Electronic structures of in-plane two-dimensional transition-metal dichalcogenide heterostructures.

Electronic structures of in-plane two-dimensional transition-metal dichalcogenide (TMD) heterostructures have been studied on the basis of the first-principles density functional calculations. In contrast to vertically stacked TMD heterostructures, true type-II band alignment could be established in in-plane TMD heterostructures due to their coherent lattice and strong electronic coupling, and thus leads to the efficient separation of electrons and holes. In in-plane TMD heterostructures interfaced along the zigzag direction, electronic reconstruction causes band bending in constituent TMDs, unveiling the great potential in achieving high efficiency of water splitting and constructing Schottky barrier solar cells. In addition, type-I alignment could also be demonstrated in in-plane TMD heterostructures, enriching the photoluminescence features of TMD materials. In-plane TMD heterostructures with the ultimate thickness limit for semiconductor heterostructures will definitely spark a surge in research activity.