II-VI族半导体芯/壳纳米线异质结中的应变和掺杂

项目名称： II-VI族半导体芯/壳纳米线异质结中的应变和掺杂

项目编号： No.11474274

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 杨身园

作者单位： 中国科学院半导体研究所

项目金额： 96万元

中文摘要： 改变组分、形状、尺寸以及掺杂可以大范围调节半导体纳米异质结的电子结构和光学性质，因此这类体系在光伏器件、发光二极管等诸多领域有着广泛的应用前景。晶格失配导致纳米异质结中存在相当大的应变。然而，量子受限效应、应变、掺杂等因素对异质结的电子结构分别有怎样的影响，目前仍缺乏全面细致的研究。本项目拟利用基于密度泛函理论的第一性原理计算，系统地研究II-VI族半导体芯/壳纳米线异质结的原子结构和电子结构性质，寻找内建各向异性应变与组分、尺寸的依赖关系，定量分析量子受限效应和应变效应两者分别对电子结构的影响。在此基础上引入外加应变和杂质，分析外加应变对纳米线异质结的结构和电子结构性质的影响，探讨利用内建应变来调控掺杂浓度和掺杂位置的可能性。这些研究有助于人们进一步理解纳米异质结中应变对电子结构性质的重要调控作用，并为人们利用尺寸、应变和掺杂等多重手段调控纳米异质结的性质提供一定的理论指导。

中文关键词： 第一性原理；纳米线异质结；应变；掺杂

英文摘要： By controlling the material components, morphology, size, and doping, the electronic and optical properties of nanoscale heterostructures can be tuned over a wide range, leading to their potential applications in diverse areas such as photovoltaic devices and light-emitting diodes. Large lattice mismatch induces a significant built-in strain within the nanoscale heterostructures. However, there still a lack of comprehensive study on the separate impacts of quantum confinement, strain, and doping on the electronic structures of the heterostructures. In this proposal, we plan to systematically study the atomic and electronic structures of II-VI semiconductor core/shell nanowire heterostructures, based on first-principles calculations within density functional theory. We will investigate the dependence of built-in anisotropic strain on component and size, and quantify the relative impacts of quantum confinement and strain effects on electronic structures. We will further introduce external strain and dopants, analyzing the influence of external strain on the atomic and electronic properties, and exploring the possibility of controlling doping concentrations and doping sites by built-in strain. These studies will improve our understanding of the importance of strain in tuning the electronic properties of nanoscale heterostructures, and provide theoretical guidance for controlling the physical properties of nanoscale heterostructures by size, strain, and doping effects.

英文关键词： first-principles;nanowire heterostructures;strain;doping