Rotational Dynamics of Organic Cations in Formamidinium Lead Iodide Perovskites
Artikel i vetenskaplig tidskrift, 2023

We report results from quasi-elastic neutron scattering studies on the rotational dynamics of formamidinium (HC[NH2]2+, FA) and methylammonium (CH3NH3+, MA) cations in FA1-xMAxPbI3 with x = 0 and 0.4 and compare it to the dynamics in MAPbI3. For FAPbI3, the FA cation dynamics evolve from nearly isotropic rotations in the high-temperature (T > 285 K) cubic phase through reorientations between preferred orientations in the intermediate-temperature tetragonal phase (140 K < T ⩽ 285 K) to an even more complex dynamics, due to a disordered arrangement of the FA cations, in the low-temperature tetragonal phase (T ⩽ 140 K). For FA0.6MA0.4PbI3, the dynamics of the respective organic cations evolve from a relatively similar behavior to FAPbI3 and MAPbI3 at room temperature to a different behavior in the lower-temperature phases where the MA cation dynamics are a factor of 50 faster as compared to those of MAPbI3. This insight suggests that tuning the MA/FA cation ratio may be a promising approach to tailoring the dynamics and, in effect, optical properties of FA1-xMAxPbI3

Författare

Rasmus Lavén

Chalmers, Kemi och kemiteknik, Energi och material

M. Koza

Institut Laue-Langevin

Lorenzo Malavasi

Universita degli studi di Pavia

Adrien Perrichon

STFC Rutherford Appleton Laboratory

Markus Appel

Institut Laue-Langevin

Maths Karlsson

Chalmers, Kemi och kemiteknik, Energi och material

Journal of Physical Chemistry Letters

1948-7185 (eISSN)

Vol. 14 2784-2791

Yt/gränsskiktsdynamik undersökt med neutronspridning

Vetenskapsrådet (VR) (2016-06958), 2017-01-01 -- 2020-12-31.

Ämneskategorier

Oorganisk kemi

Fysikalisk kemi

Den kondenserade materiens fysik

DOI

10.1021/acs.jpclett.3c00185

PubMed

36898059

Mer information

Senast uppdaterat

2024-07-17