Investigation of high In-composition InGaN

摘要：技术：高成分合金（InGaN, xIn 0.25）是iii -氮化物体系中尚未开发的材料之一。虽然InGaN合金的带隙范围可以覆盖从紫外（例如，GaN ~ 3.4 eV）到红外（例如，InN ~ 0.7 eV）的整个光谱，但迄今为止的技术应用仅限于该光谱的较高能量范围。低带隙iii型氮化合金的应用数量相对较少，这是由于外延生长的挑战，以及对这些材料的电学、缺陷和光学特性的了解不足。该项目将解决与生长和结构特性有关的关键问题，包括电学、光学和缺陷特性，以实现氮化镓n极取向的高成分InGaN薄膜。本项目将研究该材料在富金属和富氮条件下的生长动力学，以建立Ga-和n-极性InGaN的综合生长模型。本研究将包括厚InGaN薄膜和在GaN上的应变InGaN薄膜，以了解相分离、位错介导的弛豫和表面形貌的物理起源。薄膜的电学和光学特性将导致对p型和n型掺杂的理解，以及薄膜中背景缺陷的掺入（通过深能级光学光谱）。非技术：该研究将使开发iii -氮化物大带隙范围的器件应用成为可能。将iii -氮化物发射器的巨大商业成功扩展到更大范围的光学和电子应用将对半导体技术行业产生变革。pi在将研究活动扩展到高中生方面有着良好的记录。这个项目的跨学科性质要求参与的不同小组之间的密切合作，并将对参与的本科生和研究生进行极好的培训。

Abstract:Technical: High In-composition alloys (InGaN, xIn 0.25) are among the most unexplored materials in the III-nitride system. While the bandgap range of InGaN alloys can cover the entire spectrum from ultra-violet (Eg, GaN ~ 3.4 eV) to infrared (Eg, InN ~ 0.7 eV), technological applications until now are restricted to the higher energy range of this spectrum. The relatively low number of applications in the lower bandgap III-nitride alloys is due to the challenges associated with epitaxial growth, and poor understanding of the electrical, defect, and optical characteristics of these materials. This project will address the critical issues relating growth and structural properties to electrical, optical, and defect properties to achieve higher composition InGaN films on N-polar orientation of GaN. This project will investigate the growth kinetics for this material in metal-rich and nitrogen-rich regimes to create a comprehensive growth model for Ga- and N-polar InGaN. This study will include thick InGaN films and strained InGaN films on GaN to understand the physical origins of phase segragation, dislocation-mediated relaxation, and surface morphologies. Electrical and optical characterizations of the films will lead to an understanding of p-type and n-type doping, as well as the background defect incorporation in the films (through deep level optical spectroscopy). Non-Technical: The study will enable device applications that exploit the large bandgap range of III-nitrides. Extending the tremendous commercial success of III-nitride emitters to a larger range of optical and electronic applications will be transformative to the semiconductor technology industry. The PIs have a strong record of extending their research activities to involve high school students. The interdisciplinary nature of this project requires close collaboration between the different groups involved, and will be excellent training for undergraduate and graduate students involved.