Optimizing InGaN Micro-LED Efficiency: Investigating the Internal Quantum Efficiency and Ideality Factor Connection

Mengyuan Zhanghu1; Yibo Liu2; Byung-Ryool Hyun1; Yanfei Li1; Zhaojun Liu1

2024

10.1109/TED.2024.3449829

IEEE Transactions on Electron Devices   影响因子和分区

1557-9646

We present a significant enhancement of internal quantum efficiency (IQE) exceeding 90% in InGaN-based Micro-light-emitting diodes (Micro-LEDs) achieved through sidewall passivation using atomic layer deposition (ALD). An intriguing observation is an inverse correlation between the diode ideality factor and IQE; devices boasting over 90% IQE consistently exhibit a diode ideality factor below 1.5. Specifically, for 10- $\mu$ m-sized devices, an IQE of 95.6% paired with a remarkably low ideality factor of 1.27 is realized, representing the pinnacle of achievable IQE at room temperature. In addition, enhanced light extraction efficiency (LEE) is observed through a low-refractive-index dielectric layer for passivation, facilitating a large critical angle at the interfaces. However, despite these advancements, the LEE for passivated devices remains at approximately 26%, resulting in an external quantum efficiency (EQE) of 25%. Consequently, our findings strongly advocate further device performance improvements in Micro-LEDs by enhancing LEE, necessitating novel device structures. In addition, we report the groundbreaking verification of the unity ideality factor for radiative recombination current in InGaN-based Micro-LEDs. This achievement is realized through the isolation of the radiative current component from the total current, thus substantiating the legitimacy of employing the Shockley–Read–Hall (SRH) to analyze the electrical characteristics of InGaN Micro-LEDs.

第一

1.Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen, China
2.Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Hong Kong, China

Mengyuan Zhanghu,Yibo Liu,Byung-Ryool Hyun,et al. Optimizing InGaN Micro-LED Efficiency: Investigating the Internal Quantum Efficiency and Ideality Factor Connection[J]. IEEE Transactions on Electron Devices,2024,PP(99).

Mengyuan Zhanghu,Yibo Liu,Byung-Ryool Hyun,Yanfei Li,&Zhaojun Liu.(2024).Optimizing InGaN Micro-LED Efficiency: Investigating the Internal Quantum Efficiency and Ideality Factor Connection.IEEE Transactions on Electron Devices,PP(99).

Mengyuan Zhanghu,et al."Optimizing InGaN Micro-LED Efficiency: Investigating the Internal Quantum Efficiency and Ideality Factor Connection".IEEE Transactions on Electron Devices PP.99(2024).