The role of the alkali metal cations in halide perovskite solar cells is not well understood. Using synchrotron-based nano-x-ray fluorescence and complementary measurements, we found that the halide distribution becomes homogenized upon addition of cesium iodide, either alone or with rubidium iodide, for substoichiometric, stoichiometric, and overstoichiometric preparations, where the lead halide is varied with respect to organic halide precursors. Halide homogenization coincides with long-lived charge carrier decays, spatially homogeneous carrier dynamics (as visualized by ultrafast microscopy), and improved photovoltaic device performance. We found that rubidium and potassium phase-segregate in highly concentrated clusters. Alkali metals are beneficial at low concentrations, where they homogenize the halide distribution, but at higher concentrations, they form recombination-active second-phase clusters.
Journal article
Homogenized halides and alkali cation segregation in alloyed organic-inorganic perovskites
Science, Vol.363(6427), pp.627-631
08/Feb/2019
Abstract
Details
- Title
- Homogenized halides and alkali cation segregation in alloyed organic-inorganic perovskites
- Creators
- Juan-Pablo Correa-Baena (Corresponding Author) - Massachusetts Institute of TechnologyYanqi Luo (null) - University of California, San DiegoThomas M. Brenner (null) - The Weizmann Institute of ScienceJordan Snaider (null) - Purdue University SystemShijing Sun (null) - Massachusetts Institute of TechnologyXueying Li (null) - University of California, San DiegoMallory A. Jensen (null) - Massachusetts Institute of TechnologyNoor Titan Putri Hartono (null) - Massachusetts Institute of TechnologyLea Nienhaus (null) - Massachusetts Institute of TechnologySarah Wieghold (null) - Massachusetts Institute of TechnologyJeremy R. Poindexter (null) - Massachusetts Institute of TechnologyShen Wang (null) - University of California, San DiegoYing Shirley Meng (null) - University of California, San DiegoTi Wang (null) - Purdue University SystemBarry Lai (null) - University of ChicagoMartin V. Holt (null) - University of ChicagoZhonghou Cai (null) - University of ChicagoMoungi G. Bawendi (null) - Massachusetts Institute of TechnologyLibai Huang (null) - Purdue University SystemTonio Buonassisi (null) - Massachusetts Institute of TechnologyDavid P. Fenning (null) - University of California, San Diego
- Resource Type
- Journal article
- Publication Details
- Science, Vol.363(6427), pp.627-631; 08/Feb/2019
- Number of pages
- 5
- Language
- English
- DOI
- https://doi.org/10.1126/science.aah5065
- Grant note
- We thank P. Parikh for FIB sample preparation. Funding: Supported by the U.S. Department of Energy (DOE) EERE Postdoctoral Research Award (J.-P.C.-B); NSF grant CBET-1605495 (T.B.); Skoltech grant 1913/R as part of the Skoltech NGP Program (T.B., J.-P.C.-B., N.T.P.H., and S.W.); NSF grant DMR-1507803 (J.S., T.W., and L.H.); NSF grant GRFP 1122374 (M.A.J.); DOE grant DE-SC0001088 (L.N. and M.G.B.); California Energy Commission Advance Breakthrough EPC-16-050 (Y.L., S.W., Y.S.M., and D.P.F.); Hellman Fellowship (X.L. and D.P.F.); DOE grant DE-AC02-06CH11357 (Center for Nanoscale Materials and Advanced Photon Source, both Office of Science user facilities); NSF grant CHE-1338173 (TEM work at UC, Irvine, IMRI); and San Diego Nanotechnology Infrastructure with NSF grant ECCS-1542148 (FIB and EBIC). Author contributions: J.-P.C.-B. and T.B. conceived and designed the overall project; J.-P.C.-B. conducted SEM and XRD experiments, and prepared the perovskite devices; J.-P.C.-B., M.A.J., J.R.P., B.L., N.T.P.H., and S.W. conducted the initial synchrotron measurement (n-XRF); D.P.F., X.L., and Y.L. conducted follow-up n-XRF, XBIC, and SXDM experiments; T.M.B., S.W., Y.L., Y.S.M., and D.P.F. conducted the EBIC measurements; S.W. and Y.S.M. conducted the TEM measurements; J.S., T.W., and L.H. conducted confocal transient absorption microscopy for mapping; L.N. and M.G.B. conducted the PL measurements; T.B., D.P.F., and J.-P.C.-B. directed and supervised the research; J.-P.C.-B. and Y.L. wrote the first draft of the paper; and all authors contributed to the discussion and writing of the paper. Competing interests: The authors declare no competing financial interests. Data and materials availability: All data are available in the manuscript or the supplementary materials.
- Record Identifier
- 993264995103596
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