Fullerenes covalently anchored on Si(100): An experimental study

Various [60]fullerene derivatives were covalently anchored via a Si-C bond to hydrogen-terminated Si(100) following wet-chemistry recipes. The applied reactions require a two-step approach consisting of a pre-modification of the Si(100) surface with an organic monolayer bearing a terminal functionality that undergoes a bond-forming reaction with a [60]fullerene synthon. The resulting Si-C bound hybrids were characterized by a combination of XPS, AFM, contact angle, and electrochemical analysis. The hybrid surfaces containing [60rsqb;fullerene-ferrocene fragments are exceptionally robust towards repeated reduction-oxidation cycles. Moreover, several surface-confined redox couples were observed in CH₃CN solution. The surface coverage was measured to be ca. 2.5×10^-11molcm^-2.