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

Abstract P-type silver oxide (Ag x O) films were magnetron sputtered on the glass substrates at different substrate temperatures (T sub ) with use of high dc discharge power density. The variation of the microstructure, optical properties and electrical properties of the films with increase of T sub was studied using x-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, transmittance spectra, absorbance spectra and electrical transportation parameters. The Ag x O 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 T sub . The Ag atoms are uniformly dispersed in the films, and the O atoms are randomly distributed with increase of T sub . 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 Ag 2 O phases are 175 °C and 275 °C, respectively. The absorption edge of the films varies in the range of 2.60 eV through 2. 81 eV with increase of T sub , due to the phase transition from pure AgO to Ag 2 O 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.