Effect of doping and sintering temperature on the optical characterization of CdS films prepared by screen printing technique

Abstract

Two sets of CdS films, doped and undoped films by screen printing technique, were prepared and investigated by UV-Visible spectrophotometer. The undoped as-printed films showed high transmittance (90%) and lower reflectance (10%), while the films sintered at 400◦C and 600◦C showed less transmittance (60%) and little increase in reflectance (20%), the band gap energy of these films have decreased from 2.44 eV to 2.35 eV with an increase in the sintering temperature. The Doped films showed (70%) transmittance and reflectance of (20%) and increase in the band gap energy up to 3.45 eV. These results nominates the CdS films to be used as n-type window layer in solar cells. Other optical constants like refractive index (n), extinction coefficient value (K) and dielectric values have been calculated.