Enhancing the performance of blue quantum-dot light-emitting diodes through the incorporation of polyethylene glycol to passivate ZnO as an electron transport layer. Issue 39 (17th June 2020)

• Record Type: Journal Article
• Authors: Sun, Jun-hao; Huang, Jia-hui; Lan, Xu-yan; Zhang, Feng-chun; Zhao, Ling-zhi; Zhang, Yong
• Is Part Of: RSC advances. Volume 10:Issue 39(2020)
• Page Start: 23121
• Page End: 23127
• Publication Date: 2020-06-17
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/d0ra03846f
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Highly efficient blue quantum-dot light-emitting diodes have been realized by blending PEG into ZnO nanoparticles as an electron transport layer due to regulating charge balance and passivating the surface defect states of ZnO nanoparticles. Abstract : The balance between charge transport and charge injection is always a key factor in enhancing the performance of quantum-dot light-emitting diodes (QD-LEDs), particularly for the blue QDs due to their large optical band gap and relatively low valence band level compared with their green and red counterparts. High performance blue QD-LEDs have been demonstrated by blending polyethylene glycol (PEG) into solution-processed ZnO nanocrystals as the electron transport layer. PEG can effectively tune the electron mobility of ZnO and simultaneously passivate its surface defect states. As a result, the maximum current efficiency (CE) and external quantum efficiency (EQE) of the blue QD-LEDs increased from 4.33 cd A −1 and 9.98% for pure ZnO to 8.03 cd A −1 and 14.84% for 4% PEG blended into ZnO, respectively. Furthermore, operational lifetime of the device is also significantly improved from 8.95 h to 25.06 h. This result indicates that PEG is a promising material for regulating the charge balance of the blue QD-LEDs.