Owing to quantum confinement of optical and electrical transitions within isolated [PbBr₆]^4– octahedral units, zero-dimensional perovskite Cs₄PbBr₆ exhibits appealing molecular-like quantum optoelectronic behavior. Although much effort has been made thus far, the origin of the visible photoluminescence observed in Cs₄PbBr₆ still remains unclear. In addition, its stimulated emission and potential applications are rarely explored. Here, phase-pure Cs₄PbBr₆ microcrystals with well-defined morphology are developed via an antisolvent approach and exhibit intense photoluminescence centered at ∼518 nm with a photoluminescence quantum yield of ∼30% and a rather large binding energy of ∼267 meV. Optical spectroscopic and systematic structural analyses consistently suggest that the obtained product is phase-pure Cs₄PbBr₆. In particular, optical spectroscopic analyses reveal for the first time the agreement between the photoluminescence excitation spectrum and localized optical absorption of Pb²⁺ in isolated [PbBr₆]^4– octahedra. Thus, the green photoluminescence is viewed intrinsic to Cs₄PbBr₆. Single- and multimode lasing resonances are demonstrated in individual Cs₄PbBr₆ microcrystals upon optical pumping. Potential application of the Cs₄PbBr₆ laser is demonstrated to achieve speckle-free imaging of micrometer-scaled objects when a single Cs₄PbBr₆ microcrystal laser is utilized as the illumination source. The results suggest that zero-dimensional perovskites support lasing resonance and hold important potential applications in optoelectronics.

中文翻译：

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从零维钙钛矿和光学成像应用中获取激光

由于在孤立的[PbBr ₆ ] ^4–八面体单元内光学和电跃迁的量子限制，零维钙钛矿Cs ₄ PbBr ₆表现出吸引人的分子状量子光电行为。尽管到目前为止已经做了很多努力，但是在Cs ₄ PbBr _6中观察到的可见光致发光的起源仍然不清楚。此外，极少探索其受激发射及其潜在应用。在此，纯Cs ₄ PbBr ₆通过反溶剂方法可形成具有明确形态的微晶，并显示出以〜518 nm为中心的强光致发光，光致发光的量子产率为〜30％，结合能相当大，为〜267 meV。光谱和系统结构分析一致地表明，所获得的产物是纯相的Cs ₄ PbBr ₆。特别是，光谱分析首次揭示了在分离的[PbBr ₆ ] ^4–八面体中光致发光激发光谱与Pb ^2+的局部光吸收之间的一致性。因此，绿色光致发光被视为Cs ₄ PbBr ₆固有的。光泵浦后，在单个Cs ₄ PbBr ₆微晶中证明了单模和多模激射共振。当将单个Cs ₄ PbBr ₆微晶激光器用作照明源时，Cs ₄ PbBr ₆激光器的潜在应用被证明可以实现微米级物体的无斑点成像。结果表明，零维钙钛矿支持激光共振，并在光电子学中具有重要的潜在应用。