DOI: 10.5176/2301-3516_OPAP13.41
Authors: Prabhakar Misra, Daniel Casimir, Raul Garcia-Sanchez
Abstract:
Single-walled carbon nanotubes are predicted to significantly impact semiconductor physics, owing to their unique electronic properties and reduced dimensionality. Some of the semiconductor technologies in which carbon nanotubes (CNTs) are expected to hold significant promise are in super-capacitors, hydrogen storage materials, nanoprobes, and bio-chemical sensors. For future applications there is a great need for understanding their thermal properties, since nano-devices based on single-walled and/or multi-walled nanotubes may have to experience high temperatures during the manufacturing process, or while being operated. This, in turn, affects the reliability of the devices due to thermal expansion and the ensuing strain. The coefficient of thermal expansion (CTE) is a key property for nano-electronic applications based on the use of CNTs. We utilize Raman Spectroscopy, with a 780 nm laser, to characterize our carbon nanotube samples and determine vibrational modes and bond lengths. Raman spectroscopy is applied to the various sp2 carbonaceous materials primarily as a characterization tool since these materials each exhibit structural differences. In our CNT samples, we have been able to identify the main features seen in CNTs for our purified and unpurified High Pressure Carbon Monoxide Process CNTs. The values of these features have been well studied and our results match well with known literature, and we have been able to properly characterize the vibrational modes of our samples. Though CNTs come in a variety of sizes and shapes, this study serves as the first step in finding a generalized way to categorize the thermal properties of CNTs. This work, along with Molecular Dynamic simulations, will provide us with insight on the thermal properties of single-walled carbon nanotubes.
Keywords: raman spectroscopy; carbon nanotubes; thermal expansion; near infrared
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