A novel Eu3+-doped garnet-type tellurate red-emitting phosphor with high thermal stability and color purity

A series of novel garnet-type tellurate red-emitting phosphors Li3Gd3(1-x)Te2O12:xEu(3+) (x = 0.01-0.30) were successfully synthesized by a high-temperature solid-state reaction method. The phase structure, photoluminescence properties and thermal stability of the phosphor were investigated in detail. The phosphor shows dominant emission peak at 613 nm belonging to the D-5(0) -> F-7(2) electric dipole transition under 396 nm excitation. The luminescence intensity keeps increasing with increasing the content of Eu3+ to 15 mol%, and the critical transfer distance of Eu3+ was calculated to be 14 angstrom. The quenching temperature for Li3Gd3Te2O12:0.15Eu(3+) was estimated to be above 500 K. This spectral feature reveals high color purity and excellent chromaticity coordinate characteristics. Therefore, Eu3+-doped Li3Gd3Te2O12 phosphors are potential red phosphors for near UV chip-based white light-emitting diode and display devices.