Interface effects of Schottky devices built from MoS2 and high work function metals. (20th April 2022)

• Record Type: Journal Article
• Authors: Li, Y D; Zhen, W L; Weng, S R; Hu, H J; Niu, R; Yue, Z L; Xu, F; Zhu, W K; Zhang, C J
• Is Part Of: Journal of physics. Volume 34:Number 16(2022)
• Publication Date: 2022-04-20
• Subjects: two-dimensional materials -- van der Waals interface -- Schottky diodes -- doping concentration; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/1361-648X/ac50db
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: Schottky junctions, formed by high work function metals and semiconductors, are important devices in electronics and optoelectronics. The metal deposition in traditional Schottky interfaces usually damages the semiconductor surface and causes defect states, which reduces the Schottky barrier height and device performance. This can be avoided in the atomically smooth interface formed by two-dimensional (2D) metals and semiconductors. For better interface tailoring engineering, it is particularly important to understand various interface effects in such 2D Schottky devices under critical or boundary conditions. Here we report the fabrication and testing of three types of MoS2 devices, i.e., using PtTe2, Cr and Au as contact materials. While the Cr/MoS2 contact is an ohmic contact, the other two are Schottky contacts. The van-der-Waals interface of PtTe2 –MoS2 results in a well-defined OFF state and a significant rectification ratio of 10 4 . This parameter, together with an ideality factor 2.1, outperforms the device based on evaporated Au. Moreover, a device in the intermediate condition is also presented. An abrupt increase in the reverse current is observed and understood based on the enhanced tunneling current. Our work manifests the essential role of doping concentration and provides another example for 2D Schottky interface design.