Enhanced and angle dependent blue fluorescence of perovskite nanocrystals on three typical photonic crystals

Abstract

Photonic crystals (PCs) are promising structures for the modulation and enhancement of fluorescent emissions, however, there is still a lack of systematic investigation on the fluorescence of perovskite nanocrystals (PNCs) coupling with different PCs. In this work, the blue emitting PNCs are coated on three typical PCs, i.e. biological Menelaus butterfly wings (MBWs), hexagonal closely-packed SiO2 nanoparticles, and TiO2 nanotubes array, which show fluorescence enhancement factors of 5.14, 3.38, and 3.43, respectively. The fluorescence enhancement is jointly attributed to the increased recombination rate caused by the near field effect and the enhanced extraction of emission due to the overlap of the leaky mode of the PCs with the emission wavelength of the PNCs. The higher enhancement factor of the MBWs is ascribed to the fluorescent proteins and melanin. Moreover, fluorescence intensity of the PNCs on all the three PCs strongly depends on the observation angle, which will enable their applications in anti-peeping screen and anti-counterfeiting pattern.