High-mobility induced high-performance self-powered ultraviolet photodetector based on single ZnO microwire/PEDOT:PSS heterojunction via slight ga-doping

Semiconductor micro/nanostructures with broad bandgap can provide powerful candidates for fabricating ultraviolet photodetectors (PDs) due to their proper bandgap, unique optoelectronic properties, large surface-to-volume ratio and good integration. However, semiconducting micro/nanostructures suffer from low electron conductivity and abundant surface defects, which greatly limits their practical application in developing PDs. In this work, an ultraviolet PD consisting of single Ga-doped ZnO microwire (ZnO:Ga MW) and p-type poly(3,4ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) was designed. When exposed to ultraviolet illumination, the PD exhibits excellent performance (responsivity similar to 185 mA/W, detectivity similar to 2.4 x10(11) Jones, and fast response speed of 212 mu s for rise time and similar to 387 its for decay time) under self-driven conditions. Compared with that of an undoped ZnO MW based PD, the responsivity and detectivity of ZnO:Ga MW/PEDOT:PSS PD are significantly enhanced over 400 % and 600 % , respectively. Due to the incorporation of Ga element, the charge transport properties of a ZnO:Ga MW, specifically for the mobility, are effectively enhanced, which can substantially facilitate the generation, separation, transport and harvest efficiency of photo-generated carriers in the as fabricated PD. Besides, the Ga-incorporation improves the crystalline quality of MWs and reduces surface state density, further suggesting a high-quality ZnO:Ga MW/PEDOT:PSS heterojunction. This work provides a potential approach for designing high-performance self-powered ultraviolet PDs from the aspect of enhancing carrier transport through fine doping. (C) 2021 Published by Elsevier Ltd on behalf of Chinese Society for Metals.

Automated summary

This study designed a high-performance self-powered ultraviolet photodetector by enhancing carrier transport through fine doping, which showed significantly improved responsivity and detectivity compared to undoped detectors.