title: Laser patterning of Y3Al5O12:Ce3+ceramic phosphor platelets for enhanced forward light extraction and angular color uniformity of white LEDs.
abstract: We present a facile fabrication process to directly fabricate cone-shaped microwells arrays on single crystal Y3Al5O12:Ce3+(YAG:Ce) ceramic phosphor platelets (CPPs) by short-pulse laser direct patterning. Compared to unpatterned YAG:Ce CPP with smooth surface, the forward-to-total ratio of emission photons of patterned YAG:Ce CPPs was enhanced from 53.2% up to 78.2%, and the total emission within 4-π degree is 6% higher. The fabricated patterns are also beneficial in increasing the color conversion efficiency of YAG:Ce CPPs by 7.6%. The patterned YAG:Ce CPPs display much better correlated color temperature (CCT) uniformity under varied currents. The angular correlated color temperature uniformity (ACU) of patterned YAG:Ce CPPs reaches as high as 0.933 compared to 0.730 of the unpatterned one. These results suggest that laser patterning of YAG:Ce CPP could effectively manipulate its luminance, chromaticity and illumination pattern, which may lead to further technological advancements for diversified applications of film-type CPPs in highly efficient white LEDs.
authors.forename: Shuai
authors.initials: S
authors.lastname: Wang
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Li
authors.forename: Lungang
authors.initials: L
authors.lastname: Feng
authors.forename: Linzhao
authors.initials: L
authors.lastname: Zhang
authors.forename: Ye
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xilin
authors.initials: X
authors.lastname: Su
authors.forename: Wen
authors.initials: W
authors.lastname: Ding
authors.forename: Feng
authors.initials: F
authors.lastname: Yun