Warm white light phosphors Sc2W3O12: Dy3+, Eu3+ with ultrahigh thermal stability and tunable luminescence
Xiaoqing Pei, Miao Yan, Yifan Liu, Lin Fan, Tao Jiang, Zetian Mi, Lina Liu, Chun Li, Hai Lin, Shasha Li, Weiling Yang, Fanming Zeng, Zhong‐Min Su
Abstract
Phosphors for lighting applications often face challenges such as limited thermal stability, restricted tunability of emission colors, and moderate quantum efficiency. In this study, a series of Sc 2 W 3 O 12 : x Dy 3+ , y Eu 3+ phosphors were synthesized via a high-temperature solid-state method to address these issues. Under 350 nm excitation, Sc 2 W 3 O 12 : x Dy 3+ phosphor exhibits blue (485 nm) and yellow emission peaks (577 nm), and the optimal doping concentration of Dy 3+ is 3 mol%. In Sc 2 W 3 O 12 : 0.03Dy 3+ , y Eu 3+ phosphor, energy transfer is revealed through spectral overlap and fluorescence decay curve analysis of Dy 3+ and Eu 3+ . The energy transfer efficiency is as high as 75 %, and the reason is explained through a combination of energy transfer mechanism and J-O theoretical calculation. By adjusting the range of y in Sc 2 W 3 O 12 : 0.03Dy 3+ , y Eu 3+ , the correlated color temperature can be adjusted within the range of 4450 K to 3945 K, thereby achieving tunable luminescence from neutral white light to warm white light. The thermal stability of the synthesized warm white phosphor Sc 2 W 3 O 12 : 0.03Dy 3+ , 0.05Eu 3+ is 90.38 % (423 K). The fluorescence intensity ratio of Eu 3+ and Dy 3+ at 303 K − 483 K was calculated, and its temperature sensing performance was analyzed. At 303 K, the thermal sensing factors are S amax = 0.97 % K −1 and S rmax = 0.0962 % K −1 , and the actual quantum efficiency is IQE = 50.67 %. Finally, a WLED device was prepared using Sc 2 W 3 O 12 : 0.03Dy 3+ , 0.05Eu 3+ phosphors. The device emits warm white light with a correlated color temperature of 3686 K. In summary, the prepared Sc 2 W 3 O 12 : Dy 3+ , Eu 3+ phosphor successfully solved the challenges of limited thermal stability, tunable luminescence color and moderate quantum efficiency, and it has potential value in white light-emitting diodes (WLEDs) and optical thermometers.