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Pregled bibliografske jedinice broj: 314012

How good conductors are pi-conjugated molecules ?


Crljen, Željko
How good conductors are pi-conjugated molecules ? // NANOVED 2007.
Bratislava, Slovačka, 2007. (predavanje, međunarodna recenzija, sažetak, znanstveni)


Naslov
How good conductors are pi-conjugated molecules ?

Autori
Crljen, Željko

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
NANOVED 2007. / - , 2007

Skup
NANOVED 2007, 4th International Conference on Nanosciences and Nanotechnologies

Mjesto i datum
Bratislava, Slovačka, 11-14. 11. 2007

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Molecular junctions; Conductance

Sažetak
In the field of molecular nanoelectronics the transport properties of single molecule are of crucial impotance. Molecular junction with pi-conjugated molecules have often been studied primarily for their promising molecular wire behaviour. However, the discrepances between theoretical predictions and experimental data have blured out the ability of pi-conjugated systems. The precise knowledge of the contact geometry of the molecular junction, as the adsorption site and bonding between the molecule and the electrode has been difficult to achieve experimentally and the dependence of the conductivity on the length of the molecule has not been precisely known. In order to get a reliable description of the molecular conducting properties the electronic structure of the electrodes, the electrode surfaces, the molecule, and the molecule-induced gap states, should be fully considered. Moreover, as the junction is subject to the nonequilibrium conditions the transmission should be obtained self-consistently for each bias voltage applied across the junction. We used a full self-consistent ab initio method based on the density functional theory and nonequilibrium Green's function technique. We performed series of calculations of the conductance of certain classes of p-conjugated molecules: phenyl ethylene oligomers (Tour wires), phenylene vinylene oligomers (OPV) and polyynes. The considered geometry consisted of the molecule between the gold electrodes. In the low bias regime we found that polyynes show the highest conductance with the value of 100 microS at zero bias. In Tour wires and OPV molecules, the conductance shows the decrease proportional to the number of benzene rings in the molecule. We showed that the conductance of polyynes is stable with respect to the applied bias and the length of the molecule while in Tour wires and OPVn it exibits the nonlinear behaviour as a consequnce of different electronic structure around the Fermi level of the system.

Izvorni jezik
Engleski

Znanstvena područja
Fizika



POVEZANOST RADA


Projekt / tema
098-0352828-3118 - Elektronska svojstva hibridnih nanostruktura (Željko Crljen, )

Ustanove
Institut "Ruđer Bošković", Zagreb

Autor s matičnim brojem:
Željko Crljen, (7066)