The reliable production of two-dimensional crystals is essential for the development of new technologies based on 2D materials. However, current synthesis methods suffer from a variety of drawbacks, including limitations in crystal size and stability. Here, we report the fabrication of large-area, high-quality 2D tellurium (tellurene) using a substrate-free solution process. Our approach can create crystals with a process-tunable thickness, from monolayer to tens of nanometres, and with lateral sizes of up to 100 um. The chiral-chain van der Waals structure of tellurene gives rise to strong in-plane anisotropic properties and large thickness dependent shifts in Raman vibrational modes, which is not observed in other 2D layered materials. We also fabricate tellurene field-effect transistors, which exhibit air-stable performance at room temperature for over two months, on off ratios on the order of 106 and field-effect mobilities of around 700 cm2 per Vs. Furthermore, by scaling down the channel length and integrating with high-k dielectrics, transistors with a significant on-state current density of 1 A mm-1 are demonstrated.
@article{arxiv.1704.06202,
title = {Field-effect transistors made from solution-grown two-dimensional tellurene},
author = {Yixiu Wang and Gang Qiu and Ruoxing Wang and Shouyuan Huang and Qingxiao Wang and Yuanyue Liu and Yuchen Du and William A. Goddard and Moon J. Kim and Xianfan Xu and Peide D. Ye and Wenzhuo Wu},
journal= {arXiv preprint arXiv:1704.06202},
year = {2018}
}