This study has examined the ground-state electronic, structural and, in addition, paramagnetic properties of semiconductor MgTe in its zinc blende phase by using the density functional theory (DFT). Exchange-correlation potentials have been approximated with the Projected Augmented Wave (PAW) Generalized Gradient Approximation (GGA). From the calculated lattice parameter, we determined the bulk modulus and first pressure derivative. Also, reported are other ground state properties: density of states (DOS), band structure, projected DOS (PDOS) and magnetic properties. A direct large band-gap of 2.358 eV was observed from the band structure that has close concurrence with former reported values. Although this value is also smaller than the reported experimental values, it is the closest of all the calculated values. The magnetic state of the compound was observed to be paramagnetic in the ground state.
{"title":"Electronic, structural and paramagnetic properties of magnesium telluride","authors":"J. O. Akinlami","doi":"10.15407/spqeo22.01.005","DOIUrl":"https://doi.org/10.15407/spqeo22.01.005","url":null,"abstract":"This study has examined the ground-state electronic, structural and, in addition, paramagnetic properties of semiconductor MgTe in its zinc blende phase by using the density functional theory (DFT). Exchange-correlation potentials have been approximated with the Projected Augmented Wave (PAW) Generalized Gradient Approximation (GGA). From the calculated lattice parameter, we determined the bulk modulus and first pressure derivative. Also, reported are other ground state properties: density of states (DOS), band structure, projected DOS (PDOS) and magnetic properties. A direct large band-gap of 2.358 eV was observed from the band structure that has close concurrence with former reported values. Although this value is also smaller than the reported experimental values, it is the closest of all the calculated values. The magnetic state of the compound was observed to be paramagnetic in the ground state.","PeriodicalId":44695,"journal":{"name":"Semiconductor Physics Quantum Electronics & Optoelectronics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2019-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49224885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Brief history of terahertz (THz) and infrared (IR) science and technology, for learning lessons by historical evolution is presented and discussed identifying important (from Author’s point of view) steps for their development. THz still is the not well-known region of electro-magnetic science, even it has been lightened by starting of scientific and technological knowledge, since the end of 19 century. As concerning history of IR science and technology, it took many years since 1800 (W. Hershel) to reach the level of use that is recognized today. The link between IR and thermal science and applications was so strong that IR was for a long time synonymous of thermography. THz science and technology are showing a rapid growth. IR and, especially THz technologies, now have become one of the major fields of applied research. Nowadays, they become widely spread in their use in astrophysics, security, biomedicine, detection of hidden objects, food and art inspection, etc. The increasing requirements for fast transmission of large amounts of data will lead to the extension of operation frequencies in communications toward the THz frequency range. IR and THz medical imaging can provide guidance for surgeons in delimiting the tumor margins, help clinicians visualize diseased area, etc. A few decades ago, IR technologies were mainly the domain of military ones. In recent two decades, due to widespread of lowcost thermal uncooled arrays there were realized many IR technology advances in civil and military applications. A large amount of THz technologies mass-market applications can’t be highlighted, as these technologies do not meet yet the user requirements, especially in easiness of use and costs. Still, many of THz applications that we have now are emerging and showing their applicability in some implementations, where other methods can’t give any comprehensive information, e.g., in dry food inspection for dielectric inclusions, skin tumour margins control, THz astronomy, package and envelope inspection, etc. The brief lessons given by historical highlights in THz and IR science and applications can be important for the future developments in these directions as history frequently opens routes for new thinking. In this brief review, the missed important steps can happen. Author apologizes for these possible faults.
{"title":"Brief history of THz and IR technologies","authors":"F. Sizov","doi":"10.15407/SPQEO22.01.067","DOIUrl":"https://doi.org/10.15407/SPQEO22.01.067","url":null,"abstract":"Brief history of terahertz (THz) and infrared (IR) science and technology, for learning lessons by historical evolution is presented and discussed identifying important (from Author’s point of view) steps for their development. THz still is the not well-known region of electro-magnetic science, even it has been lightened by starting of scientific and technological knowledge, since the end of 19 century. As concerning history of IR science and technology, it took many years since 1800 (W. Hershel) to reach the level of use that is recognized today. The link between IR and thermal science and applications was so strong that IR was for a long time synonymous of thermography. THz science and technology are showing a rapid growth. IR and, especially THz technologies, now have become one of the major fields of applied research. Nowadays, they become widely spread in their use in astrophysics, security, biomedicine, detection of hidden objects, food and art inspection, etc. The increasing requirements for fast transmission of large amounts of data will lead to the extension of operation frequencies in communications toward the THz frequency range. IR and THz medical imaging can provide guidance for surgeons in delimiting the tumor margins, help clinicians visualize diseased area, etc. A few decades ago, IR technologies were mainly the domain of military ones. In recent two decades, due to widespread of lowcost thermal uncooled arrays there were realized many IR technology advances in civil and military applications. A large amount of THz technologies mass-market applications can’t be highlighted, as these technologies do not meet yet the user requirements, especially in easiness of use and costs. Still, many of THz applications that we have now are emerging and showing their applicability in some implementations, where other methods can’t give any comprehensive information, e.g., in dry food inspection for dielectric inclusions, skin tumour margins control, THz astronomy, package and envelope inspection, etc. The brief lessons given by historical highlights in THz and IR science and applications can be important for the future developments in these directions as history frequently opens routes for new thinking. In this brief review, the missed important steps can happen. Author apologizes for these possible faults.","PeriodicalId":44695,"journal":{"name":"Semiconductor Physics Quantum Electronics & Optoelectronics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2019-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44959656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Compositionally graded AlxGa1–xN alloys with the Al concentration in the (7 ≤ x ≤ 32) range were implanted with Ar + ions to study the structural and strain changes (strain engineering). It was shown that ion implantation leads to ~0.3...0.46% hydrostatic strains and a relatively low damage of the crystal structure. The ion-implantation leads mainly to an increase of the density of point defects, while the dislocation configuration is almost unaffected. The density of microdefects is sufficiently reduced after the postimplantation annealing. The structural quality of the AlxGa1–xN layers strongly depends on the Al concentration and is worsen with increasing Al. The implantation induced structural changes in highly dislocated AlxGa1–xN layers are generally less pronounced. Based on the X-ray diffraction, a model is developed to explain the strain field behavior in the AlxGa1–xN/GaN heterostructures by migration of point defects and strain field redistribution. The approach to simulate 2θ/ω scans using statistical dynamical theory of X-ray diffraction for implanted compositionally graded structures AlGaN has been developed.
{"title":"The effect of ion implantation on structural damage of сompositionally graded AlGaN layers","authors":"O. Liubchenko","doi":"10.15407/spqeo22.01.119","DOIUrl":"https://doi.org/10.15407/spqeo22.01.119","url":null,"abstract":"Compositionally graded AlxGa1–xN alloys with the Al concentration in the (7 ≤ x ≤ 32) range were implanted with Ar + ions to study the structural and strain changes (strain engineering). It was shown that ion implantation leads to ~0.3...0.46% hydrostatic strains and a relatively low damage of the crystal structure. The ion-implantation leads mainly to an increase of the density of point defects, while the dislocation configuration is almost unaffected. The density of microdefects is sufficiently reduced after the postimplantation annealing. The structural quality of the AlxGa1–xN layers strongly depends on the Al concentration and is worsen with increasing Al. The implantation induced structural changes in highly dislocated AlxGa1–xN layers are generally less pronounced. Based on the X-ray diffraction, a model is developed to explain the strain field behavior in the AlxGa1–xN/GaN heterostructures by migration of point defects and strain field redistribution. The approach to simulate 2θ/ω scans using statistical dynamical theory of X-ray diffraction for implanted compositionally graded structures AlGaN has been developed.","PeriodicalId":44695,"journal":{"name":"Semiconductor Physics Quantum Electronics & Optoelectronics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2019-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47404133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L-arginine-phosphate doped Potassium Dihydrogen Phosphate single crystals with 0.2...4.4 wt.% concentration in the solution was grown on a point seed by the method of temperature reduction. The grown KDP:LAP crystals were characterizied by UV-vis spectroscopy, powder XRD analysis, differential thermal and thermogravimetric analyses and second harmonic generation efficiency measurements. The mechanical and laser strength values of LAP doped KDP crystals have been evaluated. Slight variation in the unit cell parameters of KDP:LAP has been reported. It has been shown that the efficiency of second harmonic generation conversion in KDP:LAP crystals was higher by more than 3-fold as compared to the corresponding values of pure KDP. The experimental results evidence the suitability of the grown KDP:LAP crystals for optoelectronics, and the study is helpful for further searching and designing of hybrid NLO materials.
{"title":"Effect of L-arginine-phosphate doping on structural, optical and strength properties of KDP single crystal","authors":"E. Kostenyukova","doi":"10.15407/SPQEO22.01.060","DOIUrl":"https://doi.org/10.15407/SPQEO22.01.060","url":null,"abstract":"L-arginine-phosphate doped Potassium Dihydrogen Phosphate single crystals with 0.2...4.4 wt.% concentration in the solution was grown on a point seed by the method of temperature reduction. The grown KDP:LAP crystals were characterizied by UV-vis spectroscopy, powder XRD analysis, differential thermal and thermogravimetric analyses and second harmonic generation efficiency measurements. The mechanical and laser strength values of LAP doped KDP crystals have been evaluated. Slight variation in the unit cell parameters of KDP:LAP has been reported. It has been shown that the efficiency of second harmonic generation conversion in KDP:LAP crystals was higher by more than 3-fold as compared to the corresponding values of pure KDP. The experimental results evidence the suitability of the grown KDP:LAP crystals for optoelectronics, and the study is helpful for further searching and designing of hybrid NLO materials.","PeriodicalId":44695,"journal":{"name":"Semiconductor Physics Quantum Electronics & Optoelectronics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2019-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41834754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
O. Slobodian, Y. Milovanov, V. Skryshevsky, A. Vasin, X. Tang, J. Raskin, P. Lytvyn, K. Svezhentsova, S. Malyuta, A. Nazarov
Graphene oxide films were formed using the ultrasonic spray coating method and studied with micro-Raman spectroscopy, atomic force microscopy, and electrical dynamic response of resistance measurements. Effect of different gases (water vapor, ethanol, acetone, ammonia, and isopropyl) on the dynamic response of resistance of the Au / graphene oxide / Au structure has been studied. The dynamic response shows that adsorption of all mentioned gases results in increase of the resistance. For ethanol, acetone and isopropyl adsorption and desorption cycles are almost identical. At the same time, in the case of water vapor and ammonia the cycle of desorption is very week, especially for the former, which attests different mechanisms of adsorption/desorption processes regarding to ethanol, acetone and isopropyl. The mechanisms of studied vapors adsorption/desorption are proposed.
{"title":"Reduced graphene oxide obtained using the spray pyrolysis technique for gas sensing","authors":"O. Slobodian, Y. Milovanov, V. Skryshevsky, A. Vasin, X. Tang, J. Raskin, P. Lytvyn, K. Svezhentsova, S. Malyuta, A. Nazarov","doi":"10.15407/SPQEO22.01.098","DOIUrl":"https://doi.org/10.15407/SPQEO22.01.098","url":null,"abstract":"Graphene oxide films were formed using the ultrasonic spray coating method and studied with micro-Raman spectroscopy, atomic force microscopy, and electrical dynamic response of resistance measurements. Effect of different gases (water vapor, ethanol, acetone, ammonia, and isopropyl) on the dynamic response of resistance of the Au / graphene oxide / Au structure has been studied. The dynamic response shows that adsorption of all mentioned gases results in increase of the resistance. For ethanol, acetone and isopropyl adsorption and desorption cycles are almost identical. At the same time, in the case of water vapor and ammonia the cycle of desorption is very week, especially for the former, which attests different mechanisms of adsorption/desorption processes regarding to ethanol, acetone and isopropyl. The mechanisms of studied vapors adsorption/desorption are proposed.","PeriodicalId":44695,"journal":{"name":"Semiconductor Physics Quantum Electronics & Optoelectronics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2019-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49350327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Potassium halogenthiophosphates K6PS5Br and K6PS5Cl as well as halogen-free K7PS6 compound were synthesized using the two-step technique from elemental substances as well as potassium halides. The elemental composition of the obtained samples was determined using energy-dispersive X-ray spectroscopy. Raman spectra of K6PS5Br and K6PS5Cl show themselves to be much similar to those of chemically related Cu6PS5Br and Cu6PS5Cl argyrodite crystals. The much richer spectra of K6PS5Br and K6PS5Cl as well as K7PS6, however, reveal that their structure most likely differs from the cubic structure of Cu6PS5Br and Cu6PS5Cl argyrodites. doi: https://doi.org/10.15407/spqeo22.01.26 PACS 78.40.Ha; 77.80.Bh
{"title":"Synthesis and characterization of new potassium-containing argyrodite-type compounds","authors":"I. Studenyak","doi":"10.15407/SPQEO22.01.026","DOIUrl":"https://doi.org/10.15407/SPQEO22.01.026","url":null,"abstract":"Potassium halogenthiophosphates K6PS5Br and K6PS5Cl as well as halogen-free K7PS6 compound were synthesized using the two-step technique from elemental substances as well as potassium halides. The elemental composition of the obtained samples was determined using energy-dispersive X-ray spectroscopy. Raman spectra of K6PS5Br and K6PS5Cl show themselves to be much similar to those of chemically related Cu6PS5Br and Cu6PS5Cl argyrodite crystals. The much richer spectra of K6PS5Br and K6PS5Cl as well as K7PS6, however, reveal that their structure most likely differs from the cubic structure of Cu6PS5Br and Cu6PS5Cl argyrodites. doi: https://doi.org/10.15407/spqeo22.01.26 PACS 78.40.Ha; 77.80.Bh","PeriodicalId":44695,"journal":{"name":"Semiconductor Physics Quantum Electronics & Optoelectronics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2019-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48890666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, the method of electrophysical diagnostics of ohmic contacts to n + -n-n + structures for powerful silicon impact ionization avalanche transit-time diodes has been proposed. The specific resistivity of the Au–Ti–Pd–n + -n-n + -Si contacts and the current-flow mechanism within the temperature range 100...360 K has been investigated. The generalized method for studying the temperature dependence of the specific contact resistance in the case of multilayer structures with non-uniform doping level has been proposed. The values of the specific contact resistance have been calculated from the temperature dependence of the total resistance of the vertical structure. The offered method can be used to control the electrophysical parameters of ohmic contacts between the etching cycles in technology of manufacturing powerful silicon impact ionization avalanche transittime diodes.
{"title":"Peculiarities of study of Au–Ti–Pd–n+-n-n+-Si multilayer contact structure to avalanche transit-time diodes","authors":"P. M. Romanets","doi":"10.15407/SPQEO22.01.034","DOIUrl":"https://doi.org/10.15407/SPQEO22.01.034","url":null,"abstract":"In this work, the method of electrophysical diagnostics of ohmic contacts to n + -n-n + structures for powerful silicon impact ionization avalanche transit-time diodes has been proposed. The specific resistivity of the Au–Ti–Pd–n + -n-n + -Si contacts and the current-flow mechanism within the temperature range 100...360 K has been investigated. The generalized method for studying the temperature dependence of the specific contact resistance in the case of multilayer structures with non-uniform doping level has been proposed. The values of the specific contact resistance have been calculated from the temperature dependence of the total resistance of the vertical structure. The offered method can be used to control the electrophysical parameters of ohmic contacts between the etching cycles in technology of manufacturing powerful silicon impact ionization avalanche transittime diodes.","PeriodicalId":44695,"journal":{"name":"Semiconductor Physics Quantum Electronics & Optoelectronics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2019-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47770871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The virus of cattle enzootic leucosis leads to high losses in rural economy, implies forced slaughter of sick animals, loss of the breed, decrease in productivity, violation of reproduction processes in industrial breeding and livestock sector. Among cattle infection diseases, leucosis takes the leading position and comprises 57% of all the other nosological forms, if taking into account severity of injuries in organs, large-scale character of these diseases and economic aftermath. This disease can be transferred from animals to men faring with infected milk. The existing methods for cattle vital diagnostics are long-term and weakly-sensitive (AGID), or very complex and expensive (ELISA and PCR). In this work the alternative method for diagnostics is the method based on the SPR phenomenon was proposed. It has been shown for the first time that the SPR method enables to detect antibodies to cattle leucosis virus in the diluted solution (1 vol.%) of weakly positive blood serum taken from sick animals, which cannot be made using the methods AGID and ELISA – in this case the serum is considered as negative, and the tested animal is considered as healthy, although it is carrier of virus.
{"title":"Diagnostics of cattle leucosis by using an biosensor based on surface plasmon resonance phenomenon","authors":"Z. Klestova","doi":"10.15407/SPQEO22.01.111","DOIUrl":"https://doi.org/10.15407/SPQEO22.01.111","url":null,"abstract":"The virus of cattle enzootic leucosis leads to high losses in rural economy, implies forced slaughter of sick animals, loss of the breed, decrease in productivity, violation of reproduction processes in industrial breeding and livestock sector. Among cattle infection diseases, leucosis takes the leading position and comprises 57% of all the other nosological forms, if taking into account severity of injuries in organs, large-scale character of these diseases and economic aftermath. This disease can be transferred from animals to men faring with infected milk. The existing methods for cattle vital diagnostics are long-term and weakly-sensitive (AGID), or very complex and expensive (ELISA and PCR). In this work the alternative method for diagnostics is the method based on the SPR phenomenon was proposed. It has been shown for the first time that the SPR method enables to detect antibodies to cattle leucosis virus in the diluted solution (1 vol.%) of weakly positive blood serum taken from sick animals, which cannot be made using the methods AGID and ELISA – in this case the serum is considered as negative, and the tested animal is considered as healthy, although it is carrier of virus.","PeriodicalId":44695,"journal":{"name":"Semiconductor Physics Quantum Electronics & Optoelectronics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2019-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42579048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Materials, promising for production of luminescent solar energy concentrators were considered. It is known that the silicon oxide matrix is transparent within the spectral range where Sun emits light. Up to date, the low-temperature sol-gel method for synthesizing SiO2 coatings with the simultaneous doping of the material with quantum dots (QDs) is developed. The transmission spectrum of borosilicate glasses (BK7) is narrower than that of SiO2. Typically, the doping of BK7 with the quantum dots of the group A II B VI is carried out using the method of condensation at high temperatures, which results in a low value of the quantum yield of luminescence. Minimal losses of luminescent quanta through the leakage cone will be in the matrix of glass LASF35 022291.541, which refractive index is 2.022. In the research of the properties of photoconductors with a luminescent concentrator, the matrix is most often made of polymethylmethacrylate (PMMA). Its doping with QDs and dyes is well developed. The quantum yield of luminescence of luminophores when doping PMMA with dyes and QDs is close to unity. The magnitude of losses of luminescent quanta in matrices of glass, PMMA and silica has been estimated. Dependence of these losses in the wave range, which should be taken into account in the study of stacked fluorescent concentrators, has been analyzed.
对太阳能聚光材料的研究进展进行了展望。众所周知，氧化硅基体在太阳发光的光谱范围内是透明的。目前，研究了低温溶胶-凝胶法制备SiO2涂层，同时掺杂量子点。硼硅酸盐玻璃(BK7)的透射光谱比SiO2玻璃窄。通常，BK7与A II B VI族量子点的掺杂是采用高温缩合的方法进行的，这导致发光的量子产率值较低。在折射率为2.022的LASF35 022291.541玻璃基体中，通过漏锥的发光量子损失最小。在发光聚光器光导体性能的研究中，基质通常是聚甲基丙烯酸甲酯(PMMA)。它与量子点和染料的掺杂是很发达的。当PMMA掺杂染料和量子点时，发光团的发光量子产率接近一致。估计了玻璃、PMMA和二氧化硅基体中发光量子损失的大小。分析了这些损耗在波范围内的依赖性，这些损耗在研究堆叠荧光聚光器时应考虑到。
{"title":"Photoconverter with luminescent concentrator. Matrix material","authors":"M. Kulish","doi":"10.15407/spqeo22.01.080","DOIUrl":"https://doi.org/10.15407/spqeo22.01.080","url":null,"abstract":"Materials, promising for production of luminescent solar energy concentrators were considered. It is known that the silicon oxide matrix is transparent within the spectral range where Sun emits light. Up to date, the low-temperature sol-gel method for synthesizing SiO2 coatings with the simultaneous doping of the material with quantum dots (QDs) is developed. The transmission spectrum of borosilicate glasses (BK7) is narrower than that of SiO2. Typically, the doping of BK7 with the quantum dots of the group A II B VI is carried out using the method of condensation at high temperatures, which results in a low value of the quantum yield of luminescence. Minimal losses of luminescent quanta through the leakage cone will be in the matrix of glass LASF35 022291.541, which refractive index is 2.022. In the research of the properties of photoconductors with a luminescent concentrator, the matrix is most often made of polymethylmethacrylate (PMMA). Its doping with QDs and dyes is well developed. The quantum yield of luminescence of luminophores when doping PMMA with dyes and QDs is close to unity. The magnitude of losses of luminescent quanta in matrices of glass, PMMA and silica has been estimated. Dependence of these losses in the wave range, which should be taken into account in the study of stacked fluorescent concentrators, has been analyzed.","PeriodicalId":44695,"journal":{"name":"Semiconductor Physics Quantum Electronics & Optoelectronics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2019-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41734623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Photoelectric properties have been studied for 3С-SiC single crystals obtained by thermal decomposition of methyl trichlorosilane with addition of boron in the process of growing or using diffusion into intentionally undoped crystals. Boron-doped samples demonstrate the band of photosensitivity within the range 1.3...2.0 eV with the peak near 1.7 eV. Doping of 3С-SiC single crystals with B impurity leads to appearance of an efficient recombination center with the thermal activation energy 0.27 ± 0.02 eV inside the band gap and to widening the spectral sensitivity of the material over the impurity longwave range. Availability of boron results in changing the temperature dependence of photoconductivity from the decay characteristic to the activation one. It will allow expanding the operation range of devices based on 3C-SiC〈B〉 up to 500 °С and above it. In addition, the lux-ampere characteristics becomes linear, i.e., more convenient from the metrological viewpoint. Depending on the type of doping of 3C-SiC〈B〉 samples, pronounced variations of line positions in photoluminescence spectra in near-infrared range are revealed.
{"title":"Influence of boron doping on the photosensitivity of cubic silicon carbide","authors":"V. Rodionov","doi":"10.15407/spqeo22.01.092","DOIUrl":"https://doi.org/10.15407/spqeo22.01.092","url":null,"abstract":"Photoelectric properties have been studied for 3С-SiC single crystals obtained by thermal decomposition of methyl trichlorosilane with addition of boron in the process of growing or using diffusion into intentionally undoped crystals. Boron-doped samples demonstrate the band of photosensitivity within the range 1.3...2.0 eV with the peak near 1.7 eV. Doping of 3С-SiC single crystals with B impurity leads to appearance of an efficient recombination center with the thermal activation energy 0.27 ± 0.02 eV inside the band gap and to widening the spectral sensitivity of the material over the impurity longwave range. Availability of boron results in changing the temperature dependence of photoconductivity from the decay characteristic to the activation one. It will allow expanding the operation range of devices based on 3C-SiC〈B〉 up to 500 °С and above it. In addition, the lux-ampere characteristics becomes linear, i.e., more convenient from the metrological viewpoint. Depending on the type of doping of 3C-SiC〈B〉 samples, pronounced variations of line positions in photoluminescence spectra in near-infrared range are revealed.","PeriodicalId":44695,"journal":{"name":"Semiconductor Physics Quantum Electronics & Optoelectronics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2019-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46996461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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