Effect of a ZnO buffer layer on structural and electrical properties of ZnO:Al,P thin films grown by RF magnetron sputtering

Abstract Structural and electrical properties of ZnO:Al 0.01 P 0.04 thin films were investigated with respect to the growth temperature of the ZnO buffer layers deposited by RF magnetron sputtering. The ZnO buffer layers on c -plane sapphires showed three different types of in-plane orientation relationships between ZnO and Al 2 O 3 at different growth temperatures: ZnO[10 1 0] // Al 2 O 3 [10 1 0] at 200 °C, a mixture of ZnO[10 1 0] // Al 2 O 3 [10 1 0] and ZnO[10 1 0] // Al 2 O 3 [11 2 0] at 300 °C, and ZnO[10 1 0] // Al 2 O 3 [11 2 0] at 600 °C. The in-plane orientation of the ZnO:Al 0.01 P 0.04 thin film followed the orientation of the ZnO buffer layer regardless of its growth temperature. The ZnO:Al 0.01 P 0.04 film grown on a ZnO buffer layer deposited at 600 °C had a carrier concentration of 1.18 × 10 16 cm −3 , mobility of 7.16 × 10° cm 2 /(V s), and resistivity of 7.36 × 10 1 Ω cm, indicating p -type characteristics.