Probing buried recombination pathways in perovskite structures using 3D photoluminescence tomography
Zhumekenov, Ayan A.
Barnard, Edward S.
Stranks, Samuel D.
KAUST DepartmentFunctional Nanomaterials Lab (FuNL)
KAUST Catalysis Center (KCC)
Material Science and Engineering Program
Physical Science and Engineering (PSE) Division
Permanent link to this recordhttp://hdl.handle.net/10754/628488
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AbstractPerovskite 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.
CitationStavrakas C, Zhumekenov AA, Brenes R, Abdi-Jalebi M, Bulović V, et al. (2018) Probing buried recombination pathways in perovskite structures using 3D photoluminescence tomography. Energy & Environmental Science. Available: http://dx.doi.org/10.1039/c8ee00928g.
SponsorsA. A. Z. and O. M. B. gratefully acknowledge the funding support from King Abdullah University of Science and Technology (KAUST). Work at the Molecular Foundry was supported by the Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. C. S. thanks the EPSRC (Nano-Doctoral Training Centre), the Cambridge Trust and a Winton Graduate Exchange Scholarship for funding. This project has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under REA grant agreement number PIOF-GA-2013-622630, and the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement number 756962). S. D. S. acknowledges support from the Royal Society and Tata Group (UF150033).
PublisherRoyal Society of Chemistry (RSC)
JournalEnergy & Environmental Science
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