Luminescence Study of Red Light Emitting Y2O3:Sm3+ Nanophosphors and Enhancement by Co-doping with Gadolinium oxide

This work presents the optical and structural properties of samarium oxide doped and gadolinium oxide co-doped yttrium oxide nanophosphors prepared by Combustion method. The photoluminescence emission intensity was maximum for 2wt% Sm3+ doped Y2O3 powders, that results 4G5/2 - 6H7/2 transition within Samarium, emits red light at 608 nm under the excitation of 260 nm. In the case of co-dopant, maximum intensity is obtained for 3wt% Gd3+ under the excitation of 255 nm.The Y:Sm:Gd exhibit luminescence intensity of 4.21 times more than that of Y:Sm nanophosphors. These results indicate that the prepared nanophosphors can be used in optoelectronic devices.

Comprehensive Comparison on Optical Properties of Samarium Oxide (Micro/nano) Particles Doped Tellurite Glass for Optoelectronics Applications

Rare-earth oxides microparticles doped tellurite-based glass have been studied extensively to improve the capability of optoelectronic devices. We report a detailed comparison between two sets of glass series containing samarium microparticles and nanoparticles denoted as ZBTSm-MPs and ZBTSm-NPs respectively. The two sets of glass have been successfully fabricated via melt-quenching technique with chemical formula {[(TeO2)0.70 (B2O3)0.30]0.7 (ZnO)0.3}1-y (Sm2O3 (MPs/NPs)) y with y = 0.005, 0.01, 0.02, 0.03, 0.04 and 0.05 mol fraction. The TEM analysis confirmed the existence and formation of nanoparticles in ZBTSm-NPs glasses. The density of ZBTSm-NPs glasses was found higher than ZBTSm-MPs glasses due to the distributions of nano-scale particles in tellurite glass network. There was a linear trend of increment in the refractive index in both sets of glass series along with the concentrations of dopants. The refractive index of ZBTSm-NPs glasses was found higher than ZBTSm-MPs glasses due to the shift in compactness of glass structure with nano-scale particles. In comparison, the absorption peaks of ZBTSm-MPs glasses were greater than ZBTSm-NPs glasses which were mainly due to the restriction of electrons mobility in glass network with nano-scale particles. The optical band gap energy in ZBTSm-NPs glasses was found greater than ZBTSm-MPs glasses which correspond to the widening of forbidden gap with nano-scale particles. The polarizability of ZBTSm-NPs and ZBTSm-MPs was found in non-linear trend along with dopant concentrations. Based on these findings, the improvement of optical properties have been made by introducing samarium oxide nanoparticles in tellurite glass which is beneficial for optoelectronic devices.