Synthesis and Luminescence Properties of Mg – Si Co‐doped Tb ₃ Al ₅ O ₁₂ : Ce ³⁺ Phosphors with Blue Excitation for White LED s

Abstract

Tb 2.94 Mg x Al 5−2 x Si x O 12: Ce 3+ 0.06 ( TMASG : Ce) were synthesized by high temperature Solid‐State Reaction ( SSR ) at different temperatures from 1650°C to 1550°C. Samples with x = 0.1, 0.2, 0.3, 0.6 were fabricated and characterized using powder X‐ray diffraction ( XRD ) and room‐temperature photoluminescence spectroscopy. In this work, the excitation and emission spectra indicate that the phosphor can be excited effectively by the blue light (450–550 nm) and exhibit a satisfactory orange–yellow emission from 550 to 575 nm. The reasons of the red‐shift of the phosphor have been discussed. A crystal field analysis of the Ce 3+ 5 d energy levels is conducted to explain the correlation between the TMASG : Ce lattice expansion and the Ce 3+ energy level changes. The chromaticity coordinates of the phosphors are tuned from (0.465, 0.527) to (0.512, 0.483). This indicates a prospective for application of this novel phosphor in white light emitting diodes ( LED s).