Ultraviolet Detector Based on TiO₂ Thin Film

Abstract

In this paper, TiO2 thin film with MSM (metal-semiconductor-metal) structure was used to fabricate ultraviolet (UV) detector. The film was fabricated via sol-gel method on silicon wafer with 300nm oxide layer and annealed at four different temperatures (400oC, 500oC, 600oC and 800oC). The quality of the thin films was characterized by means of X-ray diffraction and scanning electron microscope. Then a pair of symmetric Ag electrodes were deposited by thermal evaporation through a shade mask of interdigital structure. The photo-electric properties of the device including I-V characteristic, transfer characteristic and time response et.al. were studied with or without explored to 254nm UV light. The electrical measurements of the device show a big increase of current when explored the device to 254nm UV light, and the rise time of the device is very quick, but the fall time is relatively long. The detector with simple fabrication process, low cost, and superior performance would provide a potential application in UV detectors.