Fabrication and optical characterization of improved electroless chemically deposited strontium fluoride (SrF2) thin films at 320K

Thin semi conductor films of strontium fluoride (SrF2) were successfully deposited on glass microscope slides using simple and cheap electroless chemical bath deposition methods at 320K and pH values of 9, 10 and 12. Controlled addition of ethylenediamine tetra acetate (EDTA), another complexing agent with pH to oppose that of bath constitutions, was used to vary the deposition pH values. X-ray diffractometry technique was used to confirm the depositions. Absorbance spectra data of the films were obtained by a single bean spectrophotometer (Pharmacia LKB Biochrom 4060) at wavelength range 200 to 900nm. Other optical and solid state properties were calculated from the data and compared with other deposited thin films. Average optical and solid state properties include absorbance ranging from 0.034 to 0.086, transmittance 0.820 to 0.925, reflectance 0.041 to 0.094, refractive index 1.51 to 1.88 absorption coefficient 0.078 to 0.198x 106m) -1 , electrical conductivity 0.40 to 0.49 (ohm cm) -1 , film thickness 0.013 to 0.074μm and bandgap 2.55 to 2.75 eV. The deposited thin films could find applications in antireflection coatings for eyeglass, solar thermal control devices and solar cells JONAMP Vol. 11 2007: pp. 415-422