载流子复合机制对InGaN绿光LED的Droop效应和调制带宽的影响

Effect of Carrier Recombination Mechanism on Efficiency Droop and Modulation Bandwidth of InGaN Green LED

传统的ABC模型被广泛应用于研究InGaN量子阱中的载流子复合动态过程。本文从实验样品中分析数据,提取绿光LED的ABC模型参数。基于ABC模型,经过理论计算,随着有效有源区厚度或者量子阱层厚度的增加,在注入电流增大时,内量子效率IQE下降趋势变缓,Droop效应的拐点电流明显增加;在不同的注入电流下,随着有效有源区厚度的下降,Droop效应下降非常明显。在低注入电流下,俄歇复合损失比随着注入电流增大而快速上升;在高注入电流下,俄歇复合损失比接近于饱和状态,上升速率很慢。随着有效有源区的厚度下降,俄歇复合损失比上升。随着注入电流的增大,绿光LED的调制带宽明显增大。在相同的注入电流下,随着有效有源区厚度的增加,调制带宽明显下降;在500 mA的注入电流下,调制带宽从684 MHz下降到85 MHz。在相同的注入电流下,随着InGaN量子阱宽度的增加,调制带宽有所下降;在500 mA注入电流下,调制带宽从684 MHz下降到372 MHz。

The traditional ABC model is widely used to study the dynamic process of carrier recombination in InGaN Quantum Wells.In this paper,the ABC model parameters of green LED are extracted by analyzing the data from the experimental samples.Based on the ABC model,through theoretical calculation,with the increase of effective active zone thickness or quantum well layer thickness,when the injection current increases,the internal quantum efficiency decreases slowly,and the knee point current increases obviously.Under different injection current,with the decrease of effective active zone thickness,the drop effect decreases obviously.At low injection current,the auger loss ratio increases rapidly with the increase of injection current.At large injection current,the auger loss ratio is close to saturation state,and the rising rate is very slow.With the decrease of the effective active zone thickness,the auger loss ratio increases.With the increase of injection current,the modulation bandwidth of green LED increases obviously.At the same injection current,with the increase of the effective active zone thickness,the modulation bandwidth decreases obviously.At the injection current of 500 mA,the modulation bandwidth decreases from 684 MHz to 85 MHz.At the same injection current,the modulation bandwidth decreases with the increase of InGaN Quantum well width.At 500 mA injection current,the modulation bandwidth decreases from 684 MHz to 372 MHz.