Thin Quaternary Layer and Staggered Electron Blocking Layers for Improved Ultraviolet Light-Emitting Diodes

Abstract

We have carried out numerical investigations of AlGaN-based ultraviolet light-emitting diodes (UV LEDs). We have shown that the unequal carrier distribution, which is typical in III-N LEDs, is mitigated in the active region. To improve the performance, we have used a thin AlInGaN quaternary layer (QL) between the final quantum barrier (FQB) and the electron blocking layer (EBL). We have also compared the results with a staggered or step-graded electron blocking layer (EBL) which is known to shown enhanced device output. The hole insertion has been found to greatly improve in all the multiquantum wells (MQWs) of our numerically designed LEDs. The radiative recombination rate has been found to be enhanced by ~82% in comparison to reference LED.