Studies of the Electron Injection-Induced Effects in III-Nitride Device Structures

该项目的出发点是PI最近的发现，电子注入p型GaN会导致材料的电子性能发生相当大的变化，特别是更长的少数载流子扩散长度。这个为期三年的项目的智力优势在于探索大范围p型mg掺杂AlxGa1-xN （x 0.35）和AlxGa1-xN/GaN超晶格中的新型电子注入诱导效应。此外，还将研究掺杂了除Mg（例如锰或铁）以外的杂质的iii -氮化物和III-N合金以及除AlxGa1-xN和AlxGa1-xN/GaN（例如InxGa1-xN和InxGa1-xN/GaN）以外的超晶格中的电子注入效应。为了充分理解这种新型的电子注入诱导效应，并实现对器件性能的控制，将在具有代表性的iii -氮化物基结构范围内进行系统的电学和光学研究。电子注射前后将进行电子测量，包括深层瞬态光谱和电子束感应电流。这些测量将与阴极发光、光响应和光电导率测量相辅相成，这些测量能够提供光学和光电子特性的关键信息。这个项目更广泛的影响是在研究生和本科阶段的研究和教育的整合，以及与行业的合作（SVT Associates）。该项目更广泛影响的另外两个方面是，一名女博士生和一所历史悠久的黑人（白求恩-库克曼）学院的本科生参与了拟议的研究。最后，该项目的国际层面是PI与德国慕尼黑工业大学沃尔特肖特基研究所的一个小组密切合作。本研究的实际意义在于将iii -氮化物紫外探测器的量子效率长期提高数倍。这是因为增加的扩散长度改善了少数载流子的收集，并消除了载流子在收集前重组的“死区”。

The starting point of this project is the PI's recent findings that electron injection into p-type GaN leads to considerable changes in the material's electronic properties, in particular longer minority carrier diffusion length. The intellectual merit of this three-year project is in exploration of the novel electron injection-induced effects in the wide range of p-type Mg-doped AlxGa1-xN (x 0.35) and AlxGa1-xN/GaN superlattices. In addition, the electron injection effects in III-Nitrides doped with impurities other than Mg (manganese or iron, for example) and III-N alloys and superlattices other than AlxGa1-xN and AlxGa1-xN/GaN (InxGa1-xN and InxGa1-xN/GaN, for example) will be studied. To fully understand the novel electron injection-induced effects and to achieve control over device performance, systematic electrical and optical studies will be carried out in the representative range of III-Nitride-based structures. Electrical measurements, which include Deep Level Transient Spectroscopy and Electron Beam Induced Current, will be performed before and after electron injection. These measurements will be complemented with cathodoluminescence, photoresponse, as well as photoconductivity measurements able to provide critical information on optical and optoelectronic properties. The broader impact of this project is in integration of research and education at the graduate and undergraduate levels as well as in partnership with industry (SVT Associates). Two other aspects of the project's broader impact are in participation of a female Ph.D. student and undergraduates from a Historically Black (Bethune-Cookman) College in the proposed research. Finally, the international dimension of the project is in close collaboration of the PI with a group at the Walter Schottky Institute of Munich Technical University in Germany. The practical significance of this research is in long-term, several-fold enhancement of quantum efficiency for III-Nitride ultra-violet detectors. This is because the increased diffusion length improves minority carrier collection and eliminates the "dead space" where carriers recombine before they are collected.