▎ 摘 要
2D heterostructures based on graphene/hBN nanodots are investigated using DFT calculations. They have ferromagnetic spin ordering with spin directly proportional to the number and size of the graphene nanodots. The wide energy gap of hBN acts as confinement potential for graphene electronic states, thus the resultant system is type-I heterojunction. An applied electric field converts the type-I to type-II heterojunction. The prominent excitation of the UV-Vis spectrum, at-4 eV, is equally contributed by transitions between spin-up and spin-down orbitals. The spectrum is redshifted to a lower energy by the electric field with excitations contributed mostly by spin-down transitions.