Inorganic lead halide perovskites have gained immense scientific interest for optoelectronic applications. In this work, we present a one‐dimensional polymorph of cesium lead bromide (δ‐CsPbBr₃) synthesized through a simple anion‐exchange reaction, wherein distorted edge‐sharing PbBr₆ octahedra form 1D chains isolated by Cs ions. δ‐CsPbBr₃ was characterized by Raman spectroscopy, X‐ray diffraction, ²⁰⁷Pb and ¹³³Cs solid‐state NMR, and by optical emission and absorption spectroscopies. This non‐perovskite material irreversibly transforms into the well‐known three‐dimensional perovskite phase (γ‐CsPbBr₃) upon heating to above 151 °C. The indirect bandgap was determined by absorption measurements and calculation to be 2.9 eV. δ‐CsPbBr₃ exhibits broadband yellow photoluminescence with a quantum yield of 3.2 %±0.2 % at room temperature and 95 %±5 % at 77 K, and this emission is attributed to the recombination of self‐trapped excitons. This study emphasizes that the metastable δ‐CsPbBr₃ may be a persistent, concomitant phase in Cs−Pb‐Br‐containing materials systems, such as those used in solar cells and LEDs, and it showcases the characterization tools used for its detection.

中文翻译：

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白色CsPbBr3：表征一维铯溴化铅多晶型物

无机卤化铅钙钛矿已在光电应用中获得了巨大的科学兴趣。在这项工作中，我们提出了通过简单的阴离子交换反应合成的一维溴化铯铯（δ- CsPbBr ₃）一维多晶型，其中扭曲的边共享PbBr ₆八面体形成了由Cs离子隔离的一维链。δ- CsPbBr _3的特征在于拉曼光谱，X射线衍射，²⁰⁷ Pb和¹³³ Cs固态NMR，以及光发射和吸收光谱。这种非钙钛矿材料不可逆地转变成众所周知的三维钙钛矿相（γ- CsPbBr₃）加热到151°C以上。通过吸收测量和计算确定间接带隙为2.9 eV。δ‐ CsPbBr ₃呈现宽带黄光致发光，室温下的量子产率为3.2％±0.2％，在77 K时的量子产率为95％±5％，这是由于自陷激子的重组所致。这项研究强调，亚稳δ‐ CsPbBr ₃可能是含Cs-Pb-Br的材料系统（例如用于太阳能电池和LED的材料系统）中的持久相伴相，并且展示了用于其检测的表征工具。