Recent Contact Strategies for Two-Dimensional Electronics

Two-dimensional (2D) semiconductors such as monolayer MoS₂ and WSe₂ have rapidly gained attention as next-generation channel materials for ultrascaled electronics owing to their exceptional electrostatic control and atomic-scale thickness. Despite their promise, the high contact resistance and Fermi-level pinning at the metal-semiconductor interface continue to hinder optimal device performance and scalability. This review highlights recent breakthroughs in contact engineering─including van der Waals metal transfer, semimetallic and edge contacts, contact doping, strain engineering, and self-healing electrodes─that collectively enhance carrier injection, reduce Schottky barriers, and improve interface stability. We also examine complementary metal-oxide semiconductor-compatible integration strategies and the growing role of computational screening and machine learning in accelerating the discovery of optimal contact materials. These advances have enabled record-setting 2D field-effect transistor performance at sub-50 nm gate lengths, underscoring the increasing readiness of 2D materials for high-volume, energy-efficient applications beyond the silicon era.