II-VI族Te化物半导体中富Te相及其诱导缺陷的调控研究

项目名称： II-VI族Te化物半导体中富Te相及其诱导缺陷的调控研究

项目编号： No.51202197

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 无机非金属材料学科

项目作者： 徐亚东

作者单位： 西北工业大学

项目金额： 25万元

中文摘要： II-VI族Te化物半导体在光电子及信息技术领域具有重要的应用背景。然而，采用熔体法生长的晶体中往往存在大量的富Te相及其诱导的缺陷，成为目前制约该类器件进一步发展的主要因素。本项目拟以熔体法生长的典型II-VI族Te化物半导体-CdTe和CdZnTe为载体，主要研究：(1)富Te相的生长机理以及形态演化过程的热力学与动力学描述，并运用缺陷物理和缺陷化学方法，建立点缺陷及位错的扩散和聚集模型。(2)探索富Te相诱导缺陷的定量分析方法，揭示富Te相与其诱导缺陷耦合作用的动力学原理，掌握富Te相与其诱导缺陷相互转化的热力学条件。(3)设计"循环温度梯度"退火技术，消除生长态晶体中的富Te相，抑制杂质扩散及溶质尾迹现象，并结合"特殊气体气氛"退火，对晶体中的电活性缺陷进行优化。本项目将实现对II-VI族Te化物半导体中富Te相及其诱导缺陷的有效调控，为制备高性能光电器件提供理论依据和技术路线。

中文关键词： II-VI族Te化物；体单晶；富Te相；诱导缺陷；退火

英文摘要： II-VI telluride semiconductors have emerged as one of the most promising materials for use in a number of fields. The excellent photoelectric properties of these materials make them suitable for use in applications including optoelectronics, X and γ-ray detectors, solar cells, non-linear optics, terahertz sources and sensors. II-VI crystals grown from the melt usually have a high density of Te-rich particles and extended defects which have an adverse effect on the material properties; this has created a 'bottle-neck' in the adoption of these state of the art devices. In this project typical II-VI telluride compound semiconductors CdTe and CdZnTe will be investigated. The main research proposals are as follows:(1)The formation and morphology evolution of Te-rich particles will be defined according to the thermodynamic and kinetic theories. Models for point defects and dislocations diffusion and accumulation will be developed simultaneously based on the principles of the defect physical and quasi-chemical equilibrium theory.(2)To quantitatively analyze the extended defects in the crystals, a number of novel methods will be explored. The coupling effects between Te-rich particles and extended defects in the crystals will be revealed. The conversion of Te-rich particles and the extended defects will be interpreted i

英文关键词： Group II-VI telluride compound；Bulk crystal；Te-rich secondary phase particle；Induced defect；Annealing