The team has observed that, during normal exfoliation procedures, a thin water layer is trapped between the h-BN flake and the silicon oxide substrate (click on image for detail). Using electric force microscopy experiments and theoretical simulations, the scientists have shown that this confined water layer has a peculiar behaviour: a preferred electrical polarization direction.

Due to confining effects, a net polarization, perpendicular to the h-BN surface that sandwiches the water layer, affects its response to an electric field. In other words, there is an anomalous response of h-BN flakes to electric fields applied in its surface normal direction. Since this is the direction used to gate transistors, h-BN-based devices are likely to respond differently than expected due to the water effect.

Full details can be found in the journal Nanotechnology.