Regulating the phase distribution of quasi-2D perovskites using a three-dimensional cyclic molecule toward improved light-emitting performance.

In this study, a molecule with a three-dimensional (3D) cyclic structure, a cryptand, is demonstrated as an effective additive for the quasi-two-dimensional (quasi-2D) PEACsPbBr ( = 3, herein) to improve its light-emitting performance. The cryptand can effectively regulate the phase distribution of the quasi-2D perovskite through its intense interaction with PbBr, benefitting from its cage-like structure that can better capture the Pb ions. Due to the inhibited growth of the low- phases, a much-concentrated phase distribution is achieved for the cryptand-containing films.