Figure 2: Molecular junction diagnosis.
From: Roles of vacuum tunnelling and contact mechanics in single-molecule thermopower
(a–c) Characteristic VP states plotted as a function of Vh2 and ΔT for BDA (a), BDT (b), and ABT (c). Solid curves are linear fitting to the plots. (d–f) Change in G (d) and ΔVj (e) under mechanical elongation Δd of Au-BDA-Au junctions showing ΔVave higher than −0.5 mV at ΔT = 59 K. The exponential decay in G indicates absence of molecules in the electrode gap in case for the thermopower states of VP1 (f). (g–i) High-thermovoltage traces with ΔVave ≤ −0.5 mV (h) reveal a plateau at close to the single-molecule conductance (g) whereby suggesting electron tunnelling through Au-BDA-Au bridges for VP2. Broken lines in (d) and (g) show a linear fit to the semi-logarithmic plots and the single-molecule conductance state, respectively.
