Imperial College London
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ProfessorAndrewHorsfield

Faculty of Engineering, Department of Materials

Professor of Theory and Simulation of Materials
 
 
 
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Contact

 

+44 (0)20 7594 6753a.horsfield

 
 
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Location

 

Bessemer B331Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Thong:2018:10.1038/s41598-018-27557-0,
author = {Thong, A and Shaffer, M and Horsfield, AP},
doi = {10.1038/s41598-018-27557-0},
journal = {Scientific Reports},
title = {Rectification and negative differential resistance via orbital level pinning},
url = {http://dx.doi.org/10.1038/s41598-018-27557-0},
volume = {8},
year = {2018}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - A donor-acceptor system, 4-thiophenyl-azafulleroid (4TPA-C60), is investigated at the point of HOMO/LUMO resonance and beyond to understand how negative differential resistance (NDR) features may be observed in such systems. Our previous investigation showed that charge transfer between the occupied and unoccupied states at resonance hindered crossing of the HOMO and LUMO levels, thus preventing the formation of an NDR feature. In this work, it is shown that the negative differential resistance feature of 4TPA-C60 can be tailored based on the couplings at the metal/molecule interface. Ab initio calculations show that limited charge extraction from atomically sharp contacts results in a HOMO-LUMO pinning effect which delays the onset of the NDR feature. Subsequent unpinning of the states can only occur when additional charge extraction channels enter the bias window, highlighting an important role which non-frontier states play in charge transport. The proposed charge transfer mechanism is then exploited by introducing a fluorine atom into the C60 cage to tune the energies of the acceptor, and narrow the width of the current peak. These findings not only demonstrate the importance of the metal/molecule interface in the design of molecular electronic architectures but also serve to inform future design of molecular diodes and RTDs.
AU  - Thong,A
AU  - Shaffer,M
AU  - Horsfield,AP
DO  - 10.1038/s41598-018-27557-0
PY  - 2018///
SN  - 2045-2322
TI  - Rectification and negative differential resistance via orbital level pinning
T2  - Scientific Reports
UR  - http://dx.doi.org/10.1038/s41598-018-27557-0
UR  - http://hdl.handle.net/10044/1/60503
VL  - 8
ER  -
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