Photoelectrical and Low-Frequency Noise Characteristics of ZnO Nanorod Photodetectors Prepared on Flexible Substrate

ZnO nanorod metal-semiconductor-metal photodetectors prepared on flexible polyimide substrate have been fabricated and investigated in this study. The ZnO nanorod was selectively synthesized between the gap of interdigitated contact by aqueous method and lithography technique. Compared with the conventional ZnO film photodetectors, the ZnO nanorod photodetectors have higher wavelength responsivity. This phenomenon can be attributed to high surface-to-volume ratio of nanorod, which provide an efficient light trapping absorption and enhance the adsorption and desorption rates of oxygen at the ZnO nanorod surface. Under a 1 V applied bias, noise equivalent power and normalized detectivity (D*) were 1.72×10^-11 W and 3.08 × 10¹¹ cmHz^0.5 W^-1, respectively, for the ZnO nanorod photodetector.