Pub Date : 2022-06-12DOI: 10.3897/j.moem.8.1.89297
V. N. Abryutin, E. Davydova, M. Egorov, I. I. Maronchuk, D. Sanikovich
A combined method of profound purification of Cd, Zn and Te developed by the Authors and allowing one to produce high-purity materials in a vertical reactor unit has been considered. The method includes the following processes: filtration refinement of metal alloy with the possibility of its vacuum degassing and additional purification through an oxide layer; first distillation with the possibility to use gettering additions in the melt and gettering filters; melt degassing with the removal of highly volatile impurities to the condenser in rough vacuum; second distillation and metal casting for weighed quantities. The Authors have developed and produced a test model of the unit for the experimental profound purification of metals using the method developed herein. Physical experiments have been conducted for obtaining 99,9999 wt.% purity Cd, Zn and Te for 30 residual impurities with a product yield of at least 55%.
{"title":"Profound purification of tellurium, zinc and cadmium for electronic applications","authors":"V. N. Abryutin, E. Davydova, M. Egorov, I. I. Maronchuk, D. Sanikovich","doi":"10.3897/j.moem.8.1.89297","DOIUrl":"https://doi.org/10.3897/j.moem.8.1.89297","url":null,"abstract":"A combined method of profound purification of Cd, Zn and Te developed by the Authors and allowing one to produce high-purity materials in a vertical reactor unit has been considered. The method includes the following processes: filtration refinement of metal alloy with the possibility of its vacuum degassing and additional purification through an oxide layer; first distillation with the possibility to use gettering additions in the melt and gettering filters; melt degassing with the removal of highly volatile impurities to the condenser in rough vacuum; second distillation and metal casting for weighed quantities. The Authors have developed and produced a test model of the unit for the experimental profound purification of metals using the method developed herein. Physical experiments have been conducted for obtaining 99,9999 wt.% purity Cd, Zn and Te for 30 residual impurities with a product yield of at least 55%.","PeriodicalId":18610,"journal":{"name":"Modern Electronic Materials","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85026386","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 : 2022-05-11DOI: 10.3390/electronicmat3020016
T. Sogabe, Kodai Shiba, K. Sakamoto
The hot-carrier effect and hot-carrier dynamics in GaAs solar cell device performance were investigated. Hot-carrier solar cells based on the conventional operation principle were simulated based on the detailed balance thermodynamic model and the hydrodynamic energy transportation model. A quasi-equivalence between these two models was demonstrated for the first time. In the simulation, a specially designed GaAs solar cell was used, and an increase in the open-circuit voltage was observed by increasing the hot-carrier energy relaxation time. A detailed analysis was presented regarding the spatial distribution of hot-carrier temperature and its interplay with the electric field and three hot-carrier recombination processes: Auger, Shockley–Read–Hall, and radiative recombinations.
{"title":"Hydrodynamic and Energy Transport Model-Based Hot-Carrier Effect in GaAs pin Solar Cell","authors":"T. Sogabe, Kodai Shiba, K. Sakamoto","doi":"10.3390/electronicmat3020016","DOIUrl":"https://doi.org/10.3390/electronicmat3020016","url":null,"abstract":"The hot-carrier effect and hot-carrier dynamics in GaAs solar cell device performance were investigated. Hot-carrier solar cells based on the conventional operation principle were simulated based on the detailed balance thermodynamic model and the hydrodynamic energy transportation model. A quasi-equivalence between these two models was demonstrated for the first time. In the simulation, a specially designed GaAs solar cell was used, and an increase in the open-circuit voltage was observed by increasing the hot-carrier energy relaxation time. A detailed analysis was presented regarding the spatial distribution of hot-carrier temperature and its interplay with the electric field and three hot-carrier recombination processes: Auger, Shockley–Read–Hall, and radiative recombinations.","PeriodicalId":18610,"journal":{"name":"Modern Electronic Materials","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90633594","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 : 2022-04-12DOI: 10.3897/j.moem.8.1.85251
A. Kislyuk, T. Ilina, I. Kubasov, D. Kiselev, A. Temirov, A. Turutin, A. Shportenko, M. Malinkovich, Y. Parkhomenko
In this work, the effect of long-term room temperature exposure on the electrical conductivity of the charged domain wall (CDWs) in nonpolar x-cut congruent lithium niobate (LiNbO3, LN) crystals has been studied. Bidomain ferroelectric structures containing head-to-head charged domain boundaries have been produced by diffusion annealing in air near the Curie temperature and by infrared annealing. The crystals have been reduction annealed in a nitrogen atmosphere for the formation of color centers and growth of the electrical conductivity. The current measured during the recording of the I-V curves of the specimens using scanning probe microscope after room temperature exposure for 91 days has been found to decrease. The effect of storage conditions on the electrical conductivity of the CDWs has been studied. Degradation of the electrical conductivity does not originate from the effect of environment on the crystal surface. It has been hypothesized that the degradation is caused by distribution of charge carriers shielding the bound charge of the CDWs.
{"title":"Degradation of the electrical conductivity of charged domain walls in reduced lithium niobate crystals","authors":"A. Kislyuk, T. Ilina, I. Kubasov, D. Kiselev, A. Temirov, A. Turutin, A. Shportenko, M. Malinkovich, Y. Parkhomenko","doi":"10.3897/j.moem.8.1.85251","DOIUrl":"https://doi.org/10.3897/j.moem.8.1.85251","url":null,"abstract":"In this work, the effect of long-term room temperature exposure on the electrical conductivity of the charged domain wall (CDWs) in nonpolar x-cut congruent lithium niobate (LiNbO3, LN) crystals has been studied. Bidomain ferroelectric structures containing head-to-head charged domain boundaries have been produced by diffusion annealing in air near the Curie temperature and by infrared annealing. The crystals have been reduction annealed in a nitrogen atmosphere for the formation of color centers and growth of the electrical conductivity. The current measured during the recording of the I-V curves of the specimens using scanning probe microscope after room temperature exposure for 91 days has been found to decrease. The effect of storage conditions on the electrical conductivity of the CDWs has been studied. Degradation of the electrical conductivity does not originate from the effect of environment on the crystal surface. It has been hypothesized that the degradation is caused by distribution of charge carriers shielding the bound charge of the CDWs.","PeriodicalId":18610,"journal":{"name":"Modern Electronic Materials","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86611280","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 : 2022-04-12DOI: 10.3897/j.moem.8.1.84317
S. Boroznin
Introduction of substitution atoms into carbon nanotubes is an efficient tool of controlling their physicochemical properties which allows one to expand their practical applications. Boron is one of the most promising materials used for the modification of carbon nanotubes. However until now there has been no systematization of research data on the effect of boron impurity atoms on the properties of carbon nanotubes, and this limits potential industrial applications of this nanomaterial. In this work the most efficient currently existing methods of synthesizing carbon nanotubes containing boron impurity atoms have been discussed and the physicochemical properties of the obtained nanomaterials have been analyzed. Furthermore predictions as to their potential application domains have been made on the basis of available theoretical and experimental results. Comparison of the developed technologies has shown that the most efficient synthesis method is the catalytic vapor phase deposition. The mechanical, electronic and chemical properties of boron-carbon nanotubes have also been reviewed. For a more comprehensive analysis of the dependence of the physicochemical properties of carbon nanotubes on the concentration of boron impurity a model experiment has been carried out involving quantum mechanics instruments which has shown a direct correlation between the band gap of the material and the number of boron impurity atoms. The main practical application trends of boron-containing carbon nanotubes have been outlined.
{"title":"Carbon nanostructures containing boron impurity atoms: synthesis, physicochemical properties and potential applications","authors":"S. Boroznin","doi":"10.3897/j.moem.8.1.84317","DOIUrl":"https://doi.org/10.3897/j.moem.8.1.84317","url":null,"abstract":"Introduction of substitution atoms into carbon nanotubes is an efficient tool of controlling their physicochemical properties which allows one to expand their practical applications. Boron is one of the most promising materials used for the modification of carbon nanotubes. However until now there has been no systematization of research data on the effect of boron impurity atoms on the properties of carbon nanotubes, and this limits potential industrial applications of this nanomaterial. In this work the most efficient currently existing methods of synthesizing carbon nanotubes containing boron impurity atoms have been discussed and the physicochemical properties of the obtained nanomaterials have been analyzed. Furthermore predictions as to their potential application domains have been made on the basis of available theoretical and experimental results. Comparison of the developed technologies has shown that the most efficient synthesis method is the catalytic vapor phase deposition. The mechanical, electronic and chemical properties of boron-carbon nanotubes have also been reviewed. For a more comprehensive analysis of the dependence of the physicochemical properties of carbon nanotubes on the concentration of boron impurity a model experiment has been carried out involving quantum mechanics instruments which has shown a direct correlation between the band gap of the material and the number of boron impurity atoms. The main practical application trends of boron-containing carbon nanotubes have been outlined.","PeriodicalId":18610,"journal":{"name":"Modern Electronic Materials","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74713980","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 : 2022-04-12DOI: 10.3897/j.moem.8.1.85242
D. Agarkov, M. Borik, G. Korableva, A. V. Kulebyakin, E. Lomonova, F. Milovich, V. Myzina, P. Popov, N. Tabachkova
The phase composition and heat conductivity of (ZrO2)0.9(R2O3)0.1 solid solution single crystals have been studied, where R = (Gd, Yb, Sc, Y), (ZrO2)0.9(Sc2O3)0.09(Gd2O3)0.01 and (ZrO2)0.9(Sc2O3)0.09(Yb2O3)0.01. Single crystals have been grown by directional melt crystallization in a cold skull. The phase composition of the crystals has been studied using X-ray diffraction and Raman spectroscopy. The heat conductivity of the crystals has been studied using the absolute steady-state technique of longitudinal heat flow in the 50–300 K range. We show that at a total stabilizing oxide concentration of 10 mol.% the phase composition of the crystals depends on the ionic radius of the stabilizing cation. The (ZrO2)0.9(Sc2O3)0.1 crystals have the lowest heat conductivity in the 50–300 K range while the (ZrO2)0.9(Gd2O3)0.1 solid solutions have the lowest heat conductivity at 300 K. Analysis of the experimental data suggests that the heat conductivity of the crystals depends mainly on the phase composition and ionic radius of the stabilizing cation. Phonon scattering caused by the difference in the weight of the co-doping oxide cation has a smaller effect on the heat conductivity.
{"title":"Thermal conductivity of single crystals zirconia stabilized by scandium, yttrium, gadolinium, and ytterbium oxides","authors":"D. Agarkov, M. Borik, G. Korableva, A. V. Kulebyakin, E. Lomonova, F. Milovich, V. Myzina, P. Popov, N. Tabachkova","doi":"10.3897/j.moem.8.1.85242","DOIUrl":"https://doi.org/10.3897/j.moem.8.1.85242","url":null,"abstract":"The phase composition and heat conductivity of (ZrO2)0.9(R2O3)0.1 solid solution single crystals have been studied, where R = (Gd, Yb, Sc, Y), (ZrO2)0.9(Sc2O3)0.09(Gd2O3)0.01 and (ZrO2)0.9(Sc2O3)0.09(Yb2O3)0.01. Single crystals have been grown by directional melt crystallization in a cold skull. The phase composition of the crystals has been studied using X-ray diffraction and Raman spectroscopy. The heat conductivity of the crystals has been studied using the absolute steady-state technique of longitudinal heat flow in the 50–300 K range. We show that at a total stabilizing oxide concentration of 10 mol.% the phase composition of the crystals depends on the ionic radius of the stabilizing cation. The (ZrO2)0.9(Sc2O3)0.1 crystals have the lowest heat conductivity in the 50–300 K range while the (ZrO2)0.9(Gd2O3)0.1 solid solutions have the lowest heat conductivity at 300 K.\u0000 Analysis of the experimental data suggests that the heat conductivity of the crystals depends mainly on the phase composition and ionic radius of the stabilizing cation. Phonon scattering caused by the difference in the weight of the co-doping oxide cation has a smaller effect on the heat conductivity.","PeriodicalId":18610,"journal":{"name":"Modern Electronic Materials","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89657413","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 : 2022-04-12DOI: 10.3897/j.moem.8.1.84257
K. Shcherbachev, M. Voronova
ZnO single crystals are used for the fabrication of laser targets for high-energy electron irradiated UV laser cathode-ray tubes and homoepitaxial substrates for lasers. The technology of ZnO based UV LEDs imposes strict requirements to surface quality. Chemical-mechanical polishing delivers good surface quality but it is known that polishing of ZnO polar faces may yield different results. Surface-sensitive high-resolution X-ray diffraction (HRXRD) and X-ray reflectometry (XRR) methods have been used for studying the structure of (0001) and (000–1) polar faces of ZnO after chemical-mechanical polishing. Two double-sided polished (0001) ZnO substrates have been cut out from different hydrothermally grown ingots. The damage and density depth profiles for the Zn and O faces of the specimens have been retrieved from the X-ray diffraction curves and the specular reflection curves, respectively. Intensity distributions in the vicinity of the [0002] and [0000] reciprocal lattice sites have been taken on a D8 Discover X-ray diffractometer (Bruker-AXS, Germany) in a triple-crystal setup. For separating the coherent and incoherent scattering components, the intensity profiles have been analyzed along sections perpendicular to the diffraction vector and located at different distances from the reciprocal lattice sites. The HRXRD and XRR data have been compared with atomic force microscopy (AFM) data. The HRXRD method has revealed damaged layers at both faces of the specimens, with the layer thicknesses differing for the Zn and O faces, i.e., 5–7 nm for the Zn face and 10–11 nm for the O face. The XRR method has shown that both faces are sufficiently smooth. These results have been confirmed by AFM (RMS roughness ~ 0.23 ± 0.07 nm). However, the concentration of electrons in the superficial layers has been found to change. The layer thickness proves to be greater for the O face. We have hypothesized that the phenomena observed are caused by the difference in the chemical interaction of the Zn and O faces with the polishing agents.
{"title":"Application of X-ray diffraction and reflectometry methods for analysis of damaged layers on polar faces of ZnO after surface chemical-mechanical treatment","authors":"K. Shcherbachev, M. Voronova","doi":"10.3897/j.moem.8.1.84257","DOIUrl":"https://doi.org/10.3897/j.moem.8.1.84257","url":null,"abstract":"ZnO single crystals are used for the fabrication of laser targets for high-energy electron irradiated UV laser cathode-ray tubes and homoepitaxial substrates for lasers. The technology of ZnO based UV LEDs imposes strict requirements to surface quality. Chemical-mechanical polishing delivers good surface quality but it is known that polishing of ZnO polar faces may yield different results. Surface-sensitive high-resolution X-ray diffraction (HRXRD) and X-ray reflectometry (XRR) methods have been used for studying the structure of (0001) and (000–1) polar faces of ZnO after chemical-mechanical polishing. Two double-sided polished (0001) ZnO substrates have been cut out from different hydrothermally grown ingots. The damage and density depth profiles for the Zn and O faces of the specimens have been retrieved from the X-ray diffraction curves and the specular reflection curves, respectively. Intensity distributions in the vicinity of the [0002] and [0000] reciprocal lattice sites have been taken on a D8 Discover X-ray diffractometer (Bruker-AXS, Germany) in a triple-crystal setup. For separating the coherent and incoherent scattering components, the intensity profiles have been analyzed along sections perpendicular to the diffraction vector and located at different distances from the reciprocal lattice sites. The HRXRD and XRR data have been compared with atomic force microscopy (AFM) data. The HRXRD method has revealed damaged layers at both faces of the specimens, with the layer thicknesses differing for the Zn and O faces, i.e., 5–7 nm for the Zn face and 10–11 nm for the O face. The XRR method has shown that both faces are sufficiently smooth. These results have been confirmed by AFM (RMS roughness ~ 0.23 ± 0.07 nm). However, the concentration of electrons in the superficial layers has been found to change. The layer thickness proves to be greater for the O face. We have hypothesized that the phenomena observed are caused by the difference in the chemical interaction of the Zn and O faces with the polishing agents.","PeriodicalId":18610,"journal":{"name":"Modern Electronic Materials","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82900538","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 : 2022-04-01DOI: 10.3390/electronicmat3020015
M. Botea, C. Chirila, G. Boni, I. Pasuk, L. Trupina, I. Pintilie, L. Hrib, Becherescu Nicu, L. Pintilie
The ferroelectric and pyroelectric properties of bismuth ferrite (BFO) epitaxial thin film have been investigated. The ferroelectric epitaxial thin layer has been deposited on strontium titanate (STO) (001) substrate by pulsed laser deposition, in a capacitor geometry using as top and bottom electrode a conductive oxide of strontium ruthenate (SRO). The structural characterizations performed by X-ray diffraction and atomic force microscopy demonstrate the epitaxial character of the ferroelectric thin film. The macroscopic ferroelectric characterization of BFO revealed a rectangular shape of a polarization-voltage loop with a remnant polarization of 30 μC/c m2 and a coercive electric field of 633 KV/cm at room temperature. Due to low leakage current, the BFO capacitor structure could be totally pooled despite large coercive fields. A strong variation of polarization is obtained in 80–400 K range which determines a large pyroelectric coefficient of about 10−4 C/m2 K deduced both by an indirect and also by a direct method.
{"title":"Lead-Free BiFeO3 Thin Film: Ferroelectric and Pyroelectric Properties","authors":"M. Botea, C. Chirila, G. Boni, I. Pasuk, L. Trupina, I. Pintilie, L. Hrib, Becherescu Nicu, L. Pintilie","doi":"10.3390/electronicmat3020015","DOIUrl":"https://doi.org/10.3390/electronicmat3020015","url":null,"abstract":"The ferroelectric and pyroelectric properties of bismuth ferrite (BFO) epitaxial thin film have been investigated. The ferroelectric epitaxial thin layer has been deposited on strontium titanate (STO) (001) substrate by pulsed laser deposition, in a capacitor geometry using as top and bottom electrode a conductive oxide of strontium ruthenate (SRO). The structural characterizations performed by X-ray diffraction and atomic force microscopy demonstrate the epitaxial character of the ferroelectric thin film. The macroscopic ferroelectric characterization of BFO revealed a rectangular shape of a polarization-voltage loop with a remnant polarization of 30 μC/c m2 and a coercive electric field of 633 KV/cm at room temperature. Due to low leakage current, the BFO capacitor structure could be totally pooled despite large coercive fields. A strong variation of polarization is obtained in 80–400 K range which determines a large pyroelectric coefficient of about 10−4 C/m2 K deduced both by an indirect and also by a direct method.","PeriodicalId":18610,"journal":{"name":"Modern Electronic Materials","volume":"71 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87058641","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 : 2022-04-01DOI: 10.3390/electronicmat3020014
N. Azkona, A. Llaria, O. Curea, F. Recart
In this work, a defective commercial module with a rounded IV characteristic is analyzed in detail to identify the sources of its malfunction. The analysis of the module includes thermography images taken under diverse conditions, the IV response of the module obtained without any shadow, and shadowing one cell at a time, as recommended by the IEC 61215 Standard. Additionally, a direct measurement of the IV characteristic and resistance of single cells in the panel has been conducted to verify the isolation between the p and n areas. In parallel, theoretical cell and module behaviors are presented. In this frame, simulations show how cell mismatch can be the explanation to the rounded IV output of the solar panel under study. From the thermal images of the module, several localized hot spots related to failing cells have been revealed. During the present study, thermal breakdown is seen before avalanche breakdown in one of the cells, evidencing a hot spot. Not many papers have dealt with this problem, whereas we believe it is important to analyze the relationship between thermal breakdown and hot spotting in order to prevent it in the future, since hot spots are the main defects related to degradation of modern modules.
{"title":"Detection, Characterization and Modeling of Localized Defects and Thermal Breakdown in Photovoltaic Panels from Thermal Images and IV Curves","authors":"N. Azkona, A. Llaria, O. Curea, F. Recart","doi":"10.3390/electronicmat3020014","DOIUrl":"https://doi.org/10.3390/electronicmat3020014","url":null,"abstract":"In this work, a defective commercial module with a rounded IV characteristic is analyzed in detail to identify the sources of its malfunction. The analysis of the module includes thermography images taken under diverse conditions, the IV response of the module obtained without any shadow, and shadowing one cell at a time, as recommended by the IEC 61215 Standard. Additionally, a direct measurement of the IV characteristic and resistance of single cells in the panel has been conducted to verify the isolation between the p and n areas. In parallel, theoretical cell and module behaviors are presented. In this frame, simulations show how cell mismatch can be the explanation to the rounded IV output of the solar panel under study. From the thermal images of the module, several localized hot spots related to failing cells have been revealed. During the present study, thermal breakdown is seen before avalanche breakdown in one of the cells, evidencing a hot spot. Not many papers have dealt with this problem, whereas we believe it is important to analyze the relationship between thermal breakdown and hot spotting in order to prevent it in the future, since hot spots are the main defects related to degradation of modern modules.","PeriodicalId":18610,"journal":{"name":"Modern Electronic Materials","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83118520","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 : 2022-03-20DOI: 10.3390/electronicmat3010013
V. Dzhagan, O. Selyshchev, S. Kondratenko, N. Mazur, Y. Havryliuk, Oleksandra Raievska, O. Stroyuk, D. Zahn
Thin films of colloidal CZTS nanocrystals (NCs) synthesized using a “green” approach in water with a variation of the copper-to-tin ratio are investigated by Raman scattering, mid-infrared (molecular vibrations) and near-infrared (free carrier) absorption, X-ray photoemission spectroscopy (XPS), electrical conductivity, and conductive atomic force microscopy (cAFM). We determined the effect of the actual Cu content on the phonon spectra, electrical conductivity, and spectral parameters of the plasmon band. An increase in the electrical conductivity of the NC films upon annealing at 220 °C is explained by three factors: formation of a CuxS nanophase at the CZTS NC surface, partial removal of ligands, and improved structural perfection. The presence of the CuxS phase is concluded to be the determinant factor for the CZTS NC film conductivity. CuxS can be reliably detected based on the analysis of the modified Auger parameter of copper, derived from XPS data and corroborated by Raman spectroscopy data. Partial removal of the ligand is concluded from the agreement of the core-level XPS and vibrational IR spectra. The degree of lattice perfection can be conveniently assessed from the Raman data as well. Further important information derived from a combination of photoelectron and optical data is the work function, ionization potential, and electron affinity of the NC films.
{"title":"Copper-Content Dependent Structural and Electrical Properties of CZTS Films Formed by “Green” Colloidal Nanocrystals","authors":"V. Dzhagan, O. Selyshchev, S. Kondratenko, N. Mazur, Y. Havryliuk, Oleksandra Raievska, O. Stroyuk, D. Zahn","doi":"10.3390/electronicmat3010013","DOIUrl":"https://doi.org/10.3390/electronicmat3010013","url":null,"abstract":"Thin films of colloidal CZTS nanocrystals (NCs) synthesized using a “green” approach in water with a variation of the copper-to-tin ratio are investigated by Raman scattering, mid-infrared (molecular vibrations) and near-infrared (free carrier) absorption, X-ray photoemission spectroscopy (XPS), electrical conductivity, and conductive atomic force microscopy (cAFM). We determined the effect of the actual Cu content on the phonon spectra, electrical conductivity, and spectral parameters of the plasmon band. An increase in the electrical conductivity of the NC films upon annealing at 220 °C is explained by three factors: formation of a CuxS nanophase at the CZTS NC surface, partial removal of ligands, and improved structural perfection. The presence of the CuxS phase is concluded to be the determinant factor for the CZTS NC film conductivity. CuxS can be reliably detected based on the analysis of the modified Auger parameter of copper, derived from XPS data and corroborated by Raman spectroscopy data. Partial removal of the ligand is concluded from the agreement of the core-level XPS and vibrational IR spectra. The degree of lattice perfection can be conveniently assessed from the Raman data as well. Further important information derived from a combination of photoelectron and optical data is the work function, ionization potential, and electron affinity of the NC films.","PeriodicalId":18610,"journal":{"name":"Modern Electronic Materials","volume":"101 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79366116","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 : 2022-03-17DOI: 10.3390/electronicmat3010012
M. Arab, V. Madigou, V. Chevallier, C. Turquat, C. Leroux
This study aims to discuss the combined theoretical and experimental results of elastic properties of tungsten trioxide films supported on Quartz (YX)/45°/10° resonator to form surface acoustic wave (SAW) devices. The SAW systems with different thicknesses of WO3 thin films were imaged and structurally characterized by X-ray diffraction, atomic force, and transmission electron microscopy. The deposited WO3 films (100, 200, and 300 nm of thickness) crystallized in a single monoclinic phase. The acoustoelectric properties of the SAW system were obtained by combining theoretical simulations with experimental measurements. The modeling of the SAW devices has been performed by the finite element and boundary element methods (FEM/BEM). The elastic constants of the films at room temperature were assessed via electrical admittances experiments in light of theoretical calculations. The gravimetric effect of the deposited layers is observed by a shift of the resonance frequency to lower values as the thickness of the films increases. Moreover, the acoustic losses are affected by the dielectric losses of the WO3 films while the resonant frequency decreases almost linearly. SAW devices revealed strong displacement fields with low acoustic losses as a function of WO3 thicknesses. For all the deposited layers, the measured Young’s moduli and Poisson’s ratios are 8 GPa and 0.5, respectively.
{"title":"Investigation of Elastic Properties of WO3 Thin Films Supported on Quartz in Surface Acoustic Wave Sensing Devices","authors":"M. Arab, V. Madigou, V. Chevallier, C. Turquat, C. Leroux","doi":"10.3390/electronicmat3010012","DOIUrl":"https://doi.org/10.3390/electronicmat3010012","url":null,"abstract":"This study aims to discuss the combined theoretical and experimental results of elastic properties of tungsten trioxide films supported on Quartz (YX)/45°/10° resonator to form surface acoustic wave (SAW) devices. The SAW systems with different thicknesses of WO3 thin films were imaged and structurally characterized by X-ray diffraction, atomic force, and transmission electron microscopy. The deposited WO3 films (100, 200, and 300 nm of thickness) crystallized in a single monoclinic phase. The acoustoelectric properties of the SAW system were obtained by combining theoretical simulations with experimental measurements. The modeling of the SAW devices has been performed by the finite element and boundary element methods (FEM/BEM). The elastic constants of the films at room temperature were assessed via electrical admittances experiments in light of theoretical calculations. The gravimetric effect of the deposited layers is observed by a shift of the resonance frequency to lower values as the thickness of the films increases. Moreover, the acoustic losses are affected by the dielectric losses of the WO3 films while the resonant frequency decreases almost linearly. SAW devices revealed strong displacement fields with low acoustic losses as a function of WO3 thicknesses. For all the deposited layers, the measured Young’s moduli and Poisson’s ratios are 8 GPa and 0.5, respectively.","PeriodicalId":18610,"journal":{"name":"Modern Electronic Materials","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82806738","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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