Performance-Boosted AgNWs@ZnO:Sb Microwire/n-Si Heterojunction Self-Powered Ultraviolet Photodetector by Coupling Pyro-Phototronic and Plasmonic Effects

Ultraviolet (UV) photodetection has attracted considerable attention due to their potential applications in missile warning, wireless communication, and biomedical engineering. However, it is still challenging to realize UV detectors with both high photosensitivity and ultrafast response speeds because of insufficient photon utilization and poor separation of photo-induced carriers. Herein, a strategy for coupling pyro-phototronic effect and plasmonic effect is proposed to develop a performance-enhanced Ag nanowires-decorated ZnO:Sb microwire/Silicon (AgNWs@ZnO:Sb MW/Si) heterojunction UV photodetector. The optimized photodetector achieves self-powered performance with a maximum responsivity of 0.242 A/W, a specific detectivity of $8.3\times 10^{{12}}$ Jones, and ultrafast rising/falling photoresponse times of 17/ $41 ~\mu \text{s}$ at zero bias by fully utilizing these two effects. Compared to the pristine ZnO:Sb MW/Si device, the responsivity, detectivity, and response time are enhanced by over 257%, 382%, and 285%, respectively. The modification of AgNWs improves the thermal sensitivity of the photodetector and then further enhances the pyroelectric current and photosensitivity. In addition, the incorporation of AgNWs leads to an increase in the carrier mobility of the single MW, resulting in enhanced response speed. This work not only further investigates the synergism of the pyro-phototronic effect and the plasmonic effect, but also gives a scientific inspiration for constructing high-efficiency Si-based UV photodetection.