Growth of InGaN Multiple Quantum Wells on GaN Nano Rods and their Optical Characterization

Abstract: GaN/InGaN based nanorod (NR) core-shell structures have become increasingly popular in recent years due to their potential in optoelectronic applications such as solid state lighting however more cost effective ways are still needed for the NR fabrication and overgrowth. I present here a novel approach to form these nano structures by a top down approach which is scalable. The unique properties of the NRs due to their geometry offer great advantage, the core-shell NR structures in which the active layer (shell) is wrapped around a central three dimensional core structure offers a much larger active region compared to a planar structures hence presenting much better quantum efficiency. In this thesis I present our approach toward achieving good quality NR (core) structures through reactive ion etching (RIE) and wet chemical etching from a n-GaN planar layer and then the growth through metal organic vapour phase epitaxy (MOVPE) of the active (shell) InGaN multiple quantum wells (MQW) layer on the polarization free m-plane. These MQW active layers are then optically characterized and we can achieve a broad range of spectrum by changing the morphological growth conditions of the NR and the QW growth parameters. A p-GaN layer is then grown by epitaxy to achieve a p-i-n junction which will be further electrically characterised as part of other research hence a basic working device may be achieved in the near future.