Influence of Stress on Electronic and Optical Properties of Rocksalt and Wurtzite MgO-ZnO Nanocomposites with Varying Concentrations of Magnesium and Zinc

Yin-Pai Lin; Sergei Piskunov; Laima Trinkler; Mitch Ming-Chi Chou; Liuwen Chang

doi:10.3390/nano12193408

Influence of Stress on Electronic and Optical Properties of Rocksalt and Wurtzite MgO-ZnO Nanocomposites with Varying Concentrations of Magnesium and Zinc

Nanomaterials (Basel). 2022 Sep 28;12(19):3408. doi: 10.3390/nano12193408.

Authors

Yin-Pai Lin¹, Sergei Piskunov¹, Laima Trinkler¹, Mitch Ming-Chi Chou², Liuwen Chang²

Affiliations

¹ Institute of Solid State Physics, University of Latvia, 8 Kengaraga Str., LV-1063 Riga, Latvia.
² Center of Crystal Research, Department of Materials and Optoelectronic Science, National Sun Yat-Sen University, 70 Lienhai Rd., Kaohsiung 80424, Taiwan.

Abstract

The structural, electronic and optical properties of stressed MgO-ZnO nanocomposite alloys with concentrations of Zn and Mg varying from 0.125 to 0.875 were studied using ab initio simulations. Two crystal structures are considered for the initial MgO-ZnO alloys: the rocksalt Mg1-xZnxO and wurtzite Zn1-xMgxO phases. For rocksalt Mg1-xZnxO, the optimized structures are stable at pressures below 10 GPa. The larger the Mg concentration and pressure, the wider the Eg of the rocksalt phase. In contrast, the optimal geometries of wurtzite Zn1-xMgxO reveal a diversity of possibilities, including rocksalt, wurtzite and mixed phases. These effects lead to the fact that the optical properties of wurtzite Zn1-xMgxO not only demonstrate the properties of the wurtzite phase but also indicate the optical features of the rocksalt phase. In addition, mixed phases of Zn1-xMgxO simultaneously provide the characteristics of both wurtzite and rocksalt phases with the same structures in different dielectric matrices.

Keywords: MgO–ZnO alloys; optical properties; pressure; rocksalt Mg1−xZnxO; wurtzite Zn1−xMgxO.

Grants and funding

The financial support of M-ERA.NET project “ZnMgO materials with tunable band gap for solar-blind UV sensors” (ZMOMUVS) is greatly acknowledged. The Institute of Solid State Physics, University of Latvia, as the Center of Excellence, has received funding from the European Union’s Horizon 2020 Framework Program H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement no. 739508, project CAMART². The calculations were performed at the Latvian SuperCluster (LASC) located at the Institute of Solid State Physics, University of Latvia.