Experimental analysis of thermal and electric transport characteristics of nano-gaps

We conducted an experiment to demonstrate the thermoelectric nano-gap, which is recently expected to own high performance, in principle, because it does not have conductive heat flow between the high and low temperature region. In this study, the thermoelectric nano-gap is realized with a pair of probe and substrate where they are finely positioned. A temperature difference of ca. 10 K is imposed to the nano-gap under vacuum circumstances. A representative thermoelectric voltage, tunneling-current and gap were 250 μV, 0.3 nA and 50 nm. The obtained voltage and current, with assuming an effective probe-diameter of 10 nm, roughly agreed to a theoretical study (G. Despesse and T. Jager, J. Appl. Phys., Vol.96, p.5026-, 2004). However, the obtained gap was 25 times larger than that from the theoretical study.