Luminescence dynamics and thermal quenching of Sb3+, Mn2+ co-doped Cs2NaLuCl6 double-perovskite phosphors

Lead-free halide double perovskites are attractive luminescent materials owing to their low toxicity and structural stability, but their white-light performance is often limited by weak long-wavelength emission and inefficient energy regulation. Herein, Sb 3+ single-doped and Sb 3+ , Mn 2+ co-doped Cs 2 NaLuCl 6 phosphors were synthesized by a hydrothermal method. Sb 3+ introduces broadband blue emission associated with localized excited states, while Mn 2+ incorporation produces orange-red emission through the 4 T 1  →  6 A 1 transition. The coexistence of these two emission components enables tunable dual-emission and single-host white-light generation. Time-resolved PL analysis confirms the shortening of the Sb 3+ -related lifetime after Mn 2+ incorporation, and the energy-transfer efficiency reaches 31.25% for the optimized Cs 2 NaLuCl 6 : 0.005Sb 3+ , 0.05Mn 2+ sample. Temperature-dependent PL and Arrhenius analysis reveal improved thermal-quenching resistance, with the activation energy increasing from 0.13777 to 0.21293 eV. The optimized phosphor-based WLED exhibits neutral-white emission with CIE coordinates of (0.3287, 0.3565), a CCT of 5688 K, and a CRI of 72.4. These results provide insight into emission regulation and energy-transfer dynamics in Sb 3+ , Mn 2+ co-doped Cs 2 NaLuCl 6 phosphors for proof-of-concept white-light and optical anti-counterfeiting applications.