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http://dx.doi.org/10.3807/JOSK.2012.16.4.349

Fabrication and Characterization of a GaN Light-emitting Diode (LED) with a Centered Island Cathode  

Park, Yun Soo (School of Electrical Engineering and Computer Science, Kyungpook National University)
Lee, Hwan Gi (School of Electrical Engineering and Computer Science, Kyungpook National University)
Yang, Chung-Mo (School of Electrical Engineering and Computer Science, Kyungpook National University)
Kim, Dong-Seok (School of Electrical Engineering and Computer Science, Kyungpook National University)
Bae, Jin-Hyuk (School of Electrical Engineering and Computer Science, Kyungpook National University)
Cho, Seongjae (Department of Electrical Engineering, Stanford University)
Lee, Jung-Hee (School of Electrical Engineering and Computer Science, Kyungpook National University)
Kang, In Man (School of Electrical Engineering and Computer Science, Kyungpook National University)
Publication Information
Journal of the Optical Society of Korea / v.16, no.4, 2012 , pp. 349-353 More about this Journal
Abstract
Uniform spreading of injection current in light-emitting diodes (LEDs) is one of the crucial requirements for better device performances. It is reported that non-uniform current spreading leads to low output power, high current crowding, heating, and reliability degradation of the LED device. This paper reports on the effects of different surface and electrode geometries in the LEDs. To increase the output power of LEDs and reduce the series resistance, a rectangular-type LED (RT-LED) with a centered island cathode has been fabricated and investigated by comparison with a conventional LED (CV-LED). The performances of RT-LEDs were prominently enhanced via uniform current spreading and low current crowding. Performances in terms of increased output power and lower forward voltage of simulated RT-LEDs are much superior to those of CV-LEDs. Based on these results, we investigated the correlation between device geometries and optical characteristics through the fabricated CV and RT-LEDs. The measured output power and forward voltage of the RT-LEDs at 100 mA are 64.7% higher and 8% smaller compared with those of the CV-LEDs.
Keywords
Light-emitting diode; Electrode geometries; Centered island cathode; Output power;
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