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Light-emitting Diodes based on a Densely Packed QD Film Deposited by the Langmuir-Blodgett Technique

랭뮤어-블롯젯을 통해 형성된 고밀도 양자점 박막과 이를 기반으로 한 발광다이오드

  • Rhee, Seunghyun (Division of Advanced Materials, Korea Research Institute of Chemical Technology) ;
  • Jeong, Byeong Guk (SKKU Advanced Institute of Nano Technology and Department of Nano Engineering, Sungkyunkwan University) ;
  • Roh, Jeongkyun (Department of Electrical Engineering, Pusan National University)
  • 이승현 (한국화학연구원 에너지소재연구센터) ;
  • 정병국 (성균관대학교 나노공학과) ;
  • 노정균 (부산대학교 전기공학과)
  • Received : 2022.06.30
  • Accepted : 2022.07.12
  • Published : 2022.07.31

Abstract

To achieve high-performance colloidal quantum dot light-emitting diodes (QD-LEDs), the use of a densely packed QD film is crucial to prevent the formation of leakage current pathways and increase in interface resistance. Spin coating is the most common method to deposit QDs; however, this method often produces pinholes that can act as short-circuit paths within devices. Since state-of-the-art QD-LEDs typically employ mono- or bi-layer QDs as an emissive layer because of their low conductivities, the use of a densely packed and pinhole-free QD film is essential. Herein, we introduce the Langmuir-Blodgett (LB) technique as a deposition method for the fabricate densely packed QD films in QD-LEDs. The LB technique successfully transfers a highly dense monolayer of QDs onto the substrate, and multilayer deposition is performed by repeating the transfer process. To validate the comparability of the LB technique with the standard QD-LED fabrication process, we fabricate and compare the performance of LB-based QD-LEDs to that of the spin-coating-based device. Owing to the non-destructiveness of the LB technique, the electroluminescence efficiency of the LB-based QD-LEDs is similar to that of the standard spin coating-based device. Thus, the LB technique is promising for use in optoelectronic applications.

Keywords

Acknowledgement

이 과제는 부산대학교 기본연구지원사업(2년)에 의하여 연구되었음.

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