We report a straightforward chemical methodology for controlling the thickness of black phosphorus flakes down to the monolayer limit by layer-by-layer oxidation and thinning, using water as solubilizing agent. Moreover, the oxidation process can be stopped at will by two different passivation procedures, namely the non-covalent functionalization with perylene diimide chromophores, which prevents the photooxidation, or by using a protective ionic liquid layer. The obtained flakes preserve their electronic properties as demonstrated by fabricating a BP field-effect transistor (FET). This work paves the way for the preparation of BP devices with controlled thickness
@article{arxiv.1903.03972,
title = {Monolayer black phosphorus by sequential wet-chemical surface oxidation},
author = {Stefan Wild and Vicent Lloret and Victor Vega-Mayoral and Daniele Vella and Edurne Nuin and Martin Siebert and Maria Koleśnik-Gray and Mario Löffler and Karl J. J. Mayrhofer and Christoph Gadermaier and Vojislav Krstić and Frank Hauke and Gonzalo Abellán and Andreas Hirsch},
journal= {arXiv preprint arXiv:1903.03972},
year = {2019}
}