A self-powered UV photodetector based on TiO2 nanorod arrays

Abstract

Large-area vertical rutile TiO₂ nanorod arrays (TNAs) were grown on F/SnO₂ conductive glass using a hydrothermal method at low temperature. A self-powered ultraviolet (UV) photodetector based on TiO₂ nanorod/water solid–liquid heterojunction is designed and fabricated. These nanorods offer an enlarged TiO₂/water contact area and a direct pathway for electron transport simultaneously. By connecting this UV photodetector to an ammeter, the intensity of UV light can be quantified using the output short-circuit photocurrent without a power source. A photosensitivity of 0.025 A/W and a quick response time were observed. At the same time, a high photosensitivity in a wide range of wavelength was also demonstrated. This TNA/water UV detector can be a particularly suitable candidate for practical applications for its high photosensitivity, fast response, excellent spectral selectivity, uncomplicated low-cost fabrication process, and environment-friendly feature.