Photochemical attachment of amine-layers on H-terminated undoped single crystalline CVD diamonds

Abstract

The initial nucleation and growth characteristics of amine layers photochemically attached from 10-amino-dec-1-ene molecules protected with tri-fluoroacetic acid group to H-terminated undoped single crystal CVD diamond surfaces are characterized by tapping and contact mode atomic force microscopy (AFM) and scanning tunneling microscopy (STM) with nanometer resolution. The diamond is atomically flat which allows attributing variations of tunneling currents in STM to amine grafted surface areas. Island formation and growth of islands with increasing photochemical attachment time is revealed by these experiments. This results support the growth model, where hydrogen cleavage reactions from the diamond surface by amine molecules bonded to diamond is the major growth mechanism. These reactions might be initiated by UV light illumination of pyrolysis of organic peroxides in the presence of the adsorbate, which are proposed to break H–C bonds to create surface dangling bonds. It occurs at the periphery of islands which gives rise to island growth.