An Efficient Hole Transporting Polymer for Quantum Dot Light‐Emitting Diodes. Issue 15 (15th July 2021)

• Record Type: Journal Article
• Authors: Wu, Wenhai; Chen, Zhao; Zhan, Yunfeng; Liu, Bochen; Song, Weidong; Guo, Yue; Yan, Ji; Yang, Xiaolong; Zhou, Zhi; Wong, Wai‐Yeung
• Is Part Of: Advanced materials interfaces. Volume 8:Issue 15(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-07-15
• Subjects: high external quantum efficiencies -- high hole conductivities -- hole transporting polymers -- quantum dot light‐emitting diodes -- stabilized highest occupied molecular orbitals; Materials science -- Periodicals; 620.11
• DOI: 10.1002/admi.202100731
• Languages: English
• ISSNs: 2196-7350

Abstract

Abstract: Ideal hole transporting polymers used in quantum dot (QD) light‐emitting diodes (QLEDs) should possess the features such as high conductivities and stabilized highest occupied molecular orbitals (HOMOs). Herein, an efficient polymer (named CNPr‐TFB) is achieved by rationally adding a relatively weak electron‐withdrawing group (2‐cyanopropan‐2‐yl, CNPr) on a TFB like hole transporting polymer. CNPr‐TFB exhibits a superior hole conductivity and much more stabilized HOMO in comparison with TFB. Therefore, much more holes are delivered into the QD emissive layers and a balanced recombination of electron and hole in the QLEDs is achieved. The external quantum efficiencies of the red, green, blue, and white QLEDs made by CNPr‐TFB as the hole transporting layer (HTL) are 20.7%, 16.6%, 11.3%, and 15.0%, respectively, which are increased by 1.4–2.3 times in comparison with those of devices based on the commonly used TFB HTL. Meanwhile, the CNPr‐TFB‐based QLEDs also exhibit longer operation lifetimes than those of devices using the TFB HTL. These results confirm that CNPr‐TFB with the features of high conductivity and stabilized HOMO can be an excellent HTL material for the QLED applications Abstract : A new polymer CNPr‐TFB with high hole conductivity and stabilized highest occupied molecular orbital is used as a hole transporting polymer for quantum dot‐based light‐emitting diode (QLED) applications. It affords red, green, blue, and white QLEDs with the peak external quantum efficiencies of 20.7%, 16.6%, 11.3%, and 15.0%, respectively, which are superior to those of TFB‐based devices. Therefore, CNPr‐TFB can be an excellent hole transporting polymer for further QLED applications.