Electrochemical Formation of Close-Packed Phenyl Layers on Si(111)
Greffage électrochimique de monocouches phenyles sur des surfaces de Si(111)
Résumé
4-NO2 and 4-Br benzenediazonium salts have been electrochemically reduced on H-terminated Si(111) electrodes. Electrochemical measurements evidence that the reaction results in a robust modification of Si-(111) surfaces. XPS shows that organic films are monolayer thick and that covalent Si-Ar bonding occurs,with no oxide at the interface. In the case of the Br salt, quantitative RBS measurements suggest that layers are (2x1) close-packed and assess their stability against several rinsing procedures including exposure to
40% HF. A mechanism of grafting is discussed