The effect of 3d states on band structure feature, optical and magnetic properties of TM-doped CdS: a theoretical insights

Abstract

Based on the full-potential linearized augmented plane wave (FP-LAPW) method, we have investigated the electronic, structural, magnetic and optical properties of Cd0.9375TM0.0625S (TM = Mn, Fe, Co and Ni) compounds in the zinc-blende (ZB) ferromagnetic phase. The magnetic and electronic properties are treated using the PBE-GGA and TB-mBJ approximations. CdS is well known as a non-magnetic semiconductor. When CdS is doped with a transition metal (TM), Cd0.9375TM0.0625S (TM = Mn, Fe, Co) changes to half-semiconductors (HSC) and Cd0.9375Ni0.0625S to a half-metal (HM). It is found that the 3d-t2g states of the transition metal are responsible for generating spin polarization and magnetic moment in these compounds. All the considered compounds are ferromagnetic and the calculated total magnetic moment increases from 2 to 5 µB moving from Ni to Mn. The optical properties exhibited new peaks in the visible and ultraviolet regions due to the effect of free-carrier absorption related to the magnetic impurities. Our results show very good agreement to previous theoretical and experimental data. The results presented herein imply that TM-doped CdS has potential for applications in spintronic and optoelectronic device sectors in a wide energy range of the light spectrum from visible to ultraviolet.