Scaling-up atomically thin coplanar semiconductor-metal circuitry via phase engineered chemical assembly

Two-dimensional (2D) layered semiconductors demonstrate potential for miniaturizing transistors in integrated circuits, but achieving satisfactory electrical contacts between these materials and external metals poses challenges that hinder performance. This study explores a solution by employing coplanar 2D conductors to contact 2D semiconductors, aiming for scalable production. We present a method for large-scale, spatially controlled chemical assembly of integrated 2H-MoTe2 field-effect transistors (FETs) combined with coplanar metallic 1T′-MoTe2 contacts through phase engineering. Our findings reveal that the heterophase FETs exhibit favorable ohmic contact behavior characterized by low contact resistance, attributed to seamless contacts between the 2H and 1T′ MoTe2 phases, as confirmed by transmission electron microscopy. The heterophase FETs showcase an impressive average mobility of 23 cm2 V−1 s−1, akin to that of exfoliated single crystals, owing to the large single-crystalline domains of 2H MoTe2 (measured at 486±187 μm). By implementing a patterned growth technique, we successfully created a heterophase FET array with all components, including channels, gates, and contacts, constructed from 2D materials. We further demonstrate the viability of transferring this device array onto a flexible substrate.