Direct dehydrocoupling facilitates efficient thiophene anchoring on silicon surfaces.

Abstract

Silicon is a cornerstone material in electronics and photovoltaics due to its abundance, tunable semiconducting properties, and chemical versatility. Direct anchoring of thiophenes, with their highly delocalized aromatic backbones, onto silicon surfaces offers a promising route to tailor charge carrier migration properties. However, current methods for anchoring thiophenes commonly rely on pre-activation of precursors or transition-metal catalysts. Here, we introduce a catalyst-free radical strategy for direct linkage of thiophenes with Si atoms on organosilanes and silicon surfaces. This method leverages thermally induced homolytic cleavage of Si-H bonds to generate silicon radicals, which undergo efficient hydrosilylation with thiophene rings, forming Si-C linkages and releasing H₂. We demonstrate the successful application of this approach on silicon surfaces, achieving functionalization with thiophenes that enhance charge carrier mobilities in silicon nanocrystals significantly higher than previously reported alkyl-functionalized SiNCs, indicating the significant potential of catalyst-free dehydrocoupling for advancing silicon-based materials in optoelectronic applications.