Enhanced UV photodetection in SnO2 microwire arrays (MWAs) thin films by γ-ray irradiation

Abstract

In this study, the gamma ray irradiation-induced photoelectric responses of SnO2 microwire arrays (MWAs) UV photodetectors were investigated and compared with the unirradiated state. The corresponding surface morphology, crystal structure, and XPS spectrum were analyzed. Results indicated that low doses (≤500krad) of gamma ray irradiation led to enhanced photocurrent and responsivity, whereas high doses resulted in significant degradation of the photoelectric response. At a radiation dose of 300krad, a photocurrent of 264 μA and a responsivity of 1.83 A/W were realized under 365 nm UV light illumination at a bias voltage of 5 V. These values represent an increase of 34.6 % and 44.1 %, respectively, compared with the unirradiated sample. Surprisingly, the fabricated SnO2 MWAs UV photodetectors demonstrated resilience to gamma ray irradiation doses up to 500krad, which is equivalent to the radiation dose accumulated by satellites in low-Earth orbit over 20 years. Our findings suggested that the fabricated SnO2 microwire arrays (MWAs) UV detector has the potential to be used for long-term space missions.