Real-Time Observation of Organic Cation Reorientation in Methylammonium Lead Iodide Perovskites
File(s)Paper_MArotatioin_v31.pdf (1.16 MB)
Accepted version
Author(s)
Type
Journal Article
Abstract
The introduction of a mobile and polarized organic moiety as a cation in 3D lead-iodide perovskites brings fascinating optoelectronic properties to these materials. The extent and the time scales of the orientational mobility of the organic cation and the molecular mechanism behind its motion remain unclear, with different experimental and computational approaches providing very different qualitative and quantitative description of the molecular dynamics. Here we use ultrafast 2D vibrational spectroscopy of methylammonium (MA) lead iodide to directly resolve the rotation of the organic cations within the MAPbI3 lattice. Our results reveal two characteristic time constants of motion. Using ab initio molecular dynamics simulations, we identify these as a fast (∼300 fs) “wobbling-in-a-cone” motion around the crystal axis and a relatively slow (∼3 ps) jump-like reorientation of the molecular dipole with respect to the iodide lattice. The observed dynamics are essential for understanding the electronic properties of perovskite materials.
Date Issued
2015-09-02
Date Acceptance
2015-09-02
Citation
Journal of Physical Chemistry Letters, 2015, 6 (18), pp.3663-3669
ISSN
1948-7185
Publisher
American Chemical Society
Start Page
3663
End Page
3669
Journal / Book Title
Journal of Physical Chemistry Letters
Volume
6
Issue
18
Copyright Statement
© 2015 American Chemical Society. This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Physical Chemistry Letters , after peer review and technical editing by the publisher. To access the final edited and published work see https://dx.doi.org/10.1021/acs.jpclett.5b01555
Sponsor
The Royal Society
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000361858800024&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Grant Number
UF130178
Subjects
Science & Technology
Physical Sciences
Technology
Chemistry, Physical
Nanoscience & Nanotechnology
Materials Science, Multidisciplinary
Physics, Atomic, Molecular & Chemical
Chemistry
Science & Technology - Other Topics
Materials Science
Physics
SOLAR-CELLS
HALIDE PEROVSKITE
PHASE-TRANSITIONS
HIGH-PERFORMANCE
EFFICIENT
SPECTROSCOPY
CH3NH3PBI3
INTERPLAY
WATER
EMERGENCE
methylammonium lead iodide
molecular dynamics
transient anisotropy
ultrafast spectroscopy
vibrational spectroscopy
03 Chemical Sciences
02 Physical Sciences
Publication Status
Published