Chalcogen-driven supramolecular organization and emission modulation of ladder-type heteroacenes for high-performance organic semiconductors.

Heteroacene-based organic semiconductors hold considerable promise for high-performance organic electronics; however, precise control of their solid-state organization remains challenging. Here, we employed a five-ring-fused bis(benzo[4,5]chalcogeno)[3,2-c:2'3'-e]chalcogenophene scaffold featuring triple chalcogen integration as a versatile platform for systematic chalcogen engineering in ladder-type heteroacenes. A series of octyl-terminated derivatives incorporating sulfur, selenium, and tellurium (BBTT-8, BBSeSe-8, and BBTeTe-8, respectively) were investigated to determine how chalcogen identity governs the supramolecular assembly and electronic functionality of these semiconductors. Combined experimental and theoretical analyses revealed that chalcogen variation reorganizes the intermolecular interaction motifs and molecular packing, thereby directing supramolecular organization and modulating the physicochemical properties and charge transport. Concomitantly, the emission characteristics evolved from fluorescence to phosphorescence with heavier chalcogens, which is consistent with enhanced spin-orbit coupling. Notably, single-crystal organic field-effect transistors based on BBTT-8 demonstrated high hole mobilities exceeding 15 cm2 V-1 s-1. These results highlight chalcogen engineering as a powerful strategy for linking molecular design, supramolecular organization, and electronic functionality in organic semiconductors.