Field-effect transistors made from solution-grown two-dimensional tellurene

• Published in: Nature electronics Vol. 1; no. 4; pp. 228 - 236
• Main Authors: Wang, Yixiu, Qiu, Gang, Wang, Ruoxing, Huang, Shouyuan, Wang, Qingxiao, Liu, Yuanyue, Du, Yuchen, Goddard, William A, Kim, Moon J, Xu, Xianfan, Ye, Peide D, Wu, Wenzhuo
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group 01.04.2018
• Subjects: Crystals; Current density; Electrons; Field effect transistors; Layered materials; Morphology; Point defects; Room temperature; Semiconductor devices; Substrates; Tellurium; Thickness; Transmission electron microscopy; Two dimensional materials; Vibration mode
• ISSN: 2520-1131
• DOI: 10.1038/s41928-018-0058-4

The reliable production of two-dimensional (2D) 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 process-tunable thickness, from a monolayer to tens of nanometres, and with lateral sizes of up to 100 µm. 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 about 700 cm2 V−1 s−1. 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.A substrate-free solution process can create large-area two-dimensional tellurium crystals, which can be used to build field-effect transistors that exhibit air-stable performance at room temperature for over two months and high on-state current densities of 1 A mm–1.