Two substitution strategies realize single-phase full-spectrum emission in Ca10Na(PO4)7:Eu2+ phosphors for WLED

Herein, a variety of single-phase full-spectrum emission phosphors doped with Eu 2+ were synthesized. Under the 350 nm excitation, as K + and Y 3+ were introduced into Ca 10 Na(PO 4 ) 7 (CNP):1.5%Eu 2+ , respectively, the emission color of Ca 9.85 K y Na (1- y ) ( PO 4 ) 7 :1.5%Eu 2+ (0 ≤  y  ≤ 1.0) was tuned from yellow to cyan, while that of Ca (9.85- z ) NaY 0.667 z (PO 4 ) 7 :1.5%Eu 2+ (0 ≤  z  ≤ 1.0) was tuned from yellow to green. The internal quantum yield (QY) of Ca 9·85 K 0·4 Na 0·6 (PO 4 ) 7 (CKNP):1.5%Eu 2+ and Ca 9·45 NaY 0·267 (PO 4 ) 7 (CNYP):1.5%Eu 2+ reached 47.47 % and 27.11 %, respectively. The introduction of K + or Y 3+ made Eu 2+ selectively occupy the Ca sites and led to changes in the local environment of Eu 2+ , allowing for spectral tuning emission. In addition, the luminescence intensity of the samples retained 54.59 % and 31.34 % of their room temperature values. Eventually, two white light emitting diode (WLED) devices were fabricated, combining the synthesized white emitting phosphors with 365 nm ultraviolet (UV) chips. They exhibited high color rendering indices of 84.7 and 77.0, along with low correlated color temperatures of 5435 K and 5023 K. The Commission Internationale de L'Eclairage (CIE) color coordinates were (0.3349, 0.3975) and (0.3517, 0.4366), respectively. The results pointed to the phosphors' potential suitability for use in the WLED sector.