Atomically Thin Two-Dimensional π-Conjugated Kagomé Polymers with Dirac Cone-Driven Charge Transport.

Two-dimensional nanomaterials are at the forefront of next-generation technologies, with applications spanning quantum computing, catalysis, and sensing. Among these, on-surface synthesized two-dimensional conjugated polymers (2DCPs) with Kagomé lattice symmetry have recently emerged as promising candidates, thanks to their ability to form large, ordered domains and their unique electronic structures featuring both flat bands and Dirac cones. In this work, we report the integration of atomically thin, surface-confined 2DCPs into field-effect transistors (FETs), marking a step toward their use in functional devices. The fabricated FETs exhibit ohmic transport behavior with Pt contacts and reveal ambipolar graphene-like field-induced conductivity modulation, directly linked to the Dirac cone in the electronic band structure. These findings are supported by ab initio density functional theory (DFT) calculations and finite element simulations of the drift-diffusion equation, confirming the transport characteristics. Our results highlight the potential of 2DCPs with Kagomé lattice symmetry as highly tunable, organic systems for future applications in nanoelectronics and high-performance sensing.