10.1021/nn203520v.s001
Shannon K. Yee
Shannon K.
Yee
Jibin Sun
Jibin
Sun
Pierre Darancet
Pierre
Darancet
T. Don Tilley
T. Don
Tilley
Arun Majumdar
Arun
Majumdar
Jeffrey B. Neaton
Jeffrey B.
Neaton
Rachel A. Segalman
Rachel A.
Segalman
Inverse Rectification in Donor–Acceptor Molecular Heterojunctions
American Chemical Society
2016
rectification
acceptor moieties
nonconjugated end group
1.5 V
phenylacetylene bridge
transport model
junction
molecule
naphthalenediimide acceptor
interface
Inverse Rectification
constituent properties
Differential conductance measurements
bithiophene donor
wave functions
2016-02-22 14:09:09
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Inverse_Rectification_in_Donor_Acceptor_Molecular_Heterojunctions/2581396
The transport properties of a junction consisting of small donor–acceptor molecules bound to Au electrodes are studied and understood in terms of its hybrid donor–acceptor–electrode interfaces. A newly synthesized donor–acceptor molecule consisting of a bithiophene donor and a naphthalenediimide acceptor separated by a conjugated phenylacetylene bridge and a nonconjugated end group shows rectification in the reverse polarization, behavior opposite to that observed in mesoscopic p–n junctions. Solution-based spectroscopic measurements demonstrate that the molecule retains many of its original constituent properties, suggesting a weak hybridization between the wave functions of the donor and acceptor moieties, even in the presence of a conjugated bridge. Differential conductance measurements for biases as high as 1.5 V are reported and indicate a large asymmetry in the orbital contributions to transport arising from disproportionate electronic coupling at anode–donor and acceptor–cathode interfaces. A semi-empirical single Lorentzian coherent transport model, developed from experimental data and density functional theory based calculations, is found to explain the inverse rectification.