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Photocurrent imaging of semiconducting carbon nanotube devices with local mirrors
Author(s) -
Alam Asiful,
Flavel Benjamin S.,
Dehm Simone,
Lemmer Uli,
Krupke Ralph
Publication year - 2014
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201451272
Subject(s) - photocurrent , carbon nanotube , materials science , nanotube , optoelectronics , photoconductivity , excitation , carbon nanotube quantum dot , nanotechnology , physics , quantum mechanics
Photocurrent spectroscopy has recently been used by several research groups to study the light–matter interaction in carbon nanotubes. To achieve this, long‐channel devices with symmetric metallic contacts are typically used, where photocurrent of opposite sign is generated at the two contacts. However, in short‐channel devices (<1 µm) the diffraction‐limited laser spot results in simultaneous excitation of both metal–nanotube contacts and leads to partial cancellation of the photocurrent. In this work, we avoid simultaneous excitation of both metal–nanotube contacts by fabricating an isolated metallic mirror over one of the contacts. With the use of (6,5) carbon nanotubes we demonstrate a unipolar photocurrent signal, that is consistent with the second order interband absorption of a (6,5) nanotube.