Determining Atomic-Scale Structure and Composition of Organo-Lead Halide Perovskites by Combining High-Resolution X-ray Absorption Spectroscopy and First-Principles Calculations [electronic resource].
- Washington, D.C. : United States. Dept. of Energy. Office of Basic Energy Sciences, 2017. and Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy
- Physical Description:
- pages 1,183-1,189 : digital, PDF file
- Additional Creators:
- Lawrence Berkeley National Laboratory, United States. Department of Energy. Office of Basic Energy Sciences, and United States. Department of Energy. Office of Scientific and Technical Information
- Restrictions on Access:
- Free-to-read Unrestricted online access
- In this paper, we combine high-energy resolution fluorescence detection (HERFD) X-ray absorption spectroscopy (XAS) measurements with first-principles density functional theory (DFT) calculations to provide a molecular-scale understanding of local structure, and its role in defining optoelectronic properties, in CH<sub>3</sub>NH<sub>3</sub>Pb(I<sub>1–x</sub>Br<sub>x</sub>)<sub>3</sub> perovskites. The spectra probe a ligand field splitting in the unoccupied d states of the material, which lie well above the conduction band minimum and display high sensitivity to halide identity, Pb-halide bond length, and Pb-halide octahedral tilting, especially for apical halide sites. The spectra are also sensitive to the organic cation. We find that the halides in these mixed compositions are randomly distributed, rather than having preferred octahedral sites, and that thermal tilting motions dominate over any preferred structural distortions as a function of halide composition. Finally, these findings demonstrate the utility of the combined HERFD XAS and DFT approach for determining structural details in these materials and connecting them to optoelectronic properties observed by other characterization methods.
- Published through SciTech Connect., 04/20/2017., "ark:/13030/qt1b5598dh", ACS Energy Letters 2 5 ISSN 2380-8195 AM, and Walter S. Drisdell; Linn Leppert; Carolin M. Sutter-Fella; Yufeng Liang; Yanbo Li; Quynh P. Ngo; Liwen F. Wan; Sheraz Gul; Thomas Kroll; Dimosthenis Sokaras; Ali Javey; Junko Yano; Jeffrey B. Neaton; Francesca M. Toma; David Prendergast; Ian D. Sharp.
- Funding Information:
- AC02-05CH11231, AC02-76SF00515, and SC0004993
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