Tunable room temperature ferromagnetism and optical bandgap of CdS:Er nanoparticles

A semiconductor compound, which portrays ferromagnetism with tunable optical and photoluminescence properties after a sensible doping of suitable dopant, is vital for modern spintronic and luminescent applications. In this sense, we fabricate CdS, Cd0.98Er0.02S, and Cd0.96Er0.04S nanoparticles (NPs) via an inexpensive co-precipitation way. No structural deformation was found in cubic CdS after Er (III) doping. The as-fabricated NPs demonstrated good crystallinity as well as slight changes in sizes varying 3 nm-7 nm. An X-ray photoelectron spectroscopy results confirmed that the impure-free nature of the prepared samples. A decreasing trend in the optical band gap was found by the increase in the doping level. The 1CdS NPs showed diamagnetic character, whereas the Er (III)-doped CdS NPs exhibited frail ferromagnetic character at room temperature, which slightly increased as a function of Er (III) concentration. Based on the literature, this is the initial magnetic report on the CdS:Er system and this will be very informative for the further magnetic investigations on the Er doping. Hence, the tunable optical and ferromagnetic magnetic properties of CdS:Er NPs demonstrated in this work may be beneficial for optoelectronic, solar cell and spintronic applications.