为了探究具有双层电子阻挡层设计的GaN基黄光LED中首层电子阻挡层（EBL-1）Al组分对内量子效率的影响以及其中载流子注入的主要物理机制, 首先使用硅衬底GaN基黄光LED外延与芯片工艺, 在外延过程中通过控制三甲基铝（TMAl）流量, 分别获得EBL-1含有Al组分约20%、50%、80%的硅衬底GaN基黄光LED; 随后使用半导体仿真软件Silvaco Atlas对这3种样品的实际测试内量子效率曲线进行拟合。结果表明, EBL-1中Al组分对内量子效率的影响主要体现在两方面: 一是EBL-1的Al组分越高越有利于空穴从V形坑侧壁注入到多量子阱有源区; 二是EBL-1中过高的Al组分会降低p型GaN晶体质量, 导致空穴浓度下降; 综合表现为Al组分约50%的EBL-1在这种双层电子阻挡层的设计下最有利于提高硅衬底GaN基黄光LED的内量子效率。

This study was to investigate the dependence of internal quantum efficiency of GaN-based yellow light-emitting diodes(LEDs) with Si substrate on the Al composition of first electron blocking layer(EBL-1) in dual electron blocking layer design and the main physical mechanism of carrier injection. First, three samples were prepared by the technology of GaN-based yellow LEDs on silicon substrates with different flows of trimethyl aluminum(TMAl) during epitaxy. As a result, the Al composition in EBL-1 of the samples was about 20%, 50% and 80%, respectively. Then, the actual tested internal quantum efficiency curves of these three samples were fitted by the semiconductor simulation software Silvaco Atlas. The results show that EBL-1 in dual electron blocking layer design has two main influences on the internal quantum efficiency. One is that EBL-1 with a higher Al composition allows more holes to be injected from the sidewall of the V-shaped pits into the multiple quantum wells, and the other is that excessive aluminum composition reduces the quality of p-type GaN layers, resulting in a decrease in the effective concentration of holes. As a comprehensive performance, the EBL-1 with about 50% Al composition is the most benefit in dual electron blocking layer design to the internal quantum efficiency of GaN-based yellow LEDs.