Structural Dynamics of Two-Dimensional Ruddlesden–Popper Perovskites: A Computational Study

Abstract

Recently two-dimensional (2D) hybrid organic–inorganic perovskites have attracted a lot of interest as more stable analogues of their three-dimensional counterparts for optoelectronic applications. However, a thorough understanding of the effect that this reduced dimensionality has on dynamical and structural behavior of individual parts of the perovskite is currently lacking. We have used molecular dynamics simulations to investigate the structure and dynamics of 2D Ruddlesden–Popper perovskite with the general formula BA 2 MA n –1 Pb n I 3 n +1 , where BA is butylammonium, MA is methylammonium, and n is the number of lead–iodide layers. We discuss the dynamic behavior of both the inorganic and the organic part and compare between the different 2D structures. We show that the rigidness of the inorganic layer markedly increases with the number of lead–iodide layers and that low-temperature structural phase changes accompanied by tilting of the octahedra occurs in some but not all structures. Furthermore, the dynamic behavior of the MA ion is significantly affected by the number of inorganic layers, involving changes both in the reorientation times and in the occurrence of specific preferred orientations.

Mobility driven thermoelectric and optical properties of two-dimensional halide-based hybrid perovskites: impact of organic cation rotation

“…27 For the case of the 2D RP phase of perovskites, the molecular dynamics simulation study depicts an increase in the rigidness of the inorganic framework with the number of Pb-I layers. 28 Moreover, Maheshwari et al investigated the role of dipole direction of the organic cation on the electronic properties using ab initio calculations and demonstrated the impact of local electrostatic potential generated between the organic and inorganic part of the perovskites. 29 Furthermore, the effective mass of charge carriers reveals the significant variation with the alignment of the dipoles, which leads to modification in mobility.…”

Tuning the Structural Rigidity of Two-Dimensional Ruddlesden–Popper Perovskites through the Organic Cation

“…The force field used in the MD simulations was based on the MYP force field 39 and on our previous work on 3D perovskites 40 and 2D Ruddlesden–Popper perovskites with a varying number of inorganic layers where BA was taken as the large organic cation. 41 The intermolecular potential for lead and iodide was taken from the MYP force field 39 and consisted of a Buckingham potential, except for the interaction between either lead or iodide with hydrogen where a Lennard-Jones potential was used. Both the inter- and intramolecular parameters for BA were the same as in our previous work, 41 while the additional parameters for PEA and POB were obtained from the standard Amber force field, 42 consistent with the MYP force field.…”

“… 41 The intermolecular potential for lead and iodide was taken from the MYP force field 39 and consisted of a Buckingham potential, except for the interaction between either lead or iodide with hydrogen where a Lennard-Jones potential was used. Both the inter- and intramolecular parameters for BA were the same as in our previous work, 41 while the additional parameters for PEA and POB were obtained from the standard Amber force field, 42 consistent with the MYP force field. All intermolecular interactions between two organic molecules were described by a Lennard-Jones potential.…”

“…The force field used in the MD simulations was based on the MYP force field and on our previous work on 3D perovskites and 2D Ruddlesden–Popper perovskites with a varying number of inorganic layers where BA was taken as the large organic cation . The intermolecular potential for lead and iodide was taken from the MYP force field and consisted of a Buckingham potential, except for the interaction between either lead or iodide with hydrogen where a Lennard-Jones potential was used.…”

Influence of Inorganic Layer Thickness on Methylammonium Dynamics in Hybrid Perovskite Derivatives

“…However, to our knowledge, the organic cation dynamics of multi-layered perovskite derivatives have only been studied computationally. 17 Here, we report the cation rotational dynamics of (d-…”