High-Performance UV Photodetector via Energy Band Engineering and LSPR-Enhanced Pyro-Phototronic Effect in Au Decorated 2D-PbI2/1D-ZnO Heterojunction

Ultraviolet (UV) photodetectors have attracted extensive attention in various applications, including aerospace, optical communication, and fire warning. However, the intrinsic coupling of high responsivity and fast response as well as imperfect interface transmission impede the further improvement of UV photodetector. Here, a high-performance Au-decorated PbI2/ZnO pn junction UV photodetector with a one-dimensional (1D) and two-dimensional (2D) interspersed structure is presented. The pyro-phototronic effect and energy band engineering effect from the localized pn junction generated by the layered p-type PbI2 nanosheets along the c-axis of ZnO are coupled to modulate the separation and transport of photogenerated carriers. Furthermore, the localized surface plasmon resonance of Au nanoparticles produces transient thermal power to raise temperature fast to enhance pyroelectric current. The self-powered Au@PbI2/ZnO photodetector displays a high responsivity of 0.21 A W-1, excellent detectivity of 7.9 x 1012 Jones, and fast response/recovery time of 25/31 ms, under the illumination of 325 nm light with the power density of 0.08 mu W cm-2. This work offers an effective strategy for designing high-performance next-generation optoelectronic devices.