Low power UV photodetection characteristics of cross-linked ZnO nanorods/nanotetrapods grown on silicon chip

High-quality cross-linked ZnO nanorods/nanotetrapods have been successfully synthesized via thermal evaporation of Zn metal grains on Si (1 0 0) substrates. The growth mechanism for the formation of such cross-linked ZnO nanorods is discussed. The morphological, structural and optical properties of the nanorods have been investigated using scanning electron microscopy, X-ray diffraction, Raman spectroscopy and photoluminescence techniques. Cross-linked ZnO nanorods-based metal-semiconductor-metal UV detectors (Ag-ZnONRs-Ag MSM PD) were fabricated. The device showed a sensitivity of 595. The responsivity (R) of the device is 0.63 A W−1, which is 10 times higher than that reported for ZnO-based PDs. Under low power illumination (365 nm, 1.5 mW/cm2), the device showed a relatively fast response and baseline recovery for UV detection. The prototype device shows a simple method for cross-linked nanorods synthesis and demonstrates the possibility of constructing nanoscale photodetectors for nano-optics applications.