The super-exchange coupled Mn2+–Mn2+ dimer can be formed by doping high concentrations of Mn2+ ions. However, since the distribution of Mn2+ ions strongly depends on the crystal structure of the host lattice, the tuning of Mn2+ ion related emission properties remains limited. Here, a pressure-treated strategy is reported to induce a new red emission band of Mn2+–Mn2+ dimers in the Mn-based metal halide (C6H9N2)2MnBr4. The red and green emission bands generated by Mn2+–Mn2+ dimers and isolated Mn2+ ions exhibit different emission behaviors under pressure. Notably, the emission of the Mn2+–Mn2+ dimer exhibits a wide tunability range from 660 to 770 nm, which is attributed to the increased crystal field splitting energy resulting from the reduced Mn–Br bond length under pressure. Our findings highlight the important role of Mn2+–Mn2+ dimers in pressure-tuned optoelectronic properties and provide guidance for the design of novel optoelectronic devices with desired emission characteristics.

中文翻译：

---

Mn基金属卤化物（C6H9N2）2MnBr4中Mn2+-Mn2+二聚体的压力诱导可调发光


超级交换偶联的 Mn2+–Mn2+ 二聚体可以通过掺杂高浓度的 Mn2+ 离子来形成。然而，由于 Mn2+ 离子的分布在很大程度上取决于主体晶格的晶体结构，因此 Mn2+ 离子相关发射特性的调整仍然有限。在这里，据报道，一种加压处理策略可在 Mn 基金属卤化物 （C6H9N2）2MnBr4 中诱导 Mn2+–Mn2+ 二聚体的新红色发射带。Mn2+–Mn2+ 二聚体和分离的 Mn2+ 离子产生的红色和绿色发射带在压力下表现出不同的发射行为。值得注意的是，Mn2+–Mn2+ 二聚体的发射表现出从 660 到 770 nm 的宽可调性范围，这归因于压力下 Mn-Br 键长减小导致晶场分裂能量增加。我们的研究结果强调了 Mn2+–Mn2+ 二聚体在压力调谐光电特性中的重要作用，并为设计具有所需发射特性的新型光电器件提供了指导。