Electrochemical grafting of organic films on silica

Traditionally, self-assembled monolayers formed on silicon require the removal of the insulating and chemically inert silica layer that naturally forms on the surface of crystalline silicon. The removal of silica is thought to be necessary in order to expose the conducting Si-H surface, which is reactive towards molecules. Here we report the unexpected result of electrochemical formation of thin organic films on silica-terminated silicon with silica thickness up to 20 nm. The process is facilitated by the electrochemical generation of aryl radicals that react with silanol groups at the distal end of silica.