In one aspect, structures are provided comprising: a substrate having a first surface and a second surface; and a polymeric layer disposed on the first surface of the substrate, the polymeric layer comprising a polymer and a plurality of light-emitting nanocrystals; the polymeric layer having a patterned surface, the patterned surface having a patterned first region having a first plurality of recesses and a patterned second region having a second plurality of recesses, wherein the plurality of recesses in each region has a first periodicity in a first direction, and a second periodicity in a second direction which intersects the first direction, wherein the first periodicity of the first region is different from the first periodicity of the second region.