Optical and electrical properties of In-doped CdO thin films fabricated by pulse laser deposition

Transparent indium-doped cadmium oxide (In-CdO) thin films were deposited on quartz glass substrates by pulse laser deposition (PLD) from ablating Cd–In metallic target at a fixed pressure 10 Pa and a fixed substrate temperature 300 °C. The influences of indium concentrations in target on the microstructure, optical and electrical performances were studied. When the indium concentration reaches to 3.9 wt%, the as-deposited In-CdO film shows high optical transmission in visible light region, obviously enhanced direct band gap energy (2.97 eV), higher carrier concentration and lower electric resistivity compared with the undoped CdO film, while a further increase of indium concentration to 5.6 wt% induces the formation of In2O3, which reverse the variation of these parameters and performance.