Antenna-enhanced Optoelectronic Probing of Carbon Nanotubes

TL;DR

This paper demonstrates antenna-enhanced optoelectronic microscopy for nanoscale carbon nanotube devices, enabling localized enhancement of electroluminescence and photocurrent with high spatial resolution, revealing exciton decay mechanisms.

Contribution

First demonstration of antenna-enhanced optoelectronic microscopy on nanoscale devices, providing high spatial resolution insights into emission mechanisms.

Findings

Electroluminescence source can be point-like below 20 nm

Emission correlates with highest local electric field regions

Impact excitation causes radiative decay of excitons

Abstract

We report on the first antenna-enhanced optoelectronic microscopy studies on nanoscale devices. By coupling the emission and excitation to a scanning optical antenna, we are able to locally enhance the electroluminescence and photocurrent along a carbon nanotube device. We show that the emission source of the electroluminescence can be point-like with a spatial extension below 20 nm. Topographic and antenna-enhanced photocurrent measurements reveal that the emission takes place at the location of highest local electric field indicating that the mechanism behind the emission is the radiative decay of excitons created via impact excitation.