Facile and Reversible Carrier-Type Manipulation of Layered MoTe2 Toward Long-Term Stable Electronics
journal contributionposted on 14.09.2020, 14:54 by Mengjiao Li, Che-Yi Lin, Yuan-Ming Chang, Shih-Hsien Yang, Mu-Pai Lee, Ciao-Fen Chen, Ko-Chun Lee, Feng-Shou Yang, Yi Chou, Yi-Chun Lin, Keiji Ueno, Yumeng Shi, Yi-Chia Chou, Kazuhito Tsukagoshi, Yen-Fu Lin
Flexible manipulation of the carrier transport behaviors in two-dimensional materials determines their values of practical application in logic circuits. Here, we demonstrated the carrier-type manipulation in field-effect transistors (FETs) containing α-phase molybdenum ditelluride (MoTe2) by a rapid thermal annealing (RTA) process in dry air for hole-dominated and electron-beam (EB) treatment for electron-dominated FETs. EB treatment induced a distinct shift of the transfer curve by around 135 V compared with that of the FET-processed RTA treatment, indicating that the carrier density of the EB-treated FET was enhanced by about 1 order of magnitude. X-ray photoelectron spectroscopy analysis revealed that the atomic ratio of Te decreased from 66.4 to 60.8% in the MoTe2 channel after EB treatment. The Fermi level is pinned near the new energy level resulting from the Te vacancies produced by the EB process, leading to the electron-dominant effect of the MoTe2 FET. The electron-dominated MoTe2 FET showed excellent stability for more than 700 days. Thus, we not only realized the reversible modulation of carrier-type in layered MoTe2 FETs but also demonstrated MoTe2 channels with desirable performance, including long-term stability.