Test of the Dynamic-Domain and Critical Scattering Hypotheses in Cubic Methylammonium Lead Triiodide

Published

August 10, 2020

Author(s)

Nicholas J. Weadock, Peter M. Gehring, Aryeh Gold-Parker, Ian C. Smith, Hemamala I. Karunadasa, Michael F. Toney

Abstract

We investigate the hypothesis of dynamic tetragonal domains occuring in cubic CH₃NH₃PbI₃ using high-resolution neutron spectroscopy to study a fully deuterated single crystal. The R-point scattering above the 327.5 K tetragonal-cubic phase transition is always resolution-limited in energy and therefore inconsistent with dynamic domain predictions. This behavior is instead consistent with the central peak phenomenon observed in other perovskites. The scattering may originate from small, static, tetragonal-phase domains nucleating about crystal defects, and the temperature dependence demonstrates the transition is first-order

Citation

Physical Review Letters

Volume

125

Issue

7

Pub Type

Journals

Keywords

methylammonium lead triiodide, hybrid organic inorganic perovskites, central peak, photovoltaic, critical scattering, structural phase transitions, neutron scattering

Citation

Weadock, N. , Gehring, P. , Gold-Parker, A. , Smith, I. , Karunadasa, H. and Toney, M. (2020), Test of the Dynamic-Domain and Critical Scattering Hypotheses in Cubic Methylammonium Lead Triiodide, Physical Review Letters (Accessed October 9, 2025)