Dependence of Yellow Phosphor on Optical and Electrical Properties of the White Light Emitting Diode Chip

Abstract:

We prepared the surface mounted white light emitting diode (LED) chips by using yellow phosphors on the blue LED chip. The optical and electrical properties of prepared white LED chips were investigated. The yellow phosphor mixed with transparent epoxy was coated on the prepared LED chip. The optimum mixing conditions with epoxy and yellow phosphor is obtained at the mixing ration of epoxy: yellow phosphor = 97 : 3 wt %. The maximum luminance and light emitting efficiency are above 80,000 cd/m2 and 23.2 lm/W, respectively, at the bias voltage of 2.9 V. There was no distinct change in the luminance strength with changing of the yellow phosphor ratios. The flowing current of the white LED chip is about 30 mA at 2.9 V.

• Periodical: Materials Science Forum (Volumes 510-511)
• Pages: 106-109
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.510-511.106
• Online since: March 2006
• Authors: Chang Sik Son, Ho Jung Chang, Kang Hyun Jaekal, Young Chol Chang, Soo Wohn Lee
• Keywords: CIE Color Coordinator, Light Emitting Efficiency, Luminance, White LEDs, Yellow Phosphor

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