Inch-Size Achiral Perovskite Single Crystals for Distinguishing Circularly Polarized Light with A Large Asymmetry Factor.

Circularly polarized light (CPL) detection has sparked the booming interest for versatile chiral-optoelectronic and spintronic devices. For practical device applications, a large asymmetry factor is required to distinguish the handedness of incent light. However, for most chiral CPL active candidates, the difference in optical density or absorption anisotropy is quite subtle under CPL illumination, resulting in a relatively low asymmetry factor (usually ≤ 0.2). Up to date, it remains extremely challenging to achieve CPL response in the achiral crystals. Inch-size achiral perovskite-type crystals of (IBA)2(EA)2Pb3I10 (IBA = 4-isopropylbenzylammonium, EA = ethylammonium), which holds a promise to distinguish CPL with a large asymmetry factor up to ≈0.56 at 405 nm is presented here. This figure-of-merit is comparable or even superior than most of those chiral counterparts. Further First-principles calculations disclose such CPL-active behaviors of (IBA)2(EA)2Pb3I10 are associated with the splitting of its band spin-degeneracy, induced by the breaking of inversion symmetry and spin-orbital coupling (SOC) effects. As far as it is known, the structural origin of CPL-activities of (IBA)2(EA)2Pb3I10 is completely distinctive from the conventional chiral family, which paves a promising pathway to explore new candidates toward high-performance CPL detection. [ABSTRACT FROM AUTHOR]