Effect of withdrawal rate on the evolution of optical properties of dip-coated yttria-doped zirconia thin films

In this work, the Swanepoel method is described and applied for determining various optical parameters and thicknesses of dip-coated yttria-doped zirconia thin films. Using this method the influence of the withdrawal rate on optical parameters was studied. The characterization of the deposited thin films was carried out by optical microscopy and FT-IR spectrophotometry. As expected, coating thickness was closely related to the withdrawal rate and consequently influenced optical parameters such as refractive index, extinction coefficient, and absorption coefficient. Regarding the average refractive index of the prepared thin films, n is in the 2.0 - 2.2 range, the higher refractive index average value being obtained with films deposited at 25 mm min−1 (n = 2.19). The value of the optical band gap was also studied, this increased with withdrawal rate and was quite similar to values reported by other investigators at 50, 25 and 10 mm min−1. Thus, this study proposes analysing the influence of the withdrawal rate for the manufacture of different types of thin films with previously specified optical parameters.