TY - JOUR
T1 - Efficient and thermally stable Sm3+-activated Na2BaCa(PO4)2 phosphors for solid-state lighting and optical thermometry
AU - Kumar, Sandeep
AU - Kumar, Rajesh
AU - Gathania, Arvind K.
N1 - Publisher Copyright:
© 2025 Elsevier Ltd
PY - 2026/4
Y1 - 2026/4
N2 - Na2BaCa(PO4)2 phosphors doped with Sm3+ ions were synthesized via a urea-assisted solution combustion method, and their structural and optical properties were investigated using XRD, FTIR, XPS, and PL analyses. XRD confirmed a stable single-phase Na2BaCa(PO4)2 lattice up to 0.5 mol% doping of Sm3+ ions, while higher doping concentrations (x ≥ 1 mol%) induced a secondary Na3Ba2Ca(PO4)3 phase. PL studies revealed a maximum emission intensity at a 5 mol% doping concentration of Sm3+ ions, with concentration quenching occurring beyond this level. The optimized Na2BaCa(PO4)2: 0.05Sm3+ sample exhibited intense reddish-orange emission with CIE coordinates (0.5948, 0.4044), 99.9 % color purity, and a CCT of 1507 K. Excellent thermal stability of the optimal Na2BaCa(PO4)2:0.05Sm3+ phosphor was observed up to 443 K, with an activation energy of 0.1997eV. Furthermore, under 401 nm excitation, the phosphor exhibited promising optical thermometry performance between 293 K and 593 K, with maximum sensitivities of 10.42 × 10−4 K−1 (absolute) and 0.22 % K−1 (relative), demonstrating its potential in solid-state lighting and temperature sensing applications.
AB - Na2BaCa(PO4)2 phosphors doped with Sm3+ ions were synthesized via a urea-assisted solution combustion method, and their structural and optical properties were investigated using XRD, FTIR, XPS, and PL analyses. XRD confirmed a stable single-phase Na2BaCa(PO4)2 lattice up to 0.5 mol% doping of Sm3+ ions, while higher doping concentrations (x ≥ 1 mol%) induced a secondary Na3Ba2Ca(PO4)3 phase. PL studies revealed a maximum emission intensity at a 5 mol% doping concentration of Sm3+ ions, with concentration quenching occurring beyond this level. The optimized Na2BaCa(PO4)2: 0.05Sm3+ sample exhibited intense reddish-orange emission with CIE coordinates (0.5948, 0.4044), 99.9 % color purity, and a CCT of 1507 K. Excellent thermal stability of the optimal Na2BaCa(PO4)2:0.05Sm3+ phosphor was observed up to 443 K, with an activation energy of 0.1997eV. Furthermore, under 401 nm excitation, the phosphor exhibited promising optical thermometry performance between 293 K and 593 K, with maximum sensitivities of 10.42 × 10−4 K−1 (absolute) and 0.22 % K−1 (relative), demonstrating its potential in solid-state lighting and temperature sensing applications.
KW - CIE chromaticity color coordinates diagram
KW - Down-conversion luminescence
KW - Fluorescence intensity ratio
KW - LEDs
KW - Photoluminescence
UR - https://www.scopus.com/pages/publications/105024203435
U2 - 10.1016/j.materresbull.2025.113939
DO - 10.1016/j.materresbull.2025.113939
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AN - SCOPUS:105024203435
SN - 0025-5408
VL - 197
JO - Materials Research Bulletin
JF - Materials Research Bulletin
M1 - 113939
ER -