Influence of substrate temperature on the structural and properties of In-doped CdO films prepared by PLD

Abstract

Transparent indium-doped cadmium oxide (In—CdO) thin films were deposited on quartz glass substrates by pulsed laser deposition (PLD) from an ablating Cd—In metallic target. The effect of substrate temperature on the structural, optical and electrical properties of In-doped CdO thin films were studied in detail. The optical transmittance of In doped CdO films are obviously influenced by the substrate temperature. All films exhibit a transmittance higher than 75% in the visible region. More significantly, In-doping leads to an evident widening of optical band gap from 2.56 to 2.91 eV; and the increase in optical band gap is found to depend on the deposition temperature. It is also seen that the electrical properties of these films strongly depend on the substrate temperature. The In—CdO thin film grown at 300 °C has low resistivity (1.15 × 10−4 Ω·cm), high carrier concentration (5.35 × 1020 cm−3), and high mobility (101.43 cm2/(V·s)).