Contact-induced doping in aluminum-contacted molybdenum disulfide

Abstract

The interface between two-dimensional semiconductors and metal contacts is an important topic of research of nanoelectronic devices based on two-dimensional semiconducting materials such as molybdenum disulfide (MoS2). We report transport properties of thin MoS2 flakes in a field-effect transistor geometry with Ti/Au and Al contacts. In contrast to widely used Ti/Au contacts, the conductance of flakes with Al contacts exhibits a smaller gate-voltage dependence, which is consistent with a substantial electron doping effect of the Al contacts. The temperature dependence of two-terminal conductance for the Al contacts is also considerably smaller than for the Ti/Au contacts, in which thermionic emission and thermally assisted tunneling play a dominant role. This result is explained in terms of the assumption that the carrier injection mechanism at an Al contact is dominated by tunneling that is not thermally activated.

17 pages, 9 figures

References in corpus (5)

• Electric Field Effect in Atomically Thin Carbon Films
• Chloride Molecular Doping Technique on 2D Materials: WS2 and MoS2
• Improved Contacts to MoS2 Transistors by Ultra-High Vacuum Metal Deposition
• Electron-hole transport and photovoltaic effect in gated MoS2 Schottky junctions
• Edge-induced Schottky barrier modulation at metal contacts to exfoliated molybdenum disulfide flakes