Turn-on Circularly Polarized Luminescence in Chiral Indium Chlorides by 5s2 Metal Centers

Angew Chem Int Ed Engl. 2023 Apr 17;62(17):e202215206. doi: 10.1002/anie.202215206. Epub 2023 Jan 10.

Abstract

Introducing chirality into the metal-halide hybrids has enabled many emerging properties including chiroptical activity, spin-dependent transport, and ferroelectricity. However, most of the chiral metal-halide hybrids to date are non-emissive, and the underlying mechanism remains elusive. Here, we show a new strategy to turn on the circularly polarized luminescence (CPL) in chiral metal-halide hybrids. We demonstrate that alloying Sb3+ into chiral indium-chloride hybrids dramatically increases the photoluminescence quantum yield in two new series of chiral indium-antimony chlorides. These materials exhibit strong CPL signals with tunable energy and a high dissymmetry factor up to 1.5×10-2 . Mechanistic studies reveal that the emission originates from the self-trapped excitons centered in 5s2 Sb3+ . Moreover, near-ultraviolet pumped white light is demonstrated with a polarization up to 6.0 %. Our work demonstrates new strategies towards highly luminescent chiral metal-halide hybrids.

Keywords: Circularly Polarized Light; Excitons; Indium Antimony Chloride; Photoluminescence; Quantum Yield.