Figure 2
Resistive Switching Characteristics: Semi-logarithmic current-voltage (I–V) plots showing (a) forming and (b) bipolar resistive switching characteristics. (c) Threshold switching characteristics at the same location. I comp is kept at ~100 nA for forming and all subsequent switching cycles. (d) Semi-logarithmic I-V plot showing the hard breakdown (HBD) characteristics when I comp is set to ~10 μA. We do not observe any recovery here. Inset shows the post HBD characteristics obtained by applying a sweep voltage from 0–100 mV which shows an Ohmic behaviour with the resistance value equal to the ~10 kΩ protection resistance connected in series with the sample. (e) Adhesion force between h-BN and the Pt wire CAFM tip, measured when the tip is being retracted away from the h-BN surface. The HRS and LRS states refer to adhesion measurements taken under the resistive conditions as shown in (b) and (c). Negligible change is observed in adhesion force between the HRS and LRS state. (f) Similar adhesion measurements for the same location as in (d) prior and post HBD. Adhesion force after HBD has changed and is very high due to the formation of a metallic contact between the Pt tip and Cu substrate possibly via the rupturing of the h-BN layers.
