Premium
A Bipodal Dicyano Anchor Unit for Single‐Molecule Spintronic Devices
Author(s) -
Tsuji Yuta,
Semoto Takayuki,
Yoshizawa Kazunari
Publication year - 2013
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201300136
Subject(s) - tetracyanoquinodimethane , unpaired electron , spintronics , homo/lumo , density functional theory , chemistry , fermi level , molecule , spin (aerodynamics) , fermi energy , electron , materials science , computational chemistry , condensed matter physics , ferromagnetism , physics , organic chemistry , thermodynamics , quantum mechanics
The conductance through single 7,7,8,8‐tetracyanoquinodimethane (TCNQ) connected to gold electrodes is studied with the nonequilibrium Green’s function method combined with density functional theory. The aim of the study is to derive the effect of a dicyano anchor group, C(CN) 2 , on energy level alignment between the electrode Fermi level and a molecular energy level. The strong electron‐withdrawing nature of the dicyano anchor group lowers the LUMO level of TCNQ, resulting in an extremely small energy barrier for electron injection. At zero bias, electron transfer from electrodes easily occurs and, as a consequence, the anion radical state of TCNQ with a magnetic moment is formed. The unpaired electron in the TCNQ anion radical causes an exchange splitting between the spin‐α and spin‐β transmission spectra, allowing the single TCNQ junction to act as a spin‐filtering device.