Studies of structural, optical and electrical properties of nanostructured ZnS:F films

ZnS and ZnS:F films were produced on glass substrates heated up to 350 +/- 5 degrees C by ultrasonic spray pyrolysis method. FTIR and Raman spectroscopy measurements were applied for determining phases included in undoped and F doped ZnS films. The scanning electron microscopy (SEM) images of the film surfaces showed that F doping caused significant contraction in particle size of the films. Energy Dispersive Spectrometer (EDS) analyses verified the presence of all expected elements including Zn, S and F. The optic characteristics of F doped ZnS films were analyzed by using their transmittance and reflectance spectra obtained by UV-vis spectrophotometer. It was determined that ZnS films exhibit a relatively high transmittance of 80% in the visible region. Refractive index values of the ZnS films showed similar conduct in 400-700 nm range. The optical band gap of the ZnS films decreased with F dopant. The electrical resistivity values of the films were calculated for the ZnS films by using current-voltage change graphics drawn in 0-100 V range through the measurement results obtained in room-temperature and dark setting and it was determined that F doping decreased resistivity values of the ZnS films.