Nanoimprint lithography: Toward functional photonic crystals

In this chapter we review the use of nanoimprint lithography and its derivative soft-lithography techniques for the fabrication of functional photonic crystals. Nanoimprint is a viable, scalable, and cost-effective solution for large area patterning. While initially it relied primarily on pattern transfer from a rigid mold to a thermally softened polymer by embossing, in the last two decades the process evolved rapidly, giving rise to new technologies that allow direct imprint of functional materials such as conjugated polymers, metals, biological matter, and metal oxides. These advancements generated increasing interest in the use of nanoimprint lithography for the fabrication of photonic structures for light management in optoelectronic devices. After describing standard nanoimprint lithography and its derivative soft-lithography methods, we briefly discuss nanoimprint capabilities and prospects in photonic applications. In particular we review recent implementations of imprinted photonic structures for light management in organic light emitting diodes, solar cells, solid state lasers and sensors.