Development of nanoporous GaN on Silicon substrate for optoelectronic devices

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.