Variation of the microstructure, optical properties and electrical properties of dc magnetron sputtered p-type AgxO films with increasing substrate temperature

P-type silver oxide (AgxO) films were magnetron sputtered on the glass substrates at different substrate temperatures (Tsub) with use of high dc discharge power density. The variation of the microstructure, optical properties and electrical properties of the films with increase of Tsub was studied using X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, transmittance spectra, absorbance spectra and electrical transportation parameters. The AgxO films have p-type conduction characteristics mainly due to the oxygen vacancies existing in the films. The evolution of the composition and the preferred orientation of the films clearly occur with increase of Tsub. The Ag atoms are uniformly dispersed in the films, and the O atoms are randomly distributed with increase of Tsub. The random distribution of O atoms is due to the thermal decomposition of AgO and to the diffusion of O atoms in the films. The precise critical temperature values of the thermal decomposition of AgO and Ag2O phases are 175℃ and 275℃, respectively. The absorption edge of the films varies in the range of 2.60 eV through 2. 81 eV with increase of Tsub, due to the phase transition from pure AgO to Ag2O and the change in crystallite size. The point defect-related optical absorption results in the transmittance smaller than 70% in the transparent region. The mechanism for the evolution in composition and optical and electrical properties was also proposed and analyzed with use of the experimental data available.