Preparation of ZnO:Mo Thin Films by RF Sputtering

Abstract

Based on the electron configurations of Mo and Zn, the valence electron difference between Mo⁶⁺ and Zn²⁺ is 4. Therefore, a small amount of Mo doping can produce sufficient free carriers to reduce the ion scattering effects. The Mo doped ZnO (MZO) thin film prepared by RF sputtering was studied in this research. Structural, electrical, and optical characteristics of the films were discussed. The MZO film shows a resistivity of 1.1 × 10^-2 Ω⋅cm, a carrier concentration of 2.2 × 10²¹ cm^-3,a mobility of 0.63 cm²/V⋅s, and average transparency of 81.0% at both the powers of 20 W to the Mo target and of 125 W to the ZnO target. The MZO film becomes a stable p-type semiconductor at high power process toward Mo target. The film preserves its p-type characteristics after exposure to air for one and a half months. The crystal structure of the p-ZnO films is amorphous with an average transparency of 34.5%.