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  • Impact of large A-site cations on electron–vibrational interactions in 2D halide perovskites: Ab initio quantum dynamics
Title: Impact of large A-site cations on electron–vibrational interactions in 2D halide perovskites: Ab initio quantum dynamics
Using ab initio nonadiabatic molecular dynamics, we study the effect of large A-site cations on nonradiative electron–hole recombination in two-dimensional Ruddlesden–Popper perovskites HA2APb2I7, HA = n-hexylammonium, A = methylammonium (MA), or guanidinium (GA). The steric hindrance created by large GA cations distorts and stiffens the inorganic Pb–I lattice, reduces thermal structural fluctuations, and maintains the delocalization of electrons and holes at ambient and elevated temperatures. The delocalized charges interact more strongly in the GA system than in the MA system, and the charge recombination is accelerated. In contrast, replacement of only some MA cations with GA enhances disorder and increases charge lifetime, as seen in three-dimensional perovskites. This study highlights the key influence of structural fluctuations and disorder on the properties of charge carriers in metal halide perovskites, providing guidance for tuning materials’ optoelectronic performance.  more » « less
Award ID(s):
2154367
PAR ID:
10583471
Author(s) / Creator(s):
; ; ;
Publisher / Repository:
AIP Publishing
Date Published:
Journal Name:
The Journal of Chemical Physics
Volume:
160
Issue:
11
ISSN:
0021-9606
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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