Ultrahigh responsivity UV detector based on TiO2/Pt-doped TiO2 multilayer nanofilms

High-response UV detector based on TiO2/Pt-doped TiO2 (PT) multilayer nanofilms with Au interdigitated electrodes was fabricated. PT film was used as the main light sensitive layer of the detector. By introducing a sufficiently thin TiO2 film as an interfacial modified layer between Au electrodes and the PT film, the Schottky barrier height was effectively reduced, leading to the remarkable enhancement in the device photoresponse properties. At 5 V bias, a photocurrent of 191.77 μA and an ultrahigh responsivity of 3194 A/W were obtained under 260 nm UV illumination (15.8 μW/cm2). The rise and the recovery time were 60.12 ms and 579.9 ms, respectively. The effects of Pt doping on TiO2 film and device performance were also systematically investigated. These experimental results demonstrate the potential prospects of noble doping in fabricating high-response UV detectors.