Mesoporous thin film structures as metal nanoparticle reactors for electronic circuits: Effects of matrix crystallinity and nanoparticle functionalization

Abstract

There is an increasing interest in versatile nanoelectronic structures based on stable, accessible and spatially located arrays of metal nanoparticles. In this study, the influences of mesoporous titania thin film crystallinity and pore features over electrical conductivity of embedded Ag-nanoparticles were analyzed. Although matrices treated at lower temperatures have shown less pore connectivity, less extensive anatase fraction and lower silver content, they revealed higher electrical conductivity than matrices treated at higher temperatures. This was interpreted as better connectivity among particles from plasmon behavior. The stability of this system was significantly enhanced through upon chemisorption of 1-octanethiol self-assemble monolayers over Ag-nanoparticles. The maximum plasmon absorbance remained practically unaltered after storage for at least 15 days and the current remains stable up to 20 voltage cycles. This demonstrates that a stable and accessible conductive nanocomposite circuit consisting of alkanethiol-functionalized metal nanoparticles embedded in a mesoporous oxide thin film matrix can be produced.