TY - JOUR
T1 - First-Principles Molecular Dynamics in Metal-Halide Perovskites
T2 - Contrasting Generalized Gradient Approximation and Hybrid Functionals
AU - Kaiser, Waldemar
AU - Carignano, Marcelo
AU - Alothman, Asma A.
AU - Mosconi, Edoardo
AU - Kachmar, Ali
AU - Goddard, William A.
AU - De Angelis, Filippo
N1 - Funding Information:
The Ministero dell’Istruzione dell’Università e della Ricerca (MIUR) and Università degli Studi di Perugia are acknowledged for financial support through the program “Dipartimenti di Eccellenza 2018–2022” (Grant AMIS) to F.D.A. This research was funded by PON Project “Tecnologia per celle solari bifacciali ad alta Efficienza a 4 terminali per utility scale” (BEST-4U), of the Italian Ministry MIUR (CUP B88D19000160005). W.A.G. received support from the Liquid Sunlight Alliance, which is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Fuels from Sunlight Hub under Award Number DE-SC0021266. A.K. acknowledges stimulating discussions with Feliciano Giustino and Samuel Poncé. E.M. and A.A.A. wish to thank the Distinguished Scientist Fellowship Program (DSFP) of King Saud University, Riyadh, Saudi Arabia.
Publisher Copyright:
© 2021 American Chemical Society.
PY - 2021/12/16
Y1 - 2021/12/16
N2 - First-principles molecular dynamics (FPMD) represents a valuable tool to probe dynamical properties of metal-halide perovskites (MHPs) which are key to their success in optoelectronic devices. Most FPMD studies rely on generalized gradient approximation (GGA) functionals for computational efficiency matters, while hybrid functionals, although computationally demanding, are usually needed to accurately describe structural and electronic properties of MHPs. This Letter reports FPMD simulations on CsPbI3 based on the hybrid PBE0 functional. Our results demonstrate that PBE0 leads to lattice parameters and phonon modes in excellent agreement with experimental data, while GGA results overestimate the lattice parameter and the electronic band gap and underestimate the phonon energies. Our FPMD results also shed light on anharmonic effects and double-well instabilities in the octahedral tilting, highlighting a lowered free energy barrier for PBE0 and farther separated potential wells. Our results suggest that hybrid functionals are required to accurately describe crystal structure, lattice dynamics, and anharmonicity in MHPs.
AB - First-principles molecular dynamics (FPMD) represents a valuable tool to probe dynamical properties of metal-halide perovskites (MHPs) which are key to their success in optoelectronic devices. Most FPMD studies rely on generalized gradient approximation (GGA) functionals for computational efficiency matters, while hybrid functionals, although computationally demanding, are usually needed to accurately describe structural and electronic properties of MHPs. This Letter reports FPMD simulations on CsPbI3 based on the hybrid PBE0 functional. Our results demonstrate that PBE0 leads to lattice parameters and phonon modes in excellent agreement with experimental data, while GGA results overestimate the lattice parameter and the electronic band gap and underestimate the phonon energies. Our FPMD results also shed light on anharmonic effects and double-well instabilities in the octahedral tilting, highlighting a lowered free energy barrier for PBE0 and farther separated potential wells. Our results suggest that hybrid functionals are required to accurately describe crystal structure, lattice dynamics, and anharmonicity in MHPs.
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U2 - 10.1021/acs.jpclett.1c03428
DO - 10.1021/acs.jpclett.1c03428
M3 - Article
C2 - 34875174
AN - SCOPUS:85121035674
SN - 1948-7185
VL - 12
SP - 11886
EP - 11893
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
IS - 49
ER -