TY - JOUR
T1 - Light-Switchable One-Dimensional Photonic Crystals Based on MOFs with Photomodulatable Refractive Index
AU - Zhang, Zejun
AU - Müller, Kai
AU - Heidrich, Shahriar
AU - Koenig, Meike
AU - Hashem, Tawheed
AU - Schlöder, Tobias
AU - Bléger, David
AU - Wenzel, Wolfgang
AU - Heinke, Lars
PY - 2019/11/7
Y1 - 2019/11/7
N2 - Photonic crystals are solids with regular structures having periodicities comparable to the wavelength of light. Here, we showcase the photomodulation of the refractive index of a crystalline material and present a quasi-one-dimensional photonic crystal with remote-controllable optical properties. The photonic material is composed of layers of TiO2 and films of a nanoporous metal-organic framework (MOF) with azobenzene side groups. While the rigid MOF lattice is unaffected, the optical density is reversibly modified by the light-induced trans-cis-azobenzene isomerization. Spectroscopic ellipsometry and precise DFT calculations show the optical-density change results from the different orbital localizations of the azobenzene isomers and their tremendously different oscillator strengths. The photomodulation of the MOF refractive index controls the optical properties of the quasi-one-dimensional photonic crystal with Bragg reflexes reversibly shifted by more than 4 nm. This study may path the way to photoswitchable photonic materials applied in advanced, tunable optical components and lens coatings and in light-based information processing.
AB - Photonic crystals are solids with regular structures having periodicities comparable to the wavelength of light. Here, we showcase the photomodulation of the refractive index of a crystalline material and present a quasi-one-dimensional photonic crystal with remote-controllable optical properties. The photonic material is composed of layers of TiO2 and films of a nanoporous metal-organic framework (MOF) with azobenzene side groups. While the rigid MOF lattice is unaffected, the optical density is reversibly modified by the light-induced trans-cis-azobenzene isomerization. Spectroscopic ellipsometry and precise DFT calculations show the optical-density change results from the different orbital localizations of the azobenzene isomers and their tremendously different oscillator strengths. The photomodulation of the MOF refractive index controls the optical properties of the quasi-one-dimensional photonic crystal with Bragg reflexes reversibly shifted by more than 4 nm. This study may path the way to photoswitchable photonic materials applied in advanced, tunable optical components and lens coatings and in light-based information processing.
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U2 - 10.1021/acs.jpclett.9b02614
DO - 10.1021/acs.jpclett.9b02614
M3 - Article
C2 - 31596091
AN - SCOPUS:85073835856
VL - 10
SP - 6626
EP - 6633
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
SN - 1948-7185
IS - 21
ER -