Tunable Light-Matter Interactions in Complex Perovskite Particles Templated by Nanostructured Assemblies with Multiscale Chirality

Perovskites are known for strong and tunable luminescence, but the synthesis of materials with circularly polarized light emission is limited by sensitive metal-ligand interactions, variable crystallization patterns, and poorly predictable chirality transfer from molecular precursors. Here we show that generic achiral perovskites can be deposited on chiral ‘hedgehog’ particles (CHIPs), producing optically active perovskite-coated CHIPs (P-CHIPs) with spectroscopic bands specific of the perovskites and chirality specific of the template particles. The spectral position and chiral polarization of the emission is varied with minimal modification of the deposition protocol or crystallization parameters. Through careful comparison of the polarization of emission to the circular dichroism of P-CHIPs, we demonstrate that the observed polarized emission is due to the post-emission scattering of photons off the chiral surfaces of CHIPs. Furthermore, by examination of the inherent red-orange luminescence of CHIPs, we find that the chiral emission profile is heavily dependent on the chiral geometry of the microparticle assembly, confirming the action of a strong chiral scattering component on emission characteristics, responsible for the CPLE demonstrated by P-CHIPs. Templating on CHIPs provides a simple pathway to a wide range of complex chiroptical materials; the dispersibility of the perovskite-coated CHIPs in various solvents and the precise quantification of their chiral geometry offer significant advantages for applications such as single-particle emitters.