Fabrication of high-quality colloidal crystal films by vertical deposition method integrated with a piezoelectric actuator

In recent years the self-assembling of monodispersed colloidal spheres has gained much attention due to their potentials in many fields. Though many self-assembling methods have been put forward, the existence of many defects in colloidal crystals is still an open question restricting the dimensions of ordered domains and the performance thereof in many applications. In this paper we introduced a modified vertical deposition method to improve film quality of colloidal crystal films. A piezoelectric actuator was integrated with the conventional vertical deposition method, which excited the substrate vibrating along the vertical direction. The vibratory amplitude and frequency of the actuator could be controlled by the driving voltage. Our experimental observations indicated that, grown at proper driving parameters, frequency of 300 Hz and vibratory amplitude of 310 nm in our current observations, film quality could be greatly improved with less defects. The mechanism was also briefly illuminated.