Herein, we report the unusual broadband white-light emission as an intrinsic property from two cationic lead bromide frameworks. This is the first time that the metal halide materials adopting a purely inorganic positively-charged three-dimensional (3D) topology have been synthesized, thus affording highly distorted Pb^II centers. The single-component white-light emitters achieve an external quantum efficiency of up to 5.6% and a correlated color temperature of 5727 K, producing typical white-light close to that of fluorescent light sources. Unlike the air/moisture-sensitive 3D organolead halide perovskites, our cationic materials are chemically “inert” over a wide range of pH as well as aqueous boiling condition. Importantly, these long-sought ultrastable lead halide materials exhibit undiminished photoluminescence upon continuous UV-irradiation for 30 days under atmospheric condition (∼60% relative humidity, 1 bar). Our mechanistic studies indicate the broadband emission have contributions from the self-trapped excited states through electron-vibrational coupling in the highly deformable and anharmonic lattice, as demonstrated by variable-temperature photoluminescence/absorption spectra as well as X-ray crystallography studies. The chemical robustness and structural tunability of the 3D cationic bromoplumbates open new paths for the rational design of hybrid bulk emitters with high photostability.

中文翻译：

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超稳定的阳离子三维溴化铅骨架，可固有地发出宽带白光†

在此，我们报告了不寻常的宽带白光发射，这是两个阳离子溴化铅骨架的固有特性。这是首次合成采用纯无机带正电的三维（3D）拓扑结构的金属卤化物材料，从而提供了高度失真的Pb ^II中心。单组分白光发射器的外部量子效率高达5.6％，相关色温为5727 K，产生的典型白光接近荧光光源。与对空气/湿气敏感的3D有机卤化铅钙钛矿不同，我们的阳离子材料在宽范围的pH值和沸腾条件下具有化学“惰性”。重要的是，这些长期寻求的超稳定卤化铅材料在大气条件下（约60％相对湿度，1 bar）连续紫外线照射30天后，其光致发光不会减弱。我们的机理研究表明，宽带发射是由于在高度可变形和非谐晶格中通过电子振动耦合而产生的自陷激发态所引起的，如可变温度光致发光/吸收光谱以及X射线晶体学研究所证明。3D阳离子溴化铅的化学稳定性和结构可调性为合理设计具有高光稳定性的混合体发射器开辟了新途径。