  The spectrum of two-dimensional (2D) 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 (~5.0-6.0 eV), has clearly established that 2D nitrides are key to
advancing novel devices1. A gap, however, remains between the theoretical
prediction of 2D nitrides beyond hBN and experimental realization of such
structures. Here we demonstrate the synthesis of 2D gallium nitride (GaN) via a
novel 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. 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 novel 2D
nitrides that are difficult to prepare via traditional synthesis.
