Displacement-Field-Induced Ionization of Defect States in High-Quality hBN
Researchers used monolayer graphene encapsulated between hexagonal boron nitride (hBN) crystals as a sensor to test how an applied electric field affects hBN's electronic properties. They found that increasing the field causes defect states within hBN to ionize, leading to charge transfer with the graphene and increased disorder. This proves that even high-quality hBN is not perfectly inert, which has major implications for designing and interpreting van der Waals heterostructures.