Growth and optical properties of (Y1−xGdx)3Al5O12:Ce single crystal phosphors for high-brightness neutral white LEDs and LDs

Abstract

(Y_1−xGd_x)₃Al₅O₁₂:Ce ((Y,Gd)₃Al₅O₁₂:Ce) single crystal phosphors (SCPs) were successfully grown using the Czochralski method. The Gd segregation coefficient was determined. The lattice spacing, absorption and emission properties were systematically investigated as a function of Gd concentration in a wide temperature range. Gd incorporation red-shifts the SCP emission so that neutral white with correlated color temperatures in the range of 4098–6594 K can be achieved in conjunction with a blue light-emitting diode (LED). SCPs demonstrate high conversion efficiency (>90% above 150 °C) and better thermal stability compared to analogous ceramic powders. Additionally, SCPs are compatible with resin-free packaging, overcoming drawbacks associated with powder encapsulants. Therefore, (Y,Gd)₃Al₅O₁₂:Ce SCPs are promising candidates for high-brightness neutral white sources based on intense blue LEDs and laser diodes.