Boosting the performance of deep-ultraviolet photodetector arrays based on phase-transformed heteroepitaxial β-Ga2O3 films for solar-blind imaging

Solar-blind imaging has attracted considerable interest in both military and civilian applications, spurring the development of high-performance deep-ultraviolet photodetector arrays (PDAs) with wide-bandgap semiconductor materials. Herein, we present a novel method to enhance the performance of solar-blind PDAs (SBPDs) using beta-Ga2O3 films obtained by the phase transition of heterogeneous epitaxial sub-stable epsilon-Ga2O3, achieved through high-temperature rapid annealing. Metal-semiconductor-metaltype SBPDs based on phase-transformed beta-Ga2O3 films exhibited superior performance, including an ultrahigh responsivity of 459.38 A/W, detectivity of 10(14)-10(15) Jones, external quantum efficiency of 104%-105%, rejection ratio (R-254/R-365) of 10(5)-10(6), photo-to-dark current ratio of 10(4)-10(6), fast response speed of 1.01 s/0.06 s, and favorable stability. Notably, the ultrahigh responsivity of beta-Ga2O3-film-based devices was approximately 222-fold higher than that of epsilon-Ga2O3 film-based devices. The assembled 4 x 5 beta-Ga2O3 film-based PDAs exhibited favorable uniformity, repeatability, and high spatial resolution for solarblind imaging. Our study offers a promising approach for the development of high-performance beta-Ga2O3-based PDAs for solarblind ultraviolet imaging with potential applications in both military and civilian fields.