Achieving exceptional thermally stable white light emission in silicate phosphors via synergistic thulium-dysprosium coordination

In the field of white-light LED lighting technology, the development of single-phase white light emitting phosphors with excellent luminescent thermal stability has been the core research focus. This study introduced a color-tunable Na 3 YSi 2 O 7 : x Tm 3+ , y Dy 3+ (abbreviated as NYSO: x Tm 3+ , y Dy 3+ ) phosphor. Under an excitation wavelength of 351 nm, through the energy transfer (ET) process from Tm 3+ to Dy 3+ dominated by dipole-dipole interactions and by finely adjusting the doping ratios of Tm 3+ and Dy 3+ ions, white light emission was successfully achieved in the NYSO:5%Tm 3+ ,1%Dy 3+ phosphor. The phosphor exhibited color coordinates at (0.340, 0.344), which were extremely close to the ideal white light region. Notably, the NYSO:5%Tm 3+ ,1%Dy 3+ phosphor exhibited remarkable thermal stability luminescent performance. At high temperatures of 424 K and 474 K, its emission intensity only decreased by 3.64% and 6.10%, respectively. Moreover, at a high temperature of 474 K, the chromaticity shift ( Δε ) of the phosphor was merely 6.16×10 -3 , demonstrating far superior anti-thermal quenching and luminescent color stability performance compared with similar phosphor materials. This work provided a new strategy for addressing the thermal stability issue of white LED phosphors and was expected to facilitate the advancement of white LED lighting technology.