2D organic–inorganic hybrid perovskites (OIHPs) show obvious advantages in the field of optoelectronics due to their high luminescent stability and good solution processability. However, the thermal quenching and self-absorption of excitons caused by the strong interaction between the inorganic metal ions lead to a low luminescence efficiency of 2D perovskites. Herein, a 2D Cd-based OIHP phenylammonium cadmium chloride (PACC) with a weak red phosphorescence (Φ_P < 6%) at 620 nm and a blue afterglow is reported. Interestingly, the Mn-doped PACC exhibits very strong red emission with nearly 200% quantum yield and 15 ms lifetime, thus resulting in a red afterglow. The experimental data prove that the doping of Mn²⁺ not only induces the multiexciton generation (MEG) process of the perovskite, avoiding the energy loss of inorganic excitons, but also promotes the Dexter energy transfer from organic triplet excitons to inorganic excitons, thus realizing the superefficient red-light emission of Cd²⁺. This work suggests that guest metal ions can induce host metal ions to realize MEG in 2D bulk OIHPs, which provides a new idea for the development of optoelectronic materials and devices with ultrahigh energy utilization.

中文翻译：

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具有近 200% 红色磷光量子产率的二维有机-无机杂化钙钛矿产生多激子

二维有机-无机杂化钙钛矿（OIHPs）由于其高发光稳定性和良好的溶液加工性，在光电领域显示出明显的优势。然而，无机金属离子之间的强相互作用引起的激子热猝灭和自吸收导致二维钙钛矿的发光效率较低。 在此，报道了一种基于 2D Cd 的 OIHP 苯基氯化镉铵 (PACC)，在 620 nm 处具有弱红色磷光 (Φ _{P < 6%) 和蓝色余辉。}有趣的是，Mn 掺杂的 PACC 表现出非常强的红色发射，量子产率接近 200%，寿命为 15 ms，从而产生红色余辉。^{实验数据证明Mn 2+}的掺杂^{不仅诱导了钙钛矿的多激子产生（MEG）过程，避免了无机激子的能量损失，而且促进了有机三重态激子向无机激子的能量转移，从而实现了Cd 2+}的超高效红光发射。该工作表明客体金属离子可以诱导主体金属离子在二维块状OIHPs中实现MEG，这为开发具有超高能量利用率的光电材料和器件提供了新思路。