The first studies of a tetrathiafulvalene-sigma-acceptor molecular rectifier.
Langmuir-Blodgett monolayers of a donor-acceptor diad TTF-sigma-(trinitrofluorene) (8) with an extremely low HOMO-LUMO gap (0.3 eV) have been used to create molecular junction devices that show rectification behavior. By virtue of structural similarities and position of molecular orbitals, 8 is the closest well-studied analogue of the model Aviram-Ratner unimolecular rectifier (TTF-sigma-TCNQ). Compressing the monolayer results in aligning the molecules, and is followed by a drastic increase in the rectification ratio. The direction of rectification depends on the electrodes used and is different in n-Si/8/Ti and Au/8/C16H33S-Hg junctions. The molecular nature of such behavior was corroborated by control experiments with fatty acids and by reversing the rectification direction with changing the molecular orientation (Au/D-sigma-A versus Au/A-sigma-D).
Ho
Gregory
G
Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA.
Heath
James R
JR
Kondratenko
Mykola
M
Perepichka
Dmitrii F
DF
Arseneault
Karin
K
Pézolet
Michel
M
Bryce
Martin R
MR