Grafting Cavitands on the Si(100) Surface

• DOI: 10.1021/la060682p
• Publication Date: 2006-11-07T12:01:05Z
• Authors: Guglielmo G. Cond...; Alessandro Motta; Maria Favazza; Ignazio L. Fragalà; Marco Busi; Edoardo Menozzi; Enrico Dalcanale; Luigi Cristofolini
• Keywords: ORGANIC MONOLAYERS; SPECTROSCOPY; CRYSTALLINE SI(111); CAVITANDS; 02 engineering and technology; 1X1(100) SILICON; 540; 530; 01 natural sciences; 0104 chemical sciences; HYDROGEN-TERMINATED SILICON; ALKYL MONOLAYERS; EARLY OXYNITRIDATION STAGES; X-RAY; FUNCTIONALIZATION; COORDINATION CAGES; 0210 nano-technology

Cavitand molecules having double bond terminated alkyl chains and different bridging groups at the upper rim have been grafted on H-terminated Si(100) surface via photochemical hydrosilylation of the double bonds. Pure and mixed monolayers have been obtained from mesitylene solutions of either pure cavitand or cavitand/1-octene mixtures. Angle resolved high-resolution X-ray photoelectron spectroscopy has been used as the main tool for the monolayer characterization. The cavitand decorated surface consists of Si-C bonded layers with the upper rim at the top of the layer. Grafting of pure cavitands leads to not-well-packed layers, which are not able to efficiently passivate the Si(100) surface. By contrast, monolayers obtained from cavitand/1-octene mixtures consist of well-packed layers since they prevent silicon oxidation after aging. AFM measurements showed that these monolayers have a structured topography, with objects protruding from the Si(100) surface with average heights compatible with the expected ones for cavitand molecules.