Open AccessImproved angular color uniformity and hydrothermal reliability of phosphor-converted white light-emitting diodes by using phosphor sedimentation
Author(s) -
Won Jung Kim,
Taek Kyun Kim,
Sung Hoon Kim,
Suk Bum Yoon,
Hae Yong Jeong,
June O. Song,
Tae Yeon Seong
Publication year - 2018
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.26.028634
Subject(s) - phosphor , materials science , luminous flux , luminous efficacy , optics , sedimentation , diode , light emitting diode , dispersion (optics) , color temperature , optoelectronics , layer (electronics) , physics , composite material , paleontology , light source , sediment , biology
We investigated the effect of phosphor deposition methods on the correlated color temperature (CCT), luminous flux and thermal characteristics of packaged white light-emitting diodes (WLEDs) for use in mobile display products. For both the samples, the CCT decreased with increasing viewing angle. Phosphor sedimentation samples displayed much better angular color uniformity than phosphor dispersion samples. The phosphor sedimentation sample had higher luminous flux and luminous efficacy at 20 mA than the phosphor dispersion sample. The phosphor sedimentation sample displayed much better high-temperature/humidity (85 °C/85%) reliability and lower package temperatures compared with the phosphor dispersion sample.