Electrostatic Potential of hBN Moiré Superlattices

Twisted hexagonal boron nitride (hBN) layers have been demonstrated to exhibit ferroelectric domains due to charge redistribution at the interface. Here, we investigate the electrostatic potential at the top surface of twisted hBN bilayers, prepared by folding exfoliated thin flakes. Using Kelvin Probe Force Microscopy measurements, we show that this potential can be engineered by tuning the twist angle and adjusting the thickness of the top hBN layer. Furthermore, we study double moiré superlattices with different twist angles at each interface. These findings can be further extended to twisted multilayers to significantly expand the versatility of hBN and moiré superlattices in engineering material properties.