Synthesis and optical properties of chemical bath deposited ZnO thin film


Zinc oxide thin films were deposited on glass slide from aqueous solution of ZnCl2 and NaOH by chemical bath depositionmethod. The films of various thicknesses have been obtained by varying the concentration of TEA (1 M0.01 M). Opticalproperties, surface morphology and particle size of the deposited thin film have been studied by U.V spectrophotometer (Varian)SEM and XRD. The optical band gap of the ZnO thin film was found in the range of 2.59e3.57 ev. Optical constant is such asrefractive index, extinction coefficient, real and imaginary parts of dielectric constant were evaluated from reflectance, transmittanceand absorbance curve. The film show high transmittance in the visible/near infrared region. Reflectance (10%e20%),refractive index (2e2.6), extinction coefficient (0.04e0.075), real (4e7) and imaginary parts (0.2e.0.3) of dielectric constant areobtained in visible/near infrared region. SEM studies shown plate and powder like morphology of sample. Particles size is obtainedin nano range.