Ryu Han-Youl, Shim Jong-In
Department of Physics, Inha University, 253 Yonghyeon-dong, Incheon 402-751, South Korea.
Opt Express. 2011 Feb 14;19(4):2886-94. doi: 10.1364/OE.19.002886.
We investigate the effects of current spreading on the efficiency droop of InGaN blue light-emitting diodes with lateral injection geometry based on numerical simulation. Current crowding near the mesa edge and the decrease in the current spreading length with current density are shown to cause significant efficiency droop. It is found that the efficiency droop can be reduced considerably as the uniformity of current spreading is improved by increasing the resistivity of the p-type current spreading layer or decreasing the sheet resistance of the n-GaN layer. The droop reduction is well interpreted by the uniformity of carrier distribution in the plane of quantum wells.
基于数值模拟，我们研究了电流扩展对具有横向注入结构的氮化铟镓蓝光发光二极管效率下降的影响。结果表明，台面边缘附近的电流拥挤以及电流扩展长度随电流密度的减小会导致显著的效率下降。研究发现，通过增加p型电流扩展层的电阻率或降低n型氮化镓层的薄层电阻来提高电流扩展的均匀性，可以显著降低效率下降。量子阱平面内载流子分布的均匀性很好地解释了效率下降的降低。
