Role of the Surface in the Electrical and Optical Properties of GaN and ZnO

表面在 GaN 和 ZnO 电学和光学性质中的作用

• 批准号: 0804679
• 负责人: Alison Baski
• 金额: $ 30.75万
• 依托单位: Virginia Commonwealth University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-06-15 至 2012-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0804679&HistoricalAwards=false
• 关键词: Role; Surface; Electrical; Optical; Properties

Technical. This project addresses the role played by surfaces and interfaces in the electrical and optical properties of GaN and ZnO. It thought that surface-related effects may be responsible for reduced efficiency of emitters, shorter laser operation lifetimes, and earlier degradation of elec-tronic devices. Additionally, the irreproducible and unstable p-type conductivity of ZnO may be related to peculiarities of the surface conductivity in this material. This project aims for an in-depth investigation to gain a comprehensive understanding of the processes at and near the sur-face for both GaN and ZnO. Electrical and optical properties will be probed under different am-bient conditions, temperatures, and illumination. Band bending near the surface and its variation under illumination (photovoltage) will be studied using two methods: 1) a Kelvin probe com-bined with an optical cryostat; and 2) a microscopy technique combining local charge injection with subsequent imaging of the surface charge. The underlying mechanisms for surface band bending will be related to sample preparation, temperature, and ambient environment. Effective passivation schemes will also be explored to improve the performance of optical and electronic devices based on these wide-bandgap semiconductors.Non-Technical. The project addresses fundamental research issues in a topical area of elec-tronic/photonic materials science having technological relevance. This effort may lead to higher reliability, longer lifetime, and higher efficiency bright light sources based on GaN and ZnO. The proposed research program will leverage strong collaborations between research groups in the Departments of Physics and Electrical Engineering at Virginia Commonwealth University (VCU), as well as initiate a collaboration with the Department of Chemistry and Physics at Longwood University, a nearby undergraduate institution. The project provides support for graduate students at VCU and undergraduate students at both VCU and Longwood, where all of the students will be involved in collaborative efforts between multiple research groups. Women and underrepresented minority groups will be actively recruited and supported within this pro-ject. VCU is a growing urban university with a diverse student body (18% African American, 22% other minorities), and the PI?s have a record of mentoring students from underrepresented groups in their laboratories. An international collaboration is also planned with the Ioffe Physical Technical Institute of the Russian Academy of Science.

技术.该项目解决了表面和界面在GaN和ZnO的电学和光学特性中所起的作用。认为表面相关效应可能是导致发射体效率降低、激光器寿命缩短和电子器件过早退化的原因。此外，ZnO的不可再现和不稳定的p型导电性可能与该材料中表面导电性的特性有关。本项目旨在深入研究GaN和ZnO表面及其附近的工艺过程。将在不同的环境条件、温度和光照下探测其电学和光学性质。将使用两种方法研究表面附近的能带弯曲及其在照明（光电压）下的变化：1）Kelvin探针结合光学低温恒温器;和2）结合局部电荷注入和随后的表面电荷成像的显微镜技术。表面能带弯曲的潜在机制与样品制备、温度和周围环境有关。此外，还将探索有效的钝化方案，以提高基于这些宽带隙半导体的光学和电子器件的性能。该项目涉及电子/光子材料科学领域的基础研究问题，具有技术相关性。这一努力可能导致基于GaN和ZnO的更高可靠性、更长寿命和更高效率的亮光源。拟议的研究计划将利用弗吉尼亚联邦大学（VCU）物理和电气工程系研究小组之间的强有力合作，并与附近的本科院校朗伍德大学的化学和物理系展开合作。该项目为VCU的研究生和VCU和Longwood的本科生提供支持，所有学生都将参与多个研究小组之间的合作。妇女和代表性不足的少数群体将在该项目中积极招募和支持。VCU是一所不断发展的城市大学，拥有多元化的学生群体（18%的非洲裔美国人，22%的其他少数民族），PI？在他们的实验室里，他们有指导来自代表性不足的群体的学生的记录。还计划与俄罗斯科学院约费物理技术研究所开展国际合作。