Single-molecule quantum transport for electronic component s
Herre S.J. van der Zant
Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ, Delft, The Netherlands (E-mail: h.s.j.vanderzant@tudelft.nl) In downscaling the size of electronic components, molecules are viewed as promising alternatives as they can have additional functionality built-in by chemical design. We have developed several techniques to create solid-state, single-molecule devices [1] in which molecules are deposited from solution. These include mechanical controlled break junctions, molecular transistors made by a self-breaking electromigration technique, and room-temperature stable molecular transistors by electroburning of few-layer graphene. With these techniques in place, we investigate the quantum transport properties of a wide variety of molecules, with a special emphasis to use the intrinsic molecular structure (e.g. the orbital structure or spin degrees of freedom) to create electronic functionalities. Functionality can be based on quantum interference effects [2] or on the creation of barriers within the molecule over which substantial voltage drops occur when biasing the molecules. In this way, quantum-interference and spin-crossover switches, resonant tunneling devices [3] and single-molecule rectifiers [4] can be created.
Molecule and diode mechanism: Chemical structure (left panel) of the molecule used in our studies and its energy diagram (right panel), with the right half being lower in energy than the left one due to the electron withdrawing character of the fluorine substituents. At zero bias, transport is blocked. For one bias polarity the two levels are pulled further away from each other (blocking transport even more), while for the opposite bias polarity the levels are brought closer together thereby facilitating transport. Research supported by the national funding agencies (NWO/OCW) and by an ERC Advanced grant (Mols@Mols). References: [1] M.L. Perrin, E. Burzurí and H.S.J. van der Zant, Chem. Soc. Rev.
44 (2015) 902–919. [2] M. Koole
et al., Nano Letters
15 (2015) 5569–5573; H. Lissau
et al., Nature Communications
6 (2015) 10233; R. Frisenda et al., Nature Chemistry
8 (2016) 1099–1104. [3] M.L. Perrin
et al., Nature Nanotechnology
9 (2014) 830–834. [4] M.L. Perrin
et al., Journal of Physical Chemistry
C119 (2015) 5697-5702; M.L. Perrin
et al., Nanoscale
8 (2016) 8919-8923; M.L. Perrin
et al., Physical Chemistry Chemical Physics
19 (2017) 29187–29194.
inquires Rvargas@sas.upenn.edu
