Optical and magnetic properties of (Er, F) co-doped SnO$_{2}$ nanocrystals

Abstract

Uniformly (Er, F) co-doped SnO2 nanocrystals, obtained by a low-temperature solution-based method, were characterized by a variety of analytical techniques. The structure, morphology, and ratio of the elements were conrmed by PXRD, SEM, and TEM analysis, respectively. From XPS analysis, atomic concentrations of Sn, O, and F were quantied. Interparticle pore size increased signicantly (with a mean pore diameter of 25.82 nm) in the co- doped sample. Higher in-plane oxygen vacancies and bands due to multiphonon scattering were observed in the Raman spectrum of the sample. The defect traps in the sample were experimentally determined using TL spectroscopy. A broad intense glow curve at 485 K and a weak emission at 600 K in the TL spectrum were quenched on exposure to UV radiation. A large blue shift of the exciton absorption (due to the Moss{Burstein eect) and sharp bands due to intraconguration al f f transitions were observed for (Er, F) co-doped SnO2 with an estimated band gap of 4.18 eV. From the photoluminescence spectral studies, 3 types of emission centers at 471 nm, 546 nm, and 627 nm were detected. Co-doping stabilized ferromagnetism in SnO2 at room temperature.