Distribution control enables efficient reduced-dimensional perovskite LEDs

Dongxin Ma; Kebin Lin; Yitong Dong; Hitarth Choubisa; Andrew H Proppe; Dan Wu; Ya-Kun Wang; Bin Chen; Peicheng Li; James Z Fan; Fanglong Yuan; Andrew Johnston; Yuan Liu; Yuetong Kang; Zheng-Hong Lu; Zhanhua Wei; Edward H Sargent

doi:10.1038/s41586-021-03997-z

Distribution control enables efficient reduced-dimensional perovskite LEDs

Nature. 2021 Nov;599(7886):594-598. doi: 10.1038/s41586-021-03997-z. Epub 2021 Nov 24.

Authors

Dongxin Ma¹, Kebin Lin², Yitong Dong¹, Hitarth Choubisa¹, Andrew H Proppe¹, Dan Wu³, Ya-Kun Wang¹, Bin Chen¹, Peicheng Li⁴, James Z Fan¹, Fanglong Yuan^{1

4}, Andrew Johnston¹, Yuan Liu¹, Yuetong Kang^{5

6}, Zheng-Hong Lu⁴, Zhanhua Wei⁷, Edward H Sargent⁸

Affiliations

¹ Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario, Canada.
² Xiamen Key Laboratory of Optoelectronic Materials and Advanced Manufacturing, Institute of Luminescent Materials and Information Displays, College of Materials Science and Engineering, Huaqiao University, Xiamen, People's Republic of China.
³ College of New Materials and New Energies, Shenzhen Technology University, Shenzhen, People's Republic of China.
⁴ Department of Materials Science and Engineering, University of Toronto, Toronto, Ontario, Canada.
⁵ Department of Chemistry, University of Victoria, Victoria, British Columbia, Canada.
⁶ State Key Laboratory for Advanced Metals and Materials, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, People's Republic of China.
⁷ Xiamen Key Laboratory of Optoelectronic Materials and Advanced Manufacturing, Institute of Luminescent Materials and Information Displays, College of Materials Science and Engineering, Huaqiao University, Xiamen, People's Republic of China. weizhanhua@hqu.edu.cn.
⁸ Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario, Canada. ted.sargent@utoronto.ca.

PMID: 34819678
DOI: 10.1038/s41586-021-03997-z

Abstract

Light-emitting diodes (LEDs) based on perovskite quantum dots have shown external quantum efficiencies (EQEs) of over 23% and narrowband emission, but suffer from limited operating stability¹. Reduced-dimensional perovskites (RDPs) consisting of quantum wells (QWs) separated by organic intercalating cations show high exciton binding energies and have the potential to increase the stability and the photoluminescence quantum yield^2,3. However, until now, RDP-based LEDs have exhibited lower EQEs and inferior colour purities^4-6. We posit that the presence of variably confined QWs may contribute to non-radiative recombination losses and broadened emission. Here we report bright RDPs with a more monodispersed QW thickness distribution, achieved through the use of a bifunctional molecular additive that simultaneously controls the RDP polydispersity while passivating the perovskite QW surfaces. We synthesize a fluorinated triphenylphosphine oxide additive that hydrogen bonds with the organic cations, controlling their diffusion during RDP film deposition and suppressing the formation of low-thickness QWs. The phosphine oxide moiety passivates the perovskite grain boundaries via coordination bonding with unsaturated sites, which suppresses defect formation. This results in compact, smooth and uniform RDP thin films with narrowband emission and high photoluminescence quantum yield. This enables LEDs with an EQE of 25.6% with an average of 22.1 ±1.2% over 40 devices, and an operating half-life of two hours at an initial luminance of 7,200 candela per metre squared, indicating tenfold-enhanced operating stability relative to the best-known perovskite LEDs with an EQE exceeding 20%^1,4-6.

Publication types

Research Support, Non-U.S. Gov't