Novel yellow–orange-emitting Ba3Lu4O9: Sm3+ phosphors with good thermal stability and high color purity for solid state lighting

A series of novel Sm 3+ activated yellow–orange-emitting phosphors have been synthesized successfully by the conventional solid-state method. Their phase composition and luminescence properties have been investigated and discussed systematically. Upon excitation at 410 nm, all the studied phosphors showed intense narrow emissions with a prominent peak centered at around 610 nm, corresponding to 4 G 5/2 — 6 H 7/2 transition. The critical concentration of Sm 3+ ions was determined to be 0.02, and the concentration quenching mechanism was verified as dipole–dipole interaction. The investigation of thermal stability revealed that the photoluminescence intensity of Ba 3 Lu 3.92 O 9 :0.08Sm 3+ at 425 K remained around 81.4% of that at 298 K. Besides, when excited at 410 nm, the studied phosphor exhibited high color purity of 99.5% with the CIE chromaticity coordinates of (0.5974, 0.4010) and a low Correlation Color Temperature of 2217 K. Consequently, it could be expected that the as-synthesized Ba 3 Lu 4 O 9 :Sm 3+ phosphors would be a promising candidate of yellow–orange component for warm white or amber LEDs.