GaN表面区杂质和缺陷形成、离化及扩散行为的研究

项目名称： GaN表面区杂质和缺陷形成、离化及扩散行为的研究

项目编号： No.61264005

项目类型： 地区科学基金项目

立项/批准年度： 2013

项目学科： 无线电电子学、电信技术

项目作者： 熊志华

作者单位： 江西科技师范大学

项目金额： 48万元

中文摘要： GaN基材料是半导体照明技术的核心。实验发现GaN表面区域中的缺陷和杂质的形成、离化及扩散行为呈现出与体中明显不同的情形，由于现有工作主要集中于块体中的缺陷和杂质物理研究，目前对它们在表面区中的这些物理行为的理解还很不清晰。为此，本项目拟在前期GaN块体掺杂机制的研究基础上，以GaN表面区本征点缺陷和杂质为研究对象，系统研究表面作用下的缺陷和杂质形成、离化及其扩散等相关科学问题。我们采用计算材料学方法计算缺陷和杂质在GaN表面区不同空间位置的形成能，探讨它们在表面势场的作用下而呈现出的空间分布规律；计算缺陷和杂质的扩散势垒及扩散路径，探讨它们在GaN表面区的稳定性规律；计算缺陷和杂质在GaN表面区不同空间位置的离化能；探讨缺陷和杂质行为对表面取向和应力作用的敏感。通过分析电子结构，建立表面区域中杂质和缺陷上述物理行为与GaN表面的关系，为实验上实现高质量GaN基薄膜材料提供理论支持和指导。

中文关键词： 低维GaN；杂质和缺陷；表面和界面；电子结构；第一原理

英文摘要： The core of the semiconductor lighting technology is the GaN-based materials. Experimentally, it was found that formation, ionization and diffusion behaviours of defects and impurities located in GaN surface area are significantly different from the case of bulk GaN. Due to the current theoretical work mainly focus on the defects and impurities physics research in bulk GaN, people do not have a clear understanding of the defects and impurities physics in GaN surface till now.So, based on our previous studies of doping mechanism in bulk GaN, this project mainly focuses on physical behaviours of defects and impurities in GaN surface. The different GaN surface orientation would be considered, including polar, nonpolar and semipolar surface. Several methods in computational materials science would be used to calculate the formation energies, ionization energies, diffusion energy barriers and diffusion paths of defects and impurities in GaN surface area. Both spatial distribution and stability of defects and impurities under the surface potential would be discussed in detail. Aslo,the influence of surface orientation and stress on defects and impurities physical behaviours would be analysed, respcectively. Lastly, the electronic structure of surface system would be studied, in order to establish a relationship betwee

英文关键词： Low-dimensional GaN；Impurities and defects；Surface and Interface；Electronic structure；First-principles