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

• DOI: 10.1007/s00339-019-2590-0
• Publication Date: 2019-04-02T06:16:17Z
• Authors: Priyanka Chetri; Jay Chandra Dhar
• Keywords: Quantum Efficiency; Specific detectivity; Noise-equivalent power

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 length ~ 160 ± 5 nm with ~ 60 ± 5 nm average diameter. The reported Au/SnO2 NW/n-Si device showed a good rectifying behavior with a rectification ratio of ~ 6 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 − 2 V 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 10.8 × 1010 Jones and noise equivalent power as low as 38.8 × 10−12 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 0.18 s and a fall time of 0.25 s. The current conduction mechanism in case of Au/SnO2 NW/n-Si device is explained with respect to device band diagram.