Effects of spin coating speed on nanostructured Titanium Dioxide thin films properties

This work aims to understand the effects of spin coating speed to the structural and optical properties of TiO₂ thin films for dynamic dispense method. Film thickness is measured at three different points and the average is taken. At the lowest spin speed (2000 rpm), the resulting thin films average thickness is 187.8 nm. With the increment of spin speed, the film´s thickness decrease almost linearly which agrees with the result reported by Dewi et al [1]. As the spin speed increases, the centrifugal force will cause more TiO₂ particle to be thrown away from the substrate thus leaving only thinner film. The higher spin speed cause smaller TiO₂ particle to be removed from the substrate, leaving only larger particle which causes higher surface roughness, that eventually leads to lower optical transmittance.