Double-walled carbon nanotubes covalently grafted with photo-active molecules – GAMBIT

In summary, this project proposes a basic research approach combining: molecular and macromolecular engineering, covalent chemical functionalization, DWNT based devices elaboration, multi-technique characterizations and combined spectroscopic, electrical transport and photo-transport studies.

The first phase of the project has been dedicated to: the elaboration of DWNTs samples (powders and FET devices), the implementation of functionalization methods, the synthesis of molecules/polymers, the setting-up of the methods for the characterization and the investigation of physical properties of DWNTs and hybrid systems.

The second phase will be focused on the physical studies on hybrid systems specifically using spectral photoconductivity. During this phase, a feedback between molecular design and physical properties is envisioned to demonstrate the versatility of the approach.

D.I. Levshov et al., “Interlayer Dependence of G-Modes in Semiconducting Double-Walled Carbon Nanotubes”, JOURNAL OF PHYSICAL CHEMISTRY C 119(40), 23196-23202 (2015)

The Gambit project proposes to assess the relevance of double-walled carbon nanotubes (DWNT) functionalized with photo-active pi-conjugated molecules or macromolecules to develop innovative hybrid nanostructures. The approach aims to combine in a synergetic manner the remarkable properties of carbon nanotubes (mainly electrical and thermal transport) to those of organic systems including the versatility of their optical characteristics and their ultimate selectivity as chemical or biological sensors. In the framework of this project, pi-conjugated molecules and polymers will be synthesized and covalently bonded to the sacrificial outer layer of DWNT while the inner layer and its properties will be fully preserved. The photo-active pi-conjugated systems will be of two types: 1) polymers and 2) molecular systems consisting of multiple donor/acceptor motifs and with adjustable HOMO and LUMO levels. The electronic properties and functional groups of these molecular systems will be tailored and adjusted by molecular design in order to build new hybrid nano-systems with targeted functionalities. The DWNT covalent functionalization will be performed, on one hand by the well-known method of thermal decomposition of diazonium and, on the other hand, by a new strategy involving organometallic coupling reactions. The versatility, selectivity and efficiency of this second approach have been demonstrated by preliminary results. The photo-induced transfer between the nanotube and the pi-conjugated systems will be first evidenced by spectroscopic studies. Then, functional devices, like field effect transistors, based on individual functionalized DWNT will be elaborated and their opto-electronic properties will be investigated. Correlations between the hybrid systems characteristics and their properties will be understood via a multi-technique, sequential and iterative approach.
In summary, this project proposes a basic research approach combining: molecular and macromolecular engineering, covalent chemical functionalization, DWNT based devices elaboration, multi-technique characterizations and combined spectroscopic, electrical transport and photo-transport studies.