Carbon Nanotube-Inorganic Hybrid Systems and Devices

Abstract

We present different strategies for the generation of multifunctional nanomaterials employing single-walled carbon nanotubes (SWCNTs). In particular, we will discuss the formation of nanohybrids via the in-solution assembly of inorganic nanomaterials to SWCNTs, employed as nanoelectrodes or as nanoscale vector templates. Notably, both static and dynamic heterostructures were assembled, as well as nanoscale electronic devices; this allowed us to study and tailor various systems for different applications. We will first discuss the in-solution assembly of organic-inorganic heterostructures consisting of single Quantum Dots (QDs) univocally linked at the terminal ends of individual SWCNTs. Monofunctionalized SWCNT-QD heterostructures were obtained and photophysical investigations at the single nanohybrid level showed evidence of electronic coupling [1]. Additionally, DNA linkers of differing lengths were used as molecular rulers to control the distance, and hence tune the energy/charge transfer between the two nanostructures in these SWCNT-QD nanohybrids.[2] A dynamic SWCNT-QD hybrid was also designed and assembled using a G-quadruplex DNA aptamer linker, so that the distance between the SWCNT and QD could be dynamically modulated by the introduction and removal of potassium ions (K+);[2] the system was further found to be sensitive to K+ concentrations between 1pM and 25mM. By and large, this approach opens the possibility of assembling tailored optoelectronic and light harvesting systems with single-particle control. Finally, we will present the direct synthesis of multiplexed metal nanowire based devices using carbon nanotubes as vector templates. SWCNTs were filled with specifically designed metal precursors and dispersed in aqueous solution, enabling solution processability. The filled SWNTs were immobilized from solution onto different pre-patterned electrodes via a low-cost dielectrophoresis methodology. Metal nanowires were then grown by a facile and low temperature annealing treatment, while the nanotubes were removed using an oxygen plasma once immobilized in a device configuration. Electrical characterizations demonstrated the successful fabrication of metal nanowire electronic devices (no gate dependence).[3] Overall the strategy presented allows for a facile, low-cost and direct synthesis of multiple metal nanowire based devices for nanoelectronic applications. [1] Small, 2017,13, 1603042 [2] Advanced Science, 2018, 5, 1800596 [3] Submitted