Here, we describe synthesis of TMD crystals using a two-step flux growth method that eliminates a major potential source of contamination. Detailed characterization of TMDs grown by this two-step method reveals charged and isovalent defects with densities an order of magnitude lower than in TMDs grown by a single-step flux technique. Initial temperature-dependent electrical transport measurements of monolayer WSe2 yield room-temperature hole mobility above 840 cm2/Vs and low-temperature disorder-limited mobility above 44,000 cm2/Vs. Electrical transport measurements of graphene-WSe2 heterostructures fabricated from the two-step flux grown WSe2 also show superior performance: higher graphene mobility, lower charged impurity density, and well-resolved integer quantum Hall states.
@article{arxiv.2303.16290,
title = {Two-step flux synthesis of ultrapure transition metal dichalcogenides},
author = {Song Liu and Yang Liu and Luke Nemetz Holtzman and Baichang Li and Madisen Holbrook and Jordan Pack and Takashi Taniguchi and Kenji Watanabe and Cory R. Dean and Abhay Pasupathy and Katayun Barmak and Daniel A. Rhodes and James Hone},
journal= {arXiv preprint arXiv:2303.16290},
year = {2023}
}