针对AlGaN基多量子阱中有效的平衡载流子注入问题, 研究了有源区势垒层中Al组分调制形成的非规则H形量子势垒对AlGaN基深紫外发光二极管(LED)器件性能的影响及载流子的输运行为。研究发现, 与多量子阱中常用的单Al组分势垒相比, 加入Al组分较高的双尖峰势垒可以有效地提高内量子效率和光输出功率。进一步研究表明, 电子在有源区因凸起的尖峰势垒而得到了有效的阻挡, 减少了电子的泄露, 而空穴获得更多的动能从而穿过较高的势垒进入有源区。因此, 采用非对称H形量子势垒的深紫外LED器件中载流子输运实现了较好的平衡, 量子阱中的载流子复合速率远高于普通的深紫外发光二极管。

AlGaN-based deep ultraviolet light-emitting diodes (DUV-LEDs) employing irregular H-shaped quantum barriers in the active region by modulating Al composition have been investigated. It has been found that the H-shaped quantum barriers by insertion of double spike barriers with higher Al composition can effectively improve both the internal quantum efficiency (IQE) and light output power (LOP) compared to commonly adopted single-Al-composition barrier for AlGaN multiple quantum wells (MQWs). It is verified that electrons in the active region are effectively blocked by the raised barriers, while holes can gain more kinetic energy to cross the barrier height and then be injected into the active region. Thus the carrier recombination rate in the DUV-LEDs adopting the H-shaped quantum barriers can prevail much over the conventional one.