Photoluminescence properties and application of yellow Ca0.65Si10Al2O0.7N15.3:xEu2+ phosphors for white LEDs.

A series of yellow-emitting oxynitride Ca 0.65 Si 10 Al 2 O 0.7 N 15.3 : x Eu 2+ phosphors with α-sialon structure were synthesized. The phase composition and crystal structure were identified by X-ray diffraction and the Rietveld refinement. The excitation and emission spectra, reflectance spectra and thermal stability were investigated in detail, respectively. Results show that Ca 0.65 Si 10 Al 2 O 0.7 N 15.3 :0.12Eu 2+ phosphors can be efficiently excited by UV-Vis light in the broad range of 290–450 nm and exhibit broad emission spectra peaking at 550–575 nm. The concentration quenching mechanism are discussed in detail and determined to be the dipole-dipole interaction. When the temperature increased to 150 °C, the emission intensity of Ca 0.65 Si 10 Al 2 O 0.7 N 15.3 :0.12Eu 2+ phosphor is 88.46% of the initial value at room temperature. White LED was fabricated with N-UV LED chip combined with blue Ca 3 Si 2 O 4 N 2 :Ce 3+ and yellow Ca 0.65 Si 10 Al 2 O 0.7 N 15.3 :Eu 2+ phosphors. The color rendering index and correlated color temperature of this white LED were measured to 78.94 and 6728.12 K, respectively. All above results demonstrate that the as-prepared Ca 0.65 Si 10 Al 2 O 0.7 N 15.3 : x Eu 2+ may serve as a potential yellow phosphor for N-UV w-LEDs. [ABSTRACT FROM AUTHOR]