Single - C60 transistor

Recently we could manage to grab a Fullerene molecule into a very narrow constriction (nm size) by using in-situ evaporation technique. First, a gap was created at 4K between Pt electrodes by the process of electromigration. Then single-C60 quantum dots were introduced to the junctions by in-situ evaporation inside the cryostat. After this, the conductance of the electromigrated junctions is substantially enhanced compared to the conductance of the same device before evaporating the C60, indicating that C60 molecules reside in the junction.

Figure 1 shows an AFM image of evaporated C60 molecules at room temperature on a Si/SiO2 substrate which was taken by ESR10 (Naveen Shetty) during his secondment in Grenoble.

Fig. 1: AFM image of evaporated C60 at room temperature on Si/SiO2 substrate. (a) AFM topographic image of C60. (b) shows the profile charts taken along X axis.

The circuit diagram for the electrical transport measurement and the corresponding stability diagram of the single-C60 transistor are shown in Fig. 2, with an SEM image of the sample.

Fig. 2: (a) SEM image of sample with the circuit diagram for thermal and electrical transport measurement. (b) Stability diagram of single-C60 molecule at 75 mK.

In-situ evaporation technique can pave the way to study more exotic molecules for studying thermoelectricity.