Shi Wu, Ye Jianting, Zhang Yijin, Suzuki Ryuji, Yoshida Masaro, Miyazaki Jun, Inoue Naoko, Saito Yu, Iwasa Yoshihiro
Quantum-Phase Electronics Center and Department of Applied Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
1] Quantum-Phase Electronics Center and Department of Applied Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan [2] Zernike Institute for Advanced Materials, University of Groningen, The Netherlands.
Sci Rep. 2015 Aug 3;5:12534. doi: 10.1038/srep12534.
Functionalities of two-dimensional (2D) crystals based on semiconducting transition metal dichalcogenides (TMDs) have now stemmed from simple field effect transistors (FETs) to a variety of electronic and opto-valleytronic devices, and even to superconductivity. Among them, superconductivity is the least studied property in TMDs due to methodological difficulty accessing it in different TMD species. Here, we report the systematic study of superconductivity in MoSe2, MoTe2 and WS2 by ionic gating in different regimes. Electrostatic gating using ionic liquid was able to induce superconductivity in MoSe2 but not in MoTe2 because of inefficient electron accumulation limited by electronic band alignment. Alternative gating using KClO4/polyethylene glycol enabled a crossover from surface doping to bulk doping, which induced superconductivities in MoTe2 and WS2 electrochemically. These new varieties greatly enriched the TMD superconductor families and unveiled critical methodology to expand the capability of ionic gating to other materials.
基于半导体过渡金属二硫属化物(TMD)的二维(2D)晶体的功能,如今已从简单的场效应晶体管(FET)拓展到各种电子和光谷电子器件,甚至涉及超导性。其中,由于在不同TMD种类中研究超导性存在方法上的困难,超导性是TMD中研究最少的特性。在此,我们报告了通过在不同体系中进行离子门控,对MoSe2、MoTe2和WS2中的超导性进行的系统研究。使用离子液体的静电门控能够在MoSe2中诱导出超导性,但在MoTe2中却不能,这是因为受电子能带排列限制,电子积累效率低下。使用KClO4/聚乙二醇的替代门控实现了从表面掺杂到体掺杂的转变,从而在MoTe2和WS2中电化学诱导出超导性。这些新的变体极大地丰富了TMD超导体家族,并揭示了将离子门控能力扩展到其他材料的关键方法。