Transparent p-type Zn-doped CuCrO2 films by sol–gel processing

This study reports the preparation of transparent p-type CuCr1 − xZnxO2 (x = 0.00, 0.01, 0.03) wide-bandgap oxide semiconductor films deposited onto quartz substrates by a sol–gel process followed by a two-step annealing process. The films were first deposited onto quartz substrates by spin coating. The specimens were then annealed in air at 500 °C and post-annealed in N2 at 700 °C for 2 h. The pure CuCrO2 phase was obtained in CuCr1 − xZnxO2 films with x ≤ 0.03. The surface of the CuCr1 − xZnxO2 films exhibited dense and elongated grains. The direct optical bandgaps of the CuCr1 − xZnxO2 films were 3.0 eV (x = 0.00) and 3.05 eV (x = 0.01 and 0.03). The CuCr1 − xZnxO2 films exhibited p-type characteristics with positive Seebeck coefficients. The electrical conductivities of CuCr1 − xZnxO2 films were 0.15 S cm− 1 (x = 0.00), 0.26 S cm− 1 (x = 0.01), and 0.47 S cm− 1 (x = 0.03). The corresponding hole concentrations of CuCr1 − xZnxO2 films were 1.0 × 1018 cm− 3 (x = 0.00), 2.0 × 1018 cm− 3 (x = 0.01) and 3.2 × 1018 cm− 3 (x = 0.03). The Zn doping of CuCrO2 films can markedly enhance the electrical conductivity and hole concentration of the films. The Zn-doped CuCrO2 thin films have the potential applications in transparent devices.