This study introduces an environment‐friendly perovskite photodetector (PPD) utilizing the inorganic–organic perovskite CH3NH3SnI3 as the light‐absorbing layer. Perovskite materials, known for their exceptional optoelectronic properties, hold significant promise in photodetector fabrication. The proposed device architecture strategically employs NiO and TiO2 layers to facilitate efficient hole and electron transport. The CH3NH3SnI3‐based PPD demonstrates outstanding quantum efficiency across the visible spectrum, extending into infrared regions. It exhibits a responsivity of 0.68 A W−1 and a detectivity of 3.81 × 1013 Jones. Comprehensive defect and temperature analyses are performed to understand the behavior of the proposed device. These results underscore the potential of less toxic perovskite alternatives for high‐performance photodetectors. All simulations are conducted using the SCAPS‐1D simulator to ensure the validity of the findings.
{"title":"Design of Next‐Generation Tin‐Based Perovskite Photodetector with Enhanced Spectral Responsivity for Eco‐friendly Applications","authors":"Pallavi Pandey, Akhilesh Kumar Chaudhary, Sudhanshu Verma","doi":"10.1002/pssb.202400199","DOIUrl":"https://doi.org/10.1002/pssb.202400199","url":null,"abstract":"This study introduces an environment‐friendly perovskite photodetector (PPD) utilizing the inorganic–organic perovskite CH<jats:sub>3</jats:sub>NH<jats:sub>3</jats:sub>SnI<jats:sub>3</jats:sub> as the light‐absorbing layer. Perovskite materials, known for their exceptional optoelectronic properties, hold significant promise in photodetector fabrication. The proposed device architecture strategically employs NiO and TiO<jats:sub>2</jats:sub> layers to facilitate efficient hole and electron transport. The CH<jats:sub>3</jats:sub>NH<jats:sub>3</jats:sub>SnI<jats:sub>3</jats:sub>‐based PPD demonstrates outstanding quantum efficiency across the visible spectrum, extending into infrared regions. It exhibits a responsivity of 0.68 A W<jats:sup>−1</jats:sup> and a detectivity of 3.81 × 10<jats:sup>13</jats:sup> Jones. Comprehensive defect and temperature analyses are performed to understand the behavior of the proposed device. These results underscore the potential of less toxic perovskite alternatives for high‐performance photodetectors. All simulations are conducted using the SCAPS‐1D simulator to ensure the validity of the findings.","PeriodicalId":20406,"journal":{"name":"Physica Status Solidi B-basic Solid State Physics","volume":"38 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141532284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Herein, poor reproducibility of optical absorption edges in GeS2 glasses and films is seen. Reported spectral positions of the absorption edge in melt‐quenched glasses spread over ≈0.2 eV at ħω ≈ 3 eV. In deposited films, the edge red‐shifts to ħω ≈ 2.5 eV showing wider variations of ≈1 eV. This work considers plausible reasons of such low, spectral reproducibility, with the aid of ab initio molecular orbital analyses of Ge–S clusters and known insights on optical gaps, electron‐spin‐resonance signals, and structural data. The variation in the glass is likely to be governed by several factors including compositional fluctuation, edge/corner‐shared configurations, wrong bonds, and intimate valence‐alternation pairs. The conspicuous red‐shift in the films seems to be affected also by neutral dangling bonds.
从这里可以看出，GeS2 玻璃和薄膜中光学吸收边的再现性很差。据报道，熔淬玻璃中吸收边的光谱位置分布在ω ≈ 3 eV处≈0.2 eV。在沉积薄膜中，边缘红移到ħ ω ≈ 2.5 eV，变化范围≈1 eV。这项研究借助 Ge-S 簇的 ab initio 分子轨道分析以及对光学间隙、电子自旋共振信号和结构数据的已知见解，探讨了光谱重现性如此之低的可能原因。玻璃中的变化可能受多种因素的影响，包括成分波动、边缘/角落共享构型、错键和亲密的价偶对。薄膜中明显的红移现象似乎也受到中性悬空键的影响。
{"title":"Reproducibility of the Optical Absorption Edge in Amorphous GeS2","authors":"Keiji Tanaka","doi":"10.1002/pssb.202400198","DOIUrl":"https://doi.org/10.1002/pssb.202400198","url":null,"abstract":"Herein, poor reproducibility of optical absorption edges in GeS<jats:sub>2</jats:sub> glasses and films is seen. Reported spectral positions of the absorption edge in melt‐quenched glasses spread over ≈0.2 eV at <jats:italic>ħω</jats:italic> ≈ 3 eV. In deposited films, the edge red‐shifts to <jats:italic>ħω</jats:italic> ≈ 2.5 eV showing wider variations of ≈1 eV. This work considers plausible reasons of such low, spectral reproducibility, with the aid of <jats:italic>ab initio</jats:italic> molecular orbital analyses of Ge–S clusters and known insights on optical gaps, electron‐spin‐resonance signals, and structural data. The variation in the glass is likely to be governed by several factors including compositional fluctuation, edge/corner‐shared configurations, wrong bonds, and intimate valence‐alternation pairs. The conspicuous red‐shift in the films seems to be affected also by neutral dangling bonds.","PeriodicalId":20406,"journal":{"name":"Physica Status Solidi B-basic Solid State Physics","volume":"31 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141527471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The structural, electronic, and transport properties of CaAgAs, a recently predicted topological nodal line semimetal, are investigated using density‐functional theory with spin–orbit coupling (SOC) and Boltzmann transport theory. The material exhibits a topological phase transition from a nodal line semimetal to a topological insulator (TI) phase as a result of the SOC effect. The Voigt–Reuss–Hill approximation is used to compute various mechanical properties. The calculated Seebeck coefficient ≈153.19 μV K−1, power factor ≈5.9 × 1011 W m−1 K−2 s−1, and lattice thermal conductivity ≈6.20 W m−1 K−1 suggest that CaAgAs have superior thermoelectric performance compared to other well‐known predicted thermoelectric materials. The calculated value of figure of merit for without (NSOC) is 0.34, which increases to 0.43 with SOC at 500 K. In these findings, the potential of CaAgAs is reflected as a thermoelectric material, attributed to the topological phase transition induced by SOC.
本文采用具有自旋轨道耦合（SOC）的密度泛函理论和玻尔兹曼输运理论，研究了最近预测的拓扑节点线半金属 CaAgAs 的结构、电子和输运特性。由于自旋轨道耦合效应，该材料呈现出从结线半金属到拓扑绝缘体（TI）的拓扑相变。Voigt-Reuss-Hill 近似用于计算各种机械性能。计算得出的塞贝克系数≈153.19 μV K-1、功率因数≈5.9 × 1011 W m-1 K-2 s-1和晶格热导率≈6.20 W m-1 K-1表明，与其他著名的热电材料相比，钙钛矿具有更优越的热电性能。这些发现反映了 CaAgAs 作为热电材料的潜力，这归功于 SOC 诱导的拓扑相变。
{"title":"Thermoelectric Properties of Line‐Node Dirac Semimetal and Topological Insulating Phase in Hexagonal Pnictide CaAgAs","authors":"Narender Kumar, Nisha Sheoran, Hardev S. Saini","doi":"10.1002/pssb.202400187","DOIUrl":"https://doi.org/10.1002/pssb.202400187","url":null,"abstract":"The structural, electronic, and transport properties of CaAgAs, a recently predicted topological nodal line semimetal, are investigated using density‐functional theory with spin–orbit coupling (SOC) and Boltzmann transport theory. The material exhibits a topological phase transition from a nodal line semimetal to a topological insulator (TI) phase as a result of the SOC effect. The Voigt–Reuss–Hill approximation is used to compute various mechanical properties. The calculated Seebeck coefficient ≈153.19 μV K<jats:sup>−1</jats:sup>, power factor ≈5.9 × 10<jats:sup>11</jats:sup> W m<jats:sup>−1</jats:sup> K<jats:sup>−2</jats:sup> s<jats:sup>−1</jats:sup>, and lattice thermal conductivity ≈6.20 W m<jats:sup>−1</jats:sup> K<jats:sup>−1</jats:sup> suggest that CaAgAs have superior thermoelectric performance compared to other well‐known predicted thermoelectric materials. The calculated value of figure of merit for without (NSOC) is 0.34, which increases to 0.43 with SOC at 500 K. In these findings, the potential of CaAgAs is reflected as a thermoelectric material, attributed to the topological phase transition induced by SOC.","PeriodicalId":20406,"journal":{"name":"Physica Status Solidi B-basic Solid State Physics","volume":"165 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141508490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhiyuan Bai, Xuefeng Lu, Boyu Chen, Jiayin Zhang, Di Liu, Dan Yang, Junchen Li, Xin Guo
At present, gradient‐structure alloys with strong properties can be machined by strong surface plastic deformation. This kind of alloy also has high strength, excellent plastic toughness, and work hardening properties. Herein, nanometer polycrystalline nickel–cobalt alloys with grain gradient are studied. The change of mechanical properties and evolution mechanism of internal defects of graded polycrystalline nickel–cobalt alloys under shear loading are emphatically revealed, and the unusual strengthening mechanism brought about by gradient structure is revealed. The results show that grain gradient microstructure can improve the strength and maintain the toughness of the alloy to a certain extent. The uneven grain boundary distribution due to the gradient structure brings different hindering effects to the dislocation movement. Therefore, the mechanical properties exhibited are different from those of uniform microstructure.
{"title":"Effect of Grain Gradient on Mechanical Properties of Nanopolycrystalline Ni–Co Alloys","authors":"Zhiyuan Bai, Xuefeng Lu, Boyu Chen, Jiayin Zhang, Di Liu, Dan Yang, Junchen Li, Xin Guo","doi":"10.1002/pssb.202400117","DOIUrl":"https://doi.org/10.1002/pssb.202400117","url":null,"abstract":"At present, gradient‐structure alloys with strong properties can be machined by strong surface plastic deformation. This kind of alloy also has high strength, excellent plastic toughness, and work hardening properties. Herein, nanometer polycrystalline nickel–cobalt alloys with grain gradient are studied. The change of mechanical properties and evolution mechanism of internal defects of graded polycrystalline nickel–cobalt alloys under shear loading are emphatically revealed, and the unusual strengthening mechanism brought about by gradient structure is revealed. The results show that grain gradient microstructure can improve the strength and maintain the toughness of the alloy to a certain extent. The uneven grain boundary distribution due to the gradient structure brings different hindering effects to the dislocation movement. Therefore, the mechanical properties exhibited are different from those of uniform microstructure.","PeriodicalId":20406,"journal":{"name":"Physica Status Solidi B-basic Solid State Physics","volume":"60 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141508492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fei‐Yu Chang, Juan Gao, Zhen Jiao, Qi‐Jun Liu, Ying‐Xi Luo, Zheng‐Tang Liu
In this article, the properties of Cs2Pb2O3 have been investigated using the first‐principles method. It covers the relevant structural, stability, electronic properties, conductivity, and optical properties. The phonon spectra and elastic properties analysis show the stability of Cs2Pb2O3, band structure, density of states, charge density diagram, and bond populations are analyzed to show the electronic structure of the system more clearly. The calculated results indicate that considering spin‐orbit coupling (SOC) will reduce the band gap. The charge density diagram and bond populations indicate that the Cs–O bond is mainly ionic and the Pb–O bond is mainly covalent and partially ionic. The analysis of optical properties indicates good transparency, and the calculated hole mobility is 10.88 cm2 V−1 s−1, suggesting that it is a promising p‐type conductive oxide.
{"title":"Optical and Electronic Properties of p‐type Transparent Conductive Oxide Cs2Pb2O3: A Density Functional Theory Study","authors":"Fei‐Yu Chang, Juan Gao, Zhen Jiao, Qi‐Jun Liu, Ying‐Xi Luo, Zheng‐Tang Liu","doi":"10.1002/pssb.202400188","DOIUrl":"https://doi.org/10.1002/pssb.202400188","url":null,"abstract":"In this article, the properties of Cs<jats:sub>2</jats:sub>Pb<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> have been investigated using the first‐principles method. It covers the relevant structural, stability, electronic properties, conductivity, and optical properties. The phonon spectra and elastic properties analysis show the stability of Cs<jats:sub>2</jats:sub>Pb<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>, band structure, density of states, charge density diagram, and bond populations are analyzed to show the electronic structure of the system more clearly. The calculated results indicate that considering spin‐orbit coupling (SOC) will reduce the band gap. The charge density diagram and bond populations indicate that the Cs–O bond is mainly ionic and the Pb–O bond is mainly covalent and partially ionic. The analysis of optical properties indicates good transparency, and the calculated hole mobility is 10.88 cm<jats:sup>2</jats:sup> V<jats:sup>−1</jats:sup> s<jats:sup>−1</jats:sup>, suggesting that it is a promising p‐type conductive oxide.","PeriodicalId":20406,"journal":{"name":"Physica Status Solidi B-basic Solid State Physics","volume":"61 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141508459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study investigates low‐frequency plasmons and single‐particle excitations (SPEs) in monolayer and bilayer graphene with various stacking configurations. The dynamics of wave propagation under different time‐dependent perturbation scenarios are elucidated using the random‐phase approximation dielectric function and tight‐binding Hamiltonian. The modulation of coherent excitations, particularly affecting plasmon waves, provides insights into the spatial and temporal dynamics on graphene sheets. A 2D acoustic plasmon mode is observed in monolayer graphene under extrinsic doping effects, while in bilayer graphene, it is accompanied by higher frequency optical plasmons. The predicted dynamic behavior, indicative of plasmon resonance, SPEs, and Landau damping with respect to stacking and doping effects, can be detected through ultrafast coherent dynamics observed via nanoimaging and nanospectroscopy techniques.
{"title":"Plasmon Dynamics in Electron‐Doped Graphene and AA‐ versus AB‐Stacked Bilayer Graphene","authors":"Chang‐Ting Liu, Chiun‐Yan Lin, Chih‐Wei Chiu","doi":"10.1002/pssb.202400222","DOIUrl":"https://doi.org/10.1002/pssb.202400222","url":null,"abstract":"This study investigates low‐frequency plasmons and single‐particle excitations (SPEs) in monolayer and bilayer graphene with various stacking configurations. The dynamics of wave propagation under different time‐dependent perturbation scenarios are elucidated using the random‐phase approximation dielectric function and tight‐binding Hamiltonian. The modulation of coherent excitations, particularly affecting plasmon waves, provides insights into the spatial and temporal dynamics on graphene sheets. A 2D acoustic plasmon mode is observed in monolayer graphene under extrinsic doping effects, while in bilayer graphene, it is accompanied by higher frequency optical plasmons. The predicted dynamic behavior, indicative of plasmon resonance, SPEs, and Landau damping with respect to stacking and doping effects, can be detected through ultrafast coherent dynamics observed via nanoimaging and nanospectroscopy techniques.","PeriodicalId":20406,"journal":{"name":"Physica Status Solidi B-basic Solid State Physics","volume":"10479 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141527472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Han Zhang, Sen Huang, Fuqiang Guo, Kexin Deng, Qimeng Jiang, Haibo Yin, Ke Wei, Xinguo Gao, Zhaofu Zhang, Xinhua Wang, Bo Shen, Xinyu Liu
The ultrathin‐barrier (UTB) AlGaN/GaN heterostructure exhibits great promise as a technology for manufacturing high‐performance normally OFF GaN metal–insulator–semiconductor high‐electron‐mobility transistors (MIS–HEMTs) due to its unique gate recess‐free feature. However, a critical challenge in UTB MIS–HEMTs is the recovery of the 2D electron gas in the access region, particularly with regard to achieving low ON resistance. In this study, a new approach is proposed to address this issue by utilizing a low‐thermal‐budget Al2O3 film grown through atomic layer deposition (ALD). By analyzing the capacitance–voltage characteristic and correlating it with the threshold voltage shift versus dielectric thicknesses for SiNx and Al2O3, high density of positive fixed charges (≈2.382 × 1013 cm−2) is confirmed to be induced at the interface between ALD–Al2O3 and GaN (cap), which is also in good agreement with 1D Poisson simulations of energy band diagrams. The positive charges are probably originated from the interface AlAl bonds revealed by X‐Ray photoelectron spectroscopy analysis.
{"title":"Presence of High Density Positive Fixed Charges at ALD–Al2O3/GaN (cap) Interface for Efficient Recovery of 2‐DEG in Ultrathin‐Barrier AlGaN/GaN Heterostructure","authors":"Han Zhang, Sen Huang, Fuqiang Guo, Kexin Deng, Qimeng Jiang, Haibo Yin, Ke Wei, Xinguo Gao, Zhaofu Zhang, Xinhua Wang, Bo Shen, Xinyu Liu","doi":"10.1002/pssb.202300555","DOIUrl":"https://doi.org/10.1002/pssb.202300555","url":null,"abstract":"The ultrathin‐barrier (UTB) AlGaN/GaN heterostructure exhibits great promise as a technology for manufacturing high‐performance normally OFF GaN metal–insulator–semiconductor high‐electron‐mobility transistors (MIS–HEMTs) due to its unique gate recess‐free feature. However, a critical challenge in UTB MIS–HEMTs is the recovery of the 2D electron gas in the access region, particularly with regard to achieving low ON resistance. In this study, a new approach is proposed to address this issue by utilizing a low‐thermal‐budget Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> film grown through atomic layer deposition (ALD). By analyzing the capacitance–voltage characteristic and correlating it with the threshold voltage shift versus dielectric thicknesses for SiN<jats:sub><jats:italic>x</jats:italic></jats:sub> and Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>, high density of positive fixed charges (≈2.382 × 10<jats:sup>13</jats:sup> cm<jats:sup>−2</jats:sup>) is confirmed to be induced at the interface between ALD–Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> and GaN (cap), which is also in good agreement with 1D Poisson simulations of energy band diagrams. The positive charges are probably originated from the interface AlAl bonds revealed by X‐Ray photoelectron spectroscopy analysis.","PeriodicalId":20406,"journal":{"name":"Physica Status Solidi B-basic Solid State Physics","volume":"1 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141527476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The atomistic simulations in this article substantiate that grain boundary stress fields remain unaffected by changes in their area, aligning with the Olson–Cohen theory which supports that such area insensitivity is an inherent outcome of the combined effect of coherency and anti‐coherency dislocations. Twist grain boundaries are employed in α‐iron as a model in atomistic simulations, revealing and contrasting the dislocations and stresses of these grain boundaries when their area varies from infinity to a few square nanometers. It is discovered that the grain boundary stresses remain relatively constant, always short‐ranged. Furthermore, within the framework of the Frank–Bilby equation, the line directions and spacing of coherency and anti‐coherency dislocation arrays in a grain boundary are predicted, the stresses of these dislocations are subsequently calculated numerically, and these stresses are superimposed together to form the grain boundary stress field. The numerical calculations verify that stress fields of grain boundaries are not sensitive to changes of their area, corroborating our atomistic simulations. The preliminary atomistic simulations of various homophase and heterophase boundaries further affirm this area insensitivity.
{"title":"Insensitivity of Grain boundary Stress Fields to Area Variations","authors":"Jinbo Yang, Yaling Chen, Yu Guo, Lingxiao Meng, Jingxin Yan, Huajie Yang, Zhefeng Zhang","doi":"10.1002/pssb.202400184","DOIUrl":"https://doi.org/10.1002/pssb.202400184","url":null,"abstract":"The atomistic simulations in this article substantiate that grain boundary stress fields remain unaffected by changes in their area, aligning with the Olson–Cohen theory which supports that such area insensitivity is an inherent outcome of the combined effect of coherency and anti‐coherency dislocations. Twist grain boundaries are employed in α‐iron as a model in atomistic simulations, revealing and contrasting the dislocations and stresses of these grain boundaries when their area varies from infinity to a few square nanometers. It is discovered that the grain boundary stresses remain relatively constant, always short‐ranged. Furthermore, within the framework of the Frank–Bilby equation, the line directions and spacing of coherency and anti‐coherency dislocation arrays in a grain boundary are predicted, the stresses of these dislocations are subsequently calculated numerically, and these stresses are superimposed together to form the grain boundary stress field. The numerical calculations verify that stress fields of grain boundaries are not sensitive to changes of their area, corroborating our atomistic simulations. The preliminary atomistic simulations of various homophase and heterophase boundaries further affirm this area insensitivity.","PeriodicalId":20406,"journal":{"name":"Physica Status Solidi B-basic Solid State Physics","volume":"143 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141527473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Youssef El Arfaoui, Mohammed Khenfouch, Nabil Habiballah
Pb‐free perovskites are novel compounds that are currently being studied, essentially for their photovoltaic applications. In this article, the hybrid organic–inorganic perovskite for photovoltaic applications is studied. In fact, the structural and electronic properties of the perovskite FABI3 (B = Sn, Ge, or Pb and FA = formamidinium: CH(NH2)2) applying the density functional theory method executed in the Quantum Espresso framework are studied and discussed. The band structures of these perovskites have been presented; it is shown that these perovskites have a semiconductor nature, with a bandgap value of 1.36 eV for FASnI3, 1.72 eV for FAGeI3, and 1.61 eV for FAPbI3. Also, the density of states and partial density of states have been presented and discussed for each of these materials. Indeed, the structural properties of these perovskites are investigated and demonstrated that the optimized value of the lattice parameter is 6.35 Å for the FASnI3, while for the FAGeI3, this value is 6.3 Å and 6.5 Å for FAPbI3. Moreover, the impact of the lattice parameter on the bandgap value of FABI3 (B = Sn, Ge, or Pb) has been investigated, and it has been demonstrated that as the lattice parameter increases, the bandgap increases. The results of this work can be utilized as a guideline for the development of new efficient, lead‐free perovskite devices, including tandem solar cells.
{"title":"Spin–Orbit Coupling Effect Bandgaps Engineering of the Lead‐Free Perovskites FABI3 (B = Sn or Ge) Materials for Tandem Solar Cells: First Principle Investigation of Structural and Electronic Properties","authors":"Youssef El Arfaoui, Mohammed Khenfouch, Nabil Habiballah","doi":"10.1002/pssb.202400217","DOIUrl":"https://doi.org/10.1002/pssb.202400217","url":null,"abstract":"Pb‐free perovskites are novel compounds that are currently being studied, essentially for their photovoltaic applications. In this article, the hybrid organic–inorganic perovskite for photovoltaic applications is studied. In fact, the structural and electronic properties of the perovskite FABI3 (B = Sn, Ge, or Pb and FA = formamidinium: CH(NH<jats:sub>2</jats:sub>)<jats:sub>2</jats:sub>) applying the density functional theory method executed in the Quantum Espresso framework are studied and discussed. The band structures of these perovskites have been presented; it is shown that these perovskites have a semiconductor nature, with a bandgap value of 1.36 eV for FASnI3, 1.72 eV for FAGeI3, and 1.61 eV for FAPbI3. Also, the density of states and partial density of states have been presented and discussed for each of these materials. Indeed, the structural properties of these perovskites are investigated and demonstrated that the optimized value of the lattice parameter is 6.35 Å for the FASnI3, while for the FAGeI3, this value is 6.3 Å and 6.5 Å for FAPbI3. Moreover, the impact of the lattice parameter on the bandgap value of FABI3 (B = Sn, Ge, or Pb) has been investigated, and it has been demonstrated that as the lattice parameter increases, the bandgap increases. The results of this work can be utilized as a guideline for the development of new efficient, lead‐free perovskite devices, including tandem solar cells.","PeriodicalId":20406,"journal":{"name":"Physica Status Solidi B-basic Solid State Physics","volume":"59 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141527474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In monolayer transition metal dichalcogenides, defects, such as chalcogen vacancies, play an important role in determining their properties. Herein, monolayer MoSe2 with varying Se vacancy concentrations is successfully prepared by adjusting the amount of the precursors during the chemical vapor deposition synthesis. The Raman and low‐temperature photoluminescence spectra are systematically studied at varying defect concentrations. Furthermore, it is found that Se vacancies introduce in‐gap electronic states, leading to distinct localized exciton emissions, which can be engineered by controlling the concentration of Se vacancies. Density functional theory calculations indicate that the observed variations in localized exciton emission are attributed to the change of defect level with increasing defect concentration. The results provide insights into the influence of varying Se vacancy concentrations on defect‐induced Raman and PL spectroscopy in MoSe2.
{"title":"Defect‐Induced Localized Excitons and Raman Modes in Monolayer MoSe2","authors":"Zhiyuan Tang, Siwei Luo, Gencai Guo, Xixi Huang, Yan Peng, Xu Tang, Qiong Chen, Xiang Qi, Jianxin Zhong","doi":"10.1002/pssb.202400185","DOIUrl":"https://doi.org/10.1002/pssb.202400185","url":null,"abstract":"In monolayer transition metal dichalcogenides, defects, such as chalcogen vacancies, play an important role in determining their properties. Herein, monolayer MoSe<jats:sub>2</jats:sub> with varying Se vacancy concentrations is successfully prepared by adjusting the amount of the precursors during the chemical vapor deposition synthesis. The Raman and low‐temperature photoluminescence spectra are systematically studied at varying defect concentrations. Furthermore, it is found that Se vacancies introduce in‐gap electronic states, leading to distinct localized exciton emissions, which can be engineered by controlling the concentration of Se vacancies. Density functional theory calculations indicate that the observed variations in localized exciton emission are attributed to the change of defect level with increasing defect concentration. The results provide insights into the influence of varying Se vacancy concentrations on defect‐induced Raman and PL spectroscopy in MoSe<jats:sub>2</jats:sub>.","PeriodicalId":20406,"journal":{"name":"Physica Status Solidi B-basic Solid State Physics","volume":"72 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141527477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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