Affiliation:
1. Zhengzhou University
2. Institute of Intelligence Sensing, Zhengzhou University
3. Research Institute of Industrial Technology Co. Ltd., Zhengzhou University
4. Zhengzhou Way Do Electronics Co. Ltd.
5. North Minzu University
Abstract
Ultraviolet light emitting diodes (UV-LEDs) face the challenges including insufficient hole injection and severe electron leakage. Quantum dots (QDs) have been proven to provide three-dimensionally localized states for carriers, thereby enhancing carrier confinement. Therefore, UV-LEDs employing InGaN QDs are designed and studied in this paper. The APSYs software is used to simulate UV-LEDs. Simulation results indicate that the QDs effectively improve the electron and hole concentration in the active region. However, UV-LEDs with QDs experience efficiency droop due to serious electron leakage. What’s more, the lattice mismatch between last quantum barrier (LQB) and electron blocking layer (EBL) leads to the polarization field, which induces the downward band bending at the LQB/EBL interface and reduces effective barrier height of EBL for electrons. The AlInGaN/AlInGaN lattice matched superlattice (LMSL) EBL is designed to suppress electron leakage while mitigating lattice mismatch between LQB and EBL. The results indicate that the utilization of QDs and LMSL EBL contributes to increasing the electron and hole concentration in the active region, reducing electron leakage, enhancing radiative recombination rate, and reducing turn-on voltage. The efficiency droop caused by electron leakage is mitigated. When the injection current is 120 mA, the external quantum efficiency is increased to 9.3% and the output power is increased to 38.3 mW. This paper provides a valuable reference for addressing the challenges of insufficient hole injection and severe electron leakage.
Funder
National Natural Science Foundation of China
National Key Research and Development Program of China
Key Program for International Joint Research of Henan Province
Science and Technology Innovation 2025 Major Project of Ningbo
Zhengzhou 1125 Innovation Project
Subject
Atomic and Molecular Physics, and Optics