Zn1−xMgxO film with adjustable properties fabricated by plasma-enhanced atomic layer deposition (PEALD)

Abstract

Zn_1−xMg_xO semiconductor film has been widely applied in the optical, electronic and optoelectronic field, due to the excellent transmittance, adjustable band gap, and environmental friendliness. Herein, Zn_1−xMg_xO films with different x values were fabricated by plasma-enhanced atomic layer deposition (PEALD). The effects of Mg doping content (x value) on the structural, optical and electrical properties of Zn_1−xMg_xO were systematically investigated. As the increase of Mg doping content, the crystallization and the average grain size of Zn_1−xMg_xO film show the first increasing and then decreasing trend. The absorption edge is shifted towards the direction of shorter wavelength, and the band gap is widened, with the increase of Mg doping content. The resistivity value of film enlarges with the increase of Mg doping content. The energy of conduction band minimum (E_CBM) of Zn_1−xMg_xO is elevated by Mg doping. As the buffer layer for CZTSSe, a suitable conduction band offset can be simply obtained. Therefore, the properties of Zn_1−xMg_xO can be accurately adjusted via controlling the Mg doping content.