Transparent conductive Ga2O3/Cu/ITO multilayer films prepared on flexible substrates at room temperature

Transparent conductive Ga2O3/Cu/ITO films were prepared on the polyethylene terephthalate (PET) substrates using radio frequency (RF) and direct current (DC) magnetron sputtering without substrates heating. The effects of Ga2O3 layer thickness and Cu layer thickness on the optical and electrical properties of the Ga2O3/Cu/ITO films were studied. Changes in the optoelectrical properties of Ga2O3/Cu (4.2 nm)/ITO (30 nm) films were investigated with respect to the Ga2O3 layer thickness. The maximum transmission of 86%, the sheet resistance of 45 Ω/sq and the figure of merit of 8.89 × 10−2 Ω−1 were achieved for Ga2O3 (15 nm)/Cu (4.2 nm)/ITO (30 nm) films. The optoelectrical properties of the Ga2O3/Cu/ITO films were also significantly influenced by the thickness of the Cu layer. When the thickness of Cu layer was 3.7 nm, the maximum transmission of 87.6%, the sheet resistance of 50 Ω/sq and the figure of merit of 9.26 × 10−2 Ω−1 were obtained for the Ga2O3 (15 nm)/Cu/ITO (30 nm) films.