All‐inorganic lead halide perovskites have gained wide attention as a class of promising material for both fundamental investigations and optoelectronic applications due to their excellent optical properties. They simultaneously possess relatively high refractive index and high exciton binding energy exceeding 100 meV, making them possess high emission efficiency at room temperature and thus promise a coherent light source. High‐quality all‐inorganic lead halide perovskite microcrystal arrays exhibiting ultralow‐threshold single‐mode lasing would find promising applications in the on‐chip integration of photonic and electronic circuits. However, currently it is still challenging to synthesize high‐quality all‐inorganic perovskite arrays. Here, the seeds‐assisted space‐confined growth of all‐inorganic perovskite arrays is reported for ultralow‐threshold single‐mode lasing. The naturally vapor‐phase‐grown submicron plates possess high crystal quality, exhibiting an ultralow lasing threshold of ≈0.22 µJ cm^–2 among reported perovskite‐based lasing. Benefiting from the space‐confined effect, the as‐grown samples have small lateral size (submicron) leading to the single whispering‐gallery mode (WGM) lasing. Importantly, the method can successfully synthesize high‐quality CsPbI₃ submicron plate arrays and demonstrate single‐mode lasing in those submicron plate arrays. The study provides a convenient and effective route to controllably grow all‐inorganic submicron plate arrays for ultralow‐threshold single‐WGM lasing.

中文翻译：

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全无机钙钛矿阵列的种子辅助空间限制型生长，用于超低阈值单模激射

作为一种有前途的材料，全无机卤化钙钛矿钙钛矿因其优异的光学性能而受到广泛关注。它们同时具有相对较高的折射率和超过100 meV的高激子结合能，从而使其在室温下具有较高的发射效率，因此有望成为一种相干光源。展现超低阈值单模激光的高质量全无机卤化铅钙钛矿微晶阵列将在光子和电子电路的片上集成中找到有前途的应用。但是，目前合成高质量的全无机钙钛矿阵列仍然很困难。这里，据报道，全无机钙钛矿阵列的种子辅助空间受限生长可用于超低阈值单模激光。天然气相生长的亚微米板具有较高的晶体质量，具有约0.22 µJ cm的超低激光阈值在报告的基于钙钛矿的激光中占^–2。受益于空间限制效应，这样生长的样品具有较小的横向尺寸（亚微米），从而导致了单耳语-画廊模式（WGM）激光发射。重要的是，该方法可以成功地合成高质量的CsPbI ₃亚微米平板阵列，并证明这些亚微米平板阵列中的单模激光。该研究为可控制地生长全无机亚微米平板阵列提供了一种便捷有效的途径，以进行超低阈值的单WGM激光发射。