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

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.