Precise tunability of electronic properties of 2D nanomaterials is a key goal of current research in this field of materials science. Chemical modification of layered transition metal dichalcogenides leads to the creation of heterostructures of low-dimensional variants of these materials. In particular, the effect of oxygen-containing plasma treatment on molybdenum disulfide (MoS2) has long been thought to be detrimental to the electrical performance of the material. Here we show that the mobility and conductivity of MoS2 can be precisely controlled and improved by systematic exposure to oxygen:argon plasma, and characterise the material utilising advanced spectroscopy and microscopy. Through complementary theoretical modelling which confirms conductivity enhancement, we uncover the role of a two-dimensional phase of molybdenum trioxide (2D-MoO3) in improving the electronic behaviour of the material. Deduction of the beneficial role of MoO3 will serve to open the field to new approaches with regard to the tunability of 2D semiconductors by their low-dimensional oxides in nano-modified heterostructures.
@article{arxiv.1706.08573,
title = {Oxide-mediated self-limiting recovery of field effect mobility in plasma-treated MoS$_2$},
author = {Jakub Jadwiszczak and Colin O'Callaghan and Yangbo Zhou and Daniel S. Fox and Eamonn Weitz and Darragh Keane and Ian O'Reilly and Clive Downing and Aleksey Shmeliov and Pierce Maguire and John J. Gough and Cormac McGuinness and Mauro S. Ferreira and A. Louise Bradley and John J. Boland and Valeria Nicolosi and Hongzhou Zhang},
journal= {arXiv preprint arXiv:1706.08573},
year = {2019}
}