboratory and industrial purposes.}, keywords = {}, pubstate = {published}, tppubtype = {proceeding} } Recently reported contactless photoelectromagnetic (PEM) method of determining carrier lifetime was used for the first time to measure carrier lifetimes in variously doped GaAs:Te, GaAs:Si as well as in multiquantum well structure grown on GaAs substrate. This method uses the dependence of PEM magnetic flux evoked in AC illuminated sample on frequency of chopping of the illumination intensity. In the presented experiments the samples were illuminated with radiation of different intensities and wavelengths emitted by diode lasers. The simple inspection of semiconductor wafer for laboratory and industrial purposes. |
Kêpiñska, M; Nowak, M 1997. @proceeding{doi:10.1117/12.276214, title = {Optical and recombination parameters of GaSe obtained from interference spectroscopy of transmittance, reflectance, photoconductivity, and photomagnetoelectric responses}, author = {M. Kêpiñska and M. Nowak}, url = {http://dx.doi.org/10.1117/12.276214}, doi = {10.1117/12.276214}, year = {1997}, date = {1997-01-01}, journal = {Proc. SPIE}, volume = {3179}, pages = {147-150}, abstract = {Cleaved films of crystalline GaSe of thickness from 1500 nm to 5000 nm were investigated using optical transmittance, reflectance, photoconductivity (PC) and photoelectromagnetic effect. The investigations were performed, at room temperature for different illumination intensities and wavelengths. The oscillatory behavior of the measured spectral dependence is due to interference of radiation internally reflected in the samples were registered. The least square fitting of the experimental results with theoretical formulae allowed to determine the spectral dependencies of the real part of refractive index and absorption coefficient of radiation as well as the power coefficient in the power law dependence of PC on illumination intensity. The necessity of new theoretical description of he investigated effects is proposed.}, keywords = {}, pubstate = {published}, tppubtype = {proceeding} } Cleaved films of crystalline GaSe of thickness from 1500 nm to 5000 nm were investigated using optical transmittance, reflectance, photoconductivity (PC) and photoelectromagnetic effect. The investigations were performed, at room temperature for different illumination intensities and wavelengths. The oscillatory behavior of the measured spectral dependence is due to interference of radiation internally reflected in the samples were registered. The least square fitting of the experimental results with theoretical formulae allowed to determine the spectral dependencies of the real part of refractive index and absorption coefficient of radiation as well as the power coefficient in the power law dependence of PC on illumination intensity. The necessity of new theoretical description of he investigated effects is proposed. |
1996 |
Grabowski, A; Nowak, M; Tzanetakis, P Determination of recombination and photogeneration parameters of a-Si:H using photoconductivity measurements Journal Article Thin Solid Films, 283 (1–2), pp. 75 - 80, 1996, ISSN: 0040-6090. @article{Grabowski199675, title = {Determination of recombination and photogeneration parameters of a-Si:H using photoconductivity measurements}, author = {A. Grabowski and M. Nowak and P. Tzanetakis}, url = {http://www.sciencedirect.com/science/article/pii/0040609095085580}, doi = {http://dx.doi.org/10.1016/0040-6090(95)08558-0}, issn = {0040-6090}, year = {1996}, date = {1996-01-01}, journal = {Thin Solid Films}, volume = {283}, number = {1–2}, pages = {75 - 80}, abstract = {The non-linear dependence of photoconductivity (PC) on wavelength and intensity of illumination was used to evaluate the lifetime and quantum efficiency coefficient of carrier photogeneration in RF sputtered thin films of a-Si:H. The change of spatial distribution of radiation intensity over the sample thickness with the change of photon energy has been taken into account. Due to this, for the photon energies greater than the semiconductor energy gap, the decay of PC with an increase of absorption coefficient of radiation could be described using only one recombination parameter: the lifetime factor proportional to carrier lifetime. The comparison of the values of absorption coefficient obtained from the measurements of optical transmittance, CPM and the quantum efficiency coefficient is presented. The determination of carrier lifetime as a function of energy of photons that generate the free carriers is discussed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The non-linear dependence of photoconductivity (PC) on wavelength and intensity of illumination was used to evaluate the lifetime and quantum efficiency coefficient of carrier photogeneration in RF sputtered thin films of a-Si:H. The change of spatial distribution of radiation intensity over the sample thickness with the change of photon energy has been taken into account. Due to this, for the photon energies greater than the semiconductor energy gap, the decay of PC with an increase of absorption coefficient of radiation could be described using only one recombination parameter: the lifetime factor proportional to carrier lifetime. The comparison of the values of absorption coefficient obtained from the measurements of optical transmittance, CPM and the quantum efficiency coefficient is presented. The determination of carrier lifetime as a function of energy of photons that generate the free carriers is discussed. |
Jaglarz, J; Nowak, M Thin Solid Films, 278 (1–2), pp. 124 - 128, 1996, ISSN: 0040-6090. @article{Jaglarz1996124, title = {Determination of optical constants and average thickness of thin films on thick substrates using angular distribution of intensity of reflected radiation}, author = {J. Jaglarz and M. Nowak}, url = {http://www.sciencedirect.com/science/article/pii/0040609095081836}, doi = {http://dx.doi.org/10.1016/0040-6090(95)08183-6}, issn = {0040-6090}, year = {1996}, date = {1996-01-01}, journal = {Thin Solid Films}, volume = {278}, number = {1–2}, pages = {124 - 128}, abstract = {The angular distributions of intensity of reflected radiation (ADIRR) of thin a-Si films on thick, parallel-sided transparent substrates illuminated with light beam of finite diameter were fitted with theoretical dependencies. It enabled to evaluate refractive index, absorption coefficient, thickness and its variation over illuminated thin film area, as well as the refractive index of the substrate. The parameter values obtained are consistent with those determined by standard methods. The novel ADIRR method of investigation is complementary to multiple angle reflectometry and ellipsometry techniques and can be effectively used to determine parameters of thin films that weakly absorb the used radiation.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The angular distributions of intensity of reflected radiation (ADIRR) of thin a-Si films on thick, parallel-sided transparent substrates illuminated with light beam of finite diameter were fitted with theoretical dependencies. It enabled to evaluate refractive index, absorption coefficient, thickness and its variation over illuminated thin film area, as well as the refractive index of the substrate. The parameter values obtained are consistent with those determined by standard methods. The novel ADIRR method of investigation is complementary to multiple angle reflectometry and ellipsometry techniques and can be effectively used to determine parameters of thin films that weakly absorb the used radiation. |
1995 |
Loncierz, B; Muni, R; Nowak, M Determining carrier lifetime using frequency dependence in contactless photoelectromagnetic investigations of semiconductors Journal Article Thin Solid Films, 266 (2), pp. 274 - 277, 1995, ISSN: 0040-6090. @article{Loncierz1995274, title = {Determining carrier lifetime using frequency dependence in contactless photoelectromagnetic investigations of semiconductors}, author = {B. Loncierz and R. Muni and M. Nowak}, url = {http://www.sciencedirect.com/science/article/pii/0040609096800332}, doi = {http://dx.doi.org/10.1016/0040-6090(96)80033-2}, issn = {0040-6090}, year = {1995}, date = {1995-01-01}, journal = {Thin Solid Films}, volume = {266}, number = {2}, pages = {274 - 277}, abstract = {A new contactless method of determining the carrier lifetime in semiconductors is presented. It uses the dependence of the magnetic field evoked by photoelectromagnetic current in an illuminated semiconductor placed in an external magnetic field on the frequency of chopping the illumination intensity. This method was used to determine the electron lifetime in p-type crystalline silicon. It is suitable for rapid and simple inspection of a semiconductor wafer for laboratory and industrial purposes. The using of this method in investigations of superlattices and multi-quantum wells is proposed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A new contactless method of determining the carrier lifetime in semiconductors is presented. It uses the dependence of the magnetic field evoked by photoelectromagnetic current in an illuminated semiconductor placed in an external magnetic field on the frequency of chopping the illumination intensity. This method was used to determine the electron lifetime in p-type crystalline silicon. It is suitable for rapid and simple inspection of a semiconductor wafer for laboratory and industrial purposes. The using of this method in investigations of superlattices and multi-quantum wells is proposed. |
Nowak, M Linear distribution of intensity of radiation reflected from and transmitted through a thin film on a thick substrate Journal Article Thin Solid Films, 266 (2), pp. 258 - 262, 1995, ISSN: 0040-6090. @article{Nowak1995258, title = {Linear distribution of intensity of radiation reflected from and transmitted through a thin film on a thick substrate}, author = {M. Nowak}, url = {http://www.sciencedirect.com/science/article/pii/0040609096800307}, doi = {http://dx.doi.org/10.1016/0040-6090(96)80030-7}, issn = {0040-6090}, year = {1995}, date = {1995-01-01}, journal = {Thin Solid Films}, volume = {266}, number = {2}, pages = {258 - 262}, abstract = {A theoretical description of the linear distributions of intensities of radiation reflected from and transmitted through a thin film on a thick, transparent, parallel-sided substrate illuminated with light beam of a finite diameter is given. Results of numerical calculations show the dependences of these distributions on experiment conditions (polarization, wavelength, angle of incidence and spatial distribution of radiation in the incident light beam) as well as on optical and geometrical parameters of the sample (thickness, refractive index and absorption coefficient of the thin film, thickness and refractive index of the substrate). Investigation of the distribution of reflected radiation can be used as a new method of determining optical constants and thicknesses of thin films on thick, parallel-sided, transparent substrates.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A theoretical description of the linear distributions of intensities of radiation reflected from and transmitted through a thin film on a thick, transparent, parallel-sided substrate illuminated with light beam of a finite diameter is given. Results of numerical calculations show the dependences of these distributions on experiment conditions (polarization, wavelength, angle of incidence and spatial distribution of radiation in the incident light beam) as well as on optical and geometrical parameters of the sample (thickness, refractive index and absorption coefficient of the thin film, thickness and refractive index of the substrate). Investigation of the distribution of reflected radiation can be used as a new method of determining optical constants and thicknesses of thin films on thick, parallel-sided, transparent substrates. |
Nowak, M Determination of optical constants and average thickness of inhomogeneous-rough thin films using spectral dependence of optical transmittance Journal Article Thin Solid Films, 254 (1–2), pp. 200 - 210, 1995, ISSN: 0040-6090. @article{Nowak1995200, title = {Determination of optical constants and average thickness of inhomogeneous-rough thin films using spectral dependence of optical transmittance}, author = {M. Nowak}, url = {http://www.sciencedirect.com/science/article/pii/004060909406268P}, doi = {http://dx.doi.org/10.1016/0040-6090(94)06268-P}, issn = {0040-6090}, year = {1995}, date = {1995-01-01}, journal = {Thin Solid Films}, volume = {254}, number = {1–2}, pages = {200 - 210}, abstract = {The thickness variation, surface roughness, variation in refractive index, and illumination wavelength bandwidth strongly influence the optical transmittance of thin films. The consequences of linear and Gaussian distributions of the change in phase of radiation traversing a thin film on the spectral characteristics of optical transmittance are presented. A new method of determining the spectral dependences of the real part of the refractive index and absorption coefficient as well as thickness and standard deviation of its value is proposed for examinations of transmittance of thin films on thick substrates. This method takes into account the Gaussian distribution of the change in phase of radiation over the illuminated sample area. Its usefulness in investigations of the optical properties of a-Si:H is shown in comparison with the standard methods. The novel method gives film thickness more compatible with the result obtained using the multiple-beam interference method. The obtained values of optical parameters allow better fitting of the spectral characteristics of transmittance with the theoretical curve.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The thickness variation, surface roughness, variation in refractive index, and illumination wavelength bandwidth strongly influence the optical transmittance of thin films. The consequences of linear and Gaussian distributions of the change in phase of radiation traversing a thin film on the spectral characteristics of optical transmittance are presented. A new method of determining the spectral dependences of the real part of the refractive index and absorption coefficient as well as thickness and standard deviation of its value is proposed for examinations of transmittance of thin films on thick substrates. This method takes into account the Gaussian distribution of the change in phase of radiation over the illuminated sample area. Its usefulness in investigations of the optical properties of a-Si:H is shown in comparison with the standard methods. The novel method gives film thickness more compatible with the result obtained using the multiple-beam interference method. The obtained values of optical parameters allow better fitting of the spectral characteristics of transmittance with the theoretical curve. |
1994 |
Nowak, M Distribution of radiation intensity in a semiconductor film Journal Article Optical Engineering, 33 (5), pp. 1501-1510, 1994, ISBN: 0091-3286. @article{doi:10.1117/12.168372, title = {Distribution of radiation intensity in a semiconductor film}, author = {M. Nowak}, url = {http://dx.doi.org/10.1117/12.168372}, doi = {10.1117/12.168372}, isbn = {0091-3286}, year = {1994}, date = {1994-01-01}, journal = {Optical Engineering}, volume = {33}, number = {5}, pages = {1501-1510}, abstract = {Formulae describing the spatial distribution of radiation intensity in a semiconductor film in a multilayer structure are given for the case of non-normal incidence of radiation. Interference of radiation internally reflected in such a sample makes the radiation intensity very sensitive to geometrical and material parameters of the structure as well as to the wavelength, angle of incidence, and polarization of radiation. The influence of radiation wavelength range and uncertainties of film thickness and refractive index on the spatial distribution of radiation intensity is discussed. The case of a graded-gap semiconductor film is analyzed. The presented formulae are useful in photoelectric and photoelectromagnetic investigations of thin film semiconductors and are also useful for the optimization of photon detectors. }, keywords = {}, pubstate = {published}, tppubtype = {article} } Formulae describing the spatial distribution of radiation intensity in a semiconductor film in a multilayer structure are given for the case of non-normal incidence of radiation. Interference of radiation internally reflected in such a sample makes the radiation intensity very sensitive to geometrical and material parameters of the structure as well as to the wavelength, angle of incidence, and polarization of radiation. The influence of radiation wavelength range and uncertainties of film thickness and refractive index on the spatial distribution of radiation intensity is discussed. The case of a graded-gap semiconductor film is analyzed. The presented formulae are useful in photoelectric and photoelectromagnetic investigations of thin film semiconductors and are also useful for the optimization of photon detectors. |
1989 |
Augelli, V; Murri, R; Nowak, M Interference photoconductivity and photoelectromagnetic effect in amorphous silicon Journal Article Phys. Rev. B, 39 , pp. 8336–8346, 1989. @article{PhysRevB.39.8336, title = {Interference photoconductivity and photoelectromagnetic effect in amorphous silicon}, author = {V. Augelli and R. Murri and M. Nowak}, url = {http://link.aps.org/doi/10.1103/PhysRevB.39.8336}, doi = {10.1103/PhysRevB.39.8336}, year = {1989}, date = {1989-04-01}, journal = {Phys. Rev. B}, volume = {39}, pages = {8336--8346}, publisher = {American Physical Society}, abstract = {The existence of the so-called interference photoconductivity (PC) and photoelectromagnetic (PEM) effects in the investigated thin films of a-Si:H,F is shown. These effects appear due to interference of radiation in a sample. In this paper, the fitting of interference PC and PEM responses to theoretical relationships is presented. Values of carrier lifetime, diffusion length, and surface recombination velocity have been estimated. Spectral dependences of individual quantum efficiency coefficients for PC and PEM effects can give information about energy distribution and type of electronic states in the investigated samples. Influence of radiation intensity on optical and recombination parameters of the material is shown.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The existence of the so-called interference photoconductivity (PC) and photoelectromagnetic (PEM) effects in the investigated thin films of a-Si:H,F is shown. These effects appear due to interference of radiation in a sample. In this paper, the fitting of interference PC and PEM responses to theoretical relationships is presented. Values of carrier lifetime, diffusion length, and surface recombination velocity have been estimated. Spectral dependences of individual quantum efficiency coefficients for PC and PEM effects can give information about energy distribution and type of electronic states in the investigated samples. Influence of radiation intensity on optical and recombination parameters of the material is shown. |
Papaioannou, G J; Nowak, M; Euthymiou, P C Influence of illumination intensity on negative photoconductivity of Si ion‐implanted GaAs:Cr Journal Article Journal of Applied Physics, 65 (12), pp. 4864-4868, 1989. @article{:/content/aip/journal/jap/65/12/10.1063/1.343199, title = {Influence of illumination intensity on negative photoconductivity of Si ion‐implanted GaAs:Cr}, author = {G. J. Papaioannou and M. Nowak and P. C. Euthymiou}, url = {http://scitation.aip.org/deliver/fulltext/aip/journal/jap/65/12/1.343199.pdf?itemId=/content/aip/journal/jap/65/12/10.1063/1.343199&mimeType=pdf&containerItemId=content/aip/journal/jap}, doi = {10.1063/1.343199}, year = {1989}, date = {1989-01-01}, journal = {Journal of Applied Physics}, volume = {65}, number = {12}, pages = {4864-4868}, abstract = {Negative photoconductivity (PC) was observed in Si ion‐implanted GaAs:Cr below the fundamental band gap. The dependence of this effect on wavelength and intensity of illumination is reported. For photon energies slightly smaller than the optical energy gap the negative PC reverts into positive PC with increasing illumination intensity. Complementary investigations of PC in Si ion‐implanted, undoped GaAs also are presented. The physical reasons for the negative PC are discussed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Negative photoconductivity (PC) was observed in Si ion‐implanted GaAs:Cr below the fundamental band gap. The dependence of this effect on wavelength and intensity of illumination is reported. For photon energies slightly smaller than the optical energy gap the negative PC reverts into positive PC with increasing illumination intensity. Complementary investigations of PC in Si ion‐implanted, undoped GaAs also are presented. The physical reasons for the negative PC are discussed. |
1987 |
Nowak, M Photoelectromagnetic effect in semiconductors and its applications Journal Article Progress in Quantum Electronics, 11 (3–4), pp. 205 - 346, 1987, ISSN: 0079-6727. @article{Nowak1987205, title = {Photoelectromagnetic effect in semiconductors and its applications}, author = {M. Nowak}, url = {http://www.sciencedirect.com/science/article/pii/0079672787900012}, doi = {http://dx.doi.org/10.1016/0079-6727(87)90001-2}, issn = {0079-6727}, year = {1987}, date = {1987-01-01}, journal = {Progress in Quantum Electronics}, volume = {11}, number = {3–4}, pages = {205 - 346}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
1986 |
Kochowski, S; Nowak, M Estimation of surface state parameters using least squares in field-effect measurements Journal Article ACTA PHYSICA POLONICA A, 69 (4), pp. 517–524, 1986. @article{kochowski1986estimation, title = {Estimation of surface state parameters using least squares in field-effect measurements}, author = {S. Kochowski and M. Nowak}, year = {1986}, date = {1986-01-01}, journal = {ACTA PHYSICA POLONICA A}, volume = {69}, number = {4}, pages = {517--524}, publisher = {POLISH ACAD SCIENCES INST PHYSICS AL LOTNIKOW 32-46, 02-668 WARSAW, POLAND}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
1984 |
Nowak, M Oscillatory dependence of the interference photomagnetoelectric effect and photoconductivity on magnetic field Journal Article physica status solidi (a), 82 (1), pp. 249-256, 1984, ISSN: 1521-396X. @article{PSSA:PSSA2210820132, title = {Oscillatory dependence of the interference photomagnetoelectric effect and photoconductivity on magnetic field}, author = {M. Nowak}, url = {http://dx.doi.org/10.1002/pssa.2210820132}, doi = {10.1002/pssa.2210820132}, issn = {1521-396X}, year = {1984}, date = {1984-01-01}, journal = {physica status solidi (a)}, volume = {82}, number = {1}, pages = {249-256}, publisher = {WILEY-VCH Verlag}, abstract = {The possible existence of oscillatory dependences of interference PME and PC effects on strong but still non-quantizing magnetic fields is presented. Such dependences are evoked by the influence of magnetic field on the real part of the complex refractive index of a semiconductor. In special cases the periodicity of these oscillations varies as reciprocal of magnetic field. Due to these oscillations the PME effect can change its polarity with increasing magnetic field. Even for normal incidence of radiation upon isotropic semiconductor the PME and PC effects can be dependent on polarization of radiation.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The possible existence of oscillatory dependences of interference PME and PC effects on strong but still non-quantizing magnetic fields is presented. Such dependences are evoked by the influence of magnetic field on the real part of the complex refractive index of a semiconductor. In special cases the periodicity of these oscillations varies as reciprocal of magnetic field. Due to these oscillations the PME effect can change its polarity with increasing magnetic field. Even for normal incidence of radiation upon isotropic semiconductor the PME and PC effects can be dependent on polarization of radiation. |
Jóźwikowski, K; Nowak, M; Piotrowski, J Interference photoelectromagnetic effect in graded-gap semiconductors Journal Article Infrared Physics, 24 (4), pp. 371 - 380, 1984, ISSN: 0020-0891. @article{Jóźwikowski1984371, title = {Interference photoelectromagnetic effect in graded-gap semiconductors}, author = {K. Jóźwikowski and M. Nowak and J. Piotrowski}, url = {http://www.sciencedirect.com/science/article/pii/0020089184900289}, doi = {http://dx.doi.org/10.1016/0020-0891(84)90028-9}, issn = {0020-0891}, year = {1984}, date = {1984-01-01}, journal = {Infrared Physics}, volume = {24}, number = {4}, pages = {371 - 380}, abstract = {Numerical calculations describing the influence of the interference of internally-reflected radiation on the photoelectromagnetic (PEM) effect in graded energy-gap CdxHg1−xTe structures are presented. The spectral voltage responsivities of graded-gap IR-PEM detectors are reported as functions of the semiconductor structure thickness, composition profile of the structure, doping level, surface recombination velocity and reflection coefficient from the structure substrate. The thickness of graded-gap PEM detectors is one of the more important parameters which can affect their performance.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Numerical calculations describing the influence of the interference of internally-reflected radiation on the photoelectromagnetic (PEM) effect in graded energy-gap CdxHg1−xTe structures are presented. The spectral voltage responsivities of graded-gap IR-PEM detectors are reported as functions of the semiconductor structure thickness, composition profile of the structure, doping level, surface recombination velocity and reflection coefficient from the structure substrate. The thickness of graded-gap PEM detectors is one of the more important parameters which can affect their performance. |
Nowak, M; Polakowski, H “Dead temperature” for photoelectromagnetic detectors of infrared radiation Journal Article Infrared Physics, 24 (5), pp. 483 - 484, 1984, ISSN: 0020-0891. @article{Nowak1984483, title = {“Dead temperature” for photoelectromagnetic detectors of infrared radiation}, author = {M. Nowak and H. Polakowski}, url = {http://www.sciencedirect.com/science/article/pii/0020089184900095}, doi = {http://dx.doi.org/10.1016/0020-0891(84)90009-5}, issn = {0020-0891}, year = {1984}, date = {1984-01-01}, journal = {Infrared Physics}, volume = {24}, number = {5}, pages = {483 - 484}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Nowak, M; Łoś, S; Kończak, S Refractive index of silicon oxide surface films determined by polarization method of photomagnetoelectric investigation Journal Article Surface Science, 140 (2), pp. 446 - 454, 1984, ISSN: 0039-6028. @article{Nowak1984446, title = {Refractive index of silicon oxide surface films determined by polarization method of photomagnetoelectric investigation}, author = {M. Nowak and S. Łoś and S. Kończak}, url = {http://www.sciencedirect.com/science/article/pii/0039602884907453}, doi = {http://dx.doi.org/10.1016/0039-6028(84)90745-3}, issn = {0039-6028}, year = {1984}, date = {1984-01-01}, journal = {Surface Science}, volume = {140}, number = {2}, pages = {446 - 454}, abstract = {The polarization method of photomagnetoelectric investigation was used for determining values of refractive indexes of SiO2 surface layers. This method of investigation is complementary to ellipsometry. It is based on measurements of intensity of variously polarized radiation which enters semiconductor sample through the investigated surface layer. The SiO2 layers were obtained by thermal oxidation of 〈111〉 and 〈100〉 oriented silicon in different gases}, keywords = {}, pubstate = {published}, tppubtype = {article} } The polarization method of photomagnetoelectric investigation was used for determining values of refractive indexes of SiO2 surface layers. This method of investigation is complementary to ellipsometry. It is based on measurements of intensity of variously polarized radiation which enters semiconductor sample through the investigated surface layer. The SiO2 layers were obtained by thermal oxidation of 〈111〉 and 〈100〉 oriented silicon in different gases |
1983 |
Nowak, M Thin-film photoelectromagnetic detectors for infrared radiation Journal Article Infrared Physics, 23 (1), pp. 35 - 42, 1983, ISSN: 0020-0891. @article{Nowak198335, title = {Thin-film photoelectromagnetic detectors for infrared radiation}, author = {M. Nowak}, url = {http://www.sciencedirect.com/science/article/pii/0020089183900647}, doi = {http://dx.doi.org/10.1016/0020-0891(83)90064-7}, issn = {0020-0891}, year = {1983}, date = {1983-01-01}, journal = {Infrared Physics}, volume = {23}, number = {1}, pages = {35 - 42}, abstract = {Using the theory of the PEM effect for thin-film samples, in which the interference of radiation internally reflected from the sample surfaces is possible, the performance of PEM far-infrared detectors is discussed. The results of numerical computation done for CdHgTe at 300K are presented. The voltage responsivity, spectral responsivity, total responsivity, detectivity and time constant are reported as functions of sample thickness, magnetic field, and the semiconductor parameters: carrier lifetime, recombination velocities at illuminated and unilluminated sample surfaces, absorption coefficient and doping level. The thickness of thin-film PEM detectors is one of the more important parameters which can affect their performance.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Using the theory of the PEM effect for thin-film samples, in which the interference of radiation internally reflected from the sample surfaces is possible, the performance of PEM far-infrared detectors is discussed. The results of numerical computation done for CdHgTe at 300K are presented. The voltage responsivity, spectral responsivity, total responsivity, detectivity and time constant are reported as functions of sample thickness, magnetic field, and the semiconductor parameters: carrier lifetime, recombination velocities at illuminated and unilluminated sample surfaces, absorption coefficient and doping level. The thickness of thin-film PEM detectors is one of the more important parameters which can affect their performance. |
Nowak, M The photomagnetoelectric effect and photoconductivity for non-normal incidence of radiation Journal Article physica status solidi (a), 80 (2), pp. 691-702, 1983, ISSN: 1521-396X. @article{PSSA:PSSA2210800235, title = {The photomagnetoelectric effect and photoconductivity for non-normal incidence of radiation}, author = {M. Nowak}, url = {http://dx.doi.org/10.1002/pssa.2210800235}, doi = {10.1002/pssa.2210800235}, issn = {1521-396X}, year = {1983}, date = {1983-01-01}, journal = {physica status solidi (a)}, volume = {80}, number = {2}, pages = {691-702}, publisher = {WILEY-VCH Verlag}, abstract = {The theories of PME and PC effects are extended to the case of non-normal incidence of radiation into a semiconductor sample in which the interference of radiation internally reflected from the sample surfaces occurs. In a thin sample illuminated with weakly absorbed radiation, the dependence of PME and PC effects on the sample thickness, photon energy, and angle of incidence of radiation have oscillatory character. The PME effect can even change its polarization by increasing these experimental variables.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The theories of PME and PC effects are extended to the case of non-normal incidence of radiation into a semiconductor sample in which the interference of radiation internally reflected from the sample surfaces occurs. In a thin sample illuminated with weakly absorbed radiation, the dependence of PME and PC effects on the sample thickness, photon energy, and angle of incidence of radiation have oscillatory character. The PME effect can even change its polarization by increasing these experimental variables. |
1982 |
Nowak, M; Kończak, S; Madaj, F Some Comments on the Anomalous Photomagnetoelectric Effect Journal Article physica status solidi (a), 72 (2), pp. 503-509, 1982, ISSN: 1521-396X. @article{PSSA:PSSA2210720209, title = {Some Comments on the Anomalous Photomagnetoelectric Effect}, author = {M. Nowak and S. Kończak and F. Madaj}, url = {http://dx.doi.org/10.1002/pssa.2210720209}, doi = {10.1002/pssa.2210720209}, issn = {1521-396X}, year = {1982}, date = {1982-01-01}, journal = {physica status solidi (a)}, volume = {72}, number = {2}, pages = {503-509}, publisher = {WILEY-VCH Verlag}, abstract = {The dependence of the PME effect on the magnetic field is presented as a very sensitive material parameter function to describe the so-called anomalous PME effect. The fitting of the theoretical relation with the experimental data is done. The coexisting PME and photovoltaic effects are underlined as the possible reason for data interpretation difficulties.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The dependence of the PME effect on the magnetic field is presented as a very sensitive material parameter function to describe the so-called anomalous PME effect. The fitting of the theoretical relation with the experimental data is done. The coexisting PME and photovoltaic effects are underlined as the possible reason for data interpretation difficulties. |
Nowak, M The Dependence of the Photomagnetoelectric Effect on the Angle of Incidence of Radiation Journal Article physica status solidi (a), 74 (2), pp. 603-613, 1982, ISSN: 1521-396X. @article{PSSA:PSSA2210740227, title = {The Dependence of the Photomagnetoelectric Effect on the Angle of Incidence of Radiation}, author = {M. Nowak}, url = {http://dx.doi.org/10.1002/pssa.2210740227}, doi = {10.1002/pssa.2210740227}, issn = {1521-396X}, year = {1982}, date = {1982-01-01}, journal = {physica status solidi (a)}, volume = {74}, number = {2}, pages = {603-613}, publisher = {WILEY-VCH Verlag}, abstract = {The theory of the PME effect is extended for the case of non-normal incidence of radiation into a semiconductor covered with non-absorbing surface film. Numerical analyses performed for typical semiconductor parameters are presented. The polarization and angular dependence methods of PME investigation are proposed for determining surface film and semiconductor parameters. The results of investigations on p-Si covered with natural oxide film are reported.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The theory of the PME effect is extended for the case of non-normal incidence of radiation into a semiconductor covered with non-absorbing surface film. Numerical analyses performed for typical semiconductor parameters are presented. The polarization and angular dependence methods of PME investigation are proposed for determining surface film and semiconductor parameters. The results of investigations on p-Si covered with natural oxide film are reported. |
Nowak, M The Possible Existence of the Interference Photomagnetoelectric Effect Journal Article physica status solidi (a), 74 (1), pp. 313-322, 1982, ISSN: 1521-396X. @article{PSSA:PSSA2210740138, title = {The Possible Existence of the Interference Photomagnetoelectric Effect}, author = {M. Nowak}, url = {http://dx.doi.org/10.1002/pssa.2210740138}, doi = {10.1002/pssa.2210740138}, issn = {1521-396X}, year = {1982}, date = {1982-01-01}, journal = {physica status solidi (a)}, volume = {74}, number = {1}, pages = {313-322}, publisher = {WILEY-VCH Verlag}, abstract = {The theory of the PME effect is extended to the case of a thin sample in which the interference of the radiation reflected from the sample surfaces can be marked. The obtained results suggest the possible existence of a so-called interference photomagnetoelectric effect. The new, additional PME mechanism should be useful in optimization of the infrared PME detectors. It should also give the possibility of carrying out an electric method of measuring refractive indexes of semiconductors. As an example the dependences of the PME effect on sample thickness and wavelength of radiation are calculated for InSb.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The theory of the PME effect is extended to the case of a thin sample in which the interference of the radiation reflected from the sample surfaces can be marked. The obtained results suggest the possible existence of a so-called interference photomagnetoelectric effect. The new, additional PME mechanism should be useful in optimization of the infrared PME detectors. It should also give the possibility of carrying out an electric method of measuring refractive indexes of semiconductors. As an example the dependences of the PME effect on sample thickness and wavelength of radiation are calculated for InSb. |
1981 |
Kończak, S; Kotewicz, K; Nowak, M High-frequency photomagnetoelectric method for determining semiconductor parameters Journal Article physica status solidi (a), 65 (2), pp. 447-451, 1981, ISSN: 1521-396X. @article{PSSA:PSSA2210650205, title = {High-frequency photomagnetoelectric method for determining semiconductor parameters}, author = {S. Kończak and K. Kotewicz and M. Nowak}, url = {http://dx.doi.org/10.1002/pssa.2210650205}, doi = {10.1002/pssa.2210650205}, issn = {1521-396X}, year = {1981}, date = {1981-01-01}, journal = {physica status solidi (a)}, volume = {65}, number = {2}, pages = {447-451}, publisher = {WILEY-VCH Verlag}, abstract = {The high-frequency method of investigation of PME and PC effects is used for the measurements on silicon samples of different thickness. A method for testing the conformity of thick or thin samples, a theory to work out the experimental results is reported. An application of the acoustooptical modulation of a laser beam to the investigation of PME and PC effects is presented.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The high-frequency method of investigation of PME and PC effects is used for the measurements on silicon samples of different thickness. A method for testing the conformity of thick or thin samples, a theory to work out the experimental results is reported. An application of the acoustooptical modulation of a laser beam to the investigation of PME and PC effects is presented. |
1980 |
Kidawa, A; Nowak, M Some comments on polycrystalline Sb-S-I Journal Article Materials Science and Engineering, 46 (1), pp. 125 - 127, 1980, ISSN: 0025-5416. @article{Kidawa1980125, title = {Some comments on polycrystalline Sb-S-I}, author = {A. Kidawa and M. Nowak}, url = {http://www.sciencedirect.com/science/article/pii/0025541680901986}, doi = {http://dx.doi.org/10.1016/0025-5416(80)90198-6}, issn = {0025-5416}, year = {1980}, date = {1980-01-01}, journal = {Materials Science and Engineering}, volume = {46}, number = {1}, pages = {125 - 127}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
1979 |
Kończak, S; Nowak, M Some comments on the photomagnetoelectric effect Journal Article Surface Science, 87 (1), pp. 228 - 238, 1979, ISSN: 0039-6028. @article{Kończak1979228, title = {Some comments on the photomagnetoelectric effect}, author = {S. Kończak and M. Nowak}, url = {http://www.sciencedirect.com/science/article/pii/003960287990181X}, doi = {http://dx.doi.org/10.1016/0039-6028(79)90181-X}, issn = {0039-6028}, year = {1979}, date = {1979-01-01}, journal = {Surface Science}, volume = {87}, number = {1}, pages = {228 - 238}, abstract = {A generalization of the theory for the photomagnetoelectric effect (PME) is reported. Experimental quantities such as short circuit current, open circuit voltage and magnetoresistance are described as functions of carrier lifetime, surface velocities at the sample surfaces, electron and hole mobilities, electron and hole concentrations, absorption and quantum efficiency coefficients, intensity of light, magnetic field and sample dimensions. The results of numerical computation are also presented.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A generalization of the theory for the photomagnetoelectric effect (PME) is reported. Experimental quantities such as short circuit current, open circuit voltage and magnetoresistance are described as functions of carrier lifetime, surface velocities at the sample surfaces, electron and hole mobilities, electron and hole concentrations, absorption and quantum efficiency coefficients, intensity of light, magnetic field and sample dimensions. The results of numerical computation are also presented. |
