The Mn2+‐Doped Chiral 2D Perovskite with Strong Orange Fluorescent and Enhanced Circularly Polarized Luminescence.

Recently, the potential circularly polarized luminescence (CPL) property of chiral 2D organic–inorganic hybrid perovskites has garnered attention due to their strong stability. However, the photoluminescence (PL) intensity of chiral 2D perovskite is generally low, which undoubtedly limits its development. Therefore, improving the PL and CPL intensity of chiral 2D perovskite has become an important focal point. To overcome this problem, a series of Mn2+‐doped R/S‐(MPEA)2PbBr4 thin films is successfully synthesized. The Mn2+‐doped films can produce strong orange emission under UV excitation with the highest photoluminescence quantum yield (PLQY) of 37.37%, a high value among reported chiral 2D perovskites. Moreover, all Mn: (R/S‐MPEA)2PbBr4 films show symmetric CPL signals. The flexible regulation of CPL is meaningful for applications, which is generally lacking in current studies. Here, it is found that the strength of CPL can be effectively regulated by doping guanidine (Gua), and the maximum glum value of 1.4 × 10−2 and PLQY of 51.31% is achieved, which are the highest among reported chiral 2D perovskites. This work provides a new idea for the development of CPL‐active materials and lays the foundation for spin devices based on chiral hybrid 2D perovskite. [ABSTRACT FROM AUTHOR]