Photoluminescence Investigation of Tb Doped Yb2O3 Phosphors Produced by Precipitation Method

Abstract

In this study, un-doped and Tb doped ytterbium oxide (Yb2O3:Tb 3+ ) particles with different dopant rates (2, 4, 6 and 8 at. %) were produced by precipitation method, followed by subsequent calcination at 1000 °C for 2 h. The crystal structure of all particles was cubic Yb2O3 structure. The presence of Tb ion in Yb2O3 host structure was proved from the XRD peak shift results. The crystal structure expanded compared to un-doped Yb2O3 particles with doping, confirming calculated lattice parameter (LP) values. The LP, crystallite size (CS) and dislocation density values were in the range of 1.0428 -1.0596 nm, 16 -25 nm and 0.00189 -0.00391 nm -2 , respectively. Only one sharp emission peak was observed at 506 nm corresponding to 5 D4 -7 F6 transition (green emission) from photoluminescence (PL) spectra of the phosphor particles. The PL emission intensities were found to be strongly dependent on both CS and dopant rate. There was a positive correlation between increasing CS, decreasing lattice strain/dislocation density and PL intensity. Crystal defects decreased and PL intensity increased up to 6 at. % dopant rate.