Effect of sputtering pressure on structural and optical properties of silver oxide thin films; Kramers-Kronig method

摘要

Silver oxide nano layers were prepared by RF magnetron sputtering on amorphous SiO2 substrates. O-2 pressure in chamber was varied from 1 to 4 and 7 mTorr during growth process. The effects of different O-2 pressure on structural, morphological and optical properties of the films were investigated by means of X-ray diffraction, scanning electron microscopy, atomic force microscopy and UV-Vis spectroscopy analyses. Optical reflectance measured in the wavelength of 350-950 nm by spectroscopy. Other optical properties and optical band gaps were calculated using Kramers-Kronig relations. The X-ray diffraction measurements showed change in crystalline structure with increasing O-2 pressure. Preferred orientation has been changed to another growth orientation at 4 mTorr O-2 pressure. The Atomic force microscope images showed increasing in roughness consistently by increasing oxygen pressure. The thickness of the thin films decreases (from 217 to 180 nm) with increasing O-2 pressure. Optical results revealed that the highest optical band gap of 3.1 eV and the highest transmittance of similar to 80% were achieved at lower O-2 pressure (1 mTorr).