| 1. |
- Odell, Anders, 1979-, et al.
(författare)
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Comparison between s- and d-electron mediated transport in a photoswitching dithienylethene molecule using ab initio transport methods
- 2011
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Ingår i: Physical Review B Condensed Matter. - 0163-1829 .- 1095-3795. ; 84:16, s. 165402-
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Tidskriftsartikel (refereegranskat)abstract
- The influence of the electrode's Fermi surface on the transport properties of a photoswitching molecule is investigated with state-of-the-art ab initio transport methods. We report results for the conducting properties of the two forms of dithienylethene attached either to Ag or to nonmagnetic Ni leads. The I-V curves of the Ag/dithienylethene/Ag device are found to be very similar to those reported previously for Au. In contrast, when Ni is used as the electrode material the zero-bias transmission coefficient is profoundly different as a result of the role played by the Ni d bands in the bonding between the molecule and the electrodes. Intriguingly, despite these differences the overall conducting properties depend little on the electrode material. We thus conclude that electron transport in dithienylethene is, for the cases studied, mainly governed by the intrinsic electronic structure of the molecule.
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| 2. |
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| 3. |
- Odell, Anders, et al.
(författare)
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Investigation of the Conducting Properties of a Photoswitching Dithienylethene Molecule
- 2010
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Ingår i: ACS NANO. - : American Chemical Society (ACS). - 1936-0851 .- 1936-086X. ; 4:5, s. 2635-2642
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Tidskriftsartikel (refereegranskat)abstract
- Photoswitching molecules are attractive candidates as organic materials for optoelectronics applications because light impulses can switch them between states with different conducting characteristics. Here, we report a fully self-consistent density functional theory calculation of the electron transport properties of photoswitching dithienylethene attached to Au leads in both the open and closed conformations. The molecule is found to be a good conductor in both conformations, with the low-bias current for the closed one being about 20 times larger than that of the open. Importantly, the current voltage characteristics away from the linear response are largely determined by molecular orbital rehybridization in an electric field, in close analogy to what happens for Mn-12 molecules. However, in the case of dithienylethene attached to Au, such a mechanism is effective also in conditions of strong electronic coupling to the electrodes. This makes the dithienylethene family an intriguing materials platform for constructing highly conducting organic optoelectronics switches.
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| 4. |
- Pertsova, Anna, 1985-, et al.
(författare)
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Chapter Three : Electronic Transport as a Driver for Self-Interaction-Corrected Methods
- 2015
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Ingår i: Advances In Atomic, Molecular, and Optical Physics. - : Academic Press. - 9780128021279 ; , s. 29-86
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Bokkapitel (refereegranskat)abstract
- While spintronics often investigates striking collective spin e ects in large systems, a very important research direction deals with spin-dependent phenomena in nanostructures, reaching the extreme of a single spin conned in a quantum dot, in a molecule, or localized on an impurity or dopant. The issue considered in this chapter involves taking this extreme to the nanoscale and the quest to use rst-principles methods to predict and control the behavior of a few \spins" (down to 1 spin) when they are placed in an interesting environment. Particular interest is on environments for which addressing these systems with external elds and/or electric or spin currents is possible. The realization of such systems, including those that consist of a core of a few transition-metal (TM) atoms carrying a spin, connected and exchanged-coupled through bridging oxo-ligands has been due to work by many experimental researchers at the interface of atomic, molecular and condensed matter physics. This chapter addresses computational problems associated with understanding the behaviors of nanoand molecular-scale spin systems and reports on how the computational complexity increases when such systems are used for elements of electron transport devices. Especially for cases where these elements are attached to substrates with electronegativities that are very di erent than the molecule, or for coulomb blockade systems, or for cases where the spin-ordering within the molecules is weakly antiferromagnetic, the delocalization error in DFT is particularly problematic and one which requires solutions, such as self-interaction corrections, to move forward. We highlight the intersecting elds of spin-ordered nanoscale molecular magnets, electron transport, and coulomb blockade and highlight cases where self-interaction corrected methodologies can improve our predictive power in this emerging field.
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| 5. |
- Ulman, Kanchan, et al.
(författare)
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Spin-polarized conduction in a photoswitching dithienylethene molecule attached to Ni leads
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The finite-bias conduction properties of the photoswitching dithienyle the molecule attached to spin-polarized nickel electrodes are investigated. We find that the ratio of conduction between the open and closed isomers is around 60 at low bias, decreasing to 50 at a bias of 1 V. The I ¡ Vcharacteristics for the spin up and spin down channels are very similar, despite the fact that the Ni electrode density of states is very different for the two cases - Ni is known to be a so-called strong ferromagnet meaning that it is almost completely spin polarized at the Fermi level.
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