High-power and reliable operation of vertical light-emitting diodes on bulk GaN
High-power and reliable operation of vertical light-emitting diodes on bulk GaN
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DOI：
10.1063/1.1810631
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发表时间：
2004-11-01
影响因子：
4
通讯作者：
Arthur, SD
中科院分区：
文献类型：
--
作者：
Cao, XA;Arthur, SD
具有横向和垂直几何形状的InGaN/GaN发光二极管（led）已经在独立的GaN衬底上制造出来。垂直LED的电流扩散显著增强，导致串联电阻降低7 ω，而GaN和蓝宝石上的横向LED分别为12.2和14.2 ω。结果表明，在高注入电流下，GaN上垂直LED的光输出和功率转换效率得到了极大的提高。垂直LED在400 mA的压力测试中显示出最小的光功率下降，而同样的压力导致蓝宝石上的横向LED由于增加的电流拥挤和自热而被破坏。然而，具有优化电流扩展的蓝宝石上的横向LED表现出出色的可靠性，这表明在高达700 a /cm(2)的电流密度下，异质外延器件中存在高密度位错(类似于10（9)cm(-2)）不会加速LED的退化。(C) 2004年美国物理研究所。
InGaN/GaN light-emitting diodes (LEDs) with lateral and vertical geometries have been fabricated on free-standing GaN substrates. Current spreading was significantly enhanced in the vertical LED, leading to a reduced series resistance of 7 Omega compared to 12.2 and 14.2 Omega for the lateral LEDs on GaN and sapphire, respectively. As a result, the light output and power conversion efficiency of the vertical LED on GaN were greatly improved at high injection currents. The vertical LED was subjected to a stress test at 400 mA and showed minimal degradation of optical power, whereas the same stress resulted in the destruction of the lateral LED on sapphire due to increased current crowding and self-heating. However, lateral LEDs on sapphire with optimized current spreading exhibited excellent reliability, indicating the presence of a high density of dislocations (similar to10(9) cm(-2)) in the heteroepitaxial device does not accelerate LED degradation at current densities up to 700 A/cm(2). (C) 2004 American Institute of Physics.