Recent progress on chiral perovskites as chiroptical active layers for next-generation LEDs

Metal halide perovskites (MHPs) have drawn intensive attention as emitters for their application in light emitting diodes (LEDs). MHPs have been actively studied after the first discovery in 2009 for solar cell applications. They show excellent optoelectronic properties such as high photoluminescence quantum yields, widely tunable band gap, narrow emission width, and high charge-carrier mobility. Chiral MHPs can be utilized as circularly polarized luminescent sources, ferroelectric materials, nonlinear optical materials, etc. In this review, we discuss the recent progress of chiral perovskites as emitting materials and their applications in next generation LEDs. The ability of chiral MHPs to induce a chiral-induced spin selectivity effect positions them as efficient spin-filters in spinpolarized LEDs. Additionally, the combination of chiral properties and optoelectronic features in these MHPs renders them ideal for use as emissive layers in circularly polarized LEDs. This comprehensive discussion aims to deepen understanding of chiroptical properties in chiral MHPs, furthering the development of chiral materials, chiropto-electronics, and spin/CPL-based applications.