Inversion symmetry in methylammonium lead iodided single crystals probed by second harmonic optical anisotropy

ORAL

Abstract

Single crystals of the methylammonium lead iodide perovskite (CH3NH3PbI3) are promising candidates for solar cells due to their long (tens of microns) photo-carrier diffusion lengths.[1] It has been proposed that such long diffusion lengths are a consequence of bulk static Rashba fields resulting from an absence of bulk inversion symmetry at room temperature.[2] Here we directly probe the point group symmetries of CH3NH3PbI3 using high sensitivity optical second harmonic rotational anisotropy measurements. We show that contrary to previous proposals, the bulk crystallographic structure of tetragonal CH3NH3PbI3 at room temperature is centrosymmetric with a space group of I4/mcm. These results are consistent with our density functional theory calculations, which establish the absence of a large bulk Rashba effect and show that incorrect structural relaxations are responsible for the previously predicted large Rashba effect.

[1] S. D. Stranks et al. Science 342, 341-344 (2013).
[2] Y. Rakita et al. Proc. Natl. Ac. Sci. USA 114, 5504-5512 (2017).

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Presenters

  • Tejas Deshpande

    Department of Physics, California Institute of Technology

Authors

  • Tejas Deshpande

    Department of Physics, California Institute of Technology

  • John Harter

    Department of Physics, California Institute of Technology

  • Kyle Frohna

    Department of Applied Physics and Materials Science, California Institute of Technology

  • Wei Peng

    Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology

  • Bradford Barker

    Department of Physics, University of California, Berkeley, Univ of California - Berkeley

  • Jeffrey Neaton

    Molecular Foundry, Lawrence Berkeley National Laboratory; Department of Physics, University of California, Berkeley; Kavli Energy Nanosciences Institute at Berkeley, Physics, University of California, Berkeley; Lawrence Berkeley National Laboratory, Department of Physics, University of California, Univ of California - Berkeley, Lawrence Berkeley Natl Lab, Materials Science Division, Lawrence Berkeley National Laboratory, Molecular Foundry, Lawrence Berkeley National Lab, Physics, University of California, Berkeley, Department of Physics UCB; Molecular Foundry LBNL; Kavli ENSI, Lawrence Berkeley National Laboratory, Department of Physics, Univ of California - Berkeley, Lawrence Berkeley National Lab and University of California - Berkeley

  • Steven Louie

    Physics, University of California, Berkeley, University of California, Berkeley, Physics, Univ of California - Berkeley, Univ of California - Berkeley, Physics, UC Berkeley, Physics Department, UC Berkeley and Lawrence Berkeley National Lab, Department of Physics, University of California at Berkeley and Materials Sciences Division, Lawrence Berkeley National Laboratory, Department of Physics, University of California, Berkeley, Physics Department, University of California Berkeley and Lawrence Berkeley National Lab, Department of physics, University of California - Berkeley, Lawrence Berkeley National Lab and University of California - Berkeley, Materials Sciences Division, Lawrence Berkeley National Laboratory & Department of Physics, University of California at Berkeley, UC Berkeley and Lawrence Berkeley National Lab, Physics, University of California - Berkeley

  • Oman Bakr

    Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology

  • David Hsieh

    Institute for Quantum Information and Matter, Caltech, Department of Physics, California Institute of Technology, California Institute of Technology, Institute For Quantum Information and Matter, California Institute of Technology

  • Marco Bernardi

    Caltech, Department of Applied Physics and Materials Science, California Institute of Technology, Applied Physics and Materials Science, California Institute of Technology, Department of Applied Physics and Materials Science, Steele Laboratory, California Institute of Technology, Applied Physics and Materials Science, Caltech