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

Hikaru Sano; Mingxiu Zhao; Daiji Kasahara; Kuniaki Murase; Takashi Ichii; Hiroyuki Sugimura

doi:10.1016/j.jcis.2011.05.071

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

J Colloid Interface Sci. 2011 Sep 1;361(1):259-69. doi: 10.1016/j.jcis.2011.05.071. Epub 2011 Jun 2.

Authors

Hikaru Sano¹, Mingxiu Zhao, Daiji Kasahara, Kuniaki Murase, Takashi Ichii, Hiroyuki Sugimura

Affiliation

¹ Department of Materials Science and Engineering, Kyoto University, Sakyo-ku, Kyoto, Japan.

PMID: 21696751
DOI: 10.1016/j.jcis.2011.05.071

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.