A study of visible-blind properties of a SnO₂’s nanowires network photodetector

We developed a SnO₂ nanowire network visible-blind ultraviolet (UV) photodetector for applications in fields such as safety systems, exposure control, decontamination processes, among others. Based on the vapor-liquid-solid (VLS) growth method, a SnO₂ nanowire network was synthetized. The sensor was fabricated based on a metal-semicondutor-metal (MSM) structure and Ag paste was used as simple and efficient electrical contact. To understand the visible-blind property two light sources were used: UV (254-365 nm) and VIS (400-900 nm) Lamps. In Current – Voltage measurements, the device under dark and room ambient conditions presented rectifier contacts with different barrier heights; whereas under UV illumination, the barrier heights seem to be aligned. It was observed that the sensor’s photoresponse was optimized for UV Light with rise and decay time ~1s and 3s, respectively, and exhibiting an on/off ratio of 42.5; whereas as for the VIS light both times were longer with an on/off ratio of 1.7, both under V = + 0.1 V. These results are highly significant for developing of a visible-blind photodetector.