Defects mediated optical emissions and efficient photodetection characteristics of sol–gel derived Ag-doped ZnO nanostructures for UV sensor

Abstract

In the present work, defects mediated optical emission and efficient photodetection characteristics of ZnO:Ag (0, 2, 5, and 7 wt%) nanoparticles (NPs) synthesized by sol–gel method have been investigated for UV sensor. X-ray diffraction (XRD) patterns show the polycrystalline nature of ZnO NPs. The crystallite sizes corresponding to most intense peak (101) are found to be in the range of 10–20 nm. Effective enhancement of defect-mediated visible emissions is observed in Ag-doped ZnO NPs. Red-shift of UV peak in Ag-doped ZnO may be due the tensile strain upon Ag doping. Pure ZnO exhibits anomalous UV sensing, which is absent in ZnO NPs doped with Ag. The 7 wt% Ag-ZnO NPs is found to efficient UV photoresponsive. The results obtained by doping of Ag contents in the ZnO can be capable for making efficient and consistent prototype UV sensors.