Composition-dependent trapezoidal quantum barrier effect on efficiency droop in GaN-based light-emitting diodes

• Published in: Journal of the Korean Physical Society 2023-10, Vol.83 (7), p.581-587
• Main Authors: Kim, Sang Ryung, Oh, Semi, Jung, Sanghoon, Kang, Byoungho, Lee, Wanghoon
• Format: Article
• Language: English
• Subjects: Augers; Composition; Electric fields; Energy bands; Gallium nitrides; Light emitting diodes; Mathematical and Computational Physics; Original Paper - Cross-Disciplinary Physics and Related Areas of Science and Technology; Particle and Nuclear Physics; Physics; Physics and Astronomy; Quantum efficiency; Quantum wells; Theoretical
• ISSN: 0374-4884; 1976-8524
• DOI: 10.1007/s40042-023-00898-4

We systematically investigated GaN-based light-emitting diodes (LEDs) with composition-dependent trapezoidal quantum barriers (QBs) to analyze the efficiency droop behavior at low and high current densities. The simulation results show that the electrostatic field in the quantum wells (QWs) is gradually reduced by increasing the indium composition in the trapezoidal QBs. The electroluminescence (EL) intensity of an LED with trapezoidal QBs (In = 8%) at 300 mA was increased by 12.2% compared to the reference LED with square-type QBs. The internal quantum efficiency (IQE) droop of the LED with trapezoidal QBs (In = 10%) is 6% at 300 A·cm −2 , while the reference LED with square-type GaN barriers has 5 times higher IQE droop (31%). The increased EL intensity and reduced IQE droop in the LED with trapezoidal QBs are attributed to the reduced energy band bending, the decreased Auger nonradiative recombination, and the efficient electron blocking in multiple QWs.