Solid-state fluorescence enhancement of organic dyes by photonic crystals

Photonic crystal (PC) films were fabricated by self-assembly of colloidal crystals using a vertical deposition method at invariant temperature and humidity. Organic dyes, whose emission wavelengths overlap the photonic stopbands of selected PCs, were deposited on the surface of PC films by thermal evaporation under vacuum. The fluorescence of organic dyes deposited on PCs is obviously enhanced in comparison with that on aluminium films and glass surfaces. There were 41-fold and 20-fold fluorescence enhancements when Rhodamine B base was deposited on the surface of a yellow PC film, compared with that on glass surface and aluminium film respectively, where PCs were utilized as a Bragg reflection mirror. The results show that the PCs are more effective and selective reflection mirrors than aluminium, and have potential applications in optoelectronic and lighting devices.