Open AccessLaser patterning of Y_3Al_5O_12:Ce^3+ ceramic phosphor platelets for enhanced forward light extraction and angular color uniformity of white LEDs
Author(s) -
Shuai Wang,
Yufeng Li,
Lishuang Feng,
Linzhao Zhang,
Ye Zhang,
Xilin Su,
Wen Ding,
Feng Yun
Publication year - 2016
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.24.017522
Subject(s) - phosphor , materials science , chromaticity , laser , optics , optoelectronics , color temperature , fabrication , ceramic , light emitting diode , luminance , color rendering index , physics , composite material , medicine , alternative medicine , pathology
We present a facile fabrication process to directly fabricate cone-shaped microwells arrays on single crystal Y 3 Al 5 O 12 :Ce 3+ (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.