Applied Solar Energy Pub Date : 2020-09-15 , DOI: 10.3103/s0003701x20030093 A. S. Saidov , Sh. N. Usmonov , D. V. Saparov , A. M. Akhmedov
Abstract
One of the urgent problems of materials science in the field of photovoltaics is obtaining promising novel photoactive semiconductor materials with predetermined photoelectric parameters to provide an efficient manifestation of photovoltaic, thermovoltaic, and emitting effects in the visible and near-infrared regions of the radiation spectrum. In this aspect, it is of great practical and fundamental interest to clarify the effect of diatomic molecular impurities on the electrophysical and photoelectric properties of semiconductor materials, as well as to reveal the energy levels of impurity molecules depending on the parameters of the base material. For this purpose, several semiconductor substitutional solid solutions based on elemental semiconductors such as Si and Ge, as well as III–V isoperiodic binary compounds such as GaAs and GaP, and II–VI isoperiodic binary compounds such as ZnSe and ZnS with Si2 molecular impurities have been obtained and studied. (Si2)1 – x – y(Ge2)x(GaAs)y, (ZnSe)1 – x – y(Si2)x(GaP)y, (Si2)1 – x(GaP)x and (Si2)1 – x(ZnS)x solid solutions have been grown on silicon Si (111) substrates from a limited volume of tin and lead solution-melt by means of liquid-phase epitaxy. The grown epitaxial layers have a monocrystalline structure with mirror-like smooth surfaces. The photoluminescence spectrum of solid solutions has been studied. The spectrum covers the photon energy range from 1.18 to 1.55 eV for (GaAs)0.95(Ge2)0.05〈Si2〉, from 1.38 to 3.1 eV for (GaP)0.98(Si2)0.02, from 1.55 to 3.1 eV for (ZnSe)0.88(Si2)0.03(GaP)0.09, and from 1.55 to 3.2 eV for (ZnS)0.97(Si2)0.03. It has been found that Si2 molecules in the case of (GaAs)0.95(Ge2)0.05〈Si2〉 solid solution form deep impurity energy levels lying at 1.33 eV below the bottom of the conduction band, in the case of (GaP)0.98(Si2)0.02, it is 1.47 eV, in the case of (ZnSe)0,88(Si2)0,03(GaP), 1.67 eV, and in the case of (ZnS)0.97(Si2)0.03, 1.82 eV. It is shown that in solid solutions with Si2 molecular impurities, an increase in the dissociation energy of the covalent bond in Si–Si impurity molecules is observed with increasing band gap and with decreasing crystal lattice parameter of the base semiconductor. Change in the dissociation energy of the Si–Si covalent bond in the tetrahedral crystal lattice of different semiconductors is caused by a change in the length of the Si–Si covalent bond, as well as by a change in the hybridization of the atomic electron shells of Si2 impurity molecules and base material molecules. The studied (Si2)1 – x(GaP)x and (Si2)1 – x(ZnS)x solid solutions can be used as a photoactive material for the development of photoconverters operating in the visible and near-infrared regions of the radiation spectrum.
中文翻译:
双原子硅分子杂质对半导体固溶体发光性能的影响
摘要
光伏领域中材料科学的紧迫问题之一是获得具有预定光电参数的有前途的新型光敏半导体材料,以在辐射光谱的可见光和近红外区域提供光伏,热伏和发射效应的有效表现。在这方面,阐明双原子分子杂质对半导体材料的电物理和光电性质的影响以及揭示取决于基础材料参数的杂质分子的能级具有重大的实践和根本意义。为此,基于元素半导体(例如Si和Ge)以及III–V等规二元化合物(例如GaAs和GaP)的几种半导体替代固溶体,已获得并研究了两种分子杂质。(Si 2)1 – x – y(Ge 2)x(GaAs)y,(ZnSe)1 – x – y(Si 2)x(GaP)y,(Si 2)1 – x(GaP)x和( Si 2)1 – x(ZnS)x固溶体已经通过液相外延从有限体积的锡和铅溶液中熔融生长在硅Si(111)衬底上。生长的外延层具有单镜结构,具有镜面状的光滑表面。研究了固溶体的光致发光光谱。对于(GaAs)0.95(Ge 2)0.05〈Si 2〉,该光谱涵盖的光子能量范围为1.18至1.55 eV,对于(GaP)0.98(Si 2)0.02为1.38至3.1 eV,对于(( ZnSe)0.88(Si 2)0.03(GaP)0.09,(ZnS)0.97从1.55至3.2 eV(Si 2)0.03。已经发现,在(GaAs)的情况下,Si 2分子在(GaAs)0.95(Ge 2)0.05〈Si 2〉固溶体中形成深的能级,该能级位于导带底部以下1.33 eV。 )0.98(Si 2)0.02时,(ZnSe)0,88(Si 2)0,03(GaP)为1.47 eV,而(ZnS)0.97(Si 2)为1.47 eV 0.03,1.82电子伏特。结果表明,在固溶体中含Si 2对于分子杂质,随着带隙的增加和基础半导体晶格参数的减小,可以观察到Si-Si杂质分子中共价键解离能的增加。不同半导体的四面体晶格中Si-Si共价键解离能的变化是由于Si-Si共价键的长度变化以及原子电子壳的杂化变化引起的Si 2杂质分子和基础材料分子。研究的(Si 2)1 – x(GaP)x和(Si 2)1 – x(ZnS)x 固态溶液可以用作光敏材料,用于开发在辐射光谱的可见光和近红外区域中工作的光电转换器。