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Probing buried recombination pathways in perovskite structures using 3D photoluminescence tomography.

Published version
Peer-reviewed

Type

Article

Change log

Authors

Zhumekenov, Ayan A 
Brenes, Roberto 
Abdi-Jalebi, Mojtaba  ORCID logo  https://orcid.org/0000-0002-9430-6371
Bulović, Vladimir 

Abstract

Perovskite solar cells and light-emission devices are yet to achieve their full potential owing in part to microscale inhomogeneities and defects that act as non-radiative loss pathways. These sites have been revealed using local photoluminescence mapping techniques but the short absorption depth of photons with energies above the bandgap means that conventional one-photon excitation primarily probes the surface recombination. Here, we use two-photon time-resolved confocal photoluminescence microscopy to explore the surface and bulk recombination properties of methylammonium lead halide perovskite structures. By acquiring 2D maps at different depths, we form 3D photoluminescence tomography images to visualise the charge carrier recombination kinetics. The technique unveils buried recombination pathways in both thin film and micro-crystal structures that aren't captured in conventional one-photon mapping experiments. Specifically, we reveal that light-induced passivation approaches are primarily surface-sensitive and that nominal single crystals still contain heterogeneous defects that impact charge-carrier recombination. Our work opens a new route to sensitively probe defects and associated non-radiative processes in perovskites, highlighting additional loss pathways in these materials that will need to be addressed through improved sample processing or passivation treatments.

Description

Keywords

0912 Materials Engineering, Biotechnology

Journal Title

Energy Environ Sci

Conference Name

Journal ISSN

1754-5692
1754-5706

Volume Title

11

Publisher

Royal Society of Chemistry (RSC)
Sponsorship
European Commission (622630)
Royal Society (UF150033)
European Research Council (756962)
Engineering and Physical Sciences Research Council (EP/M005143/1)
EPSRC (Nano-Doctoral Training Centre) U.S. Department of Energy Winton Graduate Exchange Scholarship European Union’s Seventh Framework Programme (PIOF-GA-2013-622630) European Union’s Horizon 2020 research and innovation programme (ERC 756962) Royal Society and Tata Group (UF150033) EPSRC (EP/M005143/1)