Electrochemical patterning of a polyfluorene precursor polymer from a microcontact printed (μCP) monolayer

Selective area electropolymerization of a precursor polymer in a microcontact printed pattern was used to generate a patterned conjugated and fluorescent polymer thin film. The precursor polyfluorene polymer, which has photoluminescent properties defined by the polymer main chain and electropolymerizability from the pendant carbazole units, was synthesized using a Yamamoto coupling route. The polymer was then electrochemically deposited and cross-linked selectively on the alkyl SAM defined regions to form patterns (<50 nm height) with high fidelity. The patterns were characterized by atomic force microscopy and optical fluorescence microscopy. The fluorescence micrograph confirmed that the polymer main chain was largely unaffected by redox electrochemistry and showed highly regular patterning characteristics in a large area. This new combination of site-selective electropolymerization and the precursor approach should provide a unique way to make patterned conjugated polymer systems.