Two strategies to achieve color adjustment of Eu2+-doped garnet Lu2Mg2Al2Si2O12 phosphors.

Phosphors with excellent color adjustable properties have always been the research focus of scientific researchers. This work uses two strategies to control the luminescence behavior of Eu2+ ions in the Lu 2 Mg 2 Al 2 Si 2 O 12 (LMAS) matrix. Firstly, by adjusting the Eu2+ ion concentration, the emission spectra of Lu 2 Mg 2 Al 2 Si 2 O 12 :Eu2+ (LMAS:Eu2+) could achieve a 39 nm red shift from 451 to 490 nm, which provides a good blue to cyan emission. Secondly, the Lu 2 Mg 2 Al 2 Si 2 O 12 :Eu2+,Mn2+ (LMAS:Eu2+,Mn2+) realized the tuning from the cyan to the white region by introducing Mn2+ ions, which is owing to the sensitization process of Eu2+ to Mn2+ enhancing the red-light emission. The energy transfer process was explored in detail, and the energy transfer efficiency was calculated to be more than 60%. Meanwhile, the thermal stability of the material was also studied. The thermal stability illustrates its potential application in white light-emitting diode (WLED). Under 30 mA drive current, the device obtained by using 365 nm ultraviolet (UV) chip with LMAS:0.01Eu2+,0.35Mn2+ phosphor has a color rendering index (Ra) as high as 93.1, R9 = 85, LE = 1.81 lm/W, the color coordinate is (0.3076, 0.3119) and the correlated color temperature (CCT) is 6984 K, which is obviously in the white light area. The above results indicate that LMAS:Eu2+,Mn2+ phosphors with full-visible-spectrum have potential applications in solid-state lighting. Two strategies to control the luminescence behavior of Eu2+ ions in the LMAS matrix. By adjusting the Eu2+ ions concentration, the emission spectra of LMAS:Eu2+ could achieve a 39 nm red shift from 451 to 490 nm, and it demonstrated the occupying problem of Eu2+ ions in detail. Based on the energy transfer process in phosphor, white light emission is realized. The single-phase full-visible-spectra LMAS:Eu2+,Mn2+ phosphor-converted WLED achieves the ultra-high Ra (93.1) and R9 (85), near-standard CIE (0.3076, 0.3119) and CCT (6984 K). [Display omitted] • The main novelties are highlighted as follows. • By adjusting the Eu2+ ion concentration, the emission spectra of Lu 2 Mg 2 Al 2 Si 2 O 12 :Eu2+ (LMAS:Eu2+) could achieve a 39 nm red shift from 451 to 490 nm, which provides a good blue to cyan emission. • The luminescence properties of Eu2+ ions at different sites in the garnet matrix were discussed. • Through the introduction of Mn2+ ions, energy transfer is realized, and a single matrix white phosphor is obtained. • The device obtained by using 365 nm ultraviolet (UV) chip with LMAS:0.01Eu2+,0.35Mn2+ phosphor has a color rendering index (Ra) as high as 93.1, the color coordinate is (0.3076, 0.3119) and the correlated color temperature (CCT) is 6984 K. [ABSTRACT FROM AUTHOR]