See-Through Solar-Blind Photodetectors for Use in Harsh Environments

This paper demonstrates the high-temperature operation of fully transparent solar-blind deep ultraviolet (DUV) metal-semiconductor-metal (MSM) photodetectors (PDs) employing β-Ga₂O₃ thin films with transmittance up to 80% from 400 to 900 nm without image blurring. Even at a bias up to 200 V, the β-Ga₂O₃ MSM PDs show dark current as low as ~1 nA. The dark current of β-Ga₂O₃ MSM PDs under significantly different oxygen concentration in the ambiences are similar, indicating that the high inertness to surface effect. Moreover, the responsivity and the working temperature of β-Ga₂O₃ MSM PDs at 10 V bias are 0.32 mA/W and as high as 700 K, respectively. Full recovery after 700-K operation demonstrates reliability and robustness of β-Ga₂O₃ PDs. The superior see-through features, electrical tolerance, inertness to surface effect, thermal stability, and solar-blind DUV photoresponse of β-Ga₂O₃ MSM PDs support the use in next-generation DUV PDs applications under harsh environments.