Ultrahigh-Responsivity GaON Thin Film Transistor Photodetectors with Improved Air Stability

As an ultrawide-bandgap semiconductor, gallium oxide (Ga2O3) exhibits intrinsic absorption characteristics in the solar-blind ultraviolet (SBUV) spectrum, holding immense potential for SBUV detection applications. However, achieving amorphous Ga2O3 photodetectors with simultaneously high responsivity and air stability remains a critical challenge. In this work, a strategy combining N-doping and low-temperature crystallization enhances both responsivity and air stability. An aluminum oxide (Al2O3) capping layer is introduced, which further acts as an effective optical modulation layer, enhancing the selectivity in the SBUV spectrum. Notably, compared to the control group, devices with an Al2O3 capping layer exhibited nanocrystalline structures in both the Al2O3 and channel layers, demonstrating superior performance, particularly an exceptional responsivity of 7.8 × 105 A/W. The performance remains stable after being exposed to air for 100 days. These findings underscore the importance of microstructural engineering in oxide photodetector development, providing a concise and efficient technical pathway for advancing high-performance photodetectors and their industrial applications.