Fabrication of zinc oxide nano-patterns by quick gel-nanoimprint process toward optical switching devices

We investigated a quick patterning using a gel-nanoimprint process for zinc oxide (ZnO) thin films. The X-ray diffraction measurement revealed that the ZnO thin films had wurtzite structure by annealing in the ambient air or oxygen. The ZnO thin film annealed in oxygen exhibited higher refractive index of 1.92 (at 720 nm for wavelength of light) which is close to that of a conventional ZnO thin film, whereas that of ZnO thin film annealed in air atmosphere provided very low value of 1.64. We demonstrated the nano-patterning with quite short imprinting time in 5 min by the gel-nanoimprint process. We achieved that the shrinkage factor of ZnO nano-patterns was as low as 8% and 3% in the width-and height-directions, respectively.