ENHANCED PHOTOLUMINESCENCE OF Sm3+/Bi3+ CO-DOPED La2O3 NANOPHOSPHORS BY COMBUSTION SYNTHESIS

Abstract

Nanosized La 2 O 3: Sm 3+ and La 2 O 3: Sm 3+, Bi 3+ phosphor powders were prepared via combustion synthesis. The structures and morphology were examined using powder X-ray diffraction and transmission electron microscope, respectively. The photoluminescence spectra were investigated at different doping concentrations of Sm 3+ and Bi 3+ ions. The results indicate that La 2 O 3: Sm 3+ ( Bi 3+) exhibited good crystallinity and spherical-like particles. All phosphors give emission bands centered at 564, 608 and 650 nm corresponding to 4 G 5/2→6 H J ( J =5/2, 7/2 and 9/2) transitions of Sm 3+ ions, respectively. Interestingly, the emission intensity of Sm 3+ ions is significantly enhanced with the addition of Bi 3+ ions to La 2 O 3: Sm 3+ and the maximum occurs at a Bi 3+ concentration of 0.8 mol%. The La 2 O 3: Sm 3+, Bi 3+ phosphor with highly enhanced luminescence is very encouraging for applications in display and tunable solid lasers.