Improvement in Performance of GaN-based Light-emitting Diodes with Indium Tin Oxide Based Transparent Ohmic Contacts
InGaN/GaN multi-quantum welt (MQW) light-emitting diodes (LEDs) with Indium tin oxide (ITO) and Ni/Au p-contacts have been successfully fabricated. ITO (500 nm) and Ni/Au (2 nm/9 nm) films were deposited onto p-GaN epitaxial layers by e-beam evaporation system. For the LEDs with in situ annealed ITO and Ni/Au contacts, the 20 mA forward voltage was 3.5 V and 3.2 V, respectively. Moreover, under the same amount of injection current, the LED with in situ annealed ITO p-contact had higher output electroluminescence (EL) intensity and larger light output power. The ITO processing enhanced the light output power by 60％ compared to the Ni/Au processing. The light output and power conversion efficiency of ITO LEDs on GaN were greatly improved at high injection currents. The fabricated LEDs were subjected to a stress test at 30 mA and 55℃ and showed very small degradation of optical power ( ＜ 1 ％ decrease) for 24 hrs stress. The light output of MQW LEDs keeps 80％ of the original value after 1 000 hrs stressing. The fabricated LED devices have demonstrated a good reliability.
Gallium Nitride (GaN) Light Emitting Diode (LED) Indium Tin Oxide p-GaN
Y. Yao C. C. Jin Z. Dong Z. Sun S. M. Huang
Engineering Research Center for Nanophotonics and Advanced Instrument,Ministry of Education, East Ch Delight Optoelectronics Co., Ltd, Wuhan, China
国际会议
上海
英文
1633-1637
2007-03-12（万方平台首次上网日期，不代表论文的发表时间）