High-Performance Harsh-Environment-Resistant GaO_X Solar-Blind Photodetectors via Defect and Doping Engineering

Gallium oxide (Ga₂ O₃ ), with an ultrawide bandgap, is currently regarded as one of the most promising materials for solar-blind photodetectors (SBPDs), which are greatly demanded in harsh environment, such as space exploration and flame prewarning. However, realization of high-performance SBPDs with high tolerance toward harsh environments based on low-cost Ga₂ O₃ material faces great challenges. Here, defect and doping (DD) engineering towards amorphous GaO_X (a-GaO_X ) has been proposed to obtain ultrasensitive SBPDs for harsh condition application. Serious oxygen deficiency and doping compensation of the engineered a-GaO_X film ensure the high response currents and low dark currents, respectively. Annealing item in nitrogen of DD engineering also incurs the recrystallization of material, formation of nanopores by oxygen escape, and suppression of sub-bandgap defect states. As a result, the tailored GaO_X SBPD based on DD engineering not only harvests a record-high responsivity rejection ratio (R_{254 nm} /R_{365 nm} ) of 1.8 × 10⁷ , 10² times higher detectivity, and 2 × 10² times faster decay speed than the control device, but also keeps a high responsivity, high photo-to-dark current ratio, and sharp imaging capability even at high temperature (280 °C) or high bias (100 V). The proposed DD engineering provides an effective strategy towards highly harsh-environment-resistant GaO_X SBPDs.