Mr Xiuyuan Xu

Gallium nitride (GaN) based light-emitting diodes (LEDs) are highly energy-efficient and can induce significant worldwide electricity savings. High-efficiency green nitride microLEDs are required for color-tunable lighting and microdisplays. But currently their efficiency is only half that of blue and red LEDs, known as the green gap. Zincblende (zb) GaN has the potential to bridge the green gap because it is free of internal electric fields and requires less indium in the quantum wells, both of which plague the commonly used c-plane wurtzite structure. However, it is highly likely to have phase mixing and stacking faults (SFs) in zb-GaN epilayer, which may impair the device performance.

I have joined the Cambridge Centre for Gallium Nitride in October 2023 to work on the development of cubic GaN materials towards microLEDs. The aim of my PhD project is to establish the links between materials structures, their properties and the performance of microLEDs. My work primarily focuses on the characterization of zb LED devices and device substructures, and understand the influences of microstructural features on carrier recombination dynamics and polarization phenomena. This will lead to an improved and enhanced performance of zb devices.