The luminescence quantum yield of organic one-dimensional periodic nanostructures

We employed nanoimprint lithography and soft moulding techniques to print one-dimensional nanostructures with submicron periodicity onto organic films made of different light-emitting materials. We studied and compared the emission and absorption of the chromophores before and after the lithography processes, demonstrating that the lithography techniques actually preserve the optical properties of light-emitting molecules. In particular, we investigated the photoluminescence efficiency, finding that all our patterned light-emitting materials show enhanced luminescence emission (up to a factor larger than two) with respect to the untextured film, as a consequence of the printed nanostructure. This is ascribed to the decrease of the self-absorption path induced by the grating-enhanced forward scattering.