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Function: Assistant Professor Telefon: +48 32 603 4188 Email: Miroslawa.Kepinska@polsl.pl Adress: ul. Krasińskiego 8, p.162 PL-40-019 Katowice |
Research interests:
Publications:
2019 |
Jesionek, M; Toroń, B; Szperlich, P; Biniaś, W; Biniaś, D; Rabiej, S; Starczewska, A; Nowak, M; Kępińska, M; Dec, J Fabrication of a new PVDF/SbSI nanowire composite for smart wearable textile Journal Article Polymer, 180 , pp. 121729, 2019, ISSN: 0032-3861. @article{JESIONEK2019121729, title = {Fabrication of a new PVDF/SbSI nanowire composite for smart wearable textile}, author = {M. Jesionek and B. Toroń and P. Szperlich and W. Biniaś and D. Biniaś and S. Rabiej and A. Starczewska and M. Nowak and M. Kępińska and J. Dec}, url = {http://www.sciencedirect.com/science/article/pii/S0032386119307359}, doi = {https://doi.org/10.1016/j.polymer.2019.121729}, issn = {0032-3861}, year = {2019}, date = {2019-01-01}, journal = {Polymer}, volume = {180}, pages = {121729}, abstract = {In this paper, a new fabrication method for Polyvinylidene fluoride/SbSI nanowire composite is presented. Polyvinylidene fluoride (PVDF) is a specialist thermoplastic fluoropolymer with very good mechanical, chemical and thermal properties. Additionally, PVDF shows piezoelectric, pyroelectric, and ferroelectric properties. Antimony sulfoiodide (SbSI) nanowires (lateral dimensions of 10 nm–100 nm and lengths up to a few micrometres) are also piezoelectric compound with one of the best electromechanical and piezoelectric coefficient (k33 = 0.9 and dV = 0.9 × 10−9 C/N). SbSI nanowires have been added to improve piezoelectric properties of PVDF. The prepared SbSI nanowires were bound with PVDF in a mass ratio of 15:85, which was the fibre formation input with the addition of SbSI nanowires at different take-up velocities. An active layer of nanogenerator was prepared from the fabricated PVDF/SbSI nanowire composite. The preliminary investigations of compression and vibrations, allowed for the determination of the composites open circuit voltage 1.2 Vp-p and 2.5 Vp-p, respectively. Generated powers under impact have reached values PS = 408.8(52) μW/cm2 and PV = 3.464(53) mW/cm3, respectively.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this paper, a new fabrication method for Polyvinylidene fluoride/SbSI nanowire composite is presented. Polyvinylidene fluoride (PVDF) is a specialist thermoplastic fluoropolymer with very good mechanical, chemical and thermal properties. Additionally, PVDF shows piezoelectric, pyroelectric, and ferroelectric properties. Antimony sulfoiodide (SbSI) nanowires (lateral dimensions of 10 nm–100 nm and lengths up to a few micrometres) are also piezoelectric compound with one of the best electromechanical and piezoelectric coefficient (k33 = 0.9 and dV = 0.9 × 10−9 C/N). SbSI nanowires have been added to improve piezoelectric properties of PVDF. The prepared SbSI nanowires were bound with PVDF in a mass ratio of 15:85, which was the fibre formation input with the addition of SbSI nanowires at different take-up velocities. An active layer of nanogenerator was prepared from the fabricated PVDF/SbSI nanowire composite. The preliminary investigations of compression and vibrations, allowed for the determination of the composites open circuit voltage 1.2 Vp-p and 2.5 Vp-p, respectively. Generated powers under impact have reached values PS = 408.8(52) μW/cm2 and PV = 3.464(53) mW/cm3, respectively. |
2018 |
Jesionek, M; Nowak, M; Mistewicz, K; Kępińska, M; Stróż, D; Bednarczyk, I; Paszkiewicz, R Sonochemical growth of nanomaterials in carbon nanotube Journal Article Ultrasonics, 83 , pp. 179 - 187, 2018, ISSN: 0041-624X, (Ultrasonic advances applied to materials science). @article{JESIONEK2018179, title = {Sonochemical growth of nanomaterials in carbon nanotube}, author = {M. Jesionek and M. Nowak and K. Mistewicz and M. Kępińska and D. Stróż and I. Bednarczyk and R. Paszkiewicz}, url = {http://www.sciencedirect.com/science/article/pii/S0041624X16303936}, doi = {https://doi.org/10.1016/j.ultras.2017.03.014}, issn = {0041-624X}, year = {2018}, date = {2018-01-01}, journal = {Ultrasonics}, volume = {83}, pages = {179 - 187}, abstract = {Recent achievements in investigations of carbon nanotubes (CNTs) filled with ternary chalcohalides (antimony sulfoiodide (SbSI) and antimony selenoiodide (SbSeI)) are presented. Parameters of sonochemical encapsulation of nanocrystalline semiconducting ferroelectric SbSI-type materials in CNTs are reported. This low temperature technology is convenient, fast, efficient and environmentally friendly route for producing novel type of hybrid materials useful for nanodevices. Structure as well as optical and electrical properties of SbSI@CNTs and SbSeI@CNTs are described. Advantages of ultrasonic joining of such filled CNTs with metal microelectrodes are emphasized. The possible applications of these nanomaterials as gas sensors are shown.}, note = {Ultrasonic advances applied to materials science}, keywords = {}, pubstate = {published}, tppubtype = {article} } Recent achievements in investigations of carbon nanotubes (CNTs) filled with ternary chalcohalides (antimony sulfoiodide (SbSI) and antimony selenoiodide (SbSeI)) are presented. Parameters of sonochemical encapsulation of nanocrystalline semiconducting ferroelectric SbSI-type materials in CNTs are reported. This low temperature technology is convenient, fast, efficient and environmentally friendly route for producing novel type of hybrid materials useful for nanodevices. Structure as well as optical and electrical properties of SbSI@CNTs and SbSeI@CNTs are described. Advantages of ultrasonic joining of such filled CNTs with metal microelectrodes are emphasized. The possible applications of these nanomaterials as gas sensors are shown. |
2014 |
Jesionek, M; Nowak, M; Szperlich, P; Kępińska, M; Mistewicz, K; Toroń, B; Stróż, D; Szala, J; Rzychoń, T Properties of Sonochemically Prepared CuInxGa1-xS2 and CuInxGa1-xSe2 Journal Article Acta Physica Polonica A, 126 (5), pp. 1107 - 1109, 2014. @article{Jesionek2014, title = {Properties of Sonochemically Prepared CuInxGa1-xS2 and CuInxGa1-xSe2}, author = {M. Jesionek and M. Nowak and P. Szperlich and M. Kępińska and K. Mistewicz and B. Toroń and D. Stróż and J. Szala and T. Rzychoń }, url = {http://przyrbwn.icm.edu.pl/APP/PDF/126/a126z5p14.pdf}, doi = {10.12693/APhysPolA.126.1107}, year = {2014}, date = {2014-11-01}, journal = {Acta Physica Polonica A}, volume = {126}, number = {5}, pages = {1107 - 1109}, abstract = {Nanoparticles of chalcopyrites copper indium gallium sulfide (CuInxGa1-xS2 or CIGS) and copper indium gallium selenide (CuInxGa1-xSe2 or CIGSe) were fabricated sonochemically. They were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, high resolution transmission electron microscopy, selected area electron diffraction, and diffuse reflectance spectroscopy. The electrical and photoelectrical properties of the fabricated nanomaterials were investigated.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Nanoparticles of chalcopyrites copper indium gallium sulfide (CuInxGa1-xS2 or CIGS) and copper indium gallium selenide (CuInxGa1-xSe2 or CIGSe) were fabricated sonochemically. They were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, high resolution transmission electron microscopy, selected area electron diffraction, and diffuse reflectance spectroscopy. The electrical and photoelectrical properties of the fabricated nanomaterials were investigated. |
Toroń, B; Nowak, M; Kępińska, M; Szperlich, P Mobility of Ferroelectric Domains in Antimony Sulfoiodide Journal Article ACTA PHYSICA POLONICA A, 126 (5), pp. 1093-1095, 2014, ISSN: 0587-4246, (43rd Jaszowiec International School and Conference on the Physics of Semiconductors, Wisla, POLAND, JUN 07-12, 2014). @article{ISI:000346069100011, title = {Mobility of Ferroelectric Domains in Antimony Sulfoiodide}, author = {B. Toroń and M. Nowak and M. Kępińska and P. Szperlich}, url = {http://przyrbwn.icm.edu.pl/APP/PDF/126/a126z5p10.pdf}, doi = {10.12693/APhysPolA.126.1093 }, issn = {0587-4246}, year = {2014}, date = {2014-11-01}, journal = {ACTA PHYSICA POLONICA A}, volume = {126}, number = {5}, pages = {1093-1095}, organization = {Polish Acad Sci, Inst Phys; Univ Warsaw, Fac Phys, Inst Expt Phys; Univ Warsaw, Fac Phys, Inst Theoret Phys; Polish Acad Sci, Inst High Pressure Phys; Wroclaw Univ Technol, Inst Phys; Inst Elect Technol; Polish Acad Sci, Comm Phys; Fdn Pro Physica; Minist Sci & Higher Educ; US Off Naval Res Global; US Army Technol Ctr Atlantic; Ap Vacuum; Bruker; Comef; Karia; Labis; Pfeiffer Vacuum; Nano Carbon}, abstract = {Different optical energy gaps in ferroelectric and paraelectric phases as well as light scattering on domain walls allow to observe ferroelectric domains in antimony sulfoiodide (SbSI) near the Curie temperature. Mobility 8.11(44) x 10(-8) m(2)/(V s) of ferroelectric domain walls under external electric field has been determined along c-axis of SbSI single crystals using optical transmittance microscopy.}, note = {43rd Jaszowiec International School and Conference on the Physics of Semiconductors, Wisla, POLAND, JUN 07-12, 2014}, keywords = {}, pubstate = {published}, tppubtype = {article} } Different optical energy gaps in ferroelectric and paraelectric phases as well as light scattering on domain walls allow to observe ferroelectric domains in antimony sulfoiodide (SbSI) near the Curie temperature. Mobility 8.11(44) x 10(-8) m(2)/(V s) of ferroelectric domain walls under external electric field has been determined along c-axis of SbSI single crystals using optical transmittance microscopy. |
Kępińska, M; Starczewska, A; Bednarczyk, I; Szala, J; Szperlich, P; Mistewicz, K Fabrication and characterisation of SbI3-opal structures Journal Article Materials Letters, 130 (0), pp. 17 - 20, 2014, ISSN: 0167-577X. @article{Kêpiñska201417, title = {Fabrication and characterisation of SbI3-opal structures}, author = {M. Kępińska and A. Starczewska and I. Bednarczyk and J. Szala and P. Szperlich and K. Mistewicz}, url = {http://www.sciencedirect.com/science/article/pii/S0167577X1400843X}, doi = {http://dx.doi.org/10.1016/j.matlet.2014.05.063}, issn = {0167-577X}, year = {2014}, date = {2014-09-01}, journal = {Materials Letters}, volume = {130}, number = {0}, pages = {17 - 20}, abstract = {Abstract This work is focused on forming opal-antimony triiodide (SbI3) structures with direct SiO2 opal. SbI3 is a semiconductor having relatively high refractive index so potentially is very useful in fabrication of photonic crystal. Additionally, crystalline SbI3 exhibits the second-harmonic generation so obtained structures provide a wide range of opportunities for optoelectronic devices. Presented structures are fabricated by infiltration opal with SbI3 dissolved in ethanol and drying in room temperature. The morphology of the samples was characterized by scanning electron microscopy (SEM). The chemical composition of the samples was analyzed using energy dispersion spectroscopy (EDS). Optical properties were investigated by reflectance spectroscopy for wavelengths from 380 nm to 1050 nm.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Abstract This work is focused on forming opal-antimony triiodide (SbI3) structures with direct SiO2 opal. SbI3 is a semiconductor having relatively high refractive index so potentially is very useful in fabrication of photonic crystal. Additionally, crystalline SbI3 exhibits the second-harmonic generation so obtained structures provide a wide range of opportunities for optoelectronic devices. Presented structures are fabricated by infiltration opal with SbI3 dissolved in ethanol and drying in room temperature. The morphology of the samples was characterized by scanning electron microscopy (SEM). The chemical composition of the samples was analyzed using energy dispersion spectroscopy (EDS). Optical properties were investigated by reflectance spectroscopy for wavelengths from 380 nm to 1050 nm. |
Toroń, B; Nowak, M; Kępińska, M; Grabowski, A; Szala, J; Szperlich, P; Malka, I; Rzychoń, T A new heterostructures fabrication technique and properties of produced SbSI/Sb2S3 heterostructures Journal Article OPTICS AND LASERS IN ENGINEERING, 55 , pp. 232-236, 2014, ISSN: 0143-8166. @article{ISI:000331417300029, title = {A new heterostructures fabrication technique and properties of produced SbSI/Sb2S3 heterostructures}, author = {B. Toroń and M. Nowak and M. Kępińska and A. Grabowski and J. Szala and P. Szperlich and I. Malka and T. Rzychoń}, url = {http://www.sciencedirect.com/science/article/pii/S0143816613003473}, doi = {10.1016/j.optlaseng.2013.11.012}, issn = {0143-8166}, year = {2014}, date = {2014-04-01}, journal = {OPTICS AND LASERS IN ENGINEERING}, volume = {55}, pages = {232-236}, abstract = {A new technique for heterostructure fabrication in semiconducting compounds has been proposed. Heterojunctions have been made by applying CO2 laser beam. In contradistinction to currently applied methods (MBE - Molecular Beam Epitaxy and CVD - Chemical Vapor Deposition) the presented technique is simple, of low-cost and very efficient. The new technique has been tested on antimony sulfoiodide (SbSI) single crystals, i.e., a semiconducting, ferroelectric material characterized by many valuable properties. The most important structural, optical and electrical properties of the obtained heterostructures have been presented. Studies have shown that in the CO2 laser treated samples the junction exists between SbSI single crystal and amorphous phase of antimony sulfide (Sb2S3). At room temperature difference between energy gaps of both parts of SbSI/Sb2S3 heterostructure is equal to 0.3 eV. This leads to many interesting phenomena and potential applications. (C) 2013 Elsevier Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A new technique for heterostructure fabrication in semiconducting compounds has been proposed. Heterojunctions have been made by applying CO2 laser beam. In contradistinction to currently applied methods (MBE - Molecular Beam Epitaxy and CVD - Chemical Vapor Deposition) the presented technique is simple, of low-cost and very efficient. The new technique has been tested on antimony sulfoiodide (SbSI) single crystals, i.e., a semiconducting, ferroelectric material characterized by many valuable properties. The most important structural, optical and electrical properties of the obtained heterostructures have been presented. Studies have shown that in the CO2 laser treated samples the junction exists between SbSI single crystal and amorphous phase of antimony sulfide (Sb2S3). At room temperature difference between energy gaps of both parts of SbSI/Sb2S3 heterostructure is equal to 0.3 eV. This leads to many interesting phenomena and potential applications. (C) 2013 Elsevier Ltd. All rights reserved. |
Szperlich, P; Toroń, B; Nowak, M; Jesionek, M; Kępińska, M; Bogdanowicz, W Growth of large SbSI crystals Journal Article Materials Science-Poland, 32 (4), pp. 669-675, 2014, ISSN: 2083-1331. @article{, title = {Growth of large SbSI crystals}, author = {P. Szperlich and B. Toroń and M. Nowak and M. Jesionek and M. Kępińska and W. Bogdanowicz}, url = {http://dx.doi.org/10.2478/S13536-014-0247-4}, doi = {10.2478/S13536-014-0247-4}, issn = {2083-1331}, year = {2014}, date = {2014-01-01}, journal = {Materials Science-Poland}, volume = {32}, number = {4}, pages = {669-675}, publisher = {Versita}, abstract = {In this paper a novel method of SbSI single crystals fabrication is presented. In this method a sonochemically prepared SbSI gel is used as an intermediate product in a vapour growth process. The main advantages of the presented technique are as follows. First, the SbSI gel source material has lower temperature of sublimation and allows to avoid explosions during SbSI synthesis (the sonochemical synthesis is free of any explosion hazard). Second, but not least, the grown SbSI single crystals have smaller ratio of longitudinal and lateral dimensions. The cross sections of the presented crystals are relatively large (they are up to 9 mm2). The crystals have been characterized by X-ray diffraction, angle-resolved optical spectroscopy, and diffusive reflectivity.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this paper a novel method of SbSI single crystals fabrication is presented. In this method a sonochemically prepared SbSI gel is used as an intermediate product in a vapour growth process. The main advantages of the presented technique are as follows. First, the SbSI gel source material has lower temperature of sublimation and allows to avoid explosions during SbSI synthesis (the sonochemical synthesis is free of any explosion hazard). Second, but not least, the grown SbSI single crystals have smaller ratio of longitudinal and lateral dimensions. The cross sections of the presented crystals are relatively large (they are up to 9 mm2). The crystals have been characterized by X-ray diffraction, angle-resolved optical spectroscopy, and diffusive reflectivity. |
Nowak, M; Nowrot, A; Szperlich, P; Jesionek, M; Kępińska, M; Starczewska, A; Mistewicz, K; Stróż, D; Szala, J; Rzychoń, T; Talik, E; Wrzalik, R Fabrication and characterization of SbSI gel for humidity sensors Journal Article Sensors and Actuators A: Physical, 210 (0), pp. 119 - 130, 2014, ISSN: 0924-4247. @article{Nowak2014119, title = {Fabrication and characterization of SbSI gel for humidity sensors}, author = { M. Nowak and A. Nowrot and P. Szperlich and M. Jesionek and M. Kępińska and A. Starczewska and K. Mistewicz and D. Stróż and J. Szala and T. Rzychoń and E. Talik and R. Wrzalik}, url = {http://www.sciencedirect.com/science/article/pii/S0924424714000764}, doi = {10.1016/j.sna.2014.02.012}, issn = {0924-4247}, year = {2014}, date = {2014-01-01}, journal = {Sensors and Actuators A: Physical}, volume = {210}, number = {0}, pages = {119 - 130}, abstract = {A sonochemical method for direct preparation in water of a gel consisted of nanocrystalline antimony sulfoiodide (SbSI) nanowires is presented for the first time. The product was characterized by using techniques such as powder X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, high-resolution transmission electron microscopy, selected area electron diffraction, X-ray photoelectron spectroscopy, optical diffuse reflection spectroscopy and IR spectroscopy. The electrical properties of the fabricated nanomaterial have been investigated, too. The nanowires are a semiconducting ferroelectric with Curie constant equal C = 1.41(14) × 10^4 K and Curie temperature equal TC = 293.0(2) K. The indirect allowed energy band gap of this material is EgIa = 1.880(2) eV. Such prepared SbSI nanowires have optical and electrical properties suitable for ferroelectric nanosensors.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A sonochemical method for direct preparation in water of a gel consisted of nanocrystalline antimony sulfoiodide (SbSI) nanowires is presented for the first time. The product was characterized by using techniques such as powder X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, high-resolution transmission electron microscopy, selected area electron diffraction, X-ray photoelectron spectroscopy, optical diffuse reflection spectroscopy and IR spectroscopy. The electrical properties of the fabricated nanomaterial have been investigated, too. The nanowires are a semiconducting ferroelectric with Curie constant equal C = 1.41(14) × 10^4 K and Curie temperature equal TC = 293.0(2) K. The indirect allowed energy band gap of this material is EgIa = 1.880(2) eV. Such prepared SbSI nanowires have optical and electrical properties suitable for ferroelectric nanosensors. |
Starczewska, A; Nowak, M; Szperlich, P; Bednarczyk, I; Mistewicz, K; Kępińska, M; Duka, P Antimony Sulfoiodide as Novel Material for Photonic Crystals Inproceedings Frontiers in Optics 2014, pp. JW3A.28, Optical Society of America, 2014, ISBN: 1-55752-286-3. @inproceedings{Starczewska:14, title = {Antimony Sulfoiodide as Novel Material for Photonic Crystals}, author = {A. Starczewska and M. Nowak and P. Szperlich and I. Bednarczyk and K. Mistewicz and M. Kępińska and P. Duka}, url = {http://www.opticsinfobase.org/abstract.cfm?URI=LS-2014-JW3A.28}, doi = {10.1364/FIO.2014.JW3A.28}, isbn = {1-55752-286-3}, year = {2014}, date = {2014-01-01}, booktitle = {Frontiers in Optics 2014}, journal = {Frontiers in Optics 2014}, pages = {JW3A.28}, publisher = {Optical Society of America}, abstract = {Semiconducting ferroelectrics promise construction of crystals with tuned photonic band gap. Such structures were synthesized by self-assembling SiO2 spheres, followed by melt infiltration with antimony sulfoiodide and the removal of SiO2 spheres by chemical etching.}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } Semiconducting ferroelectrics promise construction of crystals with tuned photonic band gap. Such structures were synthesized by self-assembling SiO2 spheres, followed by melt infiltration with antimony sulfoiodide and the removal of SiO2 spheres by chemical etching. |
Kępińska, M; Starczewska, A; Duka, P; Nowak, M; Szperlich, P Optical Properties of SbSI photonic crystals Journal Article Acta Physica Polonica A, 126 (5), pp. 1115-1117, 2014. @article{kkepinska2014optical, title = {Optical Properties of SbSI photonic crystals}, author = {M. Kępińska and A. Starczewska and P. Duka and M. Nowak and P. Szperlich}, url = {http://przyrbwn.icm.edu.pl/APP/PDF/126/a126z5p17.pdf}, doi = {10.12693/APhysPolA.126.1115}, year = {2014}, date = {2014-01-01}, journal = {Acta Physica Polonica A}, volume = {126}, number = {5}, pages = {1115-1117}, publisher = {Institute of Physics, Polish Academy of Science}, abstract = {This paper presents optical properties of SiO2 opals infiltrated with SbSI and inverted SbSI opals for the first time. Registered reflectance spectra exhibit Bragg's peaks connected with photonic band gap. Calculated photonic band structure has been compared with experimental results.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper presents optical properties of SiO2 opals infiltrated with SbSI and inverted SbSI opals for the first time. Registered reflectance spectra exhibit Bragg's peaks connected with photonic band gap. Calculated photonic band structure has been compared with experimental results. |
2013 |
Toroń, B; Nowak, M; Grabowski, A; Kępińska, M Electrical Properties of SbSI/Sb2S3 Single and Double Heterostructures Journal Article ACTA PHYSICA POLONICA A, 124 (5), pp. 830-832, 2013, ISSN: 0587-4246, (42nd Jaszowiec International School and Conference on the Physics of Semiconductors, Wisla, POLAND, JUN 22-27, 2013). @article{ISI:000328913500022, title = {Electrical Properties of SbSI/Sb2S3 Single and Double Heterostructures}, author = {B. Toroń and M. Nowak and A. Grabowski and M. Kępińska}, url = {http://przyrbwn.icm.edu.pl/APP/PDF/124/a124z5p21.pdf}, doi = {10.12693/APhysPolA.124.830 }, issn = {0587-4246}, year = {2013}, date = {2013-11-01}, journal = {ACTA PHYSICA POLONICA A}, volume = {124}, number = {5}, pages = {830-832}, organization = {Polish Acad Sci, Inst Phys; Univ Warsaw, Fac Phys, Inst Expt Phys; Univ Warsaw, Fac Phys, Inst Theoret Phys; Polish Acad Sci, Inst High Pressure Phys; Wroclaw Univ Technol; Inst Elect Technol; Polish Acad Sci, Comm Phys; Minist Sci & Higher Educ; Kronenberg Fdn Citi Handlowy; U S Army Forward Element Command Atlantic; European Reg Dev Fund Projects Nanobiom, MIME & IntechFun; PANalyt; Labis Oxford Instruments}, abstract = {The SbSI/Sb2S3 single heterostructures as well as Sb2S3/SbSI/Sb2S3 and SbSI/Sb2S3/SbSI double heterostructures have been produced by applying CO2 laser treatment of p-type SbSI single crystals. The current-voltage and transient characteristics of these heterostructures have been measured in temperatures below and above the SbSI single crystal Curie temperature (21 = 293 K). The results have been fitted with appropriate theoretical formulae to determine the following types of the investigated heterojunctions: P-p SbSI/Sb2S3, p-P-p Sb2S3/SbSI/Sb2S3 and P-p-P SbSI/Sb2S3/SbSI. Influence of the illumination on electrical properties of SbSI/Sb2S3 single and double heterostructures has been reported. Fabricated new structures may be potentially applicable in electronics and optoelectronics as a new type of metal-ferroelectric-semiconductor devices.}, note = {42nd Jaszowiec International School and Conference on the Physics of Semiconductors, Wisla, POLAND, JUN 22-27, 2013}, keywords = {}, pubstate = {published}, tppubtype = {article} } The SbSI/Sb2S3 single heterostructures as well as Sb2S3/SbSI/Sb2S3 and SbSI/Sb2S3/SbSI double heterostructures have been produced by applying CO2 laser treatment of p-type SbSI single crystals. The current-voltage and transient characteristics of these heterostructures have been measured in temperatures below and above the SbSI single crystal Curie temperature (21 = 293 K). The results have been fitted with appropriate theoretical formulae to determine the following types of the investigated heterojunctions: P-p SbSI/Sb2S3, p-P-p Sb2S3/SbSI/Sb2S3 and P-p-P SbSI/Sb2S3/SbSI. Influence of the illumination on electrical properties of SbSI/Sb2S3 single and double heterostructures has been reported. Fabricated new structures may be potentially applicable in electronics and optoelectronics as a new type of metal-ferroelectric-semiconductor devices. |
Starczewska, A; Szala, J; Kępińska, M; Nowak, M; Mistewicz, K; Sozańska, M Comparison of the investigations of photonic crystals using SEM and optical technics Journal Article Solid State Phenomena, 197 , pp. 119124, 2013. @article{Starczewska, title = {Comparison of the investigations of photonic crystals using SEM and optical technics}, author = {A. Starczewska and J. Szala and M. Kępińska and M. Nowak and K. Mistewicz and M. Sozańska}, url = {http://www.scientific.net/SSP.197.119}, doi = {10.4028/www.scientific.net/SSP.197.119}, year = {2013}, date = {2013-02-01}, journal = {Solid State Phenomena}, volume = {197}, pages = {119124}, abstract = {All over the world the investigations of nanophotonic structures called photonic crystals (PCs) are performed. These crystals have potential applications in optoelectronics, e.g. optical filters, antireflective surface coatings, lossless frequency selective mirrors. In Institute of Physics at Silesian Technical University the opal photonic crystals consisting of monodisperse spherical particles, that have diameters of several hundred nanometers, are produced using colloidal self-assembly technics. The main aim of this work is the comparison between pieces of information on morphology of photonic crystals that can be obtained from electron microscopy and from the angular characteristics of optical transmittance and reflectance. The morphology of the samples is characterized by scanning electron microscopy (SEM). Nanosphere diameters are established from statistical analysis of SEM images. The optical properties, which are determined by the photonic band structure, are studied by means of light transmission and reflection measurements. There is a relationship between the wavelength position of transmittance minimum or reflectance maximum and the diameter of the nanospheres. The size of nanospheres obtained from optical measurement results were compared with data obtained from SEM images.}, keywords = {}, pubstate = {published}, tppubtype = {article} } All over the world the investigations of nanophotonic structures called photonic crystals (PCs) are performed. These crystals have potential applications in optoelectronics, e.g. optical filters, antireflective surface coatings, lossless frequency selective mirrors. In Institute of Physics at Silesian Technical University the opal photonic crystals consisting of monodisperse spherical particles, that have diameters of several hundred nanometers, are produced using colloidal self-assembly technics. The main aim of this work is the comparison between pieces of information on morphology of photonic crystals that can be obtained from electron microscopy and from the angular characteristics of optical transmittance and reflectance. The morphology of the samples is characterized by scanning electron microscopy (SEM). Nanosphere diameters are established from statistical analysis of SEM images. The optical properties, which are determined by the photonic band structure, are studied by means of light transmission and reflection measurements. There is a relationship between the wavelength position of transmittance minimum or reflectance maximum and the diameter of the nanospheres. The size of nanospheres obtained from optical measurement results were compared with data obtained from SEM images. |
Jesionek, M; Nowak, M; Kępińska, M; Bednarczyk, I Temperature Dependences of Optical Energy Gaps of SbSI@ CNT and SbSeI@ CNT Journal Article Acta Physica Polonica A, 124 (5), pp. 836–837, 2013. @article{jesionek2013temperature, title = {Temperature Dependences of Optical Energy Gaps of SbSI@ CNT and SbSeI@ CNT}, author = { M. Jesionek and M. Nowak and M. Kępińska and I. Bednarczyk}, url = {http://przyrbwn.icm.edu.pl/APP/PDF/124/a124z5p23.pdf}, doi = {10.12693/APhysPolA.124.836}, year = {2013}, date = {2013-01-01}, journal = {Acta Physica Polonica A}, volume = {124}, number = {5}, pages = {836--837}, publisher = {Institute of Physics, Polish Academy of Science}, abstract = {This paper presents for the first time temperature dependences of optical energy gaps of SbSI@CNT and SbSeI@CNT, i.e. carbon nanotubes (CNTs) filled with antimony sulfoiodide (SbSI) and antimony selenoiodide (SbSeI). The heterostructures were prepared sonochemically using CNTs and elemental Sb, S or Se and I in the presence of solvent under ultrasonic irradiation. Spectral characteristics of diffusive transmittance and reflectance of SbSI@CNT and SbSeI@CNT were measured in temperature range 274 K < T < 333 K. The determinal temperature dependence of indirect forbidden optical energy gap of SbSI@CNT has been fitted with E_{gIf} (T) = (1.92(2)-3.6(6) × 10^{-4} × T) eV. Indirect allowed optical energy gap of SbSeI@CNT has been fitted with E_{gIa} (T) = (1.817(5)-7.1(2) × 10^{-4} × T) eV.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper presents for the first time temperature dependences of optical energy gaps of SbSI@CNT and SbSeI@CNT, i.e. carbon nanotubes (CNTs) filled with antimony sulfoiodide (SbSI) and antimony selenoiodide (SbSeI). The heterostructures were prepared sonochemically using CNTs and elemental Sb, S or Se and I in the presence of solvent under ultrasonic irradiation. Spectral characteristics of diffusive transmittance and reflectance of SbSI@CNT and SbSeI@CNT were measured in temperature range 274 K < T < 333 K. The determinal temperature dependence of indirect forbidden optical energy gap of SbSI@CNT has been fitted with E_{gIf} (T) = (1.92(2)-3.6(6) × 10^{-4} × T) eV. Indirect allowed optical energy gap of SbSeI@CNT has been fitted with E_{gIa} (T) = (1.817(5)-7.1(2) × 10^{-4} × T) eV. |
Nowak, M; Bober, Ł; Borkowski, B; Kępińska, M; Szperlich, P; Stróż, D; Sozańska, M Quantum efficiency coefficient for photogeneration of carriers in SbSI nanowires Journal Article Optical Materials, 35 (12), pp. 2208 - 2216, 2013, ISSN: 0925-3467. @article{Nowak20132208, title = {Quantum efficiency coefficient for photogeneration of carriers in SbSI nanowires}, author = {M. Nowak and Ł. Bober and B. Borkowski and M. Kępińska and P. Szperlich and D. Stróż and M. Sozańska}, url = {http://www.sciencedirect.com/science/article/pii/S0925346713002942}, doi = {http://dx.doi.org/10.1016/j.optmat.2013.06.003}, issn = {0925-3467}, year = {2013}, date = {2013-01-01}, journal = {Optical Materials}, volume = {35}, number = {12}, pages = {2208 - 2216}, abstract = {Abstract This paper presents investigations of the quantum efficiency coefficient for the photogeneration of carriers in aligned antimony sulfoiodide (SbSI) nanowires. Therefore the spectral dependences (between 488 and 700 nm) of photoconductivity current (IPC) were measured for temperatures from 263 to 323 K and for different light intensities. The least squares method was applied to fit the experimental IPC data with appropriate theoretical dependence. From this fitting, diffusion length and surface recombination velocity of carriers as well as spectral dependences of quantum efficiency coefficients for different temperatures and different light intensities were obtained. A comparison of the values of absorption coefficient obtained from the measurements of optical diffusive reflectance and from evaluation of the quantum efficiency coefficient is presented.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Abstract This paper presents investigations of the quantum efficiency coefficient for the photogeneration of carriers in aligned antimony sulfoiodide (SbSI) nanowires. Therefore the spectral dependences (between 488 and 700 nm) of photoconductivity current (IPC) were measured for temperatures from 263 to 323 K and for different light intensities. The least squares method was applied to fit the experimental IPC data with appropriate theoretical dependence. From this fitting, diffusion length and surface recombination velocity of carriers as well as spectral dependences of quantum efficiency coefficients for different temperatures and different light intensities were obtained. A comparison of the values of absorption coefficient obtained from the measurements of optical diffusive reflectance and from evaluation of the quantum efficiency coefficient is presented. |
2012 |
Toroń, B; Nowak, M; Grabowski, A; Kępińska, M; Szala, J; Rzychoń, T Optical properties of SbSI heterostructures Inproceedings Yin, S; Guo, R (Ed.): PHOTONIC FIBER AND CRYSTAL DEVICES: ADVANCES IN MATERIALS AND INNOVATIONS IN DEVICE APPLICATIONS VI, SPIE 2012, ISSN: 0277-786X, (Conference on Photonic Fiber and Crystal Devices - Advances in Materials and Innovations in Device Applications VI, San Diego, CA, AUG 12-13, 2012). @inproceedings{ISI:000312213900033, title = {Optical properties of SbSI heterostructures}, author = {B. Toroń and M. Nowak and A. Grabowski and M. Kępińska and J. Szala and T. Rzychoń}, editor = {Yin, S and Guo, R}, url = {http://www.sciencedirect.com/science/article/pii/S1350417709001709}, doi = {10.1117/12.978937}, issn = {0277-786X}, year = {2012}, date = {2012-01-01}, booktitle = {PHOTONIC FIBER AND CRYSTAL DEVICES: ADVANCES IN MATERIALS AND INNOVATIONS IN DEVICE APPLICATIONS VI}, volume = {8497}, organization = {SPIE}, series = {Proceedings of SPIE}, abstract = {The antimony sulfoiodide (SbSI) single crystal being a ferroelectric semiconductor has a large number of interesting properties. Based on SbSI single crystal a new type of heterostructures has been produced. For the first time diodes, transistors and thyristors composed of SbSI/Sb2S3 heterojunctions have been fabricated by CO2 laser irradiation of selected sections of SbSI single crystals. Treated sections are composed of amorphous antimony (III) sulphide (Sb2S3) with energy gap 0.3 eV smaller (in room temperature) than that of SbSI. The structural optical, electrical and photoelectrical characteristics of produced devices have been investigated.}, note = {Conference on Photonic Fiber and Crystal Devices - Advances in Materials and Innovations in Device Applications VI, San Diego, CA, AUG 12-13, 2012}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } The antimony sulfoiodide (SbSI) single crystal being a ferroelectric semiconductor has a large number of interesting properties. Based on SbSI single crystal a new type of heterostructures has been produced. For the first time diodes, transistors and thyristors composed of SbSI/Sb2S3 heterojunctions have been fabricated by CO2 laser irradiation of selected sections of SbSI single crystals. Treated sections are composed of amorphous antimony (III) sulphide (Sb2S3) with energy gap 0.3 eV smaller (in room temperature) than that of SbSI. The structural optical, electrical and photoelectrical characteristics of produced devices have been investigated. |
2011 |
Kępińska, M; Nowak, M; Duka, P; Kotyczka-Morańska, M; Szperlich, P Optical properties of SbI3 single crystalline platelets Journal Article Optical Materials, 33 (11), pp. 1753 - 1759, 2011, ISSN: 0925-3467. @article{Kępińska20111753, title = {Optical properties of SbI3 single crystalline platelets}, author = {M. Kępińska and M. Nowak and P. Duka and M. Kotyczka-Morańska and P. Szperlich}, url = {http://www.sciencedirect.com/science/article/pii/S0925346711003223}, doi = {http://dx.doi.org/10.1016/j.optmat.2011.06.009}, issn = {0925-3467}, year = {2011}, date = {2011-01-01}, journal = {Optical Materials}, volume = {33}, number = {11}, pages = {1753 - 1759}, abstract = {Optical parameters of platelets of crystalline antimony triiodide (SbI3) have been evaluated using spectrogoniometric interference spectroscopy technique. Spectral characteristics of real parts of refractive indices of radiation with electric vector normal and parallel to the optical c-axis of SbI3 crystalline platelets (i.e. no, ne – refractive indices for ordinary and extraordinary rays) have been shown. The temperature dependences of spectra of optical parameters (no and absorption coefficient of radiation with electric vector normal to the optical c-axis) have been presented. The temperature dependences of fitted optical indirect allowed energy gap of SbI3, Urbach energy and phonons energies are the main findings of the presented work. The obtained results have been compared with literature data.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Optical parameters of platelets of crystalline antimony triiodide (SbI3) have been evaluated using spectrogoniometric interference spectroscopy technique. Spectral characteristics of real parts of refractive indices of radiation with electric vector normal and parallel to the optical c-axis of SbI3 crystalline platelets (i.e. no, ne – refractive indices for ordinary and extraordinary rays) have been shown. The temperature dependences of spectra of optical parameters (no and absorption coefficient of radiation with electric vector normal to the optical c-axis) have been presented. The temperature dependences of fitted optical indirect allowed energy gap of SbI3, Urbach energy and phonons energies are the main findings of the presented work. The obtained results have been compared with literature data. |
2010 |
Nowak, M; Kotyczka-Morańska, M; Szperlich, P; Bober, Ł; Jesionek, M; Kępińska, M; Stróż, D; Kusz, J; Szala, J; Moskal, G; Rzychoń, T; Młyńczak, J; Kopczyński, K Using of sonochemically prepared components for vapor phase growing of SbI3·3S8 Journal Article Ultrasonics Sonochemistry, 17 (5), pp. 892 - 901, 2010, ISSN: 1350-4177. @article{Nowak2010892, title = {Using of sonochemically prepared components for vapor phase growing of SbI3·3S8}, author = {M. Nowak and M. Kotyczka-Morańska and P. Szperlich and Ł. Bober and M. Jesionek and M. Kępińska and D. Stróż and J. Kusz and J. Szala and G. Moskal and T. Rzychoń and J. Młyńczak and K. Kopczyński}, url = {http://www.sciencedirect.com/science/article/pii/S135041771000009X}, doi = {10.1016/j.ultsonch.2010.01.008}, issn = {1350-4177}, year = {2010}, date = {2010-01-01}, journal = {Ultrasonics Sonochemistry}, volume = {17}, number = {5}, pages = {892 - 901}, abstract = {The using of sonochemically prepared components for growth of SbI3·3S8 single crystals from the vapor phase is presented for the first time. The good optical quality of the obtained crystals is important because this material is valuable for optoelectronics due to its non-linear optical properties. The products were characterized by using techniques such as X-ray crystallography, powder X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, high-resolution transmission electron microscopy, selected area electron diffraction, optical diffuse reflection spectroscopy and optical transmittance spectroscopy. The direct and indirect forbidden energy gaps of SbI3·3S8 illuminated with plane polarized light with electric field parallel and perpendicular to the c-axis of the crystal have been determined. The second harmonic generation of light in the grown crystals was observed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The using of sonochemically prepared components for growth of SbI3·3S8 single crystals from the vapor phase is presented for the first time. The good optical quality of the obtained crystals is important because this material is valuable for optoelectronics due to its non-linear optical properties. The products were characterized by using techniques such as X-ray crystallography, powder X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, high-resolution transmission electron microscopy, selected area electron diffraction, optical diffuse reflection spectroscopy and optical transmittance spectroscopy. The direct and indirect forbidden energy gaps of SbI3·3S8 illuminated with plane polarized light with electric field parallel and perpendicular to the c-axis of the crystal have been determined. The second harmonic generation of light in the grown crystals was observed. |
2009 |
Nowak, M; Kauch, B; Szperlich, P; Jesionek, M; Kępińska, M; Bober, Ł; Szala, J; Moskal, G; Rzychoń, T; Stróż, D Sonochemical preparation of SbSeI gel Journal Article Ultrasonics Sonochemistry, 16 (4), pp. 546 - 551, 2009, ISSN: 1350-4177. @article{Nowak2009546, title = {Sonochemical preparation of SbSeI gel}, author = {M. Nowak and B. Kauch and P. Szperlich and M. Jesionek and M. Kępińska and Ł. Bober and J. Szala and G. Moskal and T. Rzychoń and D. Stróż}, url = {http://www.sciencedirect.com/science/article/pii/S1350417709000029}, doi = {10.1016/j.ultsonch.2009.01.003}, issn = {1350-4177}, year = {2009}, date = {2009-01-01}, journal = {Ultrasonics Sonochemistry}, volume = {16}, number = {4}, pages = {546 - 551}, abstract = {A novel sonochemical method for direct preparation of nanocrystalline antimony selenoiodide (SbSeI) has been established. The SbSeI gel was synthesized using elemental Sb, Se, and I in the presence of ethanol under ultrasonic irradiation (35kHz, 2W/cm2) at 50°C for 2h. The product was characterized by using techniques such as powder X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), and optical diffuse reflection spectroscopy (DRS). The SEM and HRTEM investigations exhibit that the as-prepared samples are made up of large quantity nanowires with lateral dimensions of about 20–50 nm and lengths reaching up to several micrometers and single crystalline in nature.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A novel sonochemical method for direct preparation of nanocrystalline antimony selenoiodide (SbSeI) has been established. The SbSeI gel was synthesized using elemental Sb, Se, and I in the presence of ethanol under ultrasonic irradiation (35kHz, 2W/cm2) at 50°C for 2h. The product was characterized by using techniques such as powder X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), and optical diffuse reflection spectroscopy (DRS). The SEM and HRTEM investigations exhibit that the as-prepared samples are made up of large quantity nanowires with lateral dimensions of about 20–50 nm and lengths reaching up to several micrometers and single crystalline in nature. |
Kępińska, M; Nowak, M; Duka, P; Kauch, B Spectrogoniometric determination of refractive indices of GaSe Journal Article Thin Solid Films, 517 (13), pp. 3792 - 3796, 2009, ISSN: 0040-6090. @article{Kępińska20093792, title = {Spectrogoniometric determination of refractive indices of GaSe}, author = {M. Kępińska and M. Nowak and P. Duka and B. Kauch}, url = {http://www.sciencedirect.com/science/article/pii/S0040609009000716}, doi = {http://dx.doi.org/10.1016/j.tsf.2009.01.069}, issn = {0040-6090}, year = {2009}, date = {2009-01-01}, journal = {Thin Solid Films}, volume = {517}, number = {13}, pages = {3792 - 3796}, abstract = {A simple interference spectroscopy technique of determining real parts of refractive indices in thin isotropic or anisotropic films is presented. This method is based on the evaluation of the orders of extrema in interference spectra of optical transmittance and/or reflectance measured for various angles of light incidence. It also makes possible to determine thickness of the investigated sample. This method of investigations was used to determine the parameters of gallium selenide (GaSe). The determined spectral characteristics of ordinary and extraordinary refractive indices of GaSe are compared with the data presented in literature by other authors.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A simple interference spectroscopy technique of determining real parts of refractive indices in thin isotropic or anisotropic films is presented. This method is based on the evaluation of the orders of extrema in interference spectra of optical transmittance and/or reflectance measured for various angles of light incidence. It also makes possible to determine thickness of the investigated sample. This method of investigations was used to determine the parameters of gallium selenide (GaSe). The determined spectral characteristics of ordinary and extraordinary refractive indices of GaSe are compared with the data presented in literature by other authors. |
2006 |
Michalewicz, A; Nowak, M; Kępińska, M Differences between surface and bulk refractive indices of a-InxSe1−x Journal Article Applied Surface Science, 252 (21), pp. 7743 - 7747, 2006, ISSN: 0169-4332, (Proceedings of the 4th International Workshop on Semiconductor Surface Passivation SSP'05 SI). @article{Michalewicz20067743, title = {Differences between surface and bulk refractive indices of a-InxSe1−x}, author = {A. Michalewicz and M. Nowak and M. Kępińska}, url = {http://www.sciencedirect.com/science/article/pii/S0169433206003588}, doi = {http://dx.doi.org/10.1016/j.apsusc.2006.03.067}, issn = {0169-4332}, year = {2006}, date = {2006-01-01}, journal = {Applied Surface Science}, volume = {252}, number = {21}, pages = {7743 - 7747}, abstract = {Thin films of amorphous indium selenide compounds (a-InxSe1−x) are important, e.g. for photovoltaics. The feature of merit in such applications is also the real part of refractive index n of this material. The data on n in literature are divergent. In this paper, the results of investigations on n in the bulk as well as in the interface layers of thin films of a-InxSe1−x are presented. The measurements had been performed using optical transmittance and reflectance in spectral range from 1.24 to 1.96 eV of linear polarized radiation that hit the samples with angles of incidence from 0° to 80°. Investigations had been done for sample temperatures from 80 to 340 K. It was found that the refractive index for areas at the free surface nf is bigger than the refractive index nb at the interface of thin film–substrate. The averaged over thin film thickness value of real part refractive index View the MathML source have the biggest value in all spectral range. Values of these coefficients increase with increasing the temperature.}, note = {Proceedings of the 4th International Workshop on Semiconductor Surface Passivation SSP'05 SI}, keywords = {}, pubstate = {published}, tppubtype = {article} } Thin films of amorphous indium selenide compounds (a-InxSe1−x) are important, e.g. for photovoltaics. The feature of merit in such applications is also the real part of refractive index n of this material. The data on n in literature are divergent. In this paper, the results of investigations on n in the bulk as well as in the interface layers of thin films of a-InxSe1−x are presented. The measurements had been performed using optical transmittance and reflectance in spectral range from 1.24 to 1.96 eV of linear polarized radiation that hit the samples with angles of incidence from 0° to 80°. Investigations had been done for sample temperatures from 80 to 340 K. It was found that the refractive index for areas at the free surface nf is bigger than the refractive index nb at the interface of thin film–substrate. The averaged over thin film thickness value of real part refractive index View the MathML source have the biggest value in all spectral range. Values of these coefficients increase with increasing the temperature. |
Michalewicz, A; Nowak, M; Kępińska, M Temperature dependence of the energy gap of InxSe1–x compounds Journal Article Physica Status Solidi B Basic Research, 243 , pp. 685-689, 2006. @article{2006PSSBR.243..685M, title = {Temperature dependence of the energy gap of InxSe1–x compounds}, author = {A. Michalewicz and M. Nowak and M. Kępińska}, url = {http://onlinelibrary.wiley.com/doi/10.1002/pssb.200541055/epdf}, doi = {10.1002/pssb.200541055}, year = {2006}, date = {2006-01-01}, journal = {Physica Status Solidi B Basic Research}, volume = {243}, pages = {685-689}, abstract = {The optical absorption for photon energies of InxSe1–x thin films was used to determine the variation of the energy gap and the Urbach energy as a function of temperature in the range from 80 to 340 K at photon energies hν = 1.24 to 2.6 eV. The data were analyzed using the Varshni relation [Physica 34, 149 (1967)] for the temperature dependence of semiconductor band gaps. The formula by Yang et al. [cf., e.g., J. Phys. Chem. Solids 65, 1015 (2004)] for the temperature dependence of the energy width of the Urbach absorption edge was also used. }, keywords = {}, pubstate = {published}, tppubtype = {article} } The optical absorption for photon energies of InxSe1–x thin films was used to determine the variation of the energy gap and the Urbach energy as a function of temperature in the range from 80 to 340 K at photon energies hν = 1.24 to 2.6 eV. The data were analyzed using the Varshni relation [Physica 34, 149 (1967)] for the temperature dependence of semiconductor band gaps. The formula by Yang et al. [cf., e.g., J. Phys. Chem. Solids 65, 1015 (2004)] for the temperature dependence of the energy width of the Urbach absorption edge was also used. |
2003 |
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. |
1998 |
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 |
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. |
