Electron beam irradiation-induced transport and recombination in p-type Gallium Oxide grown on (001) \b{eta}-Ga2O3 substrate

TL;DR

This paper explores how electron beam irradiation affects electron transport and recombination in p-type Gallium Oxide films, revealing temperature-dependent diffusion lengths and defect-related dynamics using EBIC and CL spectroscopy.

Contribution

It provides new insights into defect-related transport phenomena in p-Ga2O3, highlighting the effects of electron beam excitation on diffusion length and recombination processes.

Findings

Electron diffusion length decreases with temperature.

Continuous electron beam exposure elongates diffusion length.

Defect-related processes influence transport and recombination.

Abstract

This study investigates minority electron diffusion length and carrier recombination phenomena within p-type, 300 nm-thick Ga2O3 epitaxial films. Utilizing Electron Beam-Induced Current (EBIC) and Cathodoluminescence (CL) spectroscopy, these characteristics were examined as a function of both temperature and the duration of electron beam excitation. While the electron diffusion length in these p-Ga2O3 films diminish with increasing temperature, a continuous electron beam excitation of a particular location on the surface of a p-Ga2O3 epitaxial layer leads to an elongation of the diffusion length. and decay of cathodoluminescence intensity in that location under beam exposure. These latter two effects are attributed to non-equilibrium electrons, generated by an electron beam, being captured at acceptor-related point defect levels in Gallium Oxide. The activation energies characterizing these processes were obtained from the independent EBIC and CL experiments to garner insight into defect landscape and its influence on transport and recombination dynamics.