Enhanced Luminescence and Mechanistic Studies on Layered Double-Perovskite Phosphors: Cs4Cd1-xMnxBi2Cl12

Halide perovskites offer great promise for optoelectronic applications, but stability issues continue to hinder their implementation and long-term stability. The stability of all-inorganic halide perovskites and the inherent quantum confinement of low-dimensional perovskites can be harnessed to synthesize materials with high PL efficiency. An example of such materials is the recently reported new family of layered double perovskites, Cs4Cd1-xMnxBi2Cl12. Herein, we report a new synthetic procedure that enhances the maximum PLQY of this family of materials to up 79.5%, a 20% enhancement from previous reports and the highest reported for a Mn-doped halide perovskite. Importantly, stability tests demonstrate that these materials are very stable toward humidity, UV irradiation, and temperature. Finally, we investigated the photophysics and the effects of magnetic coupling and temperature in the PL efficiency and proposed a mechanism for the emission process. Our results highlight the potential of this family of materials and related layered all-inorganic perovskites for solid-state lighting and optoelectronic applications.