The Contacts of the Monolayer Semiconductor C2N with 2D Metal Electrodes

Abstract

AbstractFor its easy synthesis, suitable band gap, and fine optoelectronic properties, the carbon nitride sheet C2N acts as a promising candidate material for nanoelectronics. To achieve a high‐performance C2N device, ohmic contact with metal electrodes is urgently needed. Here, based on first principles calculations, the monolayer (ML) C2N contacts with a series of 2D metal electrodes—surface‐engineered MXenes (Hf2C(OH)2, Nb2CF2, Mo2NO2) and metallic transition metal dichalcogenides (T‐VSe2, T‐VS2, H‐TaS2)—are systematically studied. With clean and saturated surfaces, these 2D metals form van der Waals (vdW) contacts with C2N, which exhibit a weak Fermi level pinning and tunable Schottky barriers. While n‐type Schottky barriers are observed for Nb2CF2/T‐VSe2 electrodes and p‐type for T‐VS2/Mo2NO2/H‐TaS2 electrodes due to their different sizes of work functions, ohmic contact is found for Hf2C(OH)2 electrode with its work function significantly smaller than electron affinity of ML C2N. Device simulations of field effect transistors based on C2N further confirmed the finding. This paper presents a fundamental understanding of 2D metal–C2N contacts and will help the future design of well‐performing C2N devices.