Issue 18, 2017

Exploring the orthorhombic–tetragonal phase transition in CH3NH3PbI3: the role of atom kinetics

Abstract

Methylammonium lead tri-iodide is a polymorphic material with two temperature-induced phase transitions at 165 K and 327 K, accompanied by an orthorhombic-to-tetragonal and a tetragonal-to-cubic lattice modification. Understanding the origins of these transitions as well as their implications on the crystal structure of the material is fundamental for its technological optimization. Here, we use the density functional theory along with ab initio molecular dynamics to study the low-temperature phase transition of CH3NH3PbI3. Considering two kinetically robust models for the orthorhombic and the tetragonal phase, we show that the vibrational features of the material can be strongly affected by the orientations of the methylammonium ions. We argue that the orthorhombic–tetragonal transition is characterized by a partial rearrangement of the organic cations that locally relaxes the stress induced by the thermal movement of atoms. We finally propose a macroscopic model for the tetragonal phase that consists of rotated noncentrosymmetric domains, where the methylammonium ions are quasi-two-dimensionally confined around the ab crystallographic plane.

Graphical abstract: Exploring the orthorhombic–tetragonal phase transition in CH3NH3PbI3: the role of atom kinetics

Supplementary files

Article information

Article type
Paper
Submitted
14 Mar 2017
Accepted
13 Apr 2017
First published
13 Apr 2017

Nanoscale, 2017,9, 5896-5903

Exploring the orthorhombic–tetragonal phase transition in CH3NH3PbI3: the role of atom kinetics

I. Deretzis and A. La Magna, Nanoscale, 2017, 9, 5896 DOI: 10.1039/C7NR01818E

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements