Efficient and heat-conducting color converter of phosphor glass film printed on sapphire substrate for high-power white LEDs/LDs

Thermal stability and heat dissipation of color converter are the key roadblocks for high-power white light-emitting diodes (LEDs) and laser diodes (LDs). In this work, we fabricated an efficient and heat-conducting color converter based on phosphor-sapphire composite (PSC) for white LEDs/LDs, in which Y3Al5O12:Ce3+ or Y3Al5O12:Ce3+/CaAlSiN3:Eu2+ phosphor glass film was sintered on a sapphire substrate by using low-melting borosilicate glass. The Y3Al5O12:Ce3+ PSC-based white LEDs achieve a high luminous efficacy of 155 lm/W, and the Y3Al5O12:Ce3+/CaAlSiN3:Eu2+ PSC-based white LEDs exhibit a warm white light with a correlated color temperature of 3509 K and a color rendering index of 88.3. The chromaticity of PSC-based white LDs shifts from cool to warm white. Furthermore, the PSC achieves a high thermal conductivity of 20.8 W m(-1) K-1, which provides the effective heat transfer channels. The working temperature of PSC is reduced by 46 degrees C compared with that of phosphor-in-silicone.