Ge4+, Eu3+‐codoped Y2SiO5 as a novel red phosphor for white LED applications

The phosphors Y2SiO5: Ge4+, Eu3+ were synthesized by solid state reaction method assisted by flux, and have been characterized by X‐ray powder diffraction and fluorescence spectrometer. The results showed that the phosphors can be effectively excited by near‐UV (394 nm), and the major peak is located at 611 nm ascribed to the electric‐dipole 5D0 → 7F2 transition of Eu3+, the critical quenching concentration of Eu3+ in the phosphor is determined to be 15 mol% and the critical transfer distance is calculated as 8.90 Å. Co‐doping Y2SiO5: Eu3+ with Ge4+ helps to improve the luminescence intensity and color purity. The red emission of the phosphor under 394 nm excitation shows a good chromaticity index (0.652, 0.347) compared to commercial red phosphors Y2O2S: Eu3+ (0.631, 0.350). The quantum efficiency of the Y2Si0.97O5: 0.03Ge4+, 0.15Eu3+phosphor under 394 nm excitation is estimated to be 45.24%. It can be concluded that efficient red light emitting diodes were fabricated using Ge4+, Eu3+ co‐doped phosphor based on near ultraviolet(NUV) excited LED lights.