Preparation and properties of p-type Ag-doped ZnMgO thin films by pulsed laser deposition

We report on p-type Ag-doped ZnMgO thin films prepared on quartz substrates by pulsed laser deposition. The effects of substrate temperature on the structural, electrical and optical properties of the films are investigated in detail. All the films we obtained have a preferred orientation with the c-axis perpendicular to the substrates. Secondary ion mass spectroscopy and X-ray photoelectron spectroscopy measurements confirm that Ag has been incorporated into the films and principally occupies Zn site in the state of Ag+ ion and acts as an acceptor. An acceptable p-type conduction, with a resistivity of 24.96 Ω cm, a Hall mobility of 0.32 cm2 V−1 s−1, and a hole concentration of 7.89 × 1017 cm−3 at room temperature, was obtained for the film grown at the optimal substrate temperature of 400 °C. The formation of good p-type conduction in this film might be due to a combined effect of the increase of substitutional-Ag (AgZn) density and the suppression of the oxygen-related defects. The p-type conduction of Ag-doped ZnMgO film is further confirmed by a rectifying Ag-doped ZnMgO/i-ZnO/Al-doped ZnMgO heterojunction.

► p-Type ZnMgO thin films with Ag doping have been realized by pulsed laser deposition
► Ag principally occupies Zn sites in the state of Ag+ ions and acts as acceptor.
► The p-type conduction is related to the increase of AgZn and the suppression of oxygen-related defects.
► The p-type conduction was confirmed by a rectifying heterojunction.