Investigation of non-equilibrium phonon populations in biased metallic single-walled carbon nanotubes (SWCNTs)
Final Report Abstract
A tip-enhanced transmission-mode Raman spectroscopy setup with integrated sample fixture for elertrical biasing of samples has been successfully implemented. Carbon nanotube device arrays have been assembled on transparent substrates and near-field enhancement by a factor 5-6 has been demonstrated. Measurements towards the determination of current-induced local hot-phonon temperature have been taken by simultaneous recording of current, topography and G-mode intensity on biased carbon nanotubes. Furthermore, in a proof-of-principle experiment towards slit-aperture enhanced measurements, electrically isloated local metallic mirrors have been fabricated on top of carbon nanotube devices. The efficient blocking of light by the local mirrors has been demonstrated via photocurrent imaging of the carbon nanotube device. Using the established configurations for the determination of local phonon temperatures in biased carbon nanotubes remains an open and rewarding target for the future.
Publications
- Enhancing Raman signals with an interferometrically controlled AFM tip. Nanotechnology 24 (2013) 415701
Matti Oron-Carl, Ralph Krupke
(See online at https://doi.org/10.1088/0957-4484/24/41/415701) - Photocurrent Imaging of Semiconducting Carbon Nanotube Devices with Local Mirrors. Phys. Status Solidi B, 18 Sep 2014
Asiful Alam, Benjamin S. Flavel, Simone Dehm, Uli Lemmer, Ralph Krupke
(See online at https://doi.org/10.1002/pssb.201451272)
