Amorphous (In2O3)x(Ga2O3)y(ZnO)1−x−y thin films with high mobility fabricated by pulsed laser deposition

We prepared a series of (In2O3)x(Ga2O3)y(ZnO)1−x−y (0.7 ≤ x ≤ 0.8, 0.05 ≤ y ≤ 0.15) (IGZO) thin films using the pulsed laser deposition (PLD) method at room temperature under same oxygen pressure. The structural, optical and electrical properties of the grown films were measured by various diagnosis tools. X-ray diffraction (XRD) patterns show that the mixing phase of crystalline and amorphous appears in the film with low In2O3 contents, and a completely amorphous phase appears in (In2O3)x(Ga2O3)y(ZnO)1−x−y (0.75 ≤ x) thin films with high In2O3 content. The maximum carrier mobility was found to be 30 cm2 V−1 s−1 in thin film with the (In2O3)x = 0.8 content. The transmitted spectrum shows that thin films with the (In2O3)x = 0.8 content exhibit better light transmission and narrow band gap. These amorphous IGZO thin films with high mobility and transparency are highly desirable for device fabrication on flexible substrates.