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

•150 keV low-energy proton with intensity up to 5 × 1015 dose to irradiate the epitaxial ε-Ga2O3 thin films.•No detectable variations of lattice structure and optical transmission were detected upon 150 keV proton radiation.•In-depth analysis of proton radiation impact on the photoresponse properties was performed.•ε-Ga2O3 exhibits excellent radiation hardness under low-energy proton irradiation conditions.