Making clean electrical contacts on 2D transition metal dichalcogenides

2D semiconductors, particularly transition metal dichalcogenides (TMDs), have emerged as highly promising for new electronic technologies. However, a key challenge in fabricating devices out of semiconductors is the need ultra-clean contacts with resistances approaching quantum limit. The lack high-quality, low-contact-resistance P-type and N-type on TMDs has limited progress towards next generation low-power devices, such tunnel field-effect transistors. In this Expert Recommendation, we summarize strategies provide guidance making clean van der Waals monolayered TMD semiconductors. We also discuss physics prospects achieving conductance. A materials good electrical contact. This Recommendation discusses provides tips improving contact quality.