Surface-dominated negative photoresponse of phosphorus-doped ZnSe nanowires and their detecting performance

Phosphorus-doped ZnSe nanowires were synthesized by using phosphorus (P) as dopant via thermal evaporation method. Their doping effect and obvious p-type conduction were confirmed through a top-gate MISFET based on individual P-doped ZnSeNW. Negative photoconductivity (the photocurrent was lower than the dark current) was found in p-type ZnSeNWs due to their surface effect. Two terminal devices based on p-type ZnSeNWs, as gas sensors, were also constructed and performed effective detecting behaviors to oxidizing gas. Furthermore, a complementary photodetector containing both n-type ZnSeNWs and p-type ZnSeNWs was first manufactured to eliminate the effects of crosstalk or false signal exist in conventional photodetectors. These results are expected to be used to develop new-type nano-devices and expand their applications.