In-depth investigation of low-energy proton irradiation effect on the structural and photoresponse properties of e-Ga2O3 thin films

Ga2O3 possesses an ultra-wide bandgap (-4.9 eV) and an extremely large breakdown field strength (-8 MV/cm), which promises extraordinary application potential in power electronics and ultraviolet opto-electronics. With the demand for highly durable devices in harsh environments such as in low earth orbit spacecraft, in-depth understanding of the particle radiation effect on the structural and performance degradation of the device is desired. In this work, we employ 150 keV low energy proton with intensity up to 5 x 10(15) dose to irradiate the epitaxial e-Ga2O3 thin films. The characterization of the structural and optical properties shows no detectable variations in lattice structure and optical transmission. In addition, with increasing irradiation dosage, a decrease of Ga3+ population and an increase of the concentration of oxygen vacancies are confirmed by X-ray photoemission spectroscopy. Photoresponse measurements further illustrate that, despite of a mild degradation in the photodetector performance, the device still shows a high photoresponsivity of 2.52 x 10-3 A/W and a large photo-to-dark current ratio over 103. Our work reveals that e-Ga2O3 exhibits excellent radiation hardness under low-energy proton irradiation conditions and highlights the potential for operational optoelectronics in extreme environment.(c) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

Ga2O3 with ultra-wide bandgap and high breakdown field strength has great potential in power electronics and UV opto-electronics. This study investigates the radiation hardness of e-Ga2O3 thin films under low-energy proton irradiation, and finds that the material maintains its structural and optical properties while exhibiting mild degradation in photodetector performance. This reveals the excellent radiation resistance of e-Ga2O3 and its potential for extreme environment optoelectronics.