Journal article
High Chloride Doping Levels Stabilize the Perovskite Phase of Cesium Lead Iodide
Nano Letters, Vol.16(6), pp.3563-3570
08/Jun/2016
Abstract
Cesium lead iodide possesses an excellent combination of band gap and absorption coefficient for photovoltaic applications in its perovskite phase. However, this is not its equilibrium structure under ambient conditions. In air, at ambient temperature it rapidly transforms to a nonfunctional, so-called yellow phase. Here we show that chloride doping, particularly at levels near the solubility limit for chloride in a cesium lead iodide host, provides a new approach to stabilizing the functional perovskite phase. In order to achieve high doping levels, we first co-deposit colloidal nanocrystals of pure cesium lead chloride and cesium lead iodide, thereby ensuring nanometer-scale mixing even at compositions that potentially exceed the bulk miscibility of the two phases. The resulting nanocrystal solid is subsequently fused into a polycrystalline thin film by chemically induced, room-temperature sintering. Spectroscopy and X-ray diffraction indicate that the chloride is further dispersed during sintering and a polycrystalline mixed phase is formed. Using density functional theory (DFT) methods in conjunction with nudged elastic band techniques, low-energy pathways for interstitial chlorine diffusion into a majority-iodide lattice were identified, consistent with the facile diffusion and fast halide exchange reactions observed. By comparison to DFT-calculated values (with the PBE exchange-correlation functional), the relative change in band gap and the lattice contraction are shown to be consistent with a Cl/I ratio of a few percent in the mixed phase. At these incorporation levels, the half-life of the functional perovskite phase in a humid atmosphere increases by more than an order of magnitude.
Details
- Title
- High Chloride Doping Levels Stabilize the Perovskite Phase of Cesium Lead Iodide
- Creators
- Subham Dastidar (null) - Drexel UniversityDavid A. Egger (null) - The Weizmann Institute of ScienceLiang Z. Tan (null) - University of PennsylvaniaSamuel B. Cromer (null) - Drexel UniversityAndrew D. Dillon (null)Shi Liu (null) - Carnegie Institution for ScienceLeeor Kronik (null) - The Weizmann Institute of ScienceAndrew M. Rappe (null)Aaron T. Fafarman (Corresponding Author) - Drexel University
- Resource Type
- Journal article
- Publication Details
- Nano Letters, Vol.16(6), pp.3563-3570; 08/Jun/2016
- Number of pages
- 8
- Language
- English
- DOI
- https://doi.org/10.1021/acs.nanolett.6b00635
- Grant note
- Drexel University; Dana and Yossie Hollander; Lise Meitner Minerva Center for Computational Chemistry; Austrian Science Fund (FWF) [J3608-N20]; Carnegie Institution for Science; Office of Naval Research [N00014-14-1-0761]; Department of Energy Office of Basic Energy Sciences [DE-FG02-07ER46431] S.D., A.D.D., and A.T.F. acknowledge support from Drexel University. D.A.E. and L.K. were supported by a research grant from Dana and Yossie Hollander, by the Lise Meitner Minerva Center for Computational Chemistry, and by the Austrian Science Fund (FWF): J3608-N20. S.L. is supported by Carnegie Institution for Science. L.Z.T. acknowledges support from the Office of Naval Research, under Grant N00014-14-1-0761. A.M.R. acknowledges support from the Department of Energy Office of Basic Energy Sciences, under Grant DE-FG02-07ER46431. The authors acknowledge computational support from the HPCMO of the DoD and the NERSC of the DOE. Author Contributions The manuscript was written through contributions of all authors. All authors have given approval to the final version of the manuscript._ALMAME_DELIMITER_
- Record Identifier
- 993264560603596
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