High Quantum Efficiency and Low Droop of 400-nm InGaN Near-Ultraviolet Light-Emitting Diodes Through Suppressed Leakage Current

High quantum efficiency and low efficiency droop of 400-nm InGaN near-ultraviolet (NUV) light-emitting diodes (LEDs) are achieved using Al<sub>0.05</sub>Ga<sub>0.95</sub>N quantum barriers and 3-nm thin Al<sub>0.3</sub>Ga<sub>0.7</sub>N insertion layer on last barrier before p-Al<sub>0.15</sub>Ga<sub>0.85</sub>N electron blocking layer. At 100 A/cm<sup>2</sup>, for the fabricated 0.1-mm<sup>2</sup>-size LEDs with special designed barriers, the external quantum efficiency increases from 23.8% to 40.7%, and the efficiency droop ratio decreases from 40.5% to as low as 10.3%, as compared with the conventional NUV LEDs. APSYS simulations reveal that a significant suppressed leakage current is the main reason for the performance enhancement.

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