Improved angular color uniformity and hydrothermal reliability of phosphor-converted white light-emitting diodes by using phosphor sedimentation

Won Jung Kim, Taek Kyun Kim, Sung Ho Kim, Suk Bum Yoon, Hwan Hee Jeong, June O. Song, Tae Yeon Seong

Research output: Contribution to journalArticle


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.

Original languageEnglish
Pages (from-to)28634-28640
Number of pages7
JournalOptics Express
Issue number22
Publication statusPublished - 2018 Oct 29


ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

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