Optical Tunneling to Improve Light Extraction in Quantum Dot and Perovskite Light-Emitting Diodes

Guanding Mei; Dan Wu; Shihao Ding; Wallace C. H. Choy; Kai Wang; Xiao Wei Sun

doi:10.1109/JPHOT.2020.3038275

IEEE Photonics Journal (Jan 2020)

Optical Tunneling to Improve Light Extraction in Quantum Dot and Perovskite Light-Emitting Diodes

Guanding Mei,
Dan Wu,
Shihao Ding,
Wallace C. H. Choy,
Kai Wang,
Xiao Wei Sun

Affiliations

Guanding Mei: Shenzhen Key Laboratory for Advanced Quantum Dot Displays and Lighting, Department of Electrical and Electronic Engineering, Guangdong University Key Lab for Advanced Quantum Dot Displays and Lighting, Southern University of Science and Technology, Shenzhen, China
Dan Wu: Shenzhen Key Laboratory for Advanced Quantum Dot Displays and Lighting, Department of Electrical and Electronic Engineering, Guangdong University Key Lab for Advanced Quantum Dot Displays and Lighting, Southern University of Science and Technology, Shenzhen, China
Shihao Ding: Shenzhen Key Laboratory for Advanced Quantum Dot Displays and Lighting, Department of Electrical and Electronic Engineering, Guangdong University Key Lab for Advanced Quantum Dot Displays and Lighting, Southern University of Science and Technology, Shenzhen, China
Wallace C. H. Choy: Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, China
Kai Wang: ORCiD; Shenzhen Key Laboratory for Advanced Quantum Dot Displays and Lighting, Department of Electrical and Electronic Engineering, Guangdong University Key Lab for Advanced Quantum Dot Displays and Lighting, Southern University of Science and Technology, Shenzhen, China
Xiao Wei Sun: ORCiD; Shenzhen Key Laboratory for Advanced Quantum Dot Displays and Lighting, Department of Electrical and Electronic Engineering, Guangdong University Key Lab for Advanced Quantum Dot Displays and Lighting, Southern University of Science and Technology, Shenzhen, China

DOI: https://doi.org/10.1109/JPHOT.2020.3038275
Journal volume & issue: Vol. 12, no. 6
pp. 1 – 14

Abstract

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An effective strategy based on optical tunneling is developed to significantly improve the efficiency of quantum dots light-emitting diodes (QLEDs) and perovskite light-emitting diodes (PeLEDs). Contrary to the common impression that the hole transport layers (HTL) with low refractive index will severely confine lights according to Snell's law, optical tunneling unlocks a channel to extract the lights through HTL. In this work, we demonstrate the light beyond the critical angle still has a chance to penetrate into the substrate and finally emit outside the device. An optical tunneling model is also presented here to quantitatively describe the light extraction through optical tunneling and reveal related factors. Applying a thin HTL (thickness = 10 nm) and a high-index substrate (refractive index = 2) in the typical device architecture (Glass/ITO/PEDOT:PSS/EML/TPBi/LiF/Al), substrate modes can be improved from 18% to 60%. Therefore, optical tunneling followed by EES is believed to be a cost-effective strategy to enhance light extraction efficiency. This work unravels the potential to further significantly improve the efficiency of QLEDs and PeLEDs.

Published in IEEE Photonics Journal

ISSN: 1943-0655 (Online)
Publisher: IEEE
Country of publisher: United States
LCC subjects: Technology: Engineering (General). Civil engineering (General): Applied optics. Photonics; Science: Physics: Optics. Light
Website: http://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=4563994

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