The properties of transparent conductive In–Ga–Zn oxide films produced by pulsed laser deposition

To obtain TCO films for wavelengths shorter than the visible range, Ga2O3 was added to the In2O3–ZnO system as an impurity. Using pulsed laser deposition (PLD), two kinds of targets, InGaZnO4 and InGaZn3O6, were deposited. Although the In–Ga–Zn–O films obtained deviated from the stoichiometry of InGaZnO4, they were amorphous at a substrate temperature below 250 °C. We obtained the lowest resistivity of 2.77 × 10−3 Ω cm within the present experiment at a carrier concentration of 1.38 × 1020 cm−3 and a Hall mobility of 16.6 cm2/Vs. The optical band gap energy shifted to higher energies and the transmittance at the blue range was improved dramatically as compared with similar amorphous IZO films.