A novel bilayer structure of ZnO nanorods (ZNRs)/nanodiamond films (NDFs) is developed on glass substrates for applications in ultraviolet (UV) photodetectors (PDs). NDFs are first grown by microwave plasma chemical vapor deposition, and are then deposited with a ZnO seed layer and Au interdigitated electrodes through a combination of sputtering and photolithography to form a metal-semiconductor-metal (MSM) structure. Finally, the ZNRs are hydrothermally synthesized at 90 degrees C for 3 h. FESEM, Raman, XRD and PL spectroscopy are respectively used to analyze the surface morphology, crystallinity and optical properties. These analyzes indicate that the bilayer structure of the ZNRs/NDFs exhibits good crystallinity to enhance the ZNR based PDs. The photoresponse (I-photo/I-dark) behavior of the ZNR/NDF PD exhibits a much higher photoresponse (594.6) than those exhibited by the NDF PD (1.2) and ZNR PD (217.1) at 5 V bias under 365 nm wavelength illumination. (C) 2013 The Electrochemical Society. All rights reserved.