Identifying and reducing interfacial losses to enhance color-pure electroluminescence in blue-emitting perovskite nanoplatelet light-emitting diodes
Author(s)
Type
Journal Article
Abstract
Perovskite nanoplatelets (NPls) hold promise for light-emitting applications, having achieved photoluminescence quantum efficiencies approaching unity in the blue wavelength range, where other metal-halide perovskites have typically been ineffective. However, the external quantum efficiencies (EQEs) of blue-emitting NPl light-emitting diodes (LEDs) have reached only 0.12%. In this work, we show that NPl LEDs are primarily limited by a poor electronic interface between the emitter and hole injector. We show that the NPls have remarkably deep ionization potentials (≥6.5 eV), leading to large barriers for hole injection, as well as substantial nonradiative decay at the NPl/hole-injector interface. We find that an effective way to reduce these nonradiative losses is by using poly(triarylamine) interlayers, which lead to an increase in the EQE of the blue (464 nm emission wavelength) and sky-blue (489 nm emission wavelength) LEDs to 0.3% and 0.55%, respectively. Our work also identifies the key challenges for further efficiency increases.
Date Issued
2019-05-10
Date Acceptance
2019-04-17
Citation
ACS Energy Letters, 2019, 4 (5), pp.1181-1188
ISSN
2380-8195
Publisher
American Chemical Society (ACS)
Start Page
1181
End Page
1188
Journal / Book Title
ACS Energy Letters
Volume
4
Issue
5
Copyright Statement
© 2019 American Chemical Society
. This is an open access article published under a Creative Commons Attribution (CC-BY)
License (http://pubs.acs.org/page/policy/authorchoice_ccby_termsofuse.html), which permits unrestricted use, distribution and reproduction in any medium,
provided the author and source are cited.
. This is an open access article published under a Creative Commons Attribution (CC-BY)
License (http://pubs.acs.org/page/policy/authorchoice_ccby_termsofuse.html), which permits unrestricted use, distribution and reproduction in any medium,
provided the author and source are cited.
Sponsor
Magdalene College, University of Cambridge
Royal Academy of Engineering
Identifier
https://pubs.acs.org/doi/10.1021/acsenergylett.9b00571
Grant Number
RF\201718\17101
Publication Status
Published
Date Publish Online
2019-04-17