Regensburg 2004 – wissenschaftliches Programm
O 10.1: Vortrag
Montag, 8. März 2004, 15:45–16:00, H43
From single particle to conducting film: percolation behaviour of a Au colloidal thin film — •Agnes A. Mewe, E. Stefan Kooij, Herbert Wormeester, and Bene Poelsema — Mesa+ Research Institute, University of Twente, P.O. Box 217, NL 7500 AE Enschede
Deposition of citrate stabilized gold nanoparticles on silicon oxide is only feasible after a suitable preparation of the substrate surface. This surface functionalization is obtained by immersion into a solution of amino-functionalized molecules, or locally, by microcontact printing. In the latter case, upon immersion in a nanocolloidal Au suspension, the colloids only adsorb on the functionalized part of the surface. The contrast in Au colloid deposition was found to strongly depend on the specific amino molecule used for patterning. In a final step electrical conductivity is achieved by electroless deposition of gold or silver onto the isolated gold nanocrystals. Spectroscopic ellipsometry is used to characterize the thin film structures in the visible and near infrared range, thereby providing information on their conductivity. The results exhibit the gradual enlargement of the particles past the percolation threshold of the overall structure.