Etude du greffage sur silicium par reduction electrochimique du methoxybenzene diazonium

Hydrogenated silicon surface has attracted the attention of many researchers through these remarkable properties however its chemical oxidation stability remains insufficient. Thus, the modification of the surface by grafting organic species could be an alternative. Forming monolayer may be chemically in several steps but the electrochemically way allows direct reaction from the hydrogenated surface. We studied the formation of the phenyl layer by electrochemical reduction of aryl diazonium cation (+N₂-ph-OCH₃) from para-methoxybenzene diazonium tetrafluoroborate on the electrode p-Si-H (111) in an aqueous medium (H₂SO₄ + HF). This reduction is confirmed by a cathodic peak around -0.3V/SCE during the potential scan. The appearance of bands of symmetric and antisymmetric vibrations of Ph-O-CH₃ bonds attests to the grafting of a polymer layer. Furthermore, an approach to reaction mechanism is formulated.