Helical Perovskite Nanowires with Strong Circularly Polarized Luminescence Self-Assembled from Red-Emitting CsPbI<sub>3</sub> Quantum Dots Following Chiral Ligand Exchange
Haochen Liu, Arsenii S. Portniagin, Bing Tang, Kunnathodi Vighnesh, Yun Li, Ye Wu, Даниил А. Русанов, Lingyi Ke, Yunfan Wang, Ding Zhu, Desui Chen, Kwok-Chung Law, Maria V. Babak, Elena V. Ushakova, Andrey L. Rogach
Abstract
Circularly polarized luminescence (CPL) of chiral perovskite nanocrystals is crucial for applications such as spin-polarized light-emitting diodes and chiral photodetectors. However, the reported luminescence dissymmetry factors are often too low for practical applications; it is also important for CPL wavelengths to cover the red emission range for display applications. Herein, we realized helical perovskite nanowires self-assembled from red-emitting CsPbI 3 quantum dots (QDs) with a strong CPL signal around 640 nm, which was enabled by chiral ligand R-/S-binaphthyl phosphoric acid. The formation of CsPbI 3 nanowires from perovskite QDs occurred by oriented attachment; QDs remaining in solution attached at the surface of the nanowires, forming helical structures. The films produced from these chiral nanowires demonstrate high dissymmetry factors of 1.1 × 10 –2 and 2.3 × 10 –2 for absorption and luminescence, respectively, surpassing many previously reported chiral nanomaterials. We employed multilayer nanowire films as chiral filters, generating left- and right-handed CPL.