Optical and Electrical Properties of F-Doped ZnO Thin Films Grown on Muscovite Mica Substrates and Their Optical Constants

Undoped and F-doped ZnO (FZO) thin films with different F concentrations were deposited on muscovite mica substrates using the sol-gel spin-coating method. All the films exhibited strong ultra-violet emissions as well as broad peaks in the visible region. The transmittances of the FZO films were slightly lower than that of the undoped film. The calculated optical band gap of the FZO films did not show any notable changes with changes in the F concentration, while the Urbach energy depended significantly on the F concentration. Using the refractive index values of the films, their optical constants, such as the single-oscillator energy, the dispersion energy, and the M-1, and M-3 moments, were determined. The electrical properties of the films improved with an increase in the F concentration up to 9 at.%, and then decreased slightly for further increase.