Hybrid metal-organic conductive network with plasmonic nanoparticles and fluorene (Conference Presentation)

For the development of new generation portable electronic devices, the realization of thin and flexible electrodes have a crucial role. Conductive organic systems can address this issue in different ways. Indeed, conductance in organic molecules were studied in different papers starting from seminal papers in last 70’s [1] up to recent ones [2]. Among organic species, conduction and electronic characteristics of Fluorene derivatives were studied in different configurations [3,4]. Unfortunately, the conductance of organic materials is limited by charge transport mechanism [5]. Hybrid system with organic conductive compounds covalently linked with metal centres can lead to enhanced conductivity [6]. Here we synthesized gold and silver nanoparticles (AuNPs and AgNPs) stabilized with a fluorene thiolate derivative, namely 9,9-Didodecyl-2,7-bis(acetylthio)fluorene (FL). In the synthesis process the metal nanoparticles (MNPs) size results to be around 5 nm in diameter [7]. When deposited on a planar substrate, the hybrid compound form a regular network of MNPs separated each other by fluorene spacers covalently linked by thiol groups [8]. We deposited the network on substrate with two interdigitated electrodes in order to measure conductive properties (I-V characteristics). In I-V measurements it results to be that AgNPs based network is 200 times more conductive than AuNPs one. Selective oxidation of AgNPs network close to positive electrodes gives rise to a Schottky diode behavior in the I-V characteristic that could find potential applications in nano-electronics devices. The fluorescence and extinction spectra of FL-AgNPs and FL-AuNPs where characterised.