Woo-Jae Kim, Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, building 66-580, Cambridge, MA 02139, Chang Young Lee, Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, NE47-577, Cambridge, MA 02139, and Michael S. Strano, 66-566 Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139.
We directly compare ensemble spectroscopic measurements to a systematic and statistically rigorous counting of individual SWNT devices using a high throughput electrical probe station. We derived simplified equation, which connects the absorption intensity ratio and the actual composition of metallic and semiconducting SWNT in SWNT mixture by only one coefficient, that is, the extinction coefficient ratio of two SWNT types. We have successfully quantified the % enrichment of each electronic type from separated SWNT samples for the first time, independently of potential spectroscopic artifacts, and report an extension coefficient ratio for metallic to semiconducting SWNT of 0.354 ± 0.012. This systematic classification of individual SWNT into metallic and semiconducting types also enables the assessment of defect generation during solution phase processing. We demonstrate that solution phase processing causes 2-3 orders of magnitude decrease in the field effect mobility distribution of the semiconducting SWNT.