Sol-Gel-derived ZnO Coating with Nanopatterns Fabricated by Nanoimprinting

Abstract

The influence of an applied pressure on the relaxation of stress for sol–gel-derived zinc oxide (ZnO) thin film and the formation of nanopatterns during nanoimprinting has been carried out. Wrinkling pattern formation in thin films caused by the relaxation of stress is a phenomenon frequently encountered. In this study, a route for sol–gel-derived ZnO film imprinted with poly(dimethylsiloxane) mold was used to attain pattern transfer with excellent uniformity and smooth profile. The ZnO nanoscale rib patterns are obtained by altering the processing parameters, such as baking conditions, applied pressure, and content of solvent within the gel films. The surface roughness that caused by the relaxation of stress, and the wrinkles generated to relieve the stress can self-assemble into the contour of the mold during the imprinting process with an applied pressure. By altering the pretreatment parameters to render some residual solvent in the film can enhance the fluidity of the film, which in turn leads to a faster and deeper penetration of the mold into the film. In conclusion, the effect of processing conditions for eliminating wrinkling pattern of sol–gel-derived ZnO, and to prepare nanopatterns with good uniformity and smooth surface has been demonstrated.