Voltage Modulated Untwist Deformations and Multispectral Optical Effects from Ion Intercalation into Chiral Ceramic Nanoparticles.

Geometric reconfiguration of chiral ceramic nanostructures after ion intercalation should favor specific nanoscale twists that should lead to unusually strong chiroptical effects. Based on multifaceted experimental, simulation, and theoretical data, here we show that V 2 O 3 nanoparticles have "built-in" chiral distortions caused by multipoint binding of enantiomers of tartaric acid to the surface of inorganic core. As evidenced by spectroscopy/microscopy techniques and calculations of nanoscale chirality measures, the intercalation of Zn 2+ ions into the V 2 O 3 lattice results in particle expansion, untwist deformations and related decrease of chirality. Coherent deformations in the particle ensemble manifest as changes in sign and positions of multiple circular polarization bands at ultraviolet, visible, mid-, near- (NIR) and infrared (IR) wavelengths originating in the electronic states of the surface ligands and the semiconductor cores. The g-factors observed for IR and NIR spectral diapasons are ∼100-400 times higher than those for previously reported dielectric, semiconductor and plasmonic nanoparticles. Nanocomposite films layer-by-layer assembled (LBL) from V 2 O 3 nanoparticles reveal cyclic voltage-driven modulation of optical activity. Device prototypes for IR and NIR range problematic for liquid crystals and other organic materials, were demonstrated. High optical activity, synthetic simplicity, sustainable processability and environmental robustness of the chiral LBL nanocomposites provide a versatile platform for photonic devices. Similar reconfigurations of particle shapes are expected for multiple chiral ceramic nanostructures with a variety of optical, electrical, and magnetic properties. This article is protected by copyright. All rights reserved.