Figure 5

(a) Comparison of the ON/OFF ratios at high temperature between a sharp-edged gap shape and a flat-edged gap shape in the polycrystalline Pt nanogap. (b) SEM image of the sharp-edged gap. (c) SEM image of the flat-edged gap. The sharp edge causes the electric field to increase to up to 1.8 times higher than that in the case of the flat edge.