Fabrication and optical properties of divalent Cu2+ ions incorporated Ce:YAG transparent ceramics for white LEDs

摘要

Transparent Ce:YAG ceramics via Cu2+ incorporating annealed at 1450 degrees C were successfully fabricated by the solid-state method to probe their potential applications in white light-emitting diodes (LEDs). The influence of Cu2+ concentration on the microstructure and optical properties of the Ce:YAG transparent ceramics were systematically investigated. The as-prepared ceramics possessed clean grain boundaries and homogeneous grain size distribution ranging from 3.7 to 6.5 mu m. With the addition amount of Cu2+ increased, the red component of ceramics gradually increased and then decreased, it reached a maximum of 13.0% at 1.5 at% Cu2+ incorporation. By combining with commercially blue LED chips (465 nm) directly, the obtained optimal chromaticity coordinates (CIE) and correlated color temperature (CCT) of ceramics were (x = 0.3335, y = 0.3412) and 5450 K, respectively, while its color render index (CRI) was nearly 70 at the thickness of 1.0 mm. Therefore, this study provided an efficient approach to tailor the luminescence property of Ce:YAG ceramic for white LEDs.