Gold nanoparticle layer deposition on silicon substrate using esterification reaction

Abstract

The methods of plasmonic nanoparticle layer deposition are essential for practical application by enhancing and controlling the collective properties coming from the plasmon coupling effect of the nanoparticle supercrystals through the control of the number of nanoparticle layers as their optical and chemical properties is dramatically influenced by the number of the nanoparticle layers as well as the morphology and the size of individual nanoparticles. Up to now, various methods of nanoparticle layer deposition have been reported, such as using electrostatic interaction, dip coating, and interface mediated method. These methods, however, have a common problem, which is the relatively weak structural stability due to the limitation of the intermolecular interactions like van der Waals or dipole interaction. Here, the covalent bond-mediated nanoparticle layer deposition method is presented to enhance the structural stability of the nanoparticle supercrystals using the covalent bond reaction, one of the intramolecular interactions, as well as to ensure the highly ordered nanoparticle array with a simple and efficient synthesizing method. In this approach, nanoparticles functionalized with certain ligands, tail groups of which are involved in the esterification reaction that is one of the covalent bond reactions, are deposited stepwise on the substrates through a percolation-type growth process to form a highly ordered array. It was confirmed that the nanoparticle supercrystals realized in this approach maintain a more stable structure than the one fabricated by the conventional nanoparticle deposition methods in various solvents. Furthermore, this study is expected to be applied to various nanotechnology fields based on highly stable supercrystal structures fabricated by the nanoparticle layer deposition.