Photoluminescence and morphological characterization of silver-doped zinc oxide novel nanostructures obtained by ultrasonic spray pyrolysis

Scanning electronic microscopy (SEM), X-ray diffraction patterns (XRD) and photoluminescence (PL) have been applied to the study of the morphological, and optical properties of silver-doped zinc oxide [ZnO:Ag] thin solid films prepared by the ultrasonic spray pyrolysis (USP) method. Both the substrate temperature and deposition time variation at the growth of ZnO:Ag films modify the ZnO preferential growth, change the size of ZnO:Ag nanostructures and vary the corresponding photoluminescence spectra. The PL spectra of the ZnO:Ag over the temperature range from 10 K to 300 K have been investigated. Temperature-dependent PL spectra show that the IR emissions correspond to the second-order diffraction of the near-band-edge (NBE) emissions. The study of NBE PL temperature dependences reveals that the acceptor bound exciton (ABE) and its secondorder diffraction peak disappeared when the temperature is higher than 200 K. The attenuation of the ABE peak intensity is ascribed to the thermal dissociation of ABE to free exciton (FE). The PL bands, related to the LO phonon replica of FE and its second-order diffraction, dominate in the PL spectra at room temperature that it is indicative on the high quality of the ZnO:Ag films prepared by the USP technology.