▎ 摘　　要

The spectrum of two-dimensional (2D) and layered materials 'beyond graphene' offers a remarkable platform to study new phenomena in condensed matter physics. Among these materials, layered hexagonal boron nitride (hBN), with its wide bandgap energy (similar to 5.0-6.0 eV), has clearly established that 2D nitrides are key to advancing 2D devices(1). A gap, however, remains between the theoretical prediction of 2D nitrides 'beyond hBN'(2,3) and experimental realization of such structures. Here we demonstrate the synthesis of 2D gallium nitride (GaN) via a migration-enhanced encapsulated growth (MEEG) technique utilizing epitaxial graphene. We theoretically predict and experimentally validate that the atomic structure of 2D GaN grown via MEEG is notably different from reported theory(2-4). Moreover, we establish that graphene plays a critical role in stabilizing the direct-bandgap (nearly 5.0 eV), 2D buckled structure. Our results provide a foundation for discovery and stabilization of 2D nitrides that are diffcult to prepare via traditional synthesis.