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Proceedings Paper

Recent development of nitride LEDs and LDs
Author(s): Atsuo Michiue; Takashi Miyoshi; Tomoya Yanamoto; Tokuya Kozaki; Shin-ichi Nagahama; Yukio Narukawa; Masahiko Sano; Takao Yamada; Takashi Mukai
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Paper Abstract

We fabricated the high efficiency white LEDs. The white LEDs, the yellow YAG-phosphors-coated small-size (290µm × 500µm) blue LED, designed for minimizing forward voltage. At a forward current of 20mA, the luminous flux, the forward voltage (Vf), the correlated color temperature (Tcp), the luminous efficiency, and the wall-plug efficiency (WPE) are 9.5lm, 2.8V, 5193K, 169Lm/W, and 50.8%, respectively. The high-power white LEDs were fabricated from the larger-size (1mm × 1mm) blue LED chips with the output power of 651mW at 350mA. Flux, Vf, Tcp, luminous efficiency, and WPE of the high-power white LED are 145Lm, 3.09V, 4988K, 134Lm/W, and 39.5%, respectively, at 350mA. This power white LEDs showed total flux of 361Lm at 1A. Moreover, we succeeded in developing high-power and high-efficiency blue laser diodes (LDs) with an emission wavelength at 445nm range by using GaN-based materials. This achievement leads to the full-color laser display applications. We fabricated multi-transverse mode LDs by a single emitter, and adopting φ9mm packages for the reduction of the thermal resistance. The typical optical-output power, voltage and wall-plug efficiency of the LDs at forward current of 1.0A at a temperature of 25ºC was 1.17W, 4.81V and 24.3%, respectively. The catastrophic optical damage at the facets of these LDs did not appear up to 3W in the optical output power. The estimated lifetime of the LDs at a temperature of 25ºC under continuous-wave operation 1.0A in automatic current control condition was over 30,000 hours.

Paper Details

Date Published: 16 February 2009
PDF: 6 pages
Proc. SPIE 7216, Gallium Nitride Materials and Devices IV, 72161Z (16 February 2009); doi: 10.1117/12.808682
Show Author Affiliations
Atsuo Michiue, Nichia Corp. (Japan)
Takashi Miyoshi, Nichia Corp. (Japan)
Tomoya Yanamoto, Nichia Corp. (Japan)
Tokuya Kozaki, Nichia Corp. (Japan)
Shin-ichi Nagahama, Nichia Corp. (Japan)
Yukio Narukawa, Nichia Corp. (Japan)
Masahiko Sano, Nichia Corp. (Japan)
Takao Yamada, Nichia Corp. (Japan)
Takashi Mukai, Nichia Corp. (Japan)

Published in SPIE Proceedings Vol. 7216:
Gallium Nitride Materials and Devices IV
Hadis Morkoç; Cole W. Litton; Jen-Inn Chyi; Yasushi Nanishi; Joachim Piprek; Euijoon Yoon, Editor(s)

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