Boosting the Efficiency of NiOx-Based Perovskite Light-Emitting Diodes by Interface Engineering

Haoran Wang; Hao Yuan; Jiahao Yu; Chen Zhang; Kang Li; Mengqing You; Wenqiang Li; Jian Shao; Jun Wei; Xiaoyu Zhang; Rui Chen; Xuyong Yang; Weiwei Zhao

doi:10.1021/acsami.0c16139

Boosting the Efficiency of NiO_x-Based Perovskite Light-Emitting Diodes by Interface Engineering

ACS Appl Mater Interfaces. 2020 Nov 25;12(47):53528-53536. doi: 10.1021/acsami.0c16139. Epub 2020 Nov 12.

Authors

Haoran Wang^{1

2}, Hao Yuan³, Jiahao Yu⁴, Chen Zhang^{1

2}, Kang Li^{1

2}, Mengqing You³, Wenqiang Li³, Jian Shao^{1

2}, Jun Wei^{1

2}, Xiaoyu Zhang⁵, Rui Chen⁴, Xuyong Yang³, Weiwei Zhao^{1

2}

Affiliations

¹ Flexible Printed Electronics Technology Center, Harbin Institute of Technology, Shenzhen 518055, China.
² State Key Laboratory of Advanced Welding & Joining, Harbin Institute of Technology, Shenzhen 518055, China.
³ Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, 149 Yanchang Road, Shanghai 200072, China.
⁴ Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China.
⁵ College of Materials Science and Engineering, Jilin University, Changchun 130012, China.

PMID: 33179493
DOI: 10.1021/acsami.0c16139

Abstract

Nickel oxide (NiO_x) is a promising hole-transporting material for perovskite light-emitting diodes (PeLEDs) because of its low cost, excellent stability, and simple fabrication process. However, the electroluminescence efficiencies of NiO_x-based PeLEDs are greatly limited by inefficient hole injection and exciton quenching at the NiO_x-perovskite interfaces. Here, a novel interfacial engineering method with sodium dodecyl sulfate-oxygen plasma (SDS-OP) is demonstrated to simultaneously overcome the aforementioned issues. Experimental results reveal that a short OP treatment on the top of the SDS-coated NiO_x significantly deepens the NiO_x work function (from 4.23 to 4.85 eV) because of the formation of a large surface dipole, allowing for efficient hole injection. Moreover, the SDS-OP layer passivates the electronic surface trap states of perovskite films and suppresses the exciton quenching by NiO_x. These improvements inhibit the nonradiative decays at the NiO_x-perovskite interface. As a result, the external quantum efficiency of CsPbBr₃ LEDs is increased from 0.052 to 2.5%; that of FAPbBr₃ nanocrystals LEDs is increased from 5.6 to 7.6%.

Keywords: NiOx; PeLEDs; SDS; electroluminescence; interface; perovskite.