All van der Waals Semiconducting PtSe₂ Field Effect Transistors with Low Contact Resistance Graphite Electrodes

Contact resistance is a multifaceted challenge faced by the 2D materials community. Large Schottky barrier heights and gap-state pinning are active obstacles that require an integrated approach to achieve the development of high-performance electronic devices based on 2D materials. In this work, we present semiconducting PtSe2 field effect transistors with all-van-der-Waals electrode and dielectric interfaces. We use graphite contacts, which enable high ION/IOFF ratios up to 109 with currents above 100 μA μm–1 and mobilities of 50 cm2 V–1 s–1 at room temperature and over 400 cm2 V–1 s–1 at 10 K. The devices exhibit high stability with a maximum hysteresis width below 36 mV nm–1. The contact resistance at the graphite–PtSe2 interface is found to be below 700 Ω μm. Our results present PtSe2 as a promising candidate for the realization of high-performance 2D circuits built solely with 2D materials.