True-color real-time imaging and spectroscopy of carbon nanotubes on substrates using enhanced Rayleigh scattering

Abstract

Single-walled carbon nanotubes (SWCNTs) illuminated by white light should appear colored due to resonance Rayleigh scattering. However, true-color imaging of SWCNTs on substrates has not been reported, because of the extremely low scattering intensity of SWCNTs and the strong substrate scattering. Here we show that Rayleigh scattering can be greatly enhanced by the interface dipole enhancement effect. Consequently colorful SWCNTs on substrates can be directly imaged under an optical microscope by wide field supercontinuum laser illumination, which facilitates high throughput chirality assignment of individual SWCNTs. This approach, termed "Rayleigh imaging microscopy", is not restricted to SWCNTs, but widely applicable to a variety of nanomaterials, which enables the colorful nanoworld to be explored under optical microscopes.

Acoustic-assisted assembly of an individual monochromatic ultralong carbon nanotube for high on-current transistors

“…Furthermore, RRS spectra with the same resonance peak shifts (Fig. 4F) are clear evidence of the consistent chirality ( 25 ). …”

“…For chiral identification of CNTs, resonance Rayleigh scattering (RRS) is significantly more accurate and effective compared to fluorescence excitation spectroscopy and Raman spectroscopy ( 24 ). A structure-property “atlas” for SWNT optical transitions ( 24 ) has been established, and real-time true-color imaging of SWNTs ( 25 ) was also achieved, whereas RRS of few-walled CNTs can be more complicated because of the interaction between the walls ( 26 ). A 100-mm-long monochromatic ultralong CNT was observed under an optical microscope by wide supercontinuum laser illumination (Fig.…”

“…3, A and B), and monochromatic serpentine CNTs with 11 segments, formed by one 400-μm-long ultralong CNT, show no color change or resonance peak shift, signifying the consistent chirality (fig. S8, C and D) ( 25 ). This is the first time that monochromatic CNTs with decimeter lengths have been observed under a microscope.…”

Perovskite photodetectors prepared by flash evaporation printing

“…To further investigate the temporal response of the photodetector, a supercontinuum white light source was employed as a modulated illumination. 31 The pulse duration of the light source was less than 2 ns and the frequency was set at 5000 Hz. The transient photocurrent response of the device was recorded by an oscilloscope and shown in Fig.…”

High‐Throughput Optical Imaging and Spectroscopy of One‐Dimensional Materials

“…10 −4 to 10 −5 ), which is too weak to be probed under conventional optical microscope, because the signal will be easily blurred by any tiny intensity fluctuations of the light source or environmental fluctuation. To address this challenge, great amount of effort has been undertaken in areas such as fluorescence microscopy, Raman spectroscopy, Rayleigh scattering, and particle‐deposition‐assisted optical image . However, the preparation of samples and the identification of CNTs are quite complex and time‐consuming by these techniques.…”