The origin of the transition voltage of gold–alkanedithiol–gold molecular junctions

Gateway state-mediated, long-range tunnelling in molecular wires

“…This feature has been previously assigned to "gateway" or "Au-S" states located on the sulfur anchors either by theoretical 30,37,43 or spectroscopic means. 56 Additional smaller but sharper resonances arise in our calculations very near to E F = 0 (labelled "Cs" in Fig. 3a), and we attribute these to the strong coupling between the two gateway states, through the molecular backbone ("coupling states"; see local density of states plots in Fig.…”

Increased Surface Density of States at the Fermi Level for Electron Transport Across Single‐Molecule Junctions

“…The iÀ V bias curves are replotted with lnðji=V 2 bias jÞ versus 1=V bias , formulated by the Fowler-Nordheim (FN) equation which has been applied to explore the transition between transporting mechanisms of coherent tunneling and field emission at small and high bias regimes, respectively. [42,[46][47][48][49][50][51] At the minimal point of the FN plot, the bias voltage (V min ) is proportional to the degree of ELA by E Fermi À E FMO j j � ð ffi ffi ffi 3 p =2ÞeV min . [9,10,51,52] Figure 4b shows an alternative FN plot, introduced by Frisbie, [9,10] by taking reciprocals of both the abscissa and ordinate.…”

“…The junction currents of SLRR‐modified electrodes are significantly larger than those of bare Au (blue curves), consistent with the conductance histograms (Figure 3). The $${{\rm { i}}{\rm { -}}{{\rm { V}}}_{{\rm { bias}}}}$$ curves are replotted with $${{\rm { ln(|}}{\rm { i}}{\rm { /}}{{\rm { V}}}_{{\rm { bias}}}^{{\rm { 2}}}{\rm { |)}}{\rm { }}}$$ versus $${{\rm { 1/}}{{\rm { V}}}_{{\rm { bias}}}}$$ , formulated by the Fowler‐Nordheim (FN) equation which has been applied to explore the transition between transporting mechanisms of coherent tunneling and field emission at small and high bias regimes, respectively [42, 46–51] . At the minimal point of the FN plot, the bias voltage ($${{{\rm { V}}}_{{\rm { min}}}}$$ ) is proportional to the degree of ELA by $${\left|{{\rm { E}}}_{{\rm { Fermi}}}{\rm { \ }}{\rm { -}}{\rm { \ }}{{\rm { E}}}_{{\rm { FMO}}}\right|\approx {\rm { (}}\sqrt{{\rm { 3}}}{\rm { /2)}}{{\rm { e}}{\rm { V}}}_{{\rm { min}}}}$$ [9, 10, 51, 52] .…”

Effect of molecular conformations on the electronic transport in oxygen-substituted alkanethiol molecular junctions

“…Among these, alkanethiol-based junctions have attracted significant attention because of their simple molecular structure and the high reproducibility of the experimental measurements. [10][11][12][19][20][21][22][23][24][25] By exploring the low-bias junction conductance as a function of the molecular length, it is generally accepted that off-resonance tunneling is the conducting mechanism of alkanethiol-based junctions. In order to further tune the electronic transport properties of alkanethiol-based molecular junctions, heteroatoms are introduced to probe the effects of local atomic and electronic a) Author to whom correspondence should be addressed: smhou@pku.edu.cn changes on the junction conductance.…”