Lowering Contact Resistances of Two-Dimensional Semiconductors by Memristive Forming

• Published in: Nano letters Vol. 22; no. 17; pp. 7094 - 7103
• Main Authors: Wu, Zilong, Zhu, Yuhan, Wang, Feng, Ding, Chuyun, Wang, Yanrong, Zhan, Xueying, He, Jun, Wang, Zhenxing
• Format: Journal Article
• Language: English
• Published: American Chemical Society 14.09.2022
• Subjects: vacancy defects; transition-metal dichalcogenides; contact resistance; memristor; Schottky barrier
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/acs.nanolett.2c02136

Two-dimensional semiconductors have great potential for beyond-silicon electronics. However, because of the lack of controllable doping methods, Fermi level pinning, and van der Waals (vdW) gaps at the metal–semiconductor interfaces, these devices exhibit high electrical contact resistances, restricting their practical applications. Here, we report a general contact-resistance-lowering strategy by constructing vertical metal–semiconductor–metal memristor structures at the contact regions and setting them into a nonvolatile low-resistance state through a memristive forming process. Through this, we reduce the contact resistances of MoS2 field-effect transistors (FETs) by at least one order of magnitude and improve the on-state current densities of MoTe2 FETs by about two orders of magnitude. We also demonstrate that this strategy is applicable to other two-dimensional semiconductors, including MoSe2, WS2, and WSe2, and a variety of contact metals, including Au, Cu, Ni, and Pd. The good stability and universality indicate the great potential for technological applications.