Au/GLAD-SnO2 nanowire array-based fast response Schottky UV detector

In this paper, we have demonstrated UV photodetector based on SnO2 nanowire (NW) arrays fabricated using a catalytic free and controlled growth process called glancing angle deposition technique. The fabricated SnO2 NWs were amorphous in nature with highly periodic and perpendicularly oriented structures of length160 +/- 5nm with60 +/- 5nm average diameter. The reported Au/SnO2 NW/n-Si device showed a good rectifying behavior with a rectification ratio of6 due to the formation of high-quality Schottky contact at the Au/SnO2 NW interface. The Au/SnO2 NW/n-Si device exhibited a high responsivity (0.142 A/W) and external quantum efficiency (56.8%) at -2V applied bias as compared to the Au/SnO2 thin-film (TF)/n-Si device. Moreover, the Au/SnO2 NW/n-Si device attained a high detectivity of 10.8x10(10) Jones and noise equivalent power as low as 38.8x10(-12) W. The high surface to volume ratio and the enormous amount of photogenerated carriers in case of SnO2 NW arrays made the Au/SnO2 NW/n-Si device to exhibit high photosensitivity. Furthermore, on UV illumination, the Au/SnO2 NW/n-Si detector showed fast device response with a rise time of 0.18s and a fall time of 0.25s. The current conduction mechanism in case of Au/SnO2 NW/n-Si device is explained with respect to device band diagram.