F-doping effects on electrical and optical properties of ZnO nanocrystalline films

F-doped and undoped ZnO nanocrystalline films were prepared from thermal oxidation of ZnF2 films deposited on a silica substrate by electron beam evaporation. The F-doped ZnO film has very low electrical resistivity of 7.95×10−4Ωcm and a high optical transmittance. The study also indicated that (1) the substitutional F atoms in the film serve as donors to increase the carrier concentration and the optical band gap with respect to undoped ZnO film, and (2) F passivation reduces the known number of Os2−/Os− surface states and increases carrier mobility.