TY  - JOUR
AU  - Grechenkov, Jurij
AU  - Gopejenko, Aleksejs
AU  - Bocharov, Dmitry
AU  - Isakoviča, Inta
AU  - Popov, Anatoli I.
AU  - Brik, Mikhail G.
AU  - Piskunov, Sergei.
PY  - 2023
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/11225
AB  - Chalcopyrites are ternary semiconductor compounds with successful applications in photovoltaics. Certain chalcopyrites are well researched, yet others remain understudied despite showing promise. In this study, we use ab initio methods to study CuGaS2, AgGaS2, and CuGaSe2 chalcopyrites with a focus on their less studied solid solutions. We use density functional theory (DFT) to study the effects that atomic configurations have on the properties of a solid solution and we calculate the optical absorption spectra using a many-body perturbation theory. Our theoretical simulations predict that excess of In and Se in the solid solutions leads to narrowing of the band gap and to the broadening of the absorption spectra. Obtained results show promise for possible photovoltaic applications, as well as developed methodology can be used for further study of other promising chalcopyritic compounds.
T2  - Energies
T1  - Ab Initio Modeling of CuGa1−xInxS2, CuGaS2(1−x)Se2x and Ag1−xCuxGaS2 Chalcopyrite Solid Solutions for Photovoltaic Applications
VL  - 16
IS  - 12
SP  - 4823
DO  - 10.3390/en16124823
ER  - 

@article{
author = "Grechenkov, Jurij and Gopejenko, Aleksejs and Bocharov, Dmitry and Isakoviča, Inta and Popov, Anatoli I. and Brik, Mikhail G. and Piskunov, Sergei.",
year = "2023",
abstract = "Chalcopyrites are ternary semiconductor compounds with successful applications in photovoltaics. Certain chalcopyrites are well researched, yet others remain understudied despite showing promise. In this study, we use ab initio methods to study CuGaS2, AgGaS2, and CuGaSe2 chalcopyrites with a focus on their less studied solid solutions. We use density functional theory (DFT) to study the effects that atomic configurations have on the properties of a solid solution and we calculate the optical absorption spectra using a many-body perturbation theory. Our theoretical simulations predict that excess of In and Se in the solid solutions leads to narrowing of the band gap and to the broadening of the absorption spectra. Obtained results show promise for possible photovoltaic applications, as well as developed methodology can be used for further study of other promising chalcopyritic compounds.",
journal = "Energies",
title = "Ab Initio Modeling of CuGa1−xInxS2, CuGaS2(1−x)Se2x and Ag1−xCuxGaS2 Chalcopyrite Solid Solutions for Photovoltaic Applications",
volume = "16",
number = "12",
pages = "4823",
doi = "10.3390/en16124823"
}

Grechenkov, J., Gopejenko, A., Bocharov, D., Isakoviča, I., Popov, A. I., Brik, M. G.,& Piskunov, Sergei.. (2023). Ab Initio Modeling of CuGa1−xInxS2, CuGaS2(1−x)Se2x and Ag1−xCuxGaS2 Chalcopyrite Solid Solutions for Photovoltaic Applications. in Energies, 16(12), 4823.
https://doi.org/10.3390/en16124823

Grechenkov J, Gopejenko A, Bocharov D, Isakoviča I, Popov AI, Brik MG, Piskunov S. Ab Initio Modeling of CuGa1−xInxS2, CuGaS2(1−x)Se2x and Ag1−xCuxGaS2 Chalcopyrite Solid Solutions for Photovoltaic Applications. in Energies. 2023;16(12):4823.
doi:10.3390/en16124823 .

Grechenkov, Jurij, Gopejenko, Aleksejs, Bocharov, Dmitry, Isakoviča, Inta, Popov, Anatoli I., Brik, Mikhail G., Piskunov, Sergei., "Ab Initio Modeling of CuGa1−xInxS2, CuGaS2(1−x)Se2x and Ag1−xCuxGaS2 Chalcopyrite Solid Solutions for Photovoltaic Applications" in Energies, 16, no. 12 (2023):4823,
https://doi.org/10.3390/en16124823 . .

TY  - JOUR
AU  - Rudysh, Myron Ya.
AU  - Fedorchuk, Anatolii O.
AU  - Brik, Mikhail G.
AU  - Grechenkov, Jurij
AU  - Bocharov, Dmitry
AU  - Piskunov, Sergei
AU  - Popov, Anatoli I.
AU  - Piasecki, Michal
PY  - 2023
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/12044
AB  - The aim of this study is to comprehensively examine the structural composition and
properties of the AgAlS2 crystal during its high-pressure phase. This analysis delves into the second
coordination environment of the crystal structure and elucidates the distinct transformations it
undergoes during the phase transition. The band energy structure was calculated, and the origin
of electronic levels was clarified. It is shown that the crystal becomes non-stratified during the
phase transition. This study also determined the values of the crystal’s carrier effective masses,
underscoring its spatial anisotropy. It was found that the calculated optical functions are similar to
the crystal in the chalcopyrite structure, and their differences are shown. Further, this study involved
the calculation of the crystal’s phonon spectrum, revealing the spectrum’s transformation during the
phase transition. The vibrational frequencies were also obtained, with a symmetrical classification of
vibrational modes. Finally, this study derived the infrared and Raman spectra of the AgAlS2 crystal,
thereby providing a comprehensive picture of the crystal during its high-pressure phase.
T2  - Materials
T1  - Electronic, Optical, and Vibrational Properties of an AgAlS2 Crystal in a High-Pressure Phase
VL  - 16
IS  - 21
SP  - 7017
DO  - 10.3390/ma16217017
ER  - 

@article{
author = "Rudysh, Myron Ya. and Fedorchuk, Anatolii O. and Brik, Mikhail G. and Grechenkov, Jurij and Bocharov, Dmitry and Piskunov, Sergei and Popov, Anatoli I. and Piasecki, Michal",
year = "2023",
abstract = "The aim of this study is to comprehensively examine the structural composition and
properties of the AgAlS2 crystal during its high-pressure phase. This analysis delves into the second
coordination environment of the crystal structure and elucidates the distinct transformations it
undergoes during the phase transition. The band energy structure was calculated, and the origin
of electronic levels was clarified. It is shown that the crystal becomes non-stratified during the
phase transition. This study also determined the values of the crystal’s carrier effective masses,
underscoring its spatial anisotropy. It was found that the calculated optical functions are similar to
the crystal in the chalcopyrite structure, and their differences are shown. Further, this study involved
the calculation of the crystal’s phonon spectrum, revealing the spectrum’s transformation during the
phase transition. The vibrational frequencies were also obtained, with a symmetrical classification of
vibrational modes. Finally, this study derived the infrared and Raman spectra of the AgAlS2 crystal,
thereby providing a comprehensive picture of the crystal during its high-pressure phase.",
journal = "Materials",
title = "Electronic, Optical, and Vibrational Properties of an AgAlS2 Crystal in a High-Pressure Phase",
volume = "16",
number = "21",
pages = "7017",
doi = "10.3390/ma16217017"
}

Rudysh, M. Ya., Fedorchuk, A. O., Brik, M. G., Grechenkov, J., Bocharov, D., Piskunov, S., Popov, A. I.,& Piasecki, M.. (2023). Electronic, Optical, and Vibrational Properties of an AgAlS2 Crystal in a High-Pressure Phase. in Materials, 16(21), 7017.
https://doi.org/10.3390/ma16217017

Rudysh MY, Fedorchuk AO, Brik MG, Grechenkov J, Bocharov D, Piskunov S, Popov AI, Piasecki M. Electronic, Optical, and Vibrational Properties of an AgAlS2 Crystal in a High-Pressure Phase. in Materials. 2023;16(21):7017.
doi:10.3390/ma16217017 .

Rudysh, Myron Ya., Fedorchuk, Anatolii O., Brik, Mikhail G., Grechenkov, Jurij, Bocharov, Dmitry, Piskunov, Sergei, Popov, Anatoli I., Piasecki, Michal, "Electronic, Optical, and Vibrational Properties of an AgAlS2 Crystal in a High-Pressure Phase" in Materials, 16, no. 21 (2023):7017,
https://doi.org/10.3390/ma16217017 . .

TY  - JOUR
AU  - Mironova-Ulmane, Nina
AU  - Brik, Mikhail G.
AU  - Grube, Jurgis
AU  - Krieke, Guna
AU  - Kemere, Meldra
AU  - Antuzevics, Andris
AU  - Gabrusenoks, E.
AU  - Skvortsova, Vera N.
AU  - Elsts, Edgars
AU  - Sarakovskis, Anatolijs
AU  - Piasecki, Michal
AU  - Popov, Anatoli I.
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10397
AB  - The optical spectra of a single crystal of α-Al2O3Cr3+ were studied in a wide temperature range. The crystal was demonstrated to have a potential for optical thermometric applications. Three ways of measuring temperature were tested and analyzed: i) luminescence intensity ratio of the R1 and R2 lines; ii) change of the full width of half maxima of the R1 and R2 lines, and iii) thermal shifts of the R1 and R2 lines maxima. The highest absolute and relative sensitivities were obtained at cryogenic temperatures. In addition, the thermal shifts of the R lines were analyzed using the McCumber-Sturge equation to estimate the Debye temperature and the electron-vibrational interaction parameter.
T2  - Optical Materials
T1  - EPR, optical and thermometric studies of Cr3+ ions in the α-Al2O3 synthetic single crystal
VL  - 132
SP  - 112859
DO  - 10.1016/j.optmat.2022.112859
ER  - 

@article{
author = "Mironova-Ulmane, Nina and Brik, Mikhail G. and Grube, Jurgis and Krieke, Guna and Kemere, Meldra and Antuzevics, Andris and Gabrusenoks, E. and Skvortsova, Vera N. and Elsts, Edgars and Sarakovskis, Anatolijs and Piasecki, Michal and Popov, Anatoli I.",
year = "2022",
abstract = "The optical spectra of a single crystal of α-Al2O3Cr3+ were studied in a wide temperature range. The crystal was demonstrated to have a potential for optical thermometric applications. Three ways of measuring temperature were tested and analyzed: i) luminescence intensity ratio of the R1 and R2 lines; ii) change of the full width of half maxima of the R1 and R2 lines, and iii) thermal shifts of the R1 and R2 lines maxima. The highest absolute and relative sensitivities were obtained at cryogenic temperatures. In addition, the thermal shifts of the R lines were analyzed using the McCumber-Sturge equation to estimate the Debye temperature and the electron-vibrational interaction parameter.",
journal = "Optical Materials",
title = "EPR, optical and thermometric studies of Cr3+ ions in the α-Al2O3 synthetic single crystal",
volume = "132",
pages = "112859",
doi = "10.1016/j.optmat.2022.112859"
}

Mironova-Ulmane, N., Brik, M. G., Grube, J., Krieke, G., Kemere, M., Antuzevics, A., Gabrusenoks, E., Skvortsova, V. N., Elsts, E., Sarakovskis, A., Piasecki, M.,& Popov, A. I.. (2022). EPR, optical and thermometric studies of Cr3+ ions in the α-Al2O3 synthetic single crystal. in Optical Materials, 132, 112859.
https://doi.org/10.1016/j.optmat.2022.112859

Mironova-Ulmane N, Brik MG, Grube J, Krieke G, Kemere M, Antuzevics A, Gabrusenoks E, Skvortsova VN, Elsts E, Sarakovskis A, Piasecki M, Popov AI. EPR, optical and thermometric studies of Cr3+ ions in the α-Al2O3 synthetic single crystal. in Optical Materials. 2022;132:112859.
doi:10.1016/j.optmat.2022.112859 .

Mironova-Ulmane, Nina, Brik, Mikhail G., Grube, Jurgis, Krieke, Guna, Kemere, Meldra, Antuzevics, Andris, Gabrusenoks, E., Skvortsova, Vera N., Elsts, Edgars, Sarakovskis, Anatolijs, Piasecki, Michal, Popov, Anatoli I., "EPR, optical and thermometric studies of Cr3+ ions in the α-Al2O3 synthetic single crystal" in Optical Materials, 132 (2022):112859,
https://doi.org/10.1016/j.optmat.2022.112859 . .