The poor hole injection severely constrains the external quantum efficiency (EQE) and light output power (LOP) of AlGaN-based deep ultraviolet light-emitting diodes (DUV LEDs). This constraint primarily stems from the insufficient energy of holes, which is strongly influenced by the p-AlGaN electric field within the hole supplier layer (HSL) for AlGaN-based DUV LEDs. In this work, we propose the incorporation of multiple thin p-AlGaN insertion layers into an Al-composition-decreasing (ACD) p-AlGaN HSL to enhance the hole injection efficiency. Significant enhancements in both EQE and LOP are observed for the investigated DUV LEDs under different current injection densities. Through analyzing the fundamental physical mechanism underlying the improved hole injection achieved by this proposed structure, we attribute these enhancements to the augmentation of the hole-accelerating electric field, facilitated by polarization-induced sheet charges at the related interfaces of the insertion layers, and the strong intraband tunneling processes for holes, favored by ultrathin insertion layers. Meanwhile, the accumulation of holes at the upper interface of the insertion layers and the existence of three-dimensional hole gas (3DHG) in the ACD p-AlGaN HSL further contribute to the enhanced hole injection. The proposed ACD p-AlGaN HSL design with the incorporation of multiple thin p-AlGaN insertion layers provides a promising approach for elevating the performance of DUV LEDs.

中文翻译：

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利用工程 p-AlGaN 空穴供应层增强 AlGaN 基深紫外发光二极管的空穴注入

较差的空穴注入严重限制了AlGaN基深紫外发光二极管（DUV LED）的外量子效率（EQE）和光输出功率（LOP）。这一限制主要源于空穴能量不足，这受到基于 AlGaN 的 DUV LED 的空穴供应层 (HSL) 内 p-AlGaN 电场的强烈影响。在这项工作中，我们建议将多个薄 p-AlGaN 插入层合并到铝成分减少 (ACD) p-AlGaN HSL 中，以提高空穴注入效率。在不同电流注入密度下，所研究的 DUV LED 的 EQE 和 LOP 均显着增强。通过分析该结构所实现的改进空穴注入的基本物理机制，我们将这些增强归因于空穴加速电场的增强，这是由插入层相关界面处的极化感应片电荷所促进的，并且孔的强带内隧道过程，受到超薄插入层的青睐。同时，插入层上界面处空穴的积累以及ACD p-AlGaN HSL中三维空穴气（3DHG）的存在进一步有助于增强空穴注入。所提出的 ACD p-AlGaN HSL 设计结合了多个薄 p-AlGaN 插入层，为提升 DUV LED 的性能提供了一种有前景的方法。