Fast UV detection by Cu-doped ZnO nanorod arrays chemically deposited on PET substrate

Well-aligned Cu-doped ZnO nanorods were successfully synthesized on polyethylene terephthalate (PET) substrate using chemical bath deposition method. The structural and optical properties of Cu-doped ZnO nanorods were investigated using X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX) and photoluminescence (PL) spectroscopy. A metal- semiconductor-metal (MSM) UV photodetector was successfully fabricated using high-quality Cu-doped ZnO nanorods. The dark current and photocurrent of the MSM photodetector based on Cu doped ZnO nanorods were 20.5 μA and 2.22 mA at bias voltage of 5 V, respectively. Under bias voltage of 5 V, the responsivity of the UV photodetector was 3.69 A/W. The calculated photosensitivity of the UV photodetector was 107.4 at bias voltage of 5 V. The fast response time (191 ms) and recovery time (261 ms) of the fabricated UV photodetectors were achieved in UV turn-on/off switching measurements.