High-performing transparent photodetectors based on Schottky contacts

Transparent UV-photodetectors exhibiting very high responsivity and fast operation are discussed. Schottky contact photoelectric devices utilizing wide band gap TiO2 absorber layer were evaluated for their performances as UV-photodetectors. Three different work function metals Cu, Mo and Ni were used to realize Schottky barrier with TiO2. Ni Schottky contacts were found to be most suitable to fabricate high responsivity (2.034 A/W) photodetector with faster rise time (0.14 ms) and wide linear dynamic range (128 dB) operating at small applied reverse bias of −1 V. However, higher barrier height in the case of Mo/TiO2 interface resulted in lowest dark current density of the value 2.21×10−8 A/cm2 with quick fall time of 0.52 ms. The modulation of the barrier height would provide a route for designing fast and high responsive Schottky photodetector with broad linear dynamic range performance.