Due to the unique and excellent optical performance and promising prospect for various photonics applications, cavity-enhanced superfluorescence (CESF) in perovskite quantum dot assembled superstructures has garnered wide attentions. However, the stringent requirements and high threshold for achieving CESF limit its further development and application. The high threshold of CESF in quantum dot superstructures is mainly attributed to the low radiation recombination rate of the quantum dot and the unsatisfactory light field limiting the ability of the assembled superstructures originating from low controllability of self-assembly. Herein, we propose a strategy to reduce the threshold of CESF in quantum dot superstructure microcavities from two aspects: facet engineering optimization of quantum dot blocks and controllability improvement of assembly method. We introduce dodecahedral quantum dots with lower nonradiative recombination, substituting frequently used cubic quantum dots as assembly blocks. Besides, we adopt the micro-emulsion droplet assembly method to obtain spherical perovskite quantum dot superparticles with high packing factors and orderly internal arrangements, which are more controllable and efficient than the conventional solvent-drying methods. Based on the dodecahedral quantum dot superparticles, we realized low-threshold CESF (Pth=15.6 μJ cm-2). Our work provides a practical and scalable avenue for realizing low threshold CESF in quantum dot assembled superstructure system.

中文翻译：

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多面体量子点超粒子中的低阈值空腔增强超荧光

由于独特而优异的光学性能以及各种光子学应用的广阔前景，钙钛矿量子点组装超结构中的腔增强超荧光（CESF）引起了广泛的关注。然而，实现CESF的严格要求和高门槛限制了其进一步发展和应用。量子点超结构中CESF的高阈值主要归因于量子点的低辐射复合率和不令人满意的光场限制了源自自组装的低可控性的组装超结构的能力。在此，我们提出了从量子点块的面工程优化和组装方法的可控性改进两个方面降低量子点超结构微腔CESF阈值的策略。我们引入具有较低非辐射复合的十二面体量子点，替代常用的立方量子点作为组装块。此外，我们采用微乳液液滴组装方法获得了球形钙钛矿量子点超粒子，其具有高堆积因子和有序的内部排列，比传统的溶剂干燥方法更加可控和高效。基于十二面体量子点超粒子，我们实现了低阈值CESF（Pth=15.6 μJ cm-2）。我们的工作为在量子点组装上部结构系统中实现低阈值CESF提供了一种实用且可扩展的途径。