Polaron difusion in pentathienoacene crystals

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Bibliographic Details
Main Author: Pereira, Marcelo Lopes
Publication Date: 2020
Other Authors: Sousa, Rafael Timóteo, Giozza, William Ferreira, Ribeiro, Luiz Antonio
Format: Article
Language: eng
Source: Repositório Institucional da UnB
Download full: https://repositorio.unb.br/handle/10482/42866
https://doi.org/10.1038/s41598-020-63699-w
Summary: Molecular crystals have been used as prototypes for studying the energetic and dynamic properties of charge carriers in organic electronics. The growing interest in oligoacenes and fused-ring oligothiophenes in the last two decades is due, in particular, to the success achieved in conceiving pentacene-based organic photovoltaic devices. In the present work, a one-dimensional Holstein-Peierls model is designed to study the temperature-dependent polaron transport in pentathienoacene (PTA) lattices. The tight-binding Hamiltonian employed here takes into account intra and intermolecular electron-lattice interactions. Results reveal that polarons in PTAs can be stable structures even at high temperatures, about 400 K. During the dynamical process, these charge carriers present a typical 1D random walk diffusive motion with a low activation energy of 13 meV and a room temperature diffusivity constant of 1.07 × 10−3 cm2 s−1. Importantly, these critical values for the polaron diffusion and activation energy are related to the choice of model parameters, which are adopted to describe pristine lattices.