Chiral All-Inorganic Perovskite Subnanowires

Abstract

The phenomenon of chiral symmetry breaking during the crystallization of achiral molecules or ions, which leads to the formation of controllable enantiomerically pure crystals, has garnered significant interest but remains a challenge to fully overcome. This presents a particularly formidable obstacle in the creation of three-dimensional (3D) structured chiral all-inorganic perovskites, further complicated by their achiral crystalline space groups. In this report, we successfully synthesized right- or left-handed (P/M) chiral 3D P/M-CsPbX₃ (X = Cl, Cl–Br, Br, Br–I) perovskite subnanowires (SNWs), in which Pb(II) can be partially substituted by hetero ions, such as Cu(II), Sn(II), and Mn(II). The selective control of the SNW handedness was achieved through the strategic incorporation of trace chiral amine enantiomers. The chiroptical activity arises from the helical structure of the SNWs. The mechanisms underlying the formation of this chiral structure were systematically investigated and interpreted by using a thermodynamic model. We utilized the chiral P/M-CsPbBr₃ SNWs to fabricate circularly polarized light (CPL) photodetectors, which exhibited an impressive photocurrent dissymmetry factor (g_Iph) of 0.75. In the field of spin light-emitting diodes (spin-LEDs), circularly polarized electroluminescence (CPEL) was accomplished by employing the SNWs as a dual-functional material that provides both chiral-induced spin selectivity (CISS) and CPL emission capabilities.