Solution‐Processed Transparent Self‐Powered p‐CuS‐ZnS/n‐ZnO UV Photodiode

Transparent diodes formed by a heterojunction between p‐type CuS–ZnS and n‐type ZnO thin films were fabricated by sequential chemical bath deposition and sol‐gel spin coating. The diodes are transparent in the visible (≈70% at 550 nm) and exhibit a good rectifying characteristics, with If/Ir ratios of up to 800 at ±1 V, higher than most of the reported solution‐processed diodes measured at a similar bias. More importantly, when operated as a self‐powered (zero bias) UV photodetector, they show stable and fast (<1 s) photoresponse with a maximum responsivity of 12 mA W−1 at 300 nm. Both the response time and responsivity of the p‐CuZnS/n‐ZnO UV photodiode are comparable or superior to similar solution‐processed devices reported in the literature.