Leveraging Hierarchical Chirality in Perovskite(-Inspired) Halides for Transformative Device Applications

Chirality is an attribute based on the structural geometry of materials, which confers a distinctive energy band structure for intriguing optical, electronic, and spintronic properties. Recent studies on chirality encountered in perovskite(-inspired) halides (PiHs) have drawn increasing attention, not only because of the large chemical diversity of PiHs seen at molecular, nanoscopic, and microscopic levels, but also due to the observation of various emergent properties for multifunctional device applications. Herein hierarchical chiral origin factors of PiHs, involving intercalation, substitution, and distortion at the intra-crystal level; modification at the crystal interface level; and micro-design beyond the crystal level are first discussed. Then, updated progress in synthesis and characterization methods of chiral PiHs is reviewed, featuring intriguing structures that distinguish chiral PiHs from other semiconductors and chiral materials. Furthermore, representative examples exploiting emergent properties of chiral PiH for achieving versatile device functions are examined. Finally, perspectives on challenges and opportunities in leveraging the chirality in PiHs for transformative device applications are provided.