Effects of Polarization Fields and Surface Charge Layers on p-Type Conductivity in In(Ga)N

极化场和表面电荷层对 In(Ga)N 中 p 型电导率的影响

• 批准号: 0907475
• 负责人: Mathias Schubert
• 金额: $ 23.19万
• 依托单位: University of Nebraska-Lincoln
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0907475&HistoricalAwards=false
• 关键词: Effects; Polarization; Fields; Surface; Charge

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Technical: This project seeks to solve two key issues of InGaN materials. First, how do lattice strain, composition, internal polarization fields, surface polarity, defect, and dopant incorporation influence p-type conductivity in InGaN? Second, what is the cause of the intrinsic surface electron layer in InN? This layer obscures the bulk free charge carrier properties in contact-based electrical measurements, in the extreme case concealing p-type conductivity. The experimental approach of this project comprises InGaN thin film analysis with variation of spontaneous and piezoelectric fields, surface orientation, composition, surface defects, and dopant incorporation. It employs a newly developed optical Hall-effect technique, which permits noncontact, noninvasive charge carrier profiling and tackles the present challenges in p-conductivity research on InGaN. The success of the project may also open a door to answer the open questions about the surface charges in InAs.Non-technical: The project addresses basic research issues in a topical area of materials science with high technological relevance. The success of the project is expected to have impacts on the further advancement of optoelectronics, solid state lighting, and solar cells. The project provides training of graduate and postdoctoral students. The PI and his students participate in education outreach activities for solar energy use in remote areas of Nebraska. The PI is also active in the professional societies and organizes several symposia on ellipsometry in scientific conferences.

该奖项根据 2009 年美国复苏和再投资法案（公法 111-5）提供资金。 技术：该项目旨在解决 InGaN 材料的两个关键问题。首先，晶格应变、成分、内部极化场、表面极性、缺陷和掺杂剂掺入如何影响 InGaN 中的 p 型导电率？其次，InN中本征表面电子层的形成原因是什么？该层掩盖了基于接触的电气测量中的体自由电荷载流子特性，在极端情况下隐藏了 p 型导电性。该项目的实验方法包括对 InGaN 薄膜进行分析，分析自发场和压电场、表面取向、成分、表面缺陷和掺杂剂掺入的变化。它采用了新开发的光学霍尔效应技术，可实现非接触、非侵入性电荷载流子分析，并解决了 InGaN p 电导率研究中当前的挑战。该项目的成功也可能为回答有关 InAs 表面电荷的悬而未决的问题打开一扇大门。非技术性：该项目解决了具有高度技术相关性的材料科学主题领域的基础研究问题。该项目的成功预计将对光电、固态照明和太阳能电池的进一步发展产生影响。该项目提供研究生和博士后的培训。 PI 和他的学生参加内布拉斯加州偏远地区太阳能使用的教育推广活动。 PI 还活跃于专业协会，并在科学会议上组织了多次关于椭圆测量的研讨会。