Applied Physics B

, Volume 95, Issue 4, pp 715–720

Improvement of electroluminescent property of blue LED coated with highly luminescent yellow-emitting phosphors

Article

DOI: 10.1007/s00340-009-3484-1

Cite this article as:
Jang, H.S., Won, YH. & Jeon, D.Y. Appl. Phys. B (2009) 95: 715. doi:10.1007/s00340-009-3484-1

Abstract

White light-emitting diodes (WLEDs) were fabricated by combining InGaN-based blue light-emitting diodes (LEDs) with highly luminescent Tb3Al5O12:Ce3+ (TAG:Ce), Y3Al5O12:Ce3+ (YAG:Ce), and Sr3SiO5:Eu2+ (SS:Eu). The TAG:Ce-based WLED showed a color rendering index (Ra) of 79 and a luminous efficiency (ηL) of 34.1 lm/W at 20 mA. The YAG:Ce-based WLED and the SS:Eu-based WLED showed low Ra values of 75 and 57 but high luminous efficiency values of 38.9 and 41.3 lm/W at 20 mA, respectively. When a mixture of YAG:Ce and SS:Eu was coated on a blue LED and the resultant WLED operated at 20 mA, the WLED showed a highly bright white light similar to daylight (ηL=40.9 lm/W, color temperature Tc=5,716 K, and Ra=76). Moreover, the WLED showed stable color coordinates against a considerable variation of applied current.

PACS

76.30.Kg 78.55.-m 85.60.Jb 

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  1. 1.Department of Materials Science and EngineeringKorea Advanced Institute of Science and TechnologyDaejeonRepublic of Korea
  2. 2.Department of ChemistryPurdue UniversityWest LafayetteUSA
  3. 3.School of Materials EngineeringPurdue UniversityWest LafayetteUSA

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