Silicon-Quantum-Dot Light-Emitting Diodes With Interlayer-Enhanced Hole Transport

Wei Gu; Xiangkai Liu; Xiaodong Pi; Xingliang Dai; Shuangyi Zhao; Li Yao; Dongsheng Li; Yizheng Jin; Mingsheng Xu; Deren Yang; Guogang Qin

doi:10.1109/JPHOT.2017.2671023

IEEE Photonics Journal (Jan 2017)

Silicon-Quantum-Dot Light-Emitting Diodes With Interlayer-Enhanced Hole Transport

Wei Gu,
Xiangkai Liu,
Xiaodong Pi,
Xingliang Dai,
Shuangyi Zhao,
Li Yao,
Dongsheng Li,
Yizheng Jin,
Mingsheng Xu,
Deren Yang,
Guogang Qin

Affiliations

Wei Gu: State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, China
Xiangkai Liu: State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, China
Xiaodong Pi: State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, China
Xingliang Dai: Center for Chemistry of High-Performance & Novel Materials, State Key Laboratory of Silicon Materials, Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang, China
Shuangyi Zhao: State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, China
Li Yao: State Key Laboratory of Silicon Materials, College of Information Science & Electronic Engineering, Zhejiang University, Hangzhou, Zhejiang, China
Dongsheng Li: State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, China
Yizheng Jin: Center for Chemistry of High-Performance & Novel Materials, State Key Laboratory of Silicon Materials, Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang, China
Mingsheng Xu: State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing, China
Deren Yang: State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, China
Guogang Qin: State Key Laboratory of Silicon Materials, College of Information Science & Electronic Engineering, Zhejiang University, Hangzhou, Zhejiang, China

DOI: https://doi.org/10.1109/JPHOT.2017.2671023
Journal volume & issue: Vol. 9, no. 2
pp. 1 – 10

Abstract

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Despite the technological importance of silicon quantum dots (Si QDs) which are solely made of abundant and nontoxic Si, Si-QD light-emitting diodes (LEDs) clearly lag behind those based on other QDs, especially Cd- or Pb-containing QDs. It is imperative that novel measures should be taken to boost the performance of Si-QD LEDs. Here, we demonstrate that Si-QD LEDs can work much more efficiently after the use of interlayers between indium tin oxide (ITO) and poly(ethylene-dioxythiophene):polystyrene sulphonate (PEDOT:PSS) to enhance the hole transport of the devices. The interlayer of dipyrazino (2, 3-f:2 ', 3 '-h) quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HAT-CN) or MoO3 increases the work function of ITO and improves the band alignment, leading to better hole injection from ITO to PEDOT:PSS. The resulting mitigated charge unbalance causes both the external quantum efficiency (EQE) and stability of Si-QD LEDs to significantly increase (up to ~170% for EQE and ~240% for device half-lifetime). The highest EQE of ~2.4% obtained in the current work is among the best values that have been reported for Si-QD LEDs. Even without encapsulation, the device half-lifetime is up to ~8.5 h. The enhancement of the hole transport induced by MoO3 is more significant than that induced by HAT-CN. Therefore, MoO3 more significantly enhances the performance of Si-QD LEDs than HAT-CN.

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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