"Organic functionalization of silicon surfaces"

G.I. LACCONI

San Servolo, Venecia, Italia.

Conferencia; 1st ECHEMS Meeting. "Electrochemistry in Nanosciences"; 2005

1st ECHEMS Meeting Electrochemistry in Nanosciences, 2005 st ECHEMS Meeting Electrochemistry in Nanosciences, 2005 Organic functionalization of silicon surfaces G.I. Lacconi INFIQC, Depto. Fisicoquímica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de La Torre y Medina Allende, Ciudad Universitaria, 5000 Córdoba, Argentina. E-mail: glacconi@mail.fcq.unc.edu.ar INFIQC, Depto. Fisicoquímica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de La Torre y Medina Allende, Ciudad Universitaria, 5000 Córdoba, Argentina. E-mail: glacconi@mail.fcq.unc.edu.ar Organic modification of oxide-free silicon surfaces offers a direct combination of molecular materials and solid-state semiconductor structures, providing technologically useful and molecularly tunable films. The formation and characterization of the organic films covalently bound to silicon surfaces promise to improve the stability toward oxidation and to maintain satisfactory electrical properties of silicon electrodes, to achieve ideal surface passivation, as well as to optimize the interaction with metallic nanostructures or biological molecules (depending on the terminal group of the monolayer). Recently, great progress has been made in the preparation of dense alkyl monolayers covalently bonded to crystalline silicon surfaces [1-4[. However, limited experimental characterization of the electrochemical properties of organic-modified silicon surfaces has been reported [ ]. In this communication, the preparation of hidrogen-terminated Si(100) surfaces derivatized with covalently attached alkyl chains and aromatic alkyl monolayers is performed. The preparation of the monolayers was performed using neat 1-octadecene or allyl-bencene, which react efficiently with the hydrogen-terminated Si(100) when heated at temperatures over 130ºC. The monolayer formation reactions are assumed to be a radical-based process thermally induced that starts at a defect (e.g., a dangling bond) at the H-terminated surface. The electrochemical charaterization of the organically functionalized silicon surface was performed by cyclic voltammetry and electrochemical impedance related to its ability to inihibit the oxide formation. Direct correlations between the coverage and the electrical properties of the film with the potential for the silicon oxide electroformation are established. The structural characterization of the surfaces derivatized through covalent Si-C linkages was performed by ex-situ AFM and STM. 1. M.R. Linford, P. Fenter, P.M. Eisenberger, C.E.D. Chidsey, J. Am. Chem. Soc. 117 (1995) 3145. 2. A.B. Sieval, V.Vleeming, H. Zuilhof, E.J.R. Sudhölter, Langmuir 15 (1999) 8288. 3. L. Zhang, L. Li, S. Chen, S. Jiang, Langmuir 18 (2002) 5448. 4. P. Allongue, C.H. de Villeneuve, G. Cherouvrier, R. Cortes, M.C. Bernard, J. Electroanal. Chem. 550-551 (2003) 161. Acknowledgements: The author is grateful to CONICET, SECYT-UNC, Agencia Córdoba Ciencia S.E. and ANPCyT for their financial support. 2. A.B. Sieval, V.Vleeming, H. Zuilhof, E.J.R. Sudhölter, Langmuir 15 (1999) 8288. 3. L. Zhang, L. Li, S. Chen, S. Jiang, Langmuir 18 (2002) 5448. 4. P. Allongue, C.H. de Villeneuve, G. Cherouvrier, R. Cortes, M.C. Bernard, J. Electroanal. Chem. 550-551 (2003) 161. Acknowledgements: The author is grateful to CONICET, SECYT-UNC, Agencia Córdoba Ciencia S.E. and ANPCyT for their financial support. The structural characterization of the surfaces derivatized through covalent Si-C linkages was performed by ex-situ AFM and STM. 1. M.R. Linford, P. Fenter, P.M. Eisenberger, C.E.D. Chidsey, J.