Solution Processed Amorphous ZnSnO Thin-Film Phototransistors

Amorphous ZnSnO (a-ZnSnO) thin films were synthesized by a combustion solution method to fabricate thin-phototransistors. The a-ZnSnO phototransistors are extremely sensitive to UV light, with evident photoelectric effect identified at various gate voltages. The UV sensitivity is rather high (similar to 10(5) for the ratio of photocurrent to dark-current) at the off-state, while it is quite low (similar to 10(1)) at the on-state. The device behaviors can completely recover to the original state within 2000 s after switching off the UV light at both on-and off-states. We demonstrate that the UV behaviors of a-ZnSnO phototransistors can be well controlled by gate voltages. This paper is expected to provide a fundamental knowledge of performances of amorphous oxide phototransistors for practical applications.