Tunable defects in colloidal photonic crystals

We present a bottom-up approach for the construction of tunable functional defects in colloidal photonic crystals (CPCs). These structures incorporate polyelectrolyte multilayer (PEM) planar defects embedded in silica CPCs through a combination of evaporation induced self-assembly and microcontact transfer printing. We show how the enormous chemical diversity inherent to PEMs can be harnessed to create chemically active defect structures responsive to solvent vapor pressures, light, temperature as well as redox cycling. A sharp transmission state within the photonic stopband, induced by the PEM defect, can be precisely, reproducibly and in some cases reversibly tuned by these external stimu…

"Smart" defects in colloidal photonic crystals

AbstractWe present a bottom-up approach for the construction of "Smart" active defects in colloidal photonic crystals (CPCs). These structures incorporate polyelectrolyte multilayer (PEM) planar defects embedded in silica CPCs through a combination of evaporation induced self-assembly and microcontact transfer printing. We show how the enormous chemical diversity inherent to PEMs can be harnessed to create chemically active defect structures responsive to solvent vapor pressures, light, temperature as well as redox cycling. A sharp transmission state within the photonic stopband, induced by the PEM defect, can be precisely, reproducibly and in some cases reversibly tuned by these external s…

Inside Front Cover: Redox-Tunable Defects in Colloidal Photonic Crystals (Adv. Mater. 20/2005)

The inside front cover illustrates reversible tuning of an intragap transmitting state induced by redox cycling, accomplished using a redox-active polyferrocenylsilane polyelectrolyte multilayer planar defect embedded in a colloidal photonic crystal (CPC) synthesized by a bottom–up method combining colloidal self-assembly and microcontact printing. In work reported on p. 2455 by Manners, Ozin, and co-workers, the wavelength position of the defect state can be changed by changing the oxidation state of the ferrocene moieties in the polymer backbone. This could find applications in electrochemically tunable microcavities, and—if light emitters are incorporated—electrochemically tunable CPC-ba…

Redox-Tunable Defects in Colloidal Photonic Crystals

DNA Designer Defects in Photonic Crystals: Optically Monitored Biochemistry