Research Highlights

Chiral optics aims to understand and manipulate interactions between chiral light and chiral materials, with the goal of advancing applications in chiral sensing, optical communication, bioimaging, and drug development. Because chirality in light provides complementary information to that characterized by wavelength and intensity, one emerging strategy uses this approach to target mesoscopic chiral structures, as their size range within the visible light wavelength (10 nm to 1 µm) promises enhanced chiral optical effects.

However, a major challenge to this strategy is the difficulty in fabricating mesoscopic structures with precise morphologies, because the scale of these objects lies just out of reach of the capabilities of both traditional bottom-up and top-down fabrication methods.

In a 2023 article, Oda and co-workers addressed this problem with a unique approach that utilizes the nanospace within self-assem bled nanometric helical silica ribbons as templates for growing perovskite nanocrystals (PNCs) by recrystallization methods¹.

Using supersaturated solutions of Cs⁺, Pb²⁺, and Br^– precursors, the resulting helical PNCs not only had precise chiral morphologies at nanometric level, but they also showed remarkable chiroptical properties, including strong circular dichroism and strong induced circularly polarized luminescence.

“Our work showed that mesoscopic helical PNCs with tailored chiral optical properties can be fabricated by combining established self-assembled templates with straightforward recrystallization methods without any chiral-ligand or chiral-molecule precursors,” says Oda. “To the best of our knowledge, this is a feat that has never been demonstrated before.”

A future direction will use this approach to fabricate 2D or 3D supra-object structures to target chiral-light chiral, including the exaltation/annulation of chiral optical signals.

(Author: Patrick Han)