High Circularly Polarized Luminescence Dissymmetry Factor and Efficient Chiral Second Harmonic Generation in Chiral Hybrid Lead‐Bromide Perovskites

Abstract Chiral organic‐inorganic hybrid perovskites have recently emerged as a promising new category of materials that display mirror optical signal responses, making them highly suitable for various applications in chiral nonlinear optics and circularly polarized luminescence emitters. However, there is a scarcity of reports on chiral hybrid perovskite materials that simultaneously possess substantial chiral second‐harmonic generation and a high asymmetric luminescence factor. In this study, 1D chiral lead‐bromide perovskites, namely ( R ‐/ S ‐2‐EP)PbBr ₄ have successfully synthesized and conducted a systematic investigation of their properties in terms of chiral second harmonic generation and circularly polarized luminescence. The effective second‐order nonlinear optical coefficient of ( R ‐2‐EP)PbBr ₄ is 0.33 pm V ⁻¹ , along with a high laser damage threshold (LDT) of 5.42 mJ cm ⁻² . Most importantly, both ( R ‐2‐EP)PbBr ₄ and ( S ‐2‐EP)PbBr ₄ demonstrate circularly polarized emission with a high dissymmetry factor g _lum of 0.03, which is the highest value among reported lead‐bromide chiral perovskites to date. These findings open new avenues for the development of high‐performance chiral materials for nonlinear chiroptical and circularly polarized luminescence emitters applications.