Influence of Al content on ZnO/Al bilayer-structure ultraviolet photodetector

Abstract

As a potential optoelectronic material, the use of ZnO in ultraviolet (UV) photodetectors is attracting significant attention. In this study, aluminum (Al) nanoparticles of different content and ZnO films are sequentially sputtered to form ZnO/Al bilayer UV photodetectors. The responsivity of the ZnO/Al bilayer photodetector, with a maximum of 380.9 A W−1 at 320 nm and 5 V bias, is higher than that of the single-layer ZnO photodetector. The enhanced responsivity of the ZnO/Al bilayer UV photodetectors can be attributed to the local surface plasmon resonance effect and the introduction of oxygen vacancies. Meanwhile, the different size and distribution density of Al nanoparticles determines the different enhanced mechanisms. Our work provides a promising route to design and fabricate a high-performance photodetector.