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

Amanda J. Neukirch, Iwnetim I. Abate, Liujiang Zhou, Wanyi Nie, Hsinhan Tsai, Laurent Pedesseau, Jacky Even, Jared J. Crochet, Aditya D. Mohite, Claudine Katan, Sergei Tretiak

Research output: Contribution to journalArticlepeer-review

37 Citations (Scopus)


Halide perovskites have demonstrated remarkable performance in optoelectronic applications. Despite extraordinary progress, questions remain about device stability. We report an in-depth computational study of small polaron formation, electronic structure, charge density, and reorganization energies of several experimentally relevant halide perovskites using isolated clusters. Local lattice symmetry, electronic structure, and electron-phonon coupling are interrelated in polaron formation in these materials. To illustrate this, first-principles calculations are performed on (MA/Cs/FA)Pb(I/Br) 3 and MASnI 3 . Across the materials studied, electron small polaron formation is manifested by Jahn-Teller-like distortions in the central octahedron, with apical PbI bonds expanding significantly more than the equatorial bonds. In contrast, hole polarons cause the central octahedron to uniformly contract. This difference in manifestation of electron and hole polaron formation can be a tool to determine what is taking place in individual systems to systematically control performance. Other trends as the anion and cations are changed are established for optimization in specific optoelectronic applications.

Original languageEnglish
Pages (from-to)7130-7136
Number of pages7
JournalJournal of Physical Chemistry Letters
Issue number24
Publication statusPublished - 20 Dec 2018
Externally publishedYes


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