Chiral Mesostructured BiOBr Films with Circularly Polarized Colour Response

Abstract

Achieving strong and broadband circularly polarized colour responses in chiral inorganic materials is challenging. Here, we fabricated chiral mesostructured bismuth oxybromide (BiOBr) films (CMBFs) via hydrothermal growth using chiral sugar alcohols as symmetry‐breaking agents. The layered slabs of BiOBr crystals with weak van‐der‐Waals interactions are prone to mismatching due to the chiral driving force, resulting in hierarchically chiral arrangements of fine size. Three levels of chirality exist in the CMBFs: primary, helical distortion crystal lattices of a nanoflake, secondary, helical stacking of nanoflakes to form nanoplates, and tertiary, chiral vortexes arranged by nanoplates. The CMBFs displayed optical activities (OAs) over a wide wavelength range of 350–2500 nm with an anisotropic factor of up to 0.99, which led to a significant chirality‐dependent colour response to circularly polarized light. The high selectivity can be considered as the result of enhanced resonance due to structural‐handedness matching and the synergistic effect of multiple OAs.

Self‐Assembled Chiral Copper Superstructures with Enhanced Circularly Polarized Light Emission

“…[ 20 ] In chiral‐interaction‐mediated self‐assembly, the contribution of asymmetric‐shaped building blocks could be strong enough to dictate the assembly behaviors and give rise to complex assembly structures. [ 12a,21 ] The formation of Cu‐Pen superstructures in our case can be understood as follows. The thiolated copper has been discovered to have a similar structure with Au or Ag thiolates that have a layered structure, [ 22 ] suggesting their general assembly mechanism.…”

Recent advances in chiral nanomaterials with unique electric and magnetic properties

“…CD bands in the visible (Vis) region are observed in various chiral metal-, ceramic-, and semiconductor-based NMs because they typically absorb visible light as shown in previous sections. Recently, CD spectra in the infrared (IR) region (> 700 nm, especially near-infrared (NIR, 700–1700 nm) and shortwave-infrared (SWIR, 1700–2500 nm) windows) are reported by using building blocks of inorganic NMs with various geometries and dimensions at submicron-scale [ 101 , 102 ]. In this section, we introduce two strategies of the bottom-up approach for synthesizing chiral inorganic NMs with the NIR-SWIR optical activity; (1) self-assembly and (2) templating approach.…”

Er3+/Yb3+ ions doped chiral inorganic nanostructured BiOCl phosphor as a novel temperature sensing material

“…In the presence of a chiral driving force, the layered units are arranged by multiple chiral, which makes it easy to synthesize chiral nanostructured BiOCl. 12 Li and co-authors 13 and Du et al 14 had reported the performance of UC temperature sensing on BiOCl. However, the UC and temperature sensing properties of chiral BiOCl have not been reported.…”