Extended Data Fig. 5: Sample full approach-withdraw thermal and electrical conductance traces and evaluation of thermal background signal in the measurement of single-molecule junctions.
a, b, Two independent recordings of thermal and electrical traces during the approach, stop, and withdrawal of the scanning thermal probe on a para-OPE3 molecule sample. Before the formation of the single-molecule junction, the approach speed of the tip is at 200 pm s–1, and the withdraw speed is at 50 pm s–1. After the junction ruptures, a 10-nm piezo withdraw is applied at 3 nm s–1 (pink shaded region) to evaluate the background level of the thermal signal, which is observed to be ~100 pW K-1 and can be largely attributed to the near-field radiative heat transfer between the tip and the sample. c, Calculated near-field radiative heat transfer between a hot Au tip and Au substrate as a function of distance using SCUFF-EM. The shaded region is the error band and is ± one standard deviation from 25 different profiles of roughness. d, Thermal background signal of this study compared to previous single-molecule thermal measurements.
