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First-principles investigation of Peierls-like distortions and charge disproportionation in complex halide perovskites

ORAL

Abstract

Halide perovskites are attractive materials for solar energy conversion applications due to their strong light-matter interactions, structural tunability, and the relative ease with which they can be synthesized and processed. Recent calculations and measurements on mixed-valent halide perovskites reveal Peierls-like distortions and charge disproportionation as a function of externally applied isotropic pressure. However, a detailed picture of the underlying microscopic mechanism, particularly the electronic states which drive distortion, as well as a characterization of material classes for which these effects occur, are still missing. In this talk, we use first principles density functional theory calculations with hybrid functionals and DFT-parameterized reduced Hamiltonians to investigate how pressure and atomic substitutions affect the electronic structure. Our findings provide insight into the precise nature of the localized states which drive charge disproportionation. Our calculations set the stage for understanding charge transport mechanisms in this important class of materials and further guide the design of next-generation halide perovskite-based photovoltaic devices.

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Presenters

  • Armin Eghdami

    Department of Physics, University of California, Berkeley, University of California, Berkeley

Authors

  • Armin Eghdami

    Department of Physics, University of California, Berkeley, University of California, Berkeley

  • Jonah B Haber

    University of California, Berkeley, Materials Sciences Division, Lawrence Berkeley National Laboratory, Lawrence Berkeley National Laboratory

  • Nathan R Wolf

    Department of Chemistry, Stanford University, Stanford

  • Hemamala I Karunadasa

    Department of Chemistry, Stanford University, Stanford; Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park

  • Jeffrey B Neaton

    Lawrence Berkeley National Laboratory, University of California, Berkeley, Department of Physics, University of California, Berkeley; Materials Sciences Division, Lawrence Berkeley National Laboratory; Kavli Energy NanoScience Institute at Berkeley