P-type transparent conductive CuAlO2 thin films prepared using atmospheric pressure plasma annealing

Transparent conductive CuAlO2 thin films prepared using atmospheric pressure plasma annealing are reported. The sol-gel-derived thin films on the quartz substrate were annealed using atmospheric pressure plasma of N-2-10%O-2 at 700-800 degrees C for 10 min. The CuAlO2 phase was obtained at 750 degrees C. The binding energies of the Cu-2p(3/2) and the Al-2p(3/2) of the thin films were centered at 932.6 +/- 0.2 eV and 73.3 +/- 0.2 eV, revealing the valence state of Cu+ and Al3+m, respectively. The direct and indirect optical bandgaps of the CuAlO2 thin films were 3.58 eV and 1.81 eV, respectively. Additionally, the CuAlO2 thin films had the conductivity of (1.42 +/- 0.1) x 10(3) S/cm with the carrier concentration of (1.32 +/- 0.13) x 10(14) cm(3). Therefore, atmospheric pressure plasma annealing provides a feasible method for preparing CulO(2) thin films. (C) 2018 Elsevier B.V. All rights reserved.