Raman spectra and images. (a) Raman spectra on the InGaAs/GaAs system with 514.5 nm laser line. TO and LO phonons appear on the substrate, while a red shift of the GaAs LO mode occurs in the tube. The InGaAs LO from the tube bilayer is observed at 285 cm−1. (b) The microscopic image of a faulty tube shown in (c) and (d). Two Raman images are displayed: (c) the intensity of unstrained LO phonon mode of the GaAs substrate and (d) the Raman intensity of the LO mode of InGaAs showing a pristine tube and misfolded tube regions.
Rodriguez et al. Nanoscale Research Letters 2012 7:594 doi:10.1186/1556-276X-7-594