Electrical devices from top-down structured platinum diselenide films

Platinum diselenide (PtSe 2 ) is an exciting new member of the two-dimensional (2D) transition metal dichalcogenide (TMD) family. It has a semimetal to semiconductor transition when approaching monolayer thickness and has already shown significant potential for use in device applications. Notably, PtSe 2 can be grown at low temperature making it potentially suitable for industrial usage. Here, we address thickness-dependent transport properties and investigate electrical contacts to PtSe 2 , a crucial and universal element of TMD-based electronic devices. PtSe 2 films have been synthesized at various thicknesses and structured to allow contact engineering and the accurate extraction of electrical properties. Contact resistivity and sheet resistance extracted from transmission line method (TLM) measurements are compared for different contact metals and different PtSe 2 film thicknesses. Furthermore, the transition from semimetal to semiconductor in PtSe 2 has been indirectly verified by electrical characterization in field-effect devices. Finally, the influence of edge contacts at the metal–PtSe 2 interface has been studied by nanostructuring the contact area using electron beam lithography. By increasing the edge contact length, the contact resistivity was improved by up to 70% compared to devices with conventional top contacts. The results presented here represent crucial steps toward realizing high-performance nanoelectronic devices based on group-10 TMDs.