Ricerc@Sapienza

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. References [1] C. K. Chiang, C. R. Fincher, Jr., Y. W. Park, A. J. Heeger, H. Shirakawa, E. J. Louis, S. C. Gau, and Alan G. MacDiarmid, Phys. Rev. Lett. 39, 1098 (1977). [2] Hylke B. Akkerman, Paul W. M. Blom, Dago M. de Leeuw and Bert de Boer, Nature 441, 69 (2006). [3] Rajendra Prasad Kalakodimi, Aletha M. Nowak, and Richard L. McCreery, Chem. Mater. 17, 4939 (2005). [4] J. Wu, K. Mobley, and R. L. Mc Creery, J. Chem. Phys. 126, 024704 (2007). [5] Cristina Hermosa, Jose Vicente Álvarez, Mohammad-Reza Azani, Carlos J. Gómez-García, Michelle Fritz, Jose M. Soler, Julio Gómez-Herrero, Cristina Gómez-Navarro and Félix Zamora, Nature Commun. 4, 1709 (2013). DOI: 10.1038/ncomms2696. [6] Nunzio Tuccitto, Violetta Ferri, Marco Cavazzini, Silvio Quici, Genady Zhavnerko, Antonino Licciardello and Maria Anita Rampi, Nature Mater. 8, 41 (2009). [7] Quintiliani, M., Bassetti, M., Pasquini, C., et al. J. Mater. Chem. C, 2014, (2), pp. 2517-2527. [8] R. Matassa, G. Familiari, E. Battaglione, Concita Sibilia et al., Nanoscale, 2016,8, 18161-18169.