Electrochemical reduction of aryl diazonium on silicon surface

Abstract

The silicon surface oxidizes promptly in air. Grafting of organic compounds can stabilize this surface and therefore maintains the electrical characteristics of the silicon. Different methods of grafting can be considered, we opted for the electrochemical process due to the relative ease in implementing and to facilitate eventual industrial application. In this case, it is imperative to carry out a hydrogenation of the surface. We were interested to grafting by cathodic reduction of 4-nitrobenzenediazonium tetrafluoroborate ( in acid medium ( on p-Si-H (111). The cathodic reduction is confirmed by a peak around -0.1V/SCE during the potential scan. The appearance of bands of symmetric and antisymmetric vibrations of Ph-NO₂ bonds in the infrared spectrum attests to the grafting. Furthermore, an approach to reaction mechanism is formulated.