Local environment-dependent dual-band photodetector with a hybrid plasmonic enhanced Pt-nanoparticles/(Mg, Zn)O structure

The generation, transfer, and collection of plasmon-derived hot electrons represent a distinctive pathway for photodetectors to utilize solar energy. However, previously reported devices have a low internal quantum efficiency due to excessively high Schottky barrier. The coupling distance between working medium and metal nanoparticles (NPs) is one of the key factors affecting the performance of optoelectronic devices. We constructed a dual-surface plasmon-enhanced (Mg, Zn)O-ultraviolet (UV) photodetector by applying Pt NPs and found that the assembled device exhibited broad sensitivity ranging from 340 to 370 nm at room temperature. Intense dual plasmonic resonance coupling is induced in a hybrid structure of two metallic layers separated by uniform ZnO-based films. Using surface plasmon-enhanced materials, the changes in the refractive index of ZnO/Pt/MgZnO and MgZnO/Pt/ZnO heterogeneous double-layer in the dielectric environment are beneficial for the tunneling of hot electrons. ZnO/Pt/MgZnO is superior to MgZnO/Pt/ZnO in terms of responsivity and response time. The responsivity of the ZnO/Pt/MgZnO device peaks at 2.87 A/W, exhibiting the great potential of dual plasmonic resonance coupling in a UV photodetector, which was finally investigated via Mie scattering. The response time of the photodetectors in a steady-state is 0.2 s, 0.3 s, while 0.1 s, 0.73 s is the response time of the photodetectors (PDs), which paves the way for future application advancements in the field of photodetection, imaging, photovoltaics, and photochemistry.