Review of improved spectral response of ultraviolet photodetectors by surface plasmon

Ultraviolet (UV) photodetectors based on wide band gap semiconductor have attracted much attention for their small volume, low working voltage, long lifetime, good chemical and thermal stability. Up to now, many researches have been done on the semiconductors based UV detectors and some kinds of detectors have been made, such as metal-semiconductor-metal (MSM), Schottky, and PIN-type detectors. However, the sensitivity values of those detectors are still far from the expectation. Recent years, surface plasmon (SP) has been considered to be an effective way to enhance the sensitivity of semiconductor based UV photodetector. When the light is matched with the resonance frequency of surface plasmon, the localized field enhancement or scattering effect will happen and thus the spectral response will be enhanced. Here, we present an overview of surface plasmon enhancing the performance of UV detectors, including the GaN, ZnO, and other wide band gap semiconductor UV detectors. Both fundamental and experimental achievements are contained in this review.