Designs of InGaN Micro-LED Structure for Improving Quantum Efficiency at Low Current Density

Shiqiang Lu; Jinchai Li; Kai Huang; Guozhen Liu; Yinghui Zhou; Duanjun Cai; Rong Zhang; Junyong Kang

doi:10.1186/s11671-021-03557-4

Nanoscale Research Letters (Jun 2021)

Designs of InGaN Micro-LED Structure for Improving Quantum Efficiency at Low Current Density

Shiqiang Lu,
Jinchai Li,
Kai Huang,
Guozhen Liu,
Yinghui Zhou,
Duanjun Cai,
Rong Zhang,
Junyong Kang

Affiliations

Shiqiang Lu: Fujian Key Laboratory of Semiconductor Materials and Applications, CI Center for OSED, College of Physical Science and Technology, Xiamen University
Jinchai Li: Fujian Key Laboratory of Semiconductor Materials and Applications, CI Center for OSED, College of Physical Science and Technology, Xiamen University
Kai Huang: Fujian Key Laboratory of Semiconductor Materials and Applications, CI Center for OSED, College of Physical Science and Technology, Xiamen University
Guozhen Liu: Fujian Key Laboratory of Semiconductor Materials and Applications, CI Center for OSED, College of Physical Science and Technology, Xiamen University
Yinghui Zhou: Fujian Key Laboratory of Semiconductor Materials and Applications, CI Center for OSED, College of Physical Science and Technology, Xiamen University
Duanjun Cai: Fujian Key Laboratory of Semiconductor Materials and Applications, CI Center for OSED, College of Physical Science and Technology, Xiamen University
Rong Zhang: Fujian Key Laboratory of Semiconductor Materials and Applications, CI Center for OSED, College of Physical Science and Technology, Xiamen University
Junyong Kang: Fujian Key Laboratory of Semiconductor Materials and Applications, CI Center for OSED, College of Physical Science and Technology, Xiamen University

DOI: https://doi.org/10.1186/s11671-021-03557-4
Journal volume & issue: Vol. 16, no. 1
pp. 1 – 16

Abstract

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Abstract Here we report a comprehensive numerical study for the operating behavior and physical mechanism of nitride micro-light-emitting-diode (micro-LED) at low current density. Analysis for the polarization effect shows that micro-LED suffers a severer quantum-confined Stark effect at low current density, which poses challenges for improving efficiency and realizing stable full-color emission. Carrier transport and matching are analyzed to determine the best operating conditions and optimize the structure design of micro-LED at low current density. It is shown that less quantum well number in the active region enhances carrier matching and radiative recombination rate, leading to higher quantum efficiency and output power. Effectiveness of the electron blocking layer (EBL) for micro-LED is discussed. By removing the EBL, the electron confinement and hole injection are found to be improved simultaneously, hence the emission of micro-LED is enhanced significantly at low current density. The recombination processes regarding Auger and Shockley–Read–Hall are investigated, and the sensitivity to defect is highlighted for micro-LED at low current density. Synopsis: The polarization-induced QCSE, the carrier transport and matching, and recombination processes of InGaN micro-LEDs operating at low current density are numerically investigated. Based on the understanding of these device behaviors and mechanisms, specifically designed epitaxial structures including two QWs, highly doped or without EBL and p-GaN with high hole concentration for the efficient micro-LED emissive display are proposed. The sensitivity to defect density is also highlighted for micro-LED.

Published in Nanoscale Research Letters

ISSN: 1931-7573 (Print); 1556-276X (Online)
Publisher: SpringerOpen
Country of publisher: United Kingdom
LCC subjects: Technology: Electrical engineering. Electronics. Nuclear engineering: Materials of engineering and construction. Mechanics of materials
Website: https://www.springer.com/journal/11671

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