Low-Cost Fabrication of UV Photodetector Based on Hexagonal Nanocrystal ZnO:Al/p-Si Heterojunction
Abstract
ZnO:Al/p-Si heterojunction was fabricated by depositing a hexagonal nanocrystal ZnO:Al film on p-type Si substrate using a simple chemical bath deposition (CBD) method. The vertically aligned hexagonal ZnO:Al nanocrystals reduce the grain boundary scattering and provide good conductivity. The ZnO:Al/Si heterojunction shows obvious photocurrent under ultraviolet (UV) illumination. A high UV-to-visible rejection ratio of the ZnO:Al/Si heterojunction indicates that the hexagonal nanocrystal ZnO:Al film is a good material for fabricating UV photodetectors. Furthermore, the response speed of the photodetector based on ZnO:Al hexagonal nanocrystal film is faster than that of most previously reported photodetectors based on ZnO:Al nanorods. We infer it is because the ZnO:Al nanocrystals film has a smaller surface to volume ratio than the ZnO:Al nanorod array.
