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Identifying and Reducing Interfacial Losses to Enhance Color-Pure Electroluminescence in Blue-Emitting Perovskite Nanoplatelet Light-Emitting Diodes.

Accepted version
Peer-reviewed

Type

Article

Change log

Authors

Hoye, Robert LZ 
Lai, May-Ling 
Anaya, Miguel 
Tong, Yu 
Gałkowski, Krzysztof 

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.

Description

Keywords

physics.optics, physics.optics, physics.app-ph

Journal Title

ACS Energy Lett

Conference Name

Journal ISSN

2380-8195
2380-8195

Volume Title

4

Publisher

American Chemical Society (ACS)

Rights

All rights reserved
Sponsorship
Royal Academy of Engineering (RAEng) (RF\201718\17101)
Engineering and Physical Sciences Research Council (EP/M005143/1)
Engineering and Physical Sciences Research Council (EP/L016087/1)
Engineering and Physical Sciences Research Council (EP/N004272/1)
Engineering and Physical Sciences Research Council (EP/L011700/1)
European Research Council (756962)
EPSRC (1647980)
European Commission Horizon 2020 (H2020) Marie Sk?odowska-Curie actions (841386)