White LEDs for solid state lighting

Isamu Niki; Yukio Narukawa; Daisuke Morita; Shin-ya Sonobe; Tomotsugu Mitani; Hiroto Tamaki; Yoshinori Murazaki; Motokazu Yamada; Takashi Mukai

doi:10.1117/12.514069

26 January 2004 White LEDs for solid state lighting

Isamu Niki, Yukio Narukawa, Daisuke Morita, Shin-ya Sonobe, Tomotsugu Mitani, Hiroto Tamaki, Yoshinori Murazaki, Motokazu Yamada, Takashi Mukai

Author Affiliations +

Proceedings Volume 5187, Third International Conference on Solid State Lighting; (2004) https://doi.org/10.1117/12.514069
Event: Optical Science and Technology, SPIE's 48th Annual Meeting, 2003, San Diego, California, United States

Abstract

We show recent results of GaN based LEDs, the high efficiency blue LED, the high efficacy white LED, the high color rendering LED, the warm white LED, and the high output power 365-nm UV LED. The output power and the external efficiency of the high efficiency blue LED at 20 mA were 19.3 mW and 35.8%, respectively. Moreover, the lifetime of the molded this lamp was improved. For the high efficacy white LED using this high efficiency blue LED, the correlated color temperature (CCT) and the luminous efficacy (η_L) at 20 mA were 5470 K and 61.4 lm/W, respectively. This luminous efficacy is close to that of a fluorescent lamp. When the high color rendering LED using new red phosphor and shorter-YAG was operated at 20 mA, the CCT, η_L and the general color rendering index (R_a) were 4670 K, 28.3 lm/W and 87.7, respectively. In particular, the red color reproduction was improved. For the warm white, the CCT, η_L and R_a at 20 mA were 2830 K, 18.9 lm/W and 87.5, respectively. It can be used as a replacement for incandescent bulbs. When the high output power 365-nm UV LED was operated at a forward bias direct current (DC) of 500 mA, P_o and η_ex were 210 mW and 12.4%, respectively.

Citation Download Citation

Isamu Niki, Yukio Narukawa, Daisuke Morita, Shin-ya Sonobe, Tomotsugu Mitani, Hiroto Tamaki, Yoshinori Murazaki, Motokazu Yamada, and Takashi Mukai "White LEDs for solid state lighting", Proc. SPIE 5187, Third International Conference on Solid State Lighting, (26 January 2004); https://doi.org/10.1117/12.514069

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