Development of nanoporous GaN on Silicon substrate for optoelectronic devices

多孔族III-氮化物是一种具有新性质和新应用的化合物半导体材料，如无应变光学反射器、化学传感器，以及从天然衬底和远程外延获得器件的关键发展途径。十年来，传感和光电子器件取得了重大进展。多孔III-氮化物的形成广泛采用自顶向下的制备方法，如电化学(EC)和光电化学(PE)刻蚀。在PE刻蚀的情况下，通过施加电压/偏压、材料掺杂密度和光照等关键参数来控制孔的形态。自发生成的多孔III-氮化物的孔形态为基片温度、III族和氮通量。自下而上的制造方法是无污染的。整个器件，如发光二极管、光电二极管和激光器，只需在一次工艺运行中改变生长参数就可以简单地生长出来。该项目将包括：发展对多孔III-N的晶体结构、电子结构和光学性质的理论理解。了解原位和非原位表征、生长机理、设计和制造多孔III-N。通过自下而上和自上而下的方法开发多孔III-N。该项目将在最先进的研究设施中发展，包括分子束外延(MBE)、X射线衍射、扫描电子显微镜和光致发光。

Porous group III-Nitrides are emerging as compound semiconductors with novel properties and applications such as strain-free optical reflectors, chemical sensors and a critical development pathway to device lift-off from the native substrates and remote epitaxy. Significant progress has been made in a decade across sensing and optoelectronic devices. Porous III-nitrides are formed widely using top-down fabrication methods such as electrochemical (EC) and photoelectrochemical (PE) etching. Pore morphology is controlled via critical parameters such as applied potential/bias, material doping density and illumination in the case of PE etching. The pore morphology of spontaneously formed porous III-Nitrides is substrate temperature, group III and N fluxes. The bottom-up fabrication approach is contamination-free. The entire device, such as light-emitting diodes, photodiodes and lasers, can be grown simply by changing the growth parameters in a single process run.The project will involve: Development of theoretical understanding of crystal structures, electronic structure, and optical properties of porous III-Nitrides.Understanding of in-situ and ex-situ characterisation, growth mechanisms, design and fabrication of porous III-Nitrides.Development of Porous III-Nitrides via bottom-up and top-bottom approaches.The project will be developed in state-of-the-art research facilities, which include molecular beam epitaxy (MBE), X-ray diffraction, Scanning electron microscopy and photoluminescence.