Comparable charge transport property based on S···S interactions with that of π-π stacking in a bis-fused tetrathiafulvalene compound

Abstract

Compact molecular packing with short π-π stacking and large π-overlap in organic semiconductors is desirable for efficient charge transport and high carrier mobility. Thus charge transport anisotropy along different directions is commonly observed in organic semiconductors. Interestingly, in this article, we found that comparable charge transport property were achieved based on the single crystals of a bis-fused tetrathiafulvalene derivative (EM-TTP) compound along two interaction directions, that is, the multiple strong S···S intermolecular interactions and the π-π stacking direction, with the measured electrical conductivity and hole mobility of 0.4 S cm⁻¹, 0.94 cm² V⁻¹ s⁻¹ and 0.2 S cm−1, 0.65 cm² V⁻¹ s⁻¹, respectively. This finding provides us a new molecular design concept for developing novel organic semiconductors with isotropic charge transport property through the synergistic effect of multiple intermolecular interactions (such as S···S interactions) and π-π stacking.