In this Phase I project and the corresponding Phase I Option, we will investigate the feasibility of utilizing density gradient ultracentrifugation (DGU) for the production of large quantities of high-purity, semiconducting single-walled carbon nanotubes with a narrow diameter distribution (1.3-1.7 nm). In Phase I, we will focus on streamlining our DGU process in order to enhance its scalability. We will subsequently adapt our streamlined process to operating parameters that will make it compatible with larger capacity equipment. In the Phase I Option, we will optimize our streamlined process to improve its key figures of merit, including yield, mass output, and purity.
Benefit: Single-walled carbon nanotubes (SWNTs) possess unique electronic, optical, and material properties which make them ideal for use in a variety of commercial applications. For example, SWNTs can be either conductors or semiconductors, are thermally stable, possess incredible tensile strength, and can be easily biofunctionalized. Semiconducting SWNTs are additionally good emitters/absorbers of light in the infrared portion of the electromagnetic spectrum and possess very high charge-carrier mobilities. Given their remarkable properties, semiconducting SWNTs can potentially be used to replace or complement traditional and organic semiconducting materials in devices such as integrated circuits, chemical sensors, near-IR emitters/detectors, photovoltaics, and transistors. However, established manufacturing techniques cannot generate SWNTs with highly uniform electronic properties. Before the above-mentioned SWNT applications can be realized, a means for producing highly uniform semiconducting SWNTs must first be developed. NanoIntegris is presently commercializing a technology, developed by the Hersam Research Group at Northwestern University, for separating as-produced SWNTs by diameter, chirality, and/or electronic type via density gradient ultracentrifugation (DGU). In this Phase I SBIR proposal, we will explore the scale-up and optimization of our DGU process. If our research efforts are successful, they will enable companies in the electronics, energy, and biomedical industries to explore fundamentally new avenues for product development using semiconducting carbon nanotubes. Furthermore, large quantities of highly uniform semiconducting SWNTs will enable new, academic research initiatives to be pursued. Research groups around the world are interested in studying the behavior of semiconducting SWNTs in (among other things): memory devices, SWNT integrated circuits, SWNT biological sensors, and SWNT/organic circuits. Such research, however, has been precluded by the limited availability of material for study.
Keywords: semiconducting, semiconducting, Single-Walled Carbon Nanotubes, carbon nanotubes, Sorting, Sensors, transistors, Monodisperse, Bandgap
