Origin of efficiency droop in GaN-based light-emitting diodes
Origin of efficiency droop in GaN-based light-emitting diodes
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DOI：
10.1063/1.2800290
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发表时间：
2007-10-29
影响因子：
4
通讯作者：
Park, Yongjo
中科院分区：
文献类型：
--
作者：
Kim, Min-Ho;Schubert, Martin F.;Park, Yongjo
研究了GaInN/GaN多量子阱(MQW)发光二极管的效率下降。测量表明，在高注入条件下出现的效率下降与结温无关。此外，作为激发功率函数的光致发光输出没有出现下垂，这表明下垂与多量子阱效率无关，而与多量子波区外载流子的复合有关。模拟结果表明，MQW和电子阻挡层中的极化场使得电子能够从MQW区域逃逸，因此是下垂的物理来源。结果表明，通过使用合适的四元AlGaInN组分，减小了偏振效应，从而减小了下垂，提高了效率。(C)2007年美国物理研究所。
The efficiency droop in GaInN/GaN multiple-quantum well (MQW) light-emitting diodes is investigated. Measurements show that the efficiency droop, occurring under high injection conditions, is unrelated to junction temperature. Furthermore, the photoluminescence output as a function of excitation power shows no droop, indicating that the droop is not related to MQW efficiency but rather to the recombination of carriers outside the MQW region. Simulations show that polarization fields in the MQW and electron blocking layer enable the escape of electrons from the MQW region and thus are the physical origin of the droop. It is shown that through the use of proper quaternary AlGaInN compositions, polarization effects are reduced, thereby minimizing droop and improving efficiency. (C) 2007 American Institute of Physics.