Abstract

Methylammonium lead iodide perovskite (MAPbI3) exhibits long charge carrier lifetimes that are linked to its high efficiency in solar cells. Yet, the mechanisms governing these unusual carrier dynamics are not completely understood. A leading hypothesis—disproved in this work—is that a large, static bulk Rashba effect slows down carrier recombination. Here, using second harmonic generation rotational anisotropy measurements on MAPbI3 crystals, we demonstrate that the bulk structure of tetragonal MAPbI3 is centrosymmetric with I4/mcm space group. Our calculations show that a significant Rashba splitting in the bandstructure requires a non-centrosymmetric lead iodide framework, and that incorrect structural relaxations are responsible for the previously predicted large Rashba effect. The small Rashba splitting allows us to compute effective masses in excellent agreement with experiment. Our findings rule out the presence of a large static Rashba effect in bulk MAPbI3, and our measurements find no evidence of dynamic Rashba effects.

Details

Title
Inversion symmetry and bulk Rashba effect in methylammonium lead iodide perovskite single crystals
Author
Frohna, Kyle 1   VIAFID ORCID Logo  ; Deshpande, Tejas 2   VIAFID ORCID Logo  ; Harter, John 2 ; Peng, Wei 3 ; Barker, Bradford A 4 ; Neaton, Jeffrey B 5 ; Louie, Steven G 4 ; Bakr, Osman M 3 ; Hsieh, David 2 ; Bernardi, Marco 6 

1  Department of Applied Physics and Materials Science, California Institute of Technology, Pasadena, CA, USA; School of Physics, Trinity College Dublin, Dublin 2, Ireland 
2  Department of Physics, California Institute of Technology, Pasadena, CA, USA 
3  Division of Physical Sciences and Engineering, KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia 
4  Department of Physics, University of California, Berkeley, CA, USA; Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA 
5  Department of Physics, University of California, Berkeley, CA, USA; Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA; Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA 
6  Department of Applied Physics and Materials Science, California Institute of Technology, Pasadena, CA, USA 
Pages
1-9
Publication year
2018
Publication date
May 2018
Publisher
Nature Publishing Group
e-ISSN
20411723
Source type
Scholarly Journal
Language of publication
English
DOI
https://doi.org/10.1038/s41467-018-04212-w
ProQuest document ID
2036168861
Copyright
© 2018. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.