We report free-standing atomic crystals that are strictly 2D and can be viewed as individual atomic planes pulled out of bulk crystals or as unrolled single-wall nanotubes. By using micromechanical cleavage, we have prepared and studied a variety of 2D crystals, including single layers of boron nitride, graphite, several dichalcogenides and complex oxides. These atomically-thin sheets (essentially gigantic 2D molecules unprotected from the immediate environment) are stable under ambient conditions, exhibit high crystal quality and are continuous on a macroscopic scale.
@article{arxiv.cond-mat/0503533,
title = {Two Dimensional Atomic Crystals},
author = {K. S. Novoselov and D. Jiang and T. Booth and V. V. Khotkevich and S. M. Morozov and A. K. Geim},
journal= {arXiv preprint arXiv:cond-mat/0503533},
year = {2007}
}