Optical Characterization of Cu-doped ZnO Nano Thin Films Prepared by Successive Ionic Layer Adsorption and Reaction (SILAR) Using EDTA as Complexing Agent

ZnO:Cu thin films were successfully deposited on glass substrates by Successive Ionic layer adsorption Reaction method. The chemical compositions and thickness were obtained by Rutherford backscattering spectrometer. Samples B1 and B2 have elemental compositions of Cu:6.68%, O:23.72%, Zn:13.60% and Cu:5.14%, O:25.45%, Zn:13.42% respectively. The films optical properties were characterized using UV double beam spectrophotometer series 1800, for transmittance measurements and other optical properties such as Absorbance, reflectance, absorption coefficient, refractive index, were determined using appropriate equations. The Transmittance increases with increasing wavelength (42%-61%) for B1 and B2(49%-63) at the UV regions of electromagnetic spectrum for the two samples. The SILAR process allowed for the controlled incorporation of Cu ions into the ZnO lattice, resulting in a tunable band gap and enhanced optical properties. The doping concentration was systematically varied to optimize the performance of the ZnO:Cu thin films for optoelectronic applications, such as UV-sensitive photodetectors and light-emitting diodes (LEDs). B1 and B2 have high optical energy band gaps of 3.40eV and 3.15eV with average of 3.30eV which make them suitable material for optoelectronic applications and transparent electrodes.