Electrochemical grafting of molecules to a silicon surface

The hydrogentated surface of silicon exhibits remarkable properties, but po or resistance to oxidation. To improve its stability, surface hydrogen has been replaced by several organic groups. Such grafting can be carried out c hemically by a multi-step reaction scheme. However, an electrochemical appr oach allows direct reaction with the hydrogenated surface. The porous-silic on surface has been partially methoxylated by a controlled anodic dissoluti on. If has also been methylated using a non-destructive anodic process, wit h a yield of 80%, limited only by steric hindrance. The methylated surface of porous silicon exhibits a stability against oxidation increased by an or der of magnitude.