Dimensionality-dependent electronic and vibrational dynamics in low-dimensional organic-inorganic tin halides

Yanmei He; Xinyi Cai; Rafael B. Araujo; Yibo Wang; Sankaran Ramesh; Junsheng Chen; Muyi Zhang; Tomas Edvinsson; Feng Gao; Tonu Pullerits

arXiv · 2505.11258

Dimensionality-dependent electronic and vibrational dynamics in low-dimensional organic-inorganic tin halides

Yanmei He·Xinyi Cai·Rafael B. Araujo·Yibo Wang·Sankaran Ramesh·Junsheng Chen·Muyi Zhang·Tomas Edvinsson·Feng Gao·Tonu Pullerits

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Abstract

Photo-induced dynamics of electronic processes in materials are driven by the coupling between electronic and nuclear degrees of freedom. Here we construct 1D and 2D organic-inorganic tin halides to investigate the functional role of dimensionality to exciton-phonon coupling (EPC) and exciton self-trapping. The results show that the 1D system has strong EPC leading to excitation-independent self-trapped exciton (STE) emission, while the 2D system exhibits over ten times weaker EPC resulting in free exciton emission. By performing femtosecond transient absorption experiments, we directly resolve the room-temperature vibrational wavepackets in the 1D system, some of which propagate along the STE potential energy surface. A combination of wagging and asymmetric stretching motions (~106 cm-1) in tin iodide is identified as such a mode inducing exciton self-trapping. While no room-temperature wavepackets are observed in the 2D system. These findings uncover the interplay between the dimensionality-dependent EPC and electronic/nuclear dynamics, offering constructive guidance to develop multifunctional organic-inorganic metal halides.

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Yanmei He, Xinyi Cai, Rafael B. Araujo, Yibo Wang, Sankaran Ramesh, Junsheng Chen, Muyi Zhang, Tomas Edvinsson, Feng Gao, Tonu Pullerits. 2025-05-16. Dimensionality-dependent electronic and vibrational dynamics in low-dimensional organic-inorganic tin halides. https://arxiv.org/abs/2505.11258

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