Journal of Sensor Science and Technology (센서학회지)

The Korean Sensors Society (한국센서학회)
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Improved Performance of All-Solution-Processed Inverted InP Quantum Dot Light-Emitting Diodes Using Electron Blocking Layer

전자차단층 도입을 통한 전체 용액공정 기반의 역구조 InP 양자점 발광다이오드의 성능 향상

  • Heejae Roh (Department of Electrical Engineering, Pusan National University) ;
  • Kyoungeun Lee (Department of Electrical Engineering, Pusan National University) ;
  • Yeyun Bae (Department of Electrical Engineering, Pusan National University) ;
  • Jaeyeop Lee (Department of Electrical Engineering, Pusan National University) ;
  • Jeongkyun Roh (Department of Electrical Engineering, Pusan National University)
  • 노희재 (부산대학교 전기공학과) ;
  • 이경은 (부산대학교 전기공학과) ;
  • 배예윤 (부산대학교 전기공학과) ;
  • 이재엽 (부산대학교 전기공학과) ;
  • 노정균 (부산대학교 전기공학과)
  • Received : 2024.06.28
  • Accepted : 2024.07.22
  • Published : 2024.07.31
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Abstract

Quantum dot light-emitting diodes (QD-LEDs) are emerging as next-generation displays owing to their high color purity, wide color gamut, and solution processability. Enhancing the efficiency of QD-LEDs involves preventing non-radiative recombination mechanisms, such as Auger and interfacial recombination. Generally, ZnO serves as the electron transport layer, which is known for its higher mobility compared to that of organic semiconductors and can lead to excessive electron injection. Some of the injected electrons pass through the quantum dot emissive layer and undergo non-radiative recombination near or within the organic hole transport layer (HTL), resulting in HTL degradation. Therefore, the implementation of electron blocking layers (EBLs) is essential; however, studies on all-solution-processed inverted InP QD-LEDs are limited. In this study, poly(9-vinylcarbazole) (PVK) is introduced as an EBL to mitigate HTL degradation and enhance the emission efficiency of inverted InP QD-LEDs. Using a single-carrier device, PVK was confirmed to effectively inhibit electron overflow into the HTL, even at extremely low thicknesses. The optimization of the PVK thickness also ensured minimal disruption of the hole-injection properties. Consequently, a 1.5-fold increase in the maximum luminance was achieved in the all-solution-processed inverted InP QD-LEDs with the EBL.

Keywords

Acknowledgement

This work was supported by a 2-Year Research Grant of Pusan National University.

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