title: Formation of uniform ferrocenyl-terminated monolayer covalently bonded to Si using reaction of hydrogen-terminated Si(111) surface with vinylferrocene/n-decane solution by visible-light excitation.
abstract: Electrochemically active self-assembled monolayers (SAM) have been successfully fabricated with atomic-scale uniformity on a silicon (Si)(111) surface by immobilizing vinylferrocene (VFC) molecules through Si-C covalent bonds. The reaction of VFC with the hydrogen-terminated Si (H-Si)(111) surface was photochemically promoted by irradiation of visible light on a H-Si(111) substrate immersed in n-decane solution of VFC. We found that aggregation and polymerization of VFC was avoided when n-decane was used as a solvent. Voltammetric quantification revealed that the surface density of ferrocenyl groups was 1.4×10(-10) mol cm(-2), i.e., 11% in substitution rate of Si-H bond. VFC-SAMs were then formed by the optimized preparation method on n-type and p-type Si wafers. VFC-SAM on n-type Si showed positive photo-responsivity, while VFC-SAM on p-type Si showed negative photo-responsivity.
authors.affiliation: Department of Materials Science and Engineering, Kyoto University, Sakyo-ku, Kyoto, Japan.
authors.forename: Hikaru
authors.initials: H
authors.lastname: Sano
authors.forename: Mingxiu
authors.initials: M
authors.lastname: Zhao
authors.forename: Daiji
authors.initials: D
authors.lastname: Kasahara
authors.forename: Kuniaki
authors.initials: K
authors.lastname: Murase
authors.forename: Takashi
authors.initials: T
authors.lastname: Ichii
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Sugimura