Effect of a buffer layer on the properties of UV photodetectors based on a ZnO/diamond film structure

In this paper, ZnO films were grown on the nucleation sides of freestanding diamond substrates with and without a ZnO homobuffer layer by the radio-frequency (RF) magnetron sputtering method. The effects of buffer layers on the properties of the ZnO film and UV photodetectors based on a ZnO/freestanding diamond film structure were studied. The experimental results suggested that the buffer layer was helpful in improving the crystalline quality of ZnO/diamond heteroepitaxial films and the electrical property of the ZnO photodetectors was relative to the crystalline quality of ZnO films. For the photodetector based on the ZnO film with a buffer layer, a higher value of photo-responsivity under a 10 V bias voltage and a better time-dependent photocurrent characteristic were obtained.