Surface Functionalization of Doped CVD Diamond via Covalent Bond. An XPS Study on the Formation of Surface-bound Quaternary Pyridinium Salt

Abstract
Lightly boron-doped polycrystalline diamond thin films prepared on single crystal silicon wafers via chemical vapor deposition (CVD) were treated with chlorine (Cl2) under ultraviolet (> 200 nm) photoirradiation and then heated in boiling pyridine. Ex situ X-ray photoelectron spectroscopic measurements suggested the plausible formation of surface-bound chloride species and quaternary pyridinium salt by these chemical processes.