Pub Date : 2022-01-27DOI: 10.33581/2520-2243-2022-1-44-51
A. Leonau, I. Feranchuk
In the present paper we investigate the approximate analytical diagonalisation of the Hamiltonian of the quantum Rabi model written in the Coulomb gauge and taking into account the gauge invariance of the system. It is shown that the Hamiltonian of the model can be diagonalised with high accuracy on the basis of a unitary operator of the gauge transformation utilising a simple basis set of state vectors. It is essential that the obtained approximate expressions do not depend on the variational parameters and are valid within the whole range of the parameter values. The zeroth-order approximation and uniformly available approximation are derived for the eigenstates of the system, and their comparison with the results of the numerical simulation is elaborated. The second-order correction to the zeroth-order approximation is deduced and its contribution to the energy of the system is estimated. The obtained results could be useful for description of the evolution of the quantum Rabi model as well as for investigation of systems of two-level atoms in the resonant quantum field.
{"title":"Analytical diagonalisation of the Hamiltonian of the quantum Rabi model in the Coulomb gauge","authors":"A. Leonau, I. Feranchuk","doi":"10.33581/2520-2243-2022-1-44-51","DOIUrl":"https://doi.org/10.33581/2520-2243-2022-1-44-51","url":null,"abstract":"In the present paper we investigate the approximate analytical diagonalisation of the Hamiltonian of the quantum Rabi model written in the Coulomb gauge and taking into account the gauge invariance of the system. It is shown that the Hamiltonian of the model can be diagonalised with high accuracy on the basis of a unitary operator of the gauge transformation utilising a simple basis set of state vectors. It is essential that the obtained approximate expressions do not depend on the variational parameters and are valid within the whole range of the parameter values. The zeroth-order approximation and uniformly available approximation are derived for the eigenstates of the system, and their comparison with the results of the numerical simulation is elaborated. The second-order correction to the zeroth-order approximation is deduced and its contribution to the energy of the system is estimated. The obtained results could be useful for description of the evolution of the quantum Rabi model as well as for investigation of systems of two-level atoms in the resonant quantum field.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"109 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76102375","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}
Pub Date : 2021-10-20DOI: 10.33581/2520-2243-2021-3-26-31
I. Romanov, N. Kovalchuk, L. Vlasukova, I. Parkhomenko, V. Saladukha, U. Pilipenka, D. V. Shestovski, S. Demidovich
Emission of the silicon oxide films grown on Si by wet thermal oxidation at 900 °С and by plasma-enhanced chemical vapor deposition from the SiH4 + N2O mixture at 350 °С has been compared using electroluminescence. The electroluminescence spectra were recorded in electrolyte – insulator – semiconductor system. The intense band in the red range with a maximum at 1.9 eV dominates the electroluminescence spectrum of the thermal oxide film. It was concluded that this band is related with the existence of silanol groups (Si — OH) in the oxide matrix. Multiband emission in the UV range is observed in the electroluminescence spectrum of the oxide film formed by plasma-enhanced chemical vapor deposition. Additional investigations using IR and RS spectroscopy revealed that observed spectrum modulation is of an oscillatory nature and is not the result of interference. Presumably, the luminescence in the UV region is due to the presence of oxygen deficiency centers containing bonds with hydrogen atoms.
{"title":"Electroluminescence of SiO2 films grown on Si by thermal oxidation and plasma-enhanced chemical vapor deposition","authors":"I. Romanov, N. Kovalchuk, L. Vlasukova, I. Parkhomenko, V. Saladukha, U. Pilipenka, D. V. Shestovski, S. Demidovich","doi":"10.33581/2520-2243-2021-3-26-31","DOIUrl":"https://doi.org/10.33581/2520-2243-2021-3-26-31","url":null,"abstract":"Emission of the silicon oxide films grown on Si by wet thermal oxidation at 900 °С and by plasma-enhanced chemical vapor deposition from the SiH4 + N2O mixture at 350 °С has been compared using electroluminescence. The electroluminescence spectra were recorded in electrolyte – insulator – semiconductor system. The intense band in the red range with a maximum at 1.9 eV dominates the electroluminescence spectrum of the thermal oxide film. It was concluded that this band is related with the existence of silanol groups (Si — OH) in the oxide matrix. Multiband emission in the UV range is observed in the electroluminescence spectrum of the oxide film formed by plasma-enhanced chemical vapor deposition. Additional investigations using IR and RS spectroscopy revealed that observed spectrum modulation is of an oscillatory nature and is not the result of interference. Presumably, the luminescence in the UV region is due to the presence of oxygen deficiency centers containing bonds with hydrogen atoms.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"88 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88955342","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}
Pub Date : 2021-10-20DOI: 10.33581/2520-2243-2021-3-20-25
E. Kolesnikova, V. Uglov, A. K. Kuleshov, D. P. Rusalsky
In the present work, the influence of the deposition temperature of InSb films on semi-insulating GaAs(100) on their phase composition, crystal perfection and electrical properties was investigated. The InSb films of various extent of crystal perfection are formed by means of explosive thermal deposition of InSb on semi-insulating GaAs(100) substrates in the temperature range of 375–460 °C. X-ray diffraction analysis established that the films are heteroepitaxial. It is shown that an increase in the deposition temperature of InSb films from 375 to 460 °C leads to a change in the film surface roughness (Ra) from 3.4 to 19.1 nm. The Hall voltage sensitivity to the magnetic field of InSb films varies in the range of 500–1500 mV/T. The electron concentration (n) and mobility (μ) changes in the range of 2 ⋅ 1016 – 6 ⋅ 1016 cm–3, 10 ⋅ 103 – 21 ⋅ 103 cm2/(V ⋅ s). The formed InSb films on semi-insulating GaAs(100) substrate are of practical interest for the manufacture of highly sensitive miniature Hall devices.
{"title":"Formation of epitaxial InSb films on semi-insulating GaAs(100) by explosive thermal evaporation: their structure and electrical properties","authors":"E. Kolesnikova, V. Uglov, A. K. Kuleshov, D. P. Rusalsky","doi":"10.33581/2520-2243-2021-3-20-25","DOIUrl":"https://doi.org/10.33581/2520-2243-2021-3-20-25","url":null,"abstract":"In the present work, the influence of the deposition temperature of InSb films on semi-insulating GaAs(100) on their phase composition, crystal perfection and electrical properties was investigated. The InSb films of various extent of crystal perfection are formed by means of explosive thermal deposition of InSb on semi-insulating GaAs(100) substrates in the temperature range of 375–460 °C. X-ray diffraction analysis established that the films are heteroepitaxial. It is shown that an increase in the deposition temperature of InSb films from 375 to 460 °C leads to a change in the film surface roughness (Ra) from 3.4 to 19.1 nm. The Hall voltage sensitivity to the magnetic field of InSb films varies in the range of 500–1500 mV/T. The electron concentration (n) and mobility (μ) changes in the range of 2 ⋅ 1016 – 6 ⋅ 1016 cm–3, 10 ⋅ 103 – 21 ⋅ 103 cm2/(V ⋅ s). The formed InSb films on semi-insulating GaAs(100) substrate are of practical interest for the manufacture of highly sensitive miniature Hall devices.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90622059","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}
Pub Date : 2021-10-13DOI: 10.33581/2520-2243-2021-3-40-48
T. A. Efimova, I. Timoshchenko, N. Abrashina-Zhadaeva
This paper studies a mathematical model of the spread of the COVID-19 pandemic based on ordinary differential equations with a time-fractional derivative. The model takes into account the susceptibility of the population to infection, the incubation period, the number of contacts between healthy and sick people, number of infected, recovered and deceased people in a certain period. To test the model a comparison was made with models obtained with a time derivative of integer orders, with known data for the Italian region of Lombardy. The results suggest that the use of a mathematical model based on a time-fractional derivative with the help of data such as susceptibility of the population to infection, incubation period, number of infected, recovered and deceased people in a certain period, ultimately can help health authorities to develop effective measures against the pandemic. This is especially possible if we expand the model and consider partial differential equations describing the convection-diffusion process, taking into account the prediction of the geographical distribution of the most important medical resources.
{"title":"Fractional differential model of the spread of COVID-19","authors":"T. A. Efimova, I. Timoshchenko, N. Abrashina-Zhadaeva","doi":"10.33581/2520-2243-2021-3-40-48","DOIUrl":"https://doi.org/10.33581/2520-2243-2021-3-40-48","url":null,"abstract":"This paper studies a mathematical model of the spread of the COVID-19 pandemic based on ordinary differential equations with a time-fractional derivative. The model takes into account the susceptibility of the population to infection, the incubation period, the number of contacts between healthy and sick people, number of infected, recovered and deceased people in a certain period. To test the model a comparison was made with models obtained with a time derivative of integer orders, with known data for the Italian region of Lombardy. The results suggest that the use of a mathematical model based on a time-fractional derivative with the help of data such as susceptibility of the population to infection, incubation period, number of infected, recovered and deceased people in a certain period, ultimately can help health authorities to develop effective measures against the pandemic. This is especially possible if we expand the model and consider partial differential equations describing the convection-diffusion process, taking into account the prediction of the geographical distribution of the most important medical resources.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78040084","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}
Pub Date : 2021-10-13DOI: 10.33581/2520-2243-2021-3-67-73
P. Orsich, K. Brinkmann, V. Dormenev, M. Korzhik, V. Mechinsky, D. Kozlov, H. Zaunick
The degradation of the optical transmittance under ionising radiation of the scintillation crystal in the scintillation spectral range leads to the losses of the light output, which results in the deterioration of the energy resolution and limits the operation time of the calorimeter made of the scintillator. This effect is especially prominent for calorimeters operating at a low temperature. The use of a lead tungstate scintillation crystal PbWO4 in calorimetry at a low temperature in the range from –20 to –45 °C provides a threefold increase in its scintillation yield, which causes a significant improvement in the energy resolution in the range up to 10 MeV. Keep on this feature is critically important for hadron spectroscopy. However, as the temperature of the PbWO4 crystal is lowered, the rate of spontaneous relaxation of colour centers created under ionising radiation significantly slows down, which shifts the dynamic level of the induced absorption towards a higher value under long-term irradiation of high-energy physics experiments. A comparison is made of the spontaneous relaxation of induced absorption in the spectral region of scintillations with stimulated relaxation upon irradiation of samples by infrared photons of different wavelengths. It is shown that the relaxation of colour centers can be accelerated up to one thousand times. Thus, recovery stimulation allows fast and efficient in situ recovery of the crystal optical transmittance either at beam-off periods or online at data acquisition. The application can substantially improve or extend the running period of the PWO based calorimeters at low temperatures by keeping the radiation damage at a tolerable level.
{"title":"PWO based electromagnetic calorimetry to operate at a low temperature","authors":"P. Orsich, K. Brinkmann, V. Dormenev, M. Korzhik, V. Mechinsky, D. Kozlov, H. Zaunick","doi":"10.33581/2520-2243-2021-3-67-73","DOIUrl":"https://doi.org/10.33581/2520-2243-2021-3-67-73","url":null,"abstract":"The degradation of the optical transmittance under ionising radiation of the scintillation crystal in the scintillation spectral range leads to the losses of the light output, which results in the deterioration of the energy resolution and limits the operation time of the calorimeter made of the scintillator. This effect is especially prominent for calorimeters operating at a low temperature. The use of a lead tungstate scintillation crystal PbWO4 in calorimetry at a low temperature in the range from –20 to –45 °C provides a threefold increase in its scintillation yield, which causes a significant improvement in the energy resolution in the range up to 10 MeV. Keep on this feature is critically important for hadron spectroscopy. However, as the temperature of the PbWO4 crystal is lowered, the rate of spontaneous relaxation of colour centers created under ionising radiation significantly slows down, which shifts the dynamic level of the induced absorption towards a higher value under long-term irradiation of high-energy physics experiments. A comparison is made of the spontaneous relaxation of induced absorption in the spectral region of scintillations with stimulated relaxation upon irradiation of samples by infrared photons of different wavelengths. It is shown that the relaxation of colour centers can be accelerated up to one thousand times. Thus, recovery stimulation allows fast and efficient in situ recovery of the crystal optical transmittance either at beam-off periods or online at data acquisition. The application can substantially improve or extend the running period of the PWO based calorimeters at low temperatures by keeping the radiation damage at a tolerable level.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"94 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83882145","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}
Pub Date : 2021-10-11DOI: 10.33581/2520-2243-2021-3-62-66
M. Korzhik
The future nuclear physics research capabilities for scientists from Belarus are discussed. The following branches for the activity: megascience class research platforms created in Russia and the European Union, a new generation of ionizing radiation sources, use of the world nuclear science network for short-term research and, monitoring of nuclear power plants are debated. The purposes of nuclear physics research are suggested to be a balanced combining of the further penetration deep into the matter, to clarify its status and time evolution and, the routine activity associated with clarifying the details of the world, for which sufficiently well-developed models have already been created. Further, the goals of nuclear physics research are specified. They include preventing the loss of knowledge in the field of nuclear physics; conservation of the acceptable qualification and its reproducibility, maintaining the appropriate level of the engineering corps for the perception of the latest knowledge. This article is based on the author’s personal experience in participating in projects of high scientific significance. The route of considering the areas of application of nuclear physics scientists’ efforts is formed according to the principle of maximum return from the highly qualified personnel (PhDs and doctors of science). Ain importance of training undergraduates and graduate students for a scientific career is underlined. Finally, a need to maintain a high level of knowledge in the branch for the expertise upon the request of the government to secure and develop the country is pointed out.
{"title":"Outlook for nuclear physics research in Belarus","authors":"M. Korzhik","doi":"10.33581/2520-2243-2021-3-62-66","DOIUrl":"https://doi.org/10.33581/2520-2243-2021-3-62-66","url":null,"abstract":"The future nuclear physics research capabilities for scientists from Belarus are discussed. The following branches for the activity: megascience class research platforms created in Russia and the European Union, a new generation of ionizing radiation sources, use of the world nuclear science network for short-term research and, monitoring of nuclear power plants are debated. The purposes of nuclear physics research are suggested to be a balanced combining of the further penetration deep into the matter, to clarify its status and time evolution and, the routine activity associated with clarifying the details of the world, for which sufficiently well-developed models have already been created. Further, the goals of nuclear physics research are specified. They include preventing the loss of knowledge in the field of nuclear physics; conservation of the acceptable qualification and its reproducibility, maintaining the appropriate level of the engineering corps for the perception of the latest knowledge. This article is based on the author’s personal experience in participating in projects of high scientific significance. The route of considering the areas of application of nuclear physics scientists’ efforts is formed according to the principle of maximum return from the highly qualified personnel (PhDs and doctors of science). Ain importance of training undergraduates and graduate students for a scientific career is underlined. Finally, a need to maintain a high level of knowledge in the branch for the expertise upon the request of the government to secure and develop the country is pointed out.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"46 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77783961","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}
Pub Date : 2021-10-08DOI: 10.33581/2520-2243-2021-3-12-19
V. I. Halauchuk, Michail G. Lukashevich
The transverse magnetoresistance (MR) hysteresis loops of a magnetically ordered Corbino disk have been studied in the temperature range 300–2 K in an external magnetic field with induction up to 1 T oriented in the plane of the disk (ϕ = 0°) and perpendicularly to its plane (ϕ = 90°). The Corbino disk is made of a thin permalloy film obtained on an insulating sitall substrate by ion-beam sputtering. Independently of the temperature and measurement geometry, the field dependences of MR in the range of weak magnetic fields up to the magnetisation saturation exhibit sharp peaks of the negative MR caused by the domain walls motion during the magnetisation reversal of the sample. The position of the peak in the magnetic field (Bp) is determined by the temperature as well as the angle between magnetic field direction and the disk plane. It was found that a temperature change in the range of T = 300–2 K leads to a change in its position in the range of 0.2–6.0 mT and 8–22 mT at ϕ = 0° and ϕ = 90°, respectively. The magnetic field direction reorientation from in-plane to out-of-pane at T = 2 K leads to the Bp change from 6 to 22 mT. In the range of strong magnetic fields above the magnetization saturation field at ϕ = 0° the positive MR component decreases with induction and has a linear non-saturable dependence down to T ≈ 40–50 K due to the magnon MR component dominance. The complete freezing of magnons at T = 2 K leads to the absence of high-field magnetoresistive effect. At ϕ = 90° in weak fields, the MR changes its sign from positive to negative due to the anisotropic MR component dominance because of the disk magnetisation reorientation perpendicular to the current lines. In a strong field it changes the slope due to the saturation of negative anisotropic MR component, as well as possible additional contribution of the positive geometric Lorentzian MR.
{"title":"Peculiarity of the low temperature magnetoresistive effect in the Corbino disk with magnetic ordering","authors":"V. I. Halauchuk, Michail G. Lukashevich","doi":"10.33581/2520-2243-2021-3-12-19","DOIUrl":"https://doi.org/10.33581/2520-2243-2021-3-12-19","url":null,"abstract":"The transverse magnetoresistance (MR) hysteresis loops of a magnetically ordered Corbino disk have been studied in the temperature range 300–2 K in an external magnetic field with induction up to 1 T oriented in the plane of the disk (ϕ = 0°) and perpendicularly to its plane (ϕ = 90°). The Corbino disk is made of a thin permalloy film obtained on an insulating sitall substrate by ion-beam sputtering. Independently of the temperature and measurement geometry, the field dependences of MR in the range of weak magnetic fields up to the magnetisation saturation exhibit sharp peaks of the negative MR caused by the domain walls motion during the magnetisation reversal of the sample. The position of the peak in the magnetic field (Bp) is determined by the temperature as well as the angle between magnetic field direction and the disk plane. It was found that a temperature change in the range of T = 300–2 K leads to a change in its position in the range of 0.2–6.0 mT and 8–22 mT at ϕ = 0° and ϕ = 90°, respectively. The magnetic field direction reorientation from in-plane to out-of-pane at T = 2 K leads to the Bp change from 6 to 22 mT. In the range of strong magnetic fields above the magnetization saturation field at ϕ = 0° the positive MR component decreases with induction and has a linear non-saturable dependence down to T ≈ 40–50 K due to the magnon MR component dominance. The complete freezing of magnons at T = 2 K leads to the absence of high-field magnetoresistive effect. At ϕ = 90° in weak fields, the MR changes its sign from positive to negative due to the anisotropic MR component dominance because of the disk magnetisation reorientation perpendicular to the current lines. In a strong field it changes the slope due to the saturation of negative anisotropic MR component, as well as possible additional contribution of the positive geometric Lorentzian MR.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84169074","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}
Pub Date : 2021-10-05DOI: 10.33581/2520-2243-2021-3-4-11
Andrian M. Nastas, Mikhail S. Iovu, I. Agishev, Ilya V. Gavrusenok, E. Melnikova, I. Stashkevitch, A. Tolstik
The paper presents a study of the formation of holographic diffraction gratings in thin films of chalcogenide glassy semiconductors. The recording process of holographic gratings at the argon-laser radiation wave length 488 nm and the process of chemical etching that enables the formation of а relief holographic grating are analysed. The optimum conditions for the formation of diffraction gratings in films of arsenic sulfide As2S3 are defined. It is shown that at the 488 nm wave length of an argon laser the optimum exposure comes to ∼5–8 J/cm2. At the recording stage a quasi-phase (relief-phase) grating is formed, with the diffraction efficiency on the order of a few per cent. Etching of the exposed sample with a solution of NaOH alkali in deionised water and isopropanol makes it possible to increase considerably the relief depth and to improve the diffraction efficiency of a thin diffraction grating approximately up to 20 % for the red spectral region, and to approach the maximal value ∼34 % for the near infra-red region. The results of the study considered look promising for the creation of relief holographic gratings which are essential in present-day optical instrument building (production of spectral devices, holographic sights, and the like).
{"title":"Formation of holographic diffraction gratings in thin films of chalcogenide glassy semiconductors","authors":"Andrian M. Nastas, Mikhail S. Iovu, I. Agishev, Ilya V. Gavrusenok, E. Melnikova, I. Stashkevitch, A. Tolstik","doi":"10.33581/2520-2243-2021-3-4-11","DOIUrl":"https://doi.org/10.33581/2520-2243-2021-3-4-11","url":null,"abstract":"The paper presents a study of the formation of holographic diffraction gratings in thin films of chalcogenide glassy semiconductors. The recording process of holographic gratings at the argon-laser radiation wave length 488 nm and the process of chemical etching that enables the formation of а relief holographic grating are analysed. The optimum conditions for the formation of diffraction gratings in films of arsenic sulfide As2S3 are defined. It is shown that at the 488 nm wave length of an argon laser the optimum exposure comes to ∼5–8 J/cm2. At the recording stage a quasi-phase (relief-phase) grating is formed, with the diffraction efficiency on the order of a few per cent. Etching of the exposed sample with a solution of NaOH alkali in deionised water and isopropanol makes it possible to increase considerably the relief depth and to improve the diffraction efficiency of a thin diffraction grating approximately up to 20 % for the red spectral region, and to approach the maximal value ∼34 % for the near infra-red region. The results of the study considered look promising for the creation of relief holographic gratings which are essential in present-day optical instrument building (production of spectral devices, holographic sights, and the like).","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88703238","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}
Pub Date : 2021-09-29DOI: 10.33581/2520-2243-2021-3-4-12
M. Bakhadirkhanov, Z. Kenzhaev, B. Ismaylov, V. Odzhaev, U. Prasalovich, Yu.N. Yankovski
The possibility of adjusting the operational parameters of industrial solar cells produced by the company Suniva based on monocrystalline silicon by means of additional diffusion doping with nickel in the temperature range 700–1200 °C has been investigated. It is shown that the optimal temperature of nickel diffusion is Tdiff = 800–850 °C. In this case the value of the maximum power Pmax increases by 20–28 % in relation to the parameters of the original industrial photocell. At diffusion temperatures Tdiff > 1000 °C, a sharp decrease in Pmax occurs, which is associated with an increase in the depth of the p–n-junction due to the distillation of phosphorus atoms during high-temperature diffusion of nickel. The positive effect of diffusion alloying with nickel on the electrophysical parameters of photocells is greatest in the case when the nickel impurity clusters are in the region of the p–n-junction, i. e. with diffusion alloying to the front side of the plate. The action of electrically neutral nickel clusters is less pronounced when they are located in the region of the isotypic p–p+ transition; in case of diffusion alloying with nickel in the opposite side of the plate.
{"title":"Improving the efficiency of an industrial silicon solar cell by doping with nickel","authors":"M. Bakhadirkhanov, Z. Kenzhaev, B. Ismaylov, V. Odzhaev, U. Prasalovich, Yu.N. Yankovski","doi":"10.33581/2520-2243-2021-3-4-12","DOIUrl":"https://doi.org/10.33581/2520-2243-2021-3-4-12","url":null,"abstract":"The possibility of adjusting the operational parameters of industrial solar cells produced by the company Suniva based on monocrystalline silicon by means of additional diffusion doping with nickel in the temperature range 700–1200 °C has been investigated. It is shown that the optimal temperature of nickel diffusion is Tdiff = 800–850 °C. In this case the value of the maximum power Pmax increases by 20–28 % in relation to the parameters of the original industrial photocell. At diffusion temperatures Tdiff > 1000 °C, a sharp decrease in Pmax occurs, which is associated with an increase in the depth of the p–n-junction due to the distillation of phosphorus atoms during high-temperature diffusion of nickel. The positive effect of diffusion alloying with nickel on the electrophysical parameters of photocells is greatest in the case when the nickel impurity clusters are in the region of the p–n-junction, i. e. with diffusion alloying to the front side of the plate. The action of electrically neutral nickel clusters is less pronounced when they are located in the region of the isotypic p–p+ transition; in case of diffusion alloying with nickel in the opposite side of the plate.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74102846","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}
Pub Date : 2021-09-29DOI: 10.33581/2520-2243-2021-3-81-85
V. Anishchik, V. A. Harushka, U. Pilipenka, V. Ponariadov, V. Saladukha, A. Omelchenko
The results of the effect of rapid heat treatment on the optical characteristics of a silicon wafer surface in the region of the G-point in the Brillouin zone are presented for different types of silicon wafers conductivity, their doping level, the covalent radii of dopants and the crystallographic orientation of the wafer surface. The absorption coefficient and refractive index of the initial 100 mm diameter samples KDB-12 <100>, KDB-10 <111>, KDB-0.005 <100> and KES-0.015 <100>, underwent standard chemical-mechanical polishing, was measured on a Uvisel 2 ellipsometer (Horiba Scientific, France) in the spectral range 0.6–6.0 eV (200–2100 nm) before and after rapid heat treatment. The incidence angle of the light beam was 70° relative to the sample plane. It is shown that the changes in the optical characteristics of the silicon surface in the spectral region of the location of the G-point in the Brillouin zone after rapid heat treatment is due to a decrease in the surface deformation potential due to solid-phase recrystallisation of the mechanically damaged layer. It has been established that carrying out the rapid heat treatment of silicon samples with a high boron concentration leads to a more significant decrease in the refractive index and absorption compared with silicon with a low boron concentration, due to an increase in the depletion of the silicon surface with boron as a result of diffusion processes at the silicon – silicon dioxide interface.
{"title":"Variation of the silicon optical parameters after rapid heat treatment","authors":"V. Anishchik, V. A. Harushka, U. Pilipenka, V. Ponariadov, V. Saladukha, A. Omelchenko","doi":"10.33581/2520-2243-2021-3-81-85","DOIUrl":"https://doi.org/10.33581/2520-2243-2021-3-81-85","url":null,"abstract":"The results of the effect of rapid heat treatment on the optical characteristics of a silicon wafer surface in the region of the G-point in the Brillouin zone are presented for different types of silicon wafers conductivity, their doping level, the covalent radii of dopants and the crystallographic orientation of the wafer surface. The absorption coefficient and refractive index of the initial 100 mm diameter samples KDB-12 <100>, KDB-10 <111>, KDB-0.005 <100> and KES-0.015 <100>, underwent standard chemical-mechanical polishing, was measured on a Uvisel 2 ellipsometer (Horiba Scientific, France) in the spectral range 0.6–6.0 eV (200–2100 nm) before and after rapid heat treatment. The incidence angle of the light beam was 70° relative to the sample plane. It is shown that the changes in the optical characteristics of the silicon surface in the spectral region of the location of the G-point in the Brillouin zone after rapid heat treatment is due to a decrease in the surface deformation potential due to solid-phase recrystallisation of the mechanically damaged layer. It has been established that carrying out the rapid heat treatment of silicon samples with a high boron concentration leads to a more significant decrease in the refractive index and absorption compared with silicon with a low boron concentration, due to an increase in the depletion of the silicon surface with boron as a result of diffusion processes at the silicon – silicon dioxide interface.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"112 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87706756","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：