Mica-based β-Ga2O3 photodetector: Enabling solar-blind deep-ultraviolet detection with flexibility and transparency

Abstract

Flexible, transparent solar-blind deep-ultraviolet photodetectors (SBPDs) based on Ga2O3 are gaining momentum for a wide range of future military and civilian applications. However, the fabrication of flexible, transparent SBPDs based on β-Ga2O3 faces challenges due to the inability of commonly used polymer substrates to withstand the high temperatures needed for growth. In this study, the challenge was addressed by producing highly transparent β-phase Ga2O3 thin films on mica substrates using rf magnetron sputtering and annealing techniques. Subsequently, flexible and transparent SBPDs were developed utilizing a metal-semiconductor-metal (MSM) configuration, combining the β-Ga2O3 thin films with an aluminum-doped zinc oxide (AZO) transparent conductive layer. The device with full transparency to visible light revealed a remarkable responsivity of 1.25 A/W and rapid photoresponse rates of 0.18/0.06 s under 254 nm illumination, placing their performance at the forefront among β-Ga2O3-based flexible SBPDs. Notably, even after undergoing numerous mechanical bending tests at varying diameters and cycling counts, the device maintained consistent stability across all performance parameters. This study highlights the potential of mica-based β-Ga2O3 photodetectors for enabling flexible and transparent solar-blind deep-ultraviolet detection.