Reddish-orange-emitting CaLa4Ti4O15:Sm3+phosphors with good thermal stability for WLED applications

Reddish-orange emitting CaLa4Ti4O15:Sm3+ phosphors were synthesized via a simple solid-state reaction. The synthesized CaLa4Ti4O15:Sm3+ phosphors revealed dominant excitation at 408 nm and emission at 601 nm with the 6H5/2-* 4F7/2 and 4G5/2-* 6H7/2 transitions, respectively. The transitions are governed by dipole-dipole interaction in the CaLa4Ti4O15:Sm3+ luminescent material. The morphology and crystal structure were investigated, and the material synthesis and chemical compositions were also confirmed. In a study of the effect of Sm3+ ion concentration on the luminescent properties of CaLa4Ti4O15:Sm3+ phos-phors, the optimized concentration was found to be 5 mol%. The optimized phosphor powder exhibited Commission Internationale de l ' Eclairage (CIE) chromaticity coordinate of (0.610, 0.390) under 408 nm il-lumination, and the thermal stability was also measured, exhibiting good thermal stability of about 81.7% at 423 K and 67.95% at 483 K. The white light-emitting diode (WLED) device was packaged using CaLa4Ti4O15:Sm3+ phosphors, together with commercial phosphors. The fabricated WLED device exhibited good correlated color temperature and color rendering index values of 5461 K and 83.97, respectively with (0.3341, 0.3997) CIE chromaticity coordinate. The CaLa4Ti4O15:Sm3+ materials as a reddish-orange emitting phosphor are expected to be a highly promising candidate for WLED applications. (c) 2023 Elsevier B.V. All rights reserved.

Automated summary

Reddish-orange emitting CaLa4Ti4O15:Sm3+ phosphors were synthesized via a simple solid-state reaction. The phosphors exhibited dominant excitation at 408 nm and emission at 601 nm, driven by dipole-dipole interaction. The optimal Sm3+ ion concentration for luminescent properties was found to be 5 mol%.