Direct dehydrocoupling facilitates efficient thiophene anchoring on silicon surfaces

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.