Pub Date : 2022-02-08DOI: 10.33581/2520-2243-2022-1-52-64
Darya Meniailava, Maksim B Shundalau, Yong‐Chang Han
Based on state-of-the-art ab initio potential energy functions and classical kinetic theory, some transport properties (diffusion, viscosity and thermal conductivity coefficients) of two-component dilute gas media of radium and halogen (F, Cl, Br, I) atoms were predicted as functions of the translation temperature up to 3000 K. Calculations were performed by sequential analytical and (or) numerical computations of deflection angle, cross-section and collision integrals. A detailed methodology for the calculation of the transport properties using the Morse potential was developed. Some numerical difficulties arising due to the singularity of the integrands and discontinuous character of the variable of integration are considered. The dependence of transport properties on isotope mass is also shown. Possible errors introduced by using the model Morse potential function instead of the real potential for the interaction between atoms are estimated. These data can be useful for the planning of the experiments on the direct laser cooling of the monohalides of alkaline earth metals.
{"title":"Transport properties of two-component radium – halogen dilute gas media","authors":"Darya Meniailava, Maksim B Shundalau, Yong‐Chang Han","doi":"10.33581/2520-2243-2022-1-52-64","DOIUrl":"https://doi.org/10.33581/2520-2243-2022-1-52-64","url":null,"abstract":"Based on state-of-the-art ab initio potential energy functions and classical kinetic theory, some transport properties (diffusion, viscosity and thermal conductivity coefficients) of two-component dilute gas media of radium and halogen (F, Cl, Br, I) atoms were predicted as functions of the translation temperature up to 3000 K. Calculations were performed by sequential analytical and (or) numerical computations of deflection angle, cross-section and collision integrals. A detailed methodology for the calculation of the transport properties using the Morse potential was developed. Some numerical difficulties arising due to the singularity of the integrands and discontinuous character of the variable of integration are considered. The dependence of transport properties on isotope mass is also shown. Possible errors introduced by using the model Morse potential function instead of the real potential for the interaction between atoms are estimated. These data can be useful for the planning of the experiments on the direct laser cooling of the monohalides of alkaline earth metals.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82948984","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 : 2022-02-03DOI: 10.33581/2520-2243-2022-1-4-13
M. Demesh, K. Gorbachenya, V. Kisel, E. Volkova, V. Maltsev, E. Koporulina, A. Kornienko, E. Dunina, N. Kuleshov
A Pr3+ : YAl3(BO3)4 crystal with sizes of 20 × 10 × 10 mm was grown from high-temperature solution and its structural and spectroscopic properties were investigated. The distribution coefficient of praseodymium ranged from 0.6 to 0.8, that yield to the Pr3+ ion concentration of 1.1 ⋅1020 cm–3. Visible and infrared groundstate absorption (3H4) was measurement in dependence on the polarisation. The absorption spectra of the Pr3+ : YAl3(BO3)4 exhibit pronounced polarisation anisotropy. The modified Judd – Offelt theory was applied to evaluate the transitions intensities in absorption and emission, branching ratios and radiative lifetimes of the metastable levels 3P0 and 1D2.
{"title":"Crystal growth and f – f transition intensities analysis of praseodymium ions in yttrium-aluminum orthoborates","authors":"M. Demesh, K. Gorbachenya, V. Kisel, E. Volkova, V. Maltsev, E. Koporulina, A. Kornienko, E. Dunina, N. Kuleshov","doi":"10.33581/2520-2243-2022-1-4-13","DOIUrl":"https://doi.org/10.33581/2520-2243-2022-1-4-13","url":null,"abstract":"A Pr3+ : YAl3(BO3)4 crystal with sizes of 20 × 10 × 10 mm was grown from high-temperature solution and its structural and spectroscopic properties were investigated. The distribution coefficient of praseodymium ranged from 0.6 to 0.8, that yield to the Pr3+ ion concentration of 1.1 ⋅1020 cm–3. Visible and infrared groundstate absorption (3H4) was measurement in dependence on the polarisation. The absorption spectra of the Pr3+ : YAl3(BO3)4 exhibit pronounced polarisation anisotropy. The modified Judd – Offelt theory was applied to evaluate the transitions intensities in absorption and emission, branching ratios and radiative lifetimes of the metastable levels 3P0 and 1D2.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"72 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76787548","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 : 2022-02-03DOI: 10.33581/2520-2243-2022-1-35-43
Y. Nikitjuk, A. N. Serdyukov, I. Aushev
The current work takes the results of the numerical experiment implemented in the Ansys finite element analysis program to create the neural network and regression models of two-beam laser splitting of silicate glasses. The regression models of two-beam laser glass cutting have been obtained in the DesignXplorer module of Ansys Workbench using a face-centered version of the central composite design. The processing speed, the parameters of laser beams, the glass plate thickness, and the distance between the laser radiation and the refrigerant affected zones were used as variable factors. The maximum temperatures and thermoelastic tensile stresses in the laser processing area were used as responses. The artificial neural networks have been constructed and trained using the TensorFlow package. The results of determining the maximum temperatures and thermoelastic stresses in the laser treatment area using the neural network and regression models have been compared.
{"title":"Determination of the parameters of two-beam laser splitting of silicate glasses using regression and neural network models","authors":"Y. Nikitjuk, A. N. Serdyukov, I. Aushev","doi":"10.33581/2520-2243-2022-1-35-43","DOIUrl":"https://doi.org/10.33581/2520-2243-2022-1-35-43","url":null,"abstract":"The current work takes the results of the numerical experiment implemented in the Ansys finite element analysis program to create the neural network and regression models of two-beam laser splitting of silicate glasses. The regression models of two-beam laser glass cutting have been obtained in the DesignXplorer module of Ansys Workbench using a face-centered version of the central composite design. The processing speed, the parameters of laser beams, the glass plate thickness, and the distance between the laser radiation and the refrigerant affected zones were used as variable factors. The maximum temperatures and thermoelastic tensile stresses in the laser processing area were used as responses. The artificial neural networks have been constructed and trained using the TensorFlow package. The results of determining the maximum temperatures and thermoelastic stresses in the laser treatment area using the neural network and regression models have been compared.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"50 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75083803","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 : 2022-02-01DOI: 10.33581/2520-2243-2022-1-14-19
S. Slussarenko, E. Melnikova, A. Tolstik
We report on experimental realisation of polarisation dynamic gratings recording in pure nematic liquid crystal. This work is devoted to the experimental implementation of writing polarisation dynamic gratings in a pure nematic liquid crystal. The registration mechanism is based on the photorefractive effect in a cell filled with a pure nematic crystal under the action of an applied constant electric field. This phenomenon does not require the presence of photoexcited charge carriers in the liquid crystal and is explained by the extremely high anisotropy of the liquid crystal. The article provides an elementary theoretical model of this process. The dependences of the grating writing process on the spatial frequency of the interference field and the intensity of the recording beams are investigated. It was found that the spatial grating does not coincide with the interference field – the response of the medium is non-local. However, we do not associate this property with that in photorefractive crystals. In our case, a mechanism of purely geometric mismatch is more likely due to the peculiarity of the recording mechanism. One of the fundamental properties of the described processes is their independence from the wavelength of the recording radiation, which confirms the model of the recording mechanism we have chosen.
{"title":"Recording the dynamic polarisation gratings in pure nematic liquid crystal","authors":"S. Slussarenko, E. Melnikova, A. Tolstik","doi":"10.33581/2520-2243-2022-1-14-19","DOIUrl":"https://doi.org/10.33581/2520-2243-2022-1-14-19","url":null,"abstract":"We report on experimental realisation of polarisation dynamic gratings recording in pure nematic liquid crystal. This work is devoted to the experimental implementation of writing polarisation dynamic gratings in a pure nematic liquid crystal. The registration mechanism is based on the photorefractive effect in a cell filled with a pure nematic crystal under the action of an applied constant electric field. This phenomenon does not require the presence of photoexcited charge carriers in the liquid crystal and is explained by the extremely high anisotropy of the liquid crystal. The article provides an elementary theoretical model of this process. The dependences of the grating writing process on the spatial frequency of the interference field and the intensity of the recording beams are investigated. It was found that the spatial grating does not coincide with the interference field – the response of the medium is non-local. However, we do not associate this property with that in photorefractive crystals. In our case, a mechanism of purely geometric mismatch is more likely due to the peculiarity of the recording mechanism. One of the fundamental properties of the described processes is their independence from the wavelength of the recording radiation, which confirms the model of the recording mechanism we have chosen.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"126 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75033720","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 : 2022-01-28DOI: 10.33581/2520-2243-2022-1-80-87
N. Kovalchuk, Yuliya A. Marudo, A. Omelchenko, U. Pilipenka, V. Saladukha, S. Demidovich, V. Kolos, V. Anishchik, V. A. Filipenia, D. V. Shestovski
The charge properties of thin dielectrics, obtained by rapid thermal processing (RTP), and their interfaces with silicon for MOS transistors are investigated. The production of insulator layers was carried out by a two- or three-stage RTP with photon processing regimes similar for each stage (duration – 12 s, maximum temperature – 1250 °C). After the third stage of RTP in a nitrogen atmosphere of the gate oxides, obtained by a two-stage process in oxygen atmosphere, the defects responsible for local charge centers are partially eliminated. There is also an increase in the relative value of the surface potential by an average of 100 relative units. The elimination of defects is a consequence of the rearrangement of the structure of the dielectric, its interface with silicon, and the diffusion of oxygen and silicon atoms along the interface of the insulator layer. For samples obtained by a two-stage RTP in an oxygen atmosphere and subjected to the third stage of processing in a forming gas, there is an almost complete elimination of local charge centers and an increase in the relative value of the surface potential by an average of 300 relative units. In this case, in addition to the processes occurring during the treatment of SiO2 by the RTP method in an nitrogen atmosphere, the liquidation of charge centers is a consequence of the passivation of defects by hydrogen atoms.
{"title":"Charging properties of thin gate dielectrics, obtained by the method of rapid thermal processing","authors":"N. Kovalchuk, Yuliya A. Marudo, A. Omelchenko, U. Pilipenka, V. Saladukha, S. Demidovich, V. Kolos, V. Anishchik, V. A. Filipenia, D. V. Shestovski","doi":"10.33581/2520-2243-2022-1-80-87","DOIUrl":"https://doi.org/10.33581/2520-2243-2022-1-80-87","url":null,"abstract":"The charge properties of thin dielectrics, obtained by rapid thermal processing (RTP), and their interfaces with silicon for MOS transistors are investigated. The production of insulator layers was carried out by a two- or three-stage RTP with photon processing regimes similar for each stage (duration – 12 s, maximum temperature – 1250 °C). After the third stage of RTP in a nitrogen atmosphere of the gate oxides, obtained by a two-stage process in oxygen atmosphere, the defects responsible for local charge centers are partially eliminated. There is also an increase in the relative value of the surface potential by an average of 100 relative units. The elimination of defects is a consequence of the rearrangement of the structure of the dielectric, its interface with silicon, and the diffusion of oxygen and silicon atoms along the interface of the insulator layer. For samples obtained by a two-stage RTP in an oxygen atmosphere and subjected to the third stage of processing in a forming gas, there is an almost complete elimination of local charge centers and an increase in the relative value of the surface potential by an average of 300 relative units. In this case, in addition to the processes occurring during the treatment of SiO2 by the RTP method in an nitrogen atmosphere, the liquidation of charge centers is a consequence of the passivation of defects by hydrogen atoms.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"70 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76055578","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 : 2022-01-28DOI: 10.33581/2520-2243-2022-1-75-79
V. Shepelevich
The results of study of the microstructure and texture of aluminum alloys, containing 0.12 and 0.25 at. % Bi, obtained with high-speed solidification, are presented (melt cooling rate liquid – not less 105 K /s). Texture (111) aluminum is formed in the rapidly solidified foils of investigated alloys and it is conserved under annealing at 523 K during 2 h. The average chord of bismuth sections does not exceed 0.05 µm. As the crystallisation front moves from surface A contacted with crystalliser to the surface B, the average size of dispersed bismuth particles increases. Foils of the alloys dissolve in water at room temperature actively forming hydrogen bubbles in vessel with water, white powder of aluminum oxide in an amorphous state and bismuth precipitations. Isotermical annealing of foils at 573 K for 5 h causes a change in distribution of chords in size groups and increases their average value. After the annealing bismuth particles are localised on low- and high-angle boundaries. The rapidly solidified foils of Al – Bi system can be used to produced hydrogen, aluminum oxide powder and create technical devices using hydrogen.
研究了含0.12和0.25 at的铝合金的显微组织和织构。给出了高速凝固得到的% Bi(熔体冷却速率不低于105 K /s)。织构(111)铝在快速凝固的合金箔中形成，并在523 K下退火2 h时保持不变。铋截面的平均弦长不超过0.05µm。随着结晶锋从与结晶剂接触的表面A向表面B移动，分散铋颗粒的平均尺寸增大。合金箔在室温下溶于水，在有水的容器中活跃地形成氢气泡，无定形的白色氧化铝粉末和铋沉淀。在573k下等温退火5h后，弦在尺寸组中的分布发生了变化，其平均值增大。退火后铋粒子在低角和高角边界上局部化。铝铋体系的快速凝固箔可用于制氢、制氧化铝粉末和制氢技术装置。
{"title":"The structure of rapidly solidified foil of Al – Bi alloys","authors":"V. Shepelevich","doi":"10.33581/2520-2243-2022-1-75-79","DOIUrl":"https://doi.org/10.33581/2520-2243-2022-1-75-79","url":null,"abstract":"The results of study of the microstructure and texture of aluminum alloys, containing 0.12 and 0.25 at. % Bi, obtained with high-speed solidification, are presented (melt cooling rate liquid – not less 105 K /s). Texture (111) aluminum is formed in the rapidly solidified foils of investigated alloys and it is conserved under annealing at 523 K during 2 h. The average chord of bismuth sections does not exceed 0.05 µm. As the crystallisation front moves from surface A contacted with crystalliser to the surface B, the average size of dispersed bismuth particles increases. Foils of the alloys dissolve in water at room temperature actively forming hydrogen bubbles in vessel with water, white powder of aluminum oxide in an amorphous state and bismuth precipitations. Isotermical annealing of foils at 573 K for 5 h causes a change in distribution of chords in size groups and increases their average value. After the annealing bismuth particles are localised on low- and high-angle boundaries. The rapidly solidified foils of Al – Bi system can be used to produced hydrogen, aluminum oxide powder and create technical devices using hydrogen.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91534892","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 : 2022-01-27DOI: 10.33581/2520-2243-2022-1-20-34
A. Ryzhevich, I. V. Balykin
Power spectral density (PSD) of the intensity distribution of an ideal Bessel light beam (BLB) expressions are obtained. It is shown that the PSD of the intensity distribution of an ideal BLB is limited and the upper boundary of the PSD is equal to the doubled cone parameter (the product of the wave number and the sine of the half angle of the cone of wave vectors), and the number of zeros in the PSD of an ideal BLB located in the interval from zero frequency to the upper boundary of the spectrum, is equal to the order of the beam. A technique is proposed for estimating the cone parameter of BLBs by analysing the PSD estimates of diametral distributions – one-dimensional intensity distributions obtained in the transverse plane of the beam along a line passing through the beam axis from transverse two-dimensional BLB intensity distributions recorded in the form of digital computer images. The influence of clipping (the end of the distribution at the boundary of the sensitive sensor), Gaussian and cosine modulations of the diametral distribution on the shape of the spectrum and, in case of clipping, the error in the cone parameter estimation using the proposed method is investigated. The technique is tested on the example of the analysis of experimental BLBs of different orders (BLBm, m = 0, 1, 2). The proposed technique can be used to assess the quality parameters of the BLB. The results of the analysis of the influence of cosine modulation on the shape of the PSD can be used to assess the magnitude of the rounding of the apex of the axicon forming the BLB for control the quality of the axicon manufacturing.
得到了理想贝塞尔光束强度分布的功率谱密度(PSD)表达式。结果表明,理想的强度分布的PSD BLB有限和PSD的上限等于翻了一番锥参数(波数的乘积和的正弦半波向量的锥角),和PSD的零理想BLB位于区间从零频率的上限,等于梁的顺序。本文提出了一种通过分析以数字计算机图像形式记录的BLB横向二维强度分布在光束横切面沿穿过光束轴的直线得到的直径分布-一维强度分布的PSD估计来估计BLB锥参数的技术。研究了裁剪(敏感传感器边界处分布的末端)、直径分布的高斯调制和余弦调制对光谱形状的影响，以及在裁剪的情况下，使用所提出的方法进行锥参数估计的误差。以不同阶次实验BLB (BLBm, m = 0,1, 2)的分析为例，对该方法进行了验证，该方法可用于评估BLB的质量参数。余弦调制对PSD形状的影响分析结果可用于评估形成BLB的轴顶点的圆角大小，以控制轴顶点的制造质量。
{"title":"Determination of the Bessel light beam cone parameter by Fourier analysis of the diametral distribution of the intensity","authors":"A. Ryzhevich, I. V. Balykin","doi":"10.33581/2520-2243-2022-1-20-34","DOIUrl":"https://doi.org/10.33581/2520-2243-2022-1-20-34","url":null,"abstract":"Power spectral density (PSD) of the intensity distribution of an ideal Bessel light beam (BLB) expressions are obtained. It is shown that the PSD of the intensity distribution of an ideal BLB is limited and the upper boundary of the PSD is equal to the doubled cone parameter (the product of the wave number and the sine of the half angle of the cone of wave vectors), and the number of zeros in the PSD of an ideal BLB located in the interval from zero frequency to the upper boundary of the spectrum, is equal to the order of the beam. A technique is proposed for estimating the cone parameter of BLBs by analysing the PSD estimates of diametral distributions – one-dimensional intensity distributions obtained in the transverse plane of the beam along a line passing through the beam axis from transverse two-dimensional BLB intensity distributions recorded in the form of digital computer images. The influence of clipping (the end of the distribution at the boundary of the sensitive sensor), Gaussian and cosine modulations of the diametral distribution on the shape of the spectrum and, in case of clipping, the error in the cone parameter estimation using the proposed method is investigated. The technique is tested on the example of the analysis of experimental BLBs of different orders (BLBm, m = 0, 1, 2). The proposed technique can be used to assess the quality parameters of the BLB. The results of the analysis of the influence of cosine modulation on the shape of the PSD can be used to assess the magnitude of the rounding of the apex of the axicon forming the BLB for control the quality of the axicon manufacturing.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81385586","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 : 2022-01-27DOI: 10.33581/2520-2243-2022-1-88-97
N. S. Mahon, O. Korolik, A. Mazanik
A method for studying photosensitive structures using the example of studying the photodegradation and dark recovery of organic-inorganic perovskite solar cells is present. The method is based on the use of a confocal spectrometer to measure Raman spectra, photo- and electroluminescence spectra and kinetics, the kinetics of the short-circuit current and the open-circuit voltage under local exposure to monochromatic radiation. Raman spectra make it possible to establish the presence or absence of secondary phases, the formation of which is possible in photosensitive layers under the influence of light. The photoluminescence spectra enable to reveal the single-phase nature of the object under study. Mapping the intensity and position of the center of mass of the photoluminescence band in the plane of the object makes it possible to judge the spatial arrangement of the centers of non-radiative recombination of charge carriers, the distribution of the regions with the highest and lowest efficiency of the extraction of charge carriers by transport-acceptor layers and the spatial homogeneity of the chemical composition. Comparison of the electroluminescence spectra before and after light exposure allows revealing the formation of non-radiative recombination centers in the photoabsorbing layer and at interfaces with the transport layers. Analysis of the kinetics of changes in the parameters of the photoluminescence band obtained by measuring the short-circuit current and the open-circuit voltage makes it possible to establish the dominant photoinduced processes leading to a change in the intensity of the photoluminescence band.
{"title":"Method for studying the photostability of solar cells based on organic-inorganic perovskites using a confocal spectrometer","authors":"N. S. Mahon, O. Korolik, A. Mazanik","doi":"10.33581/2520-2243-2022-1-88-97","DOIUrl":"https://doi.org/10.33581/2520-2243-2022-1-88-97","url":null,"abstract":"A method for studying photosensitive structures using the example of studying the photodegradation and dark recovery of organic-inorganic perovskite solar cells is present. The method is based on the use of a confocal spectrometer to measure Raman spectra, photo- and electroluminescence spectra and kinetics, the kinetics of the short-circuit current and the open-circuit voltage under local exposure to monochromatic radiation. Raman spectra make it possible to establish the presence or absence of secondary phases, the formation of which is possible in photosensitive layers under the influence of light. The photoluminescence spectra enable to reveal the single-phase nature of the object under study. Mapping the intensity and position of the center of mass of the photoluminescence band in the plane of the object makes it possible to judge the spatial arrangement of the centers of non-radiative recombination of charge carriers, the distribution of the regions with the highest and lowest efficiency of the extraction of charge carriers by transport-acceptor layers and the spatial homogeneity of the chemical composition. Comparison of the electroluminescence spectra before and after light exposure allows revealing the formation of non-radiative recombination centers in the photoabsorbing layer and at interfaces with the transport layers. Analysis of the kinetics of changes in the parameters of the photoluminescence band obtained by measuring the short-circuit current and the open-circuit voltage makes it possible to establish the dominant photoinduced processes leading to a change in the intensity of the photoluminescence band.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89850993","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 : 2022-01-27DOI: 10.33581/2520-2243-2022-1-98-108
Aleksei A. Zaharadniuk, R. Lukashevich
The article evaluates the contribution of ionising gamma radiation scattered by structural materials when measuring the dose rate in a low-background chamber. The contribution of scattered radiation to the total dose rate was estimated using Monte Carlo simulations. A model of a low-background camera and a BDKG-05K dosimeter was created in the computer program Fluka. In addition, a model of a point source of 137Cs gamma radiation was placed in the low-background chamber. The fraction of scattered radiation was calculated by comparing the dosimeter readings when measuring the dose rate inside the low-background chamber with the reference model (the dosimeter model is placed together with the source in a vacuum, as a result, scattered radiation is completely absent). The calculation was carried out for two positions of the dosimeter relative to the source (30 and 100 cm). It was found that the contribution of scattered radiation to the dose rate reaches 38 % (distance from the source to the detector is 100 cm). To minimise the contribution of scattered radiation to the readings of the dosimeter, a design in the form of a collimator, inside which the source is located, was considered. Additionally, the work investigated the dependence of the dose rate formed by the scattered radiation on the design features of the collimator. It was found that the use of a collimator makes it possible to reduce the contribution of scattered radiation to 3 %. The aim of the work was to calculate the optimal design of the collimator, in which the contribution of scattered radiation to the total dose rate will be minimal. The results of the work will be used to create a prototype of a low-background camera and an optimised collimator.
{"title":"Estimation of the contribution of scattered ionising radiation to the dosimeter readings during measurements inside a low-background chamber","authors":"Aleksei A. Zaharadniuk, R. Lukashevich","doi":"10.33581/2520-2243-2022-1-98-108","DOIUrl":"https://doi.org/10.33581/2520-2243-2022-1-98-108","url":null,"abstract":"The article evaluates the contribution of ionising gamma radiation scattered by structural materials when measuring the dose rate in a low-background chamber. The contribution of scattered radiation to the total dose rate was estimated using Monte Carlo simulations. A model of a low-background camera and a BDKG-05K dosimeter was created in the computer program Fluka. In addition, a model of a point source of 137Cs gamma radiation was placed in the low-background chamber. The fraction of scattered radiation was calculated by comparing the dosimeter readings when measuring the dose rate inside the low-background chamber with the reference model (the dosimeter model is placed together with the source in a vacuum, as a result, scattered radiation is completely absent). The calculation was carried out for two positions of the dosimeter relative to the source (30 and 100 cm). It was found that the contribution of scattered radiation to the dose rate reaches 38 % (distance from the source to the detector is 100 cm). To minimise the contribution of scattered radiation to the readings of the dosimeter, a design in the form of a collimator, inside which the source is located, was considered. Additionally, the work investigated the dependence of the dose rate formed by the scattered radiation on the design features of the collimator. It was found that the use of a collimator makes it possible to reduce the contribution of scattered radiation to 3 %. The aim of the work was to calculate the optimal design of the collimator, in which the contribution of scattered radiation to the total dose rate will be minimal. The results of the work will be used to create a prototype of a low-background camera and an optimised collimator.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75511322","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 : 2022-01-27DOI: 10.33581/2520-2243-2022-1-65-74
G. I. Zhirov, M. V. Goltsova
Hydrogen treatment of metallic materials is a promising area of controlled hydrogen action on metals and alloys in order to impart special properties to them. In this work, the changes in the mechanical properties of palladium during single hydride transformations, which are initiated in the initially non-nakleped palladium hydride, have been experimentally studied. Were investigated wire palladium samples with a purity of 99.98 %, a diameter of 0.5 mm and a length of 165 mm. Samples for research were preliminarily subjected to hydrogen treatment, and then mechanical tests were carried out. The mechanical properties of non-nakleped palladium hydride are presented. Hydrogen-phase naklep of palladium during hydrogen treatment has been studied. It is shown that palladium hydride is a plastic material with low strength characteristics. During the reverse hydride transformation, the hydrogen phase naklep of palladium develops. Experimental facts of the appearance of hydrogen-phase naklep during the interaction of hydrogen with other metals and alloys are discussed.
{"title":"Hydrogen-phase naklep as a result of single isothermal hydride transformations","authors":"G. I. Zhirov, M. V. Goltsova","doi":"10.33581/2520-2243-2022-1-65-74","DOIUrl":"https://doi.org/10.33581/2520-2243-2022-1-65-74","url":null,"abstract":"Hydrogen treatment of metallic materials is a promising area of controlled hydrogen action on metals and alloys in order to impart special properties to them. In this work, the changes in the mechanical properties of palladium during single hydride transformations, which are initiated in the initially non-nakleped palladium hydride, have been experimentally studied. Were investigated wire palladium samples with a purity of 99.98 %, a diameter of 0.5 mm and a length of 165 mm. Samples for research were preliminarily subjected to hydrogen treatment, and then mechanical tests were carried out. The mechanical properties of non-nakleped palladium hydride are presented. Hydrogen-phase naklep of palladium during hydrogen treatment has been studied. It is shown that palladium hydride is a plastic material with low strength characteristics. During the reverse hydride transformation, the hydrogen phase naklep of palladium develops. Experimental facts of the appearance of hydrogen-phase naklep during the interaction of hydrogen with other metals and alloys are discussed.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88055998","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：