Comparison between two device structures of SPR enhanced UV detectors based on ZnO

Surface plasmon resonance can be exploited to greatly enhance the photo response of photo detectors. The enhancement is highly dependent on the device structure of the detector. In this paper, we compared two types of SPR enhanced UV detectors based on ZnO in terms of fabrication process, absorption, I-V curves, and spectral response. The peak responsivity is enlarged by 22-100 times due to SPR enhancement. The embedding type detector has an advantage in dark current controlling. However, the surface type detector has a simpler fabrication process and more importantly a more prominent responsivity enhancement. Therefore, the surface type is a more favourable structure to incorporate SPR with ZnO UV detectors to realize large enhancement of responsivity.