title: Covalently attached monolayers on crystalline hydrogen-terminated silicon: extremely mild attachment by visible light.
abstract: A very mild method was developed for the attachment of high-quality organic monolayers on crystalline silicon surfaces. By using visible light sources, from 447 to 658 nm, a variety of 1-alkenes and 1-alkynes were attached to hydrogen-terminated Si(100) and Si(111) surfaces at room temperature. The presence and the quality of the monolayers were evaluated by static water contact angles, X-ray photoelectron spectroscopy, and IR spectroscopy. Monolayers prepared by thermal, UV light, or visible light initiation were compared. Additionally, the ability of infrared reflection-absorption spectroscopy to study organic monolayers on silicon was explored. A reaction mechanism is discussed on the basis of investigations of the reaction behavior of 1-alkenes with silicon wafers with varying types and levels of doping. Finally, a series of mixed monolayers derived from the mixed solutions of a 1-alkene and an omega-fluoro-1-alkene were investigated to reveal that the composition of the mixed monolayers was directly proportional to the molar ratio of the two compounds in the solutions.
authors.affiliation: Laboratory of Organic Chemistry, Wageningen University and Research Center, Dreijenplein 8, 6703 HB Wageningen, The Netherlands.
authors.forename: Qiao-Yu
authors.initials: QY
authors.lastname: Sun
authors.forename: Louis C P M
authors.initials: LC
authors.lastname: de Smet
authors.forename: Barend
authors.initials: B
authors.lastname: van Lagen
authors.forename: Marcel
authors.initials: M
authors.lastname: Giesbers
authors.forename: Peter C
authors.initials: PC
authors.lastname: Thüne
authors.forename: Johan
authors.initials: J
authors.lastname: van Engelenburg
authors.forename: Frits A
authors.initials: FA
authors.lastname: de Wolf
authors.forename: Han
authors.initials: H
authors.lastname: Zuilhof
authors.forename: Ernst J R
authors.initials: EJ
authors.lastname: Sudhölter