Low Schottky barrier contacts to 2H-MoS2 by Sn electrodes

Abstract

The semiconductor MoS 2 has attracted much attention owing to its sizable energy bandgap, significant spin-orbit coupling, and quantum effects such as the valley Hall effect and gate-induced superconductivity. However, in electronic devices, the energy bandgap usually gives rise to the formation of Schottky barriers at the interface to the contact metal, which may render devices intended for quantum transport inapplicable at low temperature. Therefore, the fabrication of Ohmic contacts operational at low temperature is crucial. Yet, it currently remains a substantial challenge to produce low resistive contacts with a simple process. We manifest that low temperature Ohmic contacts to mono- and few-layer MoS 2 can be achieved with Tin (Sn) as the contact metal. Sn is directly evaporated onto MoS 2, and hence, this establishes a much easier fabrication method than tunneling barriers, for example. We provide detailed device characterization, extract Schottky barrier heights, demonstrate multiterminal measurements, and propose a possible explanation: strain induced deformation of MoS 2 imposed by Sn.