Preparation and optical properties of transparent Ce:YAG ceramics for high power white LED

Abstract

Transparent Ce:YAG ceramics were synthesized from the Ce:YAG powder which was produced by co-preparation method of the hydroxides. The Ce:YAG ceramics exhibit a broad emission band peaked at 530 nm due to the 5d-4f transition of Ce3+. The transmittances of the samples obtained were 70 {~} 87 {%} at 800 nm. The absorption coefficient and emission intensity of Ce3+ were increased with the increase of the thickness. With increasing thickness of the sample, the color coordinates of the Ce:YAG ceramics under 465 nm LED excitation shifted from the blue region to the yellow region with passing nearby the theoretical white point. The highest value of luminous efficacy of the white LED was 73.5 lm/W.