Scientific Background                                                           

Near-infrared band-gap fluorescence from individual semiconducting single-walled carbon nanotubes (SWNT) was discovered in Dr. Weisman's laboratory at Rice University in 2001. Subsequent research deciphered the complex pattern of absorption and emission peaks seen in mixed samples. As a result, each distinct spectroscopic feature has now been assigned to a specific nanotube structure. These structural species differ in diameter and chiral angle, and are uniquely labeled by pairs of integers denoted (n,m).

Interpreted results - Diameter distribution histogram

The near-infrared emission spectra of nanotube samples serve as compositional "fingerprints." One can therefore use spectrofluorimetry to deduce detailed information about the compositions of bulk samples, which invariably contain mixtures of (n,m) species. However, general-purpose spectrofluorometers are not well suited to this task. Although such instruments are versatile, they are also large, slow, and produce raw data that require substantial interpretation to yield the desired analytical result. To provide a more efficient and automated alternative, ANF has developed a specialized fluorimetric instrument designed specifically for SWNT analysis. Our unique fluorimetric analyzer combines a compact, efficient optical system and sophisticated software that acquires and interprets the data. It allows users to easily and rapidly find the identities and amounts of specific (n,m) semiconducting nanotubes in their bulk samples.

Measured fluorescence spectra with fits