Strain tunable optical and transport properties of intrinsic ferromagnetic semiconductor CrOCl monolayer

Abstract

Based on density functional theory, the electronic structure, transport, and optical properties of monolayer CrOCl are studied theoretically. The electronic structure analysis shows that monolayer CrOCl is a ferromagnetic semiconductor with an indirect band gap of 2.45 eV, and the electronic properties of monolayer CrOCl can be changed significantly by applying external strain. When 12 % uniaxial tensile strain is applied along the a-axis, the band gap of monolayer CrOCl decreases to 1.94 eV, the hole mobility can reach 1520.11 cm2 V−1·s−1, and the mobility difference between holes and electrons increase to 1471.53 cm2 V−1·s−1. Furthermore, the applied strain, regardless of tensile or compressive, can cause the redshift of the optical absorption peak of monolayer CrOCl, thereby improving the absorption performance in the visible light region. In addition, it was found that the in-plane absorption of bilayer CrOCl increased to nearly twice as compared with the monolayer one. These results indicate that single and few layers of CrOCl have the potential application prospect in the field of optoelectronic devices.