AlGaN-based deep-ultraviolet light-emitting diodes (DUV LEDs) have been identified as a prospective mercury-free UV source. However, the observation of severe electron overflow and low hole injection efficiency in the conventional DUV LED deteriorates the device performance, attributing to the downward band bending as a result of the strong polarization-induced electric fields between the last quantum barrier (LQB) and the electron blocking layer (EBL). In this study, a composition-graded AlGaN layer with linearly increasing of Al composition from 0.5 to 0.65 is proposed to act as the LQB, replacing the conventional flat LQB to reduce the effective barrier height for hole injection while improving the electron blocking ability. Hence, a considerable enhancement of the output power can be obtained. Moreover, further investigations show that the thickness of graded LQB determine the band bending in the LQB and thus significantly suppress the electron leakage, eventually leading to...

中文翻译：

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极化设计的AlGaN最后量子屏障，用于高效的深紫外发光二极管

基于AlGaN的深紫外发光二极管（DUV LED）已被确认为潜在的无汞UV源。但是，在传统的DUV LED中观察到严重的电子溢出和低空穴注入效率会降低器件性能，这归因于最后一个量子势垒（LQB）与半导体之间的强极化感应电场所致的向下带弯曲。电子阻挡层（EBL）。在这项研究中，提出了一种将Al组成从0.5线性增加到0.65的成分渐变的AlGaN层作为LQB，以代替传统的平面LQB来减小空穴注入的有效势垒高度，同时提高电子阻挡能力。因此，可以获得输出功率的显着提高。此外，