Nature Materials Vol.5 No.3 - March 2006: Photonic Crystals to Impress
By André C. Arsenault, Timothy J. Clark, Georg von Freymann,
Ludovico Cademartiri, Riccardo Sapienza, Jacopo Bertolotti, Evangellos Vekris, Sean Wong, Vladimir Kitaev, Ian Manners, R. Z. Wang, Sajeev John,
Diederik Wiersma and Geoffrey A. Ozin
In photonic crystals (PCs), strong scattering and destructive wave interference lead to a modification of the photon density of states in particular energy regions and along certain crystallographic directions. The consequences of this range from suppression and enhancement of luminescence to narrow-band bright reflections useful for colour sensors, displays and tuneable filters. Here we demonstrate large-area films of porous elastomeric photonic crystals (EPCs) that are compressively–decompressively cycled to reversibly shift the position of the photonic band structure over a large wavelength range. Owing to their low compressive threshold, such porous EPCs can be used for imaging that is pressure and time sensitive, for example, to obtain colour fingerprints with high accuracy. Furthermore, by incorporating luminescent PbS quantum dots in the EPCs, the photonic stop-gap can be tuned through the near-infrared (NIR) quantum dot photoluminescence (PL) peak. Thereby we demonstrate a tuneable modification of photonic characteristics, including the suppression and enhancement in emission and dynamic modification of luminescence lifetimes.
