  Atom-layered hexagonal boron nitride (hBN), with excellent stability, flat
surface and large bandgap, has been reported to be the best 2D insulator to
open up the great possibilities for exciting potential applications in
electronics, optoelectronics and photovoltaics. The ability to grow
high-quality large single crystals of hBN is at the heart for those
applications, but the size of single-crystal 2D BN is less than a millimetre
till now. Here, we report the first epitaxial growth of a 10*10 cm2
single-crystal hBN monolayer on a low symmetry Cu(110) "vicinal surface". The
growth kinetics, unidirectional alignment and seamless stitching of hBN domains
are unambiguously illustrated using centimetre- to the atomic-scale
characterization techniques. The findings in this work are expected to
significantly boost the massive applications of 2D materials-based devices, and
also pave the way for the epitaxial growth of broad non-centrosymmetric 2D
materials.
