Optical Band gap of Spin-Coated ZnO: Cu/Co Thin Films Synthesized by Sol-Gel Technique

Co-doped (Cu/Co) percentage of 4% were synthesized using sol-gel spin-coating technique on glass substrate at a temperature of 100oC. The Optical properties are concluded from absorption and transmission measurements, which are obtained by using double beam UV- Visible1800 spectrophotometer in the wavelength (300-500)nm. It was found that the absorbance increases with increasing the co-doping percentage (1/1, 2/2, 3/3 and 4/4) mol%, while the transmittance is decreased. The optical properties that were measured also included the absorption coefficient, the energy gap and the Urbach energy. It was found that the energy gap values decreased in the range 3.35 – 3.23 and the transmittance rate was 90% within the visible spectrum region.