Geometry Distortion and Small Polaron Binding Energy Changes with Ionic Substitution in Halide Perovskites

ORAL

Abstract

Solution-processed organometallic perovskites have demonstrated remarkable performances in optoelectronic devices and applications. Despite the extraordinary progress associated with perovskite materials, many questions about the fundamental photophysical processes taking place in these devices, remain open. Here we report the results from an in-depth computational study of small polaron formation, electronic structure, charge density, and reorganization energies using isolated structures. Local lattice symmetry, electronic structure, and electron phonon coupling are interrelated in polaron formation in hybrid halide perovskites. To illustrate these aspects, first principles calculations are performed on CsPbI3, CsSnI3, CsPbBr3, MAPbI3, FAPbI3, MAPbBr3, FAPbBr3, MASnI3, and FASnBr3. This study will focus on how ionic substitution changes the polaron binding energy in the material. It is found that in all cases that hole polaron formation is associated with lattice contraction, while electron polaron formation is associated with lattice expansion.

*The work at Los Alamos National Laboratory was suppored by the LANL LDRD program. This work was done in part at the Center for Nonlinear Studies and the Center for Integrated Nanotechnologies.

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Presenters

  • Amanda Neukirch

    • Los Alamos National Laboratory

Authors

  • Amanda Neukirch

    • Los Alamos National Laboratory

  • Liujiang Zhou

    • Los Alamos National Laboratory

  • Iwnetim Abate

    • Stanford
    • Stanford Univ

  • Jacky Even

    • INSA FOTON
    • INSA de Rennes
    • Université de Rennes 1
    • Fonctions Optiques pour les Technologies de l’Information (FOTON), Institut National des Sciences Appliquées (INSA) de Rennes, CNRS, UMR 6082

  • Sergei Tretiak

    • Los Alamos Natl Lab
    • Los Alamos National Lab
    • Los Alamos National Laboratory
    • Physics and Chemistry of Materials, Los Alamos National Laboratory