The optimal tuning of electronic structure, magnetic, and optical properties of (Fe, V + VO/VSn) co-doped SnO2 via first-principles calculations

Abstract

Dilute magnetic semiconductors (DMSs) with both charge and spin degrees of freedom have emerged as promising candidates in the spintronic industry. However, the Curie temperature below room temperature and uncertainty about the origin of ferromagnetism hinder the application of DMSs. To address these issues, we explored a better SnO2-based co-doped method (Fe, V + VSn) using ab initio calculations. The calculation results show that the Sn13FeVO32 (Fe, V + VSn) has a high Curie temperature (716 K), good ferromagnetic properties, stronger covalency of bonds, and better optical transparency in the visible light range. In addition, the holes or electrons generated by the complexes in the (Fe, V + VO/VSn) co-doped system cause a spin-polarized double exchange effect in the Fe-3d, V-3d, and O-2p orbitals, which leads to magnetism of the co-doped systems. The static dielectric constant ɛ1(0) of the system increases after doping. Among them, Sn14FeVO31 (Fe, V + VO) has the largest ɛ1(0), indicating that Sn14FeVO31 has the strongest polarization ability and better photocatalytic properties. In Sn14FeVO31, the imaginary part of the dielectric function and the absorption spectrum all have new peaks in the low-energy region, which are caused by the jump of electrons from the guide band of the spin-polarized impurity energy level. This paper proposes a new method for preparing dilute magnetic semiconductors in spin electronic devices with high room temperature ferromagnetic properties and excellent optical properties through the (Fe, V + VO/VSn) co-doped SnO2.