LAUSR

Gallium nitride is currently being investigated for demanding applications such as high-temperature and high-power electronics as well as space-based or other high radiation exposure applications. It has a wide bandgap and is more resistant than Si to high fluxes of proton and electron radiation [1]. Electron irradiation of GaN is believed to create both N and Ga vacancies, as well as to induce threading dislocation glide. These defects can act as recombination centers which reduce the overall minority carrier lifetime and mobility. Measurements of the minority carrier diffusion length in GaN can be studied using cathodoluminescence (CL) or electron beam induced current (EBIC) in a scanning electron microscope (SEM). However, as recently reported in Yakimov et. al. [2], the EBIC planar geometry in SEM often leads to an over estimation of the minority carrier diffusion length in n-type GaN. This over estimation is attributed to the interaction volume in SEM, which is on the order of hundreds of nanometers to a few microns and overlaps with the measured minority carrier diffusion length of n-GaN, reported to be between a few tens of nanometers to a few microns [2].