基于ZnO单晶衬底的氧化物半导体发光二极管量子效率研究

项目名称： 基于ZnO单晶衬底的氧化物半导体发光二极管量子效率研究

项目编号： No.61474121

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 无线电电子学、电信技术

项目作者： 丁凯

作者单位： 中国科学院福建物质结构研究所

项目金额： 86万元

中文摘要： ZnO由于具备宽直接带隙和大激子束缚能等优异特性，在面向新能源的光电转换材料和器件领域有着广阔的应用前景。目前，低的有源区量子效率是与p型掺杂具有同样重要性的制约ZnO基发光器件发展的关键问题。本项目将利用ZnO单晶衬底在薄膜外延和p型掺杂中的优点，同时规避其对光子自吸收的缺点，开展基于ZnO单晶衬底的氧化物半导体发光二极管量子效率研究。在ZnO单晶衬底上进行薄膜的MOCVD同质外延生长，实现以二维层状模式生长的ZnMgO/ZnO低维异质结构。在器件模拟仿真基础上设计出具有高内量子效率的有源区结构，优化MOCVD生长工艺，减少非辐射复合中心数目，获得组分均匀、厚度精确、界面陡峭的有源区，获得高的内量子效率。采用衬底减薄和衬底转移技术，降低材料对光子的自吸收效应；通过表面粗糙化等手段提高光子的提取效率，从而实现具有高外量子效率的LED器件。在此过程中建立起氧化物半导体光电子器件制备工艺。

中文关键词： 氧化锌；发光二极管；量子效率；金属有机物化学气相沉积

英文摘要： Due to its wide, direct bandgap of 3.3 eV and large exciton binding energy of 60 meV, ZnO has been proposed as a potential material for the use in electro-optic conversion applications. Currently, relatively low quantum efficiency in the active region is also a key factor, as important as the well-known p-type doping, that limits the development of ZnO-based light-emitting devices. As compared with heteroepitaxy, homoepitaxy of ZnO films on bulk ZnO single crystal has great advantages both in quality control of the film and p-type doping. Therefore, this application plans to research on the quantum efficiency of ZnO-based light-emitting diodes (LEDs) on bulk ZnO. Homoepitaxy of ZnO by using metal-organic chemical vapor deposition (MOCVD) will be investigated to obtain high quality ZnMgO/ZnO low-dimensional structures with 2D layer-by-layer growth mode. Active region with high internal quantum efficiency will be designed based on device simulations. MOCVD parameters will be optimized to realize such high quality active region with low non-radiative recombination center number, homogeneous composition, accurate thickness, and abrupt interface. Substrate thinning and substrate transfer technique will be developed to minimize the self-absorption effect of the emitted photons in the material. Surface roughness method such as pyramid microstructures and nanorod arrays will be investigated to enhance the light extraction efficiency. ZnO-based LEDs with high external quantum efficiency will be eventually fabricated, and during this program, oxide semiconductor optoelectronic devices process will be set up.

英文关键词： ZnO;light-emitting diode;quantum efficiency;MOCVD