Electric‐Field‐Tunable Bandgaps in the Inverse‐Designed Nanoporous Graphene/Graphene Heterobilayers

Abstract

AbstractThe recent bottom‐up synthesis of atomically precise nanoporous graphene (NPG) offers a way of tuning graphene's properties by forming NPG/graphene (Grp) bilayers. Depending on the size, shape, and periodicity of the nanopores in NPG, the heterobilayers can exhibit various functionalities. This theoretical work presents an inverse design of NPG/Grp bilayers with electric‐field‐tunable bandgaps as a target property. The interlayer interaction in such heterobilayers can induce a bandgap in graphene either by breaking inversion symmetry (type I) or by moving and merging Dirac points of graphene (type II). The bandgap opening also requires electron–hole symmetry breaking induced by an applied perpendicular electric field, leading to two distinct, linear versus nonlinear, field dependences of the bandgap for the type‐I and type‐II cases, respectively. To translate the underlying physics of the bandgap opening in graphene into real atomic structures, the authors develop an inverse design method and find NPG/Grp bilayers with the target functionality. The field‐tunable bandgap in graphene, supported by first‐principles calculations for the inverse‐designed systems, holds promise for new types of graphene transistors.