Fabrication of SnO₂ nano-to-microscale structures from SnO₂-nanoparticle-dispersed resin via thermal nanoimprint lithography

Recently, nanoimprint lithography (NIL) has been extensively investigated as a cost-effective, high-throughput, nano-patterning method, especially for the fabrication of optical devices such as light emitting diodes and thin film solar cells. Thermal nanoimprint lithography (thermal-NIL), one of various methods of NIL, can be applied with relative ease for the fabrication of various nanoscale structures, even on flexible substrates. However, conventional thermal-NIL that uses polymeric resin such as Poly(methyl methacrylate) has limited applicability to the fabrication of optical devices, owing to the low refractive index of the resin. As such, we developed SnO₂-nanoparticle-containing imprint resin that has a high refractive index and is applicable in the thermal-NIL method. We confirmed that various SnO₂ nano-to-microscale structures were successfully fabricated via the thermal-NIL process, by using this SnO₂-dispersed resin. The optical properties of the patterned SnO₂ structures were analyzed via ultraviolet-visible spectrophotometry and crystallinity of these patterned SnO₂ structures was determined via X-ray diffraction analysis.