ABSTRACT A series of K 5 La 1 − x (MoO 4 ) 4 : x Tm 3+ and K 5 La 0.95 − y (MoO 4 ) 4 :0.05Tm 3+ , y Dy 3+ phosphors have been synthesized via high‐temperature solid‐state reaction at 600°C for 8 h, and then their luminescence property and thermal stability were investigated. It was found that the K 5 La 1 − x (MoO 4 ) 4 : x Tm 3+ phosphors exhibited two strong blue emission peaks at 452 and 458 nm under excitation at 356 nm with the strongest intensity in the case of x = 0.05, whereas the K 5 La 0.95 − y (MoO 4 ) 4 :0.05Tm 3+ , y Dy 3+ phosphors exhibited another two characteristic peaks of Dy 3+ at 479 and 574 nm, and Tm 3+ could transfer energy to Dy 3+ . Notably, even at 473 K, the emission intensity of K 5 La 0.95 (MoO 4 ) 4 :0.05Tm 3+ and K 5 La 0.875 (MoO 4 ) 4 :0.05Tm 3+ ,0.075Dy 3+ phosphors at 452 nm still kept 62.33% and 75.03% of those at room temperature, respectively, indicating a high thermal stability. Moreover, the emission spectra and color coordinates of the co‐doped phosphors can be regulated via changing the excitation wavelength. Specifically, the color coordinates of K 5 La 0.875 (MoO 4 ) 4 :0.05Tm 3+ ,0.075Dy 3+ was (0.3223, 0.3346) under excitation at 350 nm, very close to the standard white light, implying a potential in white light LED.
Yan et al. (Thu,) studied this question.