Tuning electronic behaviors of WS2 by molecular doping

WS2 has become a hot research topic because of its excellent properties in the fields of chemistry, physics, and material science. We investigate the structural and electronic behaviors of organic molecules adsorbed on the WS2 single-layer using density functional theory. The results observed that organic molecules can inject additional carriers into the WS2 single-layer. Tetracyanoethylene (TCNE) and tetracyanoquinodimethane (TCNQ) doping achieve p-type doping, while tetrathiafulvalene (TTF) doping can introduce n-type doping behavior. Furthermore, the work function of WS2 can be tuned in the range of 4.05 eV to 5.71 eV after organic molecules doping. Importantly, the doping gap of the TTF-WS2 systems is reduced with the decrease of the applied negative electric field. Especially at − 0.45 V/Å, the doping gap of the TTF-WS2 system is 0.01 eV. It demonstrated that the applied negative electric field can induce effective n-type doping behavior. Therefore, organic molecular doping can regular the electronic behaviors of WS2, which is useful for the design of nanoelectronic devices. © 2022 Elsevier Ltd