Efficient Exciton to Dopant Energy Transfer in Mn2+-Doped (C4H9NH3)2PbBr4 Two-Dimensional (2D) Layered Perovskites

Three-dimensional ABX3 perovskite material has attracted immense interest and applications in optoelectronic devices, because of their enabling properties. Recently, Mn2+ doping directly into APbCl3-type three-dimensional (3D) nanocrystals, manifesting host-to-dopant energy transfer, have been reported for LED display applications. Strongly bound excitons in the doped system can enhance the dopant-carrier exchange interactions, leading to efficient energy transfer. Here, we report the simple and scalable synthesis of Mn2+-doped (C4H9NH3)2PbBr4 two-dimensional (2D) layered perovskites. The Mn2+-doped 2D perovskite shows enhanced energy transfer efficiency from the strongly bound excitons of the host material to the d electrons of Mn2+ ions, resulting in intense orange-yellow emission, which is due to spin-forbidden internal transition (4T1 → 6A1) with the highest quantum yield (Mn2+) of 37%. Because of this high quantum yield, stability in ambient atmosphere, and simplicity and scalability of the synthetic procedure, Mn2+-doped 2D perovskites could be beneficial as color-converting phosphor material and as energy down-shift coating for perovskite solar cells. The newly developed Mn2+-doped 2D perovskites can be a suitable material to tune dopant-exciton exchange interactions to further explore their magneto-optoelectronic properties.