Investigation on improved performance of Erbium doped TiO2 nanowire based UV detector

Abstract Undoped TiO2 and Erbium doped TiO 2 nanowires (Er:TiO 2 NWs) were synthesized on respective thin films using e-beam cum glancing angle deposition technique onto n-type silicon substrates. The length of the NWs was ∼182 nm as calculated from field emission gun scanning electron microscopy images. Transmission electron microscopy showed an average NW length of 173 nm. Polycrystalline nature of both samples was obtained from the selected area electron diffraction analysis as well as from the X-ray diffraction (XRD) analysis. Energy dispersive X-ray spectroscopy and variation in the grain size (calculated from XRD) confirmed the doping of Erbium in case of Er:TiO 2 NWs. Increased absorption, as well as enhanced bandgap, was observed for Er:TiO2 NWs compared to the undoped TiO2 NWs. Superior device performance in terms of detectivity, sensitivity and photoswitching was obtained for Er:TiO2 NWs as compared to the undoped TiO2 NWs in the UV region.