Unique reflection properties of CdS/butterfly wings nanocomposites

Highly tunable optical properties are quite essential for future nanoscaled smart devices, which could be achieved on the hybrid photonic crystals (PhCs) that combine functional nanomaterials and PhC structures. However, related investigations are limited, since artificial PhCs lack either pattern variety or fabrication convenience. In this paper, the authors focus on exploring unusual optical properties by substituting the natural PhC structures in butterfly wings for artificial PhCs. Novel hybrid PhCs constructed by butterfly wings and the optical functional materials such as cadmium sulfide nanoparticles (nano-cadmium sulfide) are taken as examples. Owing to the conventionally unobtainable quasi-one dimensional PhC structures, nano-cadmium sulfide/wings (Euploea mulciber) display brilliant or gloomy colors depending on the observation directions. Such unique ‘on–off’ angle-dependent reflection properties are quite different from those of typical 1D PhCs and are intensively studied through comparison wi...