Carrier Doping in Semiconducting Carbon Nanotubes with Fluorosumanenes

This study investigates the interaction between semiconducting carbon nanotubes and fluorine-substituted sumanenes. Transfer characteristics of fluorosumanene-doped carbon nanotube thin-film transistors revealed shifts in threshold voltage depending on the type of fluorosumanene. The polarity and density of carrier doping induced by fluorosumanenes varied with the number of fluorine atoms. Density functional theory calculations on the graphene-fluorosumanene interface showed that the Dirac point shift, indicating carrier doping, was primarily determined by two types of dipole moments normal to the graphene surface, which are produced by the bowl-like structure of sumanene and by fluorine cites. Charge transfer doping was also suggested at the interface between semiconductor CNTs and a type of fluorosumanene with the lowest unoccupied level close to the carbon nanotube's conduction band.