Bottom-Up Synthesized Nanoporous Graphene Transistors

Nanoporous graphene (NPG) can exhibit a uniform electronic band gap and rationally-engineered emergent electronic properties, promising for electronic devices such as field-effect transistors (FETs), when synthesized with atomic precision. Bottom-up, on-surface synthetic approaches developed for graphene nanoribbons (GNRs) now provide the necessary atomic precision in NPG formation to access these desirable properties. However, the potential of bottom-up synthesized NPG for electronic devices has remained largely unexplored to date. Here, FETs based on bottom-up synthesized chevron-type NPG (C-NPG), consisting of ordered arrays of nanopores defined by laterally connected chevron GNRs, are demonstrated. C-NPG FETs show excellent switching performance with on–off ratios exceeding 104, which are tightly linked to the structural quality of C-NPG. The devices operate as p-type transistors in the air, while n-type transport is observed when measured under vacuum, which is associated with reversible adsorption of gases or moisture. Theoretical analysis of charge transport in C-NPG is also performed through electronic structure and transport calculations, which reveal strong conductance anisotropy effects in C-NPG. The present study provides important insights into the design of high-performance graphene-based electronic devices where ballistic conductance and conduction anisotropy are achieved, which could be used in logic applications, and ultra-sensitive sensors for chemical or biological detection.