The Vibrational and Thermodynamic Properties of CsPbI3 Polymorphs: An Improved Description Based on the SCAN meta-GGA Functional
Open Access
- 12 July 2021
- journal article
- research article
- Published by American Chemical Society (ACS) in The Journal of Physical Chemistry Letters
- Vol. 12 (28), 6613-6621
- https://doi.org/10.1021/acs.jpclett.1c01798
Abstract
We report the vibrational and thermodynamic properties of four known CsPbI3 polymorphs in the framework of the density functional theory. We compare the recently introduced strongly constrained and appropriately normed (SCAN) meta-generalized gradient approximation (meta-GGA) with the local density approximation (LDA). We found that the SCAN, compared to the LDA, could explain discrepancies between theoretical and experimental results. Evaluating the Helmholtz free energy as a function of temperature, we found that within the SCAN (a) all polymorphs had negative formation enthalpies at the room temperature and (b) CsPbI3 underwent the phase transition from the δ- to α-phase at 480 K. This is not true for the LDA. In contrast to the previous reports based on the LDA, we did not find the ferroelectric instability in the phonon spectra of the cubic and tetragonal phases at the meta-GGA level. This result agrees with the lack of observation of the ferroelectricity in CsPbI3.Keywords
Funding Information
- Narodowe Centrum Nauki (DEC-2016/21/D/ST3/03444)
This publication has 48 references indexed in Scilit:
- Density Functionals that Recognize Covalent, Metallic, and Weak BondsPhysical Review Letters, 2013
- Lead Iodide Perovskite Sensitized All-Solid-State Submicron Thin Film Mesoscopic Solar Cell with Efficiency Exceeding 9%Scientific Reports, 2012
- Theoretical Prediction of New High-Performance Lead-Free PiezoelectricsChemistry of Materials, 2005
- From ultrasoft pseudopotentials to the projector augmented-wave methodPhysical Review B, 1999
- Generalized Gradient Approximation Made SimplePhysical Review Letters, 1996
- Efficient iterative schemes forab initiototal-energy calculations using a plane-wave basis setPhysical Review B, 1996
- Projector augmented-wave methodPhysical Review B, 1994
- Self-interaction correction to density-functional approximations for many-electron systemsPhysical Review B, 1981
- A neutron diffraction study of anharmonic thermal vibrations in cubic CsPbX3Acta Crystallographica Section A, 1980
- Neutron-scattering study on phase transitions of CsPbPhysical Review B, 1974