Photoluminescence, cathodoluminescence and thermal stability of Sm3+ -activated Sr3 La(VO4 )3 red-emitting phosphors.

A series of Sm3+ -activated Sr3 La(VO4 )3 phosphors were synthesized by a facile sol-gel method. X-ray diffraction patterns and photoluminescence (PL)/cathodoluminescence (CL) spectra as well as PL decay curves were employed to characterize the obtained samples. Upon 402 nm light excitation, the characteristic emissions of Sm3+ ions corresponding to 4 G5/2 →6 HJ transitions were observed in all the as-prepared products. The PL emission intensity was increased with increase in Sm3+ ion concentration, while concentration quenching occurred when the doping concentration was over 4 mol%. The non-radiative energy transfer mechanism for concentration quenching of Sm3+ ions was dominated by dipole-dipole interaction and the critical distance was around 21.59 Å. Furthermore, temperature-dependent PL emission spectra revealed that the obtained phosphors possessed good thermal stability with an activation energy of 0.19 eV. In addition, the CL spectra of the samples were almost the same as the PL spectra, and the CL emission intensity showed a tendency to increase with increase in accelerating voltage and filament current. These results suggest that the Sm3+ -activated Sr3 La(VO4 )3 phosphors with good color coordinates, high color purity and superior thermal stability may be a potential candidate for applications in white light-emitting diodes and field-emission displays as red-emitting phosphors.