TY - JOUR
T1 - Mixed-Halide Perovskite Alloys CsPb(I1-xBrx)3 and CsPb(Br1-xClx)3
T2 - New Insight of Configurational Entropy Effect from First-Principles and Phase Diagrams
AU - Pan, Fang
AU - Zhai, Junni
AU - Chen, Jinyu
AU - Yang, Lin
AU - Dong, Hua
AU - Yuan, Fang
AU - Jiang, Zhuangde
AU - Ren, Wei
AU - Ye, Zuo Guang
AU - Zhang, Guo Xu
AU - Li, Jingrui
N1 - Publisher Copyright:
© 2024 American Chemical Society.
PY - 2024/4/23
Y1 - 2024/4/23
N2 - Stability is one of the key issues in mixed-halide perovskite alloys that are promising in emergent optoelectronics. Previous density functional theory (DFT) and machine learning studies indicate that the formation-energy convex hulls of these materials are very shallow, and stable alloy compositions are rare. In this work, we revisit this problem using DFT, with a special focus on the effects of configurational and vibrational entropies. Allowed by the 20-atomic models for the Formula Presented and Formula Presented series, the partition functions and therewith thermodynamic state functions are calculated by traversing all possible mixed-halide configurations. We can thus evaluate the temperature- and system-dependent configurational entropy, which largely corrects the conventional approach based on the ideal solution model. Finally, temperature-composition phase diagrams that include α, β, γ, and δ phases of both alloys are constructed based on the free energy data, for which the contribution of phonon vibrations is included.
AB - Stability is one of the key issues in mixed-halide perovskite alloys that are promising in emergent optoelectronics. Previous density functional theory (DFT) and machine learning studies indicate that the formation-energy convex hulls of these materials are very shallow, and stable alloy compositions are rare. In this work, we revisit this problem using DFT, with a special focus on the effects of configurational and vibrational entropies. Allowed by the 20-atomic models for the Formula Presented and Formula Presented series, the partition functions and therewith thermodynamic state functions are calculated by traversing all possible mixed-halide configurations. We can thus evaluate the temperature- and system-dependent configurational entropy, which largely corrects the conventional approach based on the ideal solution model. Finally, temperature-composition phase diagrams that include α, β, γ, and δ phases of both alloys are constructed based on the free energy data, for which the contribution of phonon vibrations is included.
UR - http://www.scopus.com/inward/record.url?scp=85190305641&partnerID=8YFLogxK
U2 - 10.1021/acs.chemmater.4c00571
DO - 10.1021/acs.chemmater.4c00571
M3 - Article
AN - SCOPUS:85190305641
SN - 0897-4756
VL - 36
SP - 3957
EP - 3969
JO - Chemistry of Materials
JF - Chemistry of Materials
IS - 8
ER -