Application of ZnO nanorods synthesized on 64° Y-cut LiNbO3 to surface acoustic wave ultraviolet photodetector

A ZnO sensing layer with nanorod arrays grown on a 64° Y-cut LiNbO3 substrate was used to fabricate a surface acoustic wave ultraviolet photodetector. ZnO nanorod arrays synthesized on the sensing layer enhance the sensitivity to ultraviolet radiation. ZnO thin films were deposited by radio frequency magnetron sputtering and ZnO nanorod arrays were then synthesized on the thin films via the hydrothermal method. The crystalline structure, surface morphology, and luminescence characteristics of the films and nanorod arrays were examined by X-ray diffraction, scanning electron microscopy, and photoluminescence spectrometry. The devices had surface acoustic wave propagation in the X- and Z-direction, respectively. The effects of the interaction between surface acoustic waves and ultraviolet radiation in the ZnO sensing layer on the shift of insertion loss and the phase shift of transmitted signal were investigated. The ultraviolet sensitivity of the surface acoustic wave photodetector was enhanced by adding nanorod arrays to the guiding layer.