Preparation, Structural and Optical Characterization of AgO Nanocrystalline Thin Films by PLD

In the current study, silver oxide thin films were deposited by Pulsed Laser Deposition (PLD) using Nd:YAG laser (1064 nm wavelength) operating at 10 Hz and 8 ns pulse width. Different ablation time (T_ab ) was used for thin deposition rom metal silver plate of 3mm thickness (>99.5%) under constant oxygen pressure of ∼ 0.3 mbar and substrate temperature of 300 K. The structure of metal silver plate showed polycrystalline structure with a single phase of pure silver as indicated from XRD technique. The structure of thin films showed nanocrystalline single phase monoclinic structure of silver oxide AgO with highest orientation at (111) line as detected by both Grazing Incidence In - plane X - Ray Diffraction (GIIXD) technique and High Resolution Transmission Electron Microscope (HRTEM). The average particle size of deposited films showed an increase from 3 to 33.3 nm with rising the ablation time to 30 min as detected by HRTEM images. The surface morphology of the examined films showed smooth homogenous surfaces with some aggregation for the film of 30 min T_ab as seen by FESEM. Optical transmission and reflection of the deposited films were carried out using UV - VIS - NIR spectrophotometer at room temperature. The optical absorption spectra were determined presenting that direct optical energy gap of the films under investigation which ranged from 3.282 to 1.072 eV showing higher value for lower particle size and lower ablation time films.The obtained data visualize that controlling the T ab at a fixed oxygen pressure of 0.3 mbar leads to high variance in the energy gap of nanocrystalline AgO films consequently the optical properties of AgO films.