Realization of UV-C absorption in ZnO nanostructures using fluorine and silver co-doping

Abstract

In this study, we realized absorption in UV-C region using silver (Ag) and fluorine (F) co-doping in zinc oxide (ZnO). Also, the influence of Ag and F co-doping in ZnO on the morphological, compositional, structural, and optical properties using the hydrothermal method were investigated. The result shows that vertically aligned nanorods (NRs) of different dimensions were observed using field emission scanning electron microscopy (FESEM). Wurtzite hexagonal structure and polycrystalline nature of the samples were confirmed through X-ray diffraction (XRD) analysis. The crystallite size increased from 29.92 to 35.81 nm and microstrains values were decreased upon co-doping. Energy dispersive X-ray (EDX) analysis confirmed the existence of zinc, oxygen, silver, fluorine, and oxygen deficiency in all the studied samples. Ultra-violet (UV) visible analysis has shown a decrement in the optical energy bandgap from 3.273 to 3.179 eV upon co-doping with the appearance of two absorption edges. The additional optical characteristics comprising absorption coefficient (α), skin depth, optical density (OD), extinction coefficient (k) were also explained. Photoluminescence (PL) analysis has shown that the ZnO native visible defects were suppressed significantly upon co-doping, showing crystal quality improvement as revealed by XRD analysis.