CsPbBr₃ rhombic dodecahedra, octahedra, and nanocubes have been synthesized using typical reagents but by adjusting the amounts of organic capping molecules used and the reaction temperature. Although some Cs₄PbBr₆ has been identified, its presence was found not to affect optical property examination. With increasing sizes of CsPbBr₃ rhombic dodecahedra from 59 to 168 nm, their band gaps decrease gradually. Remarkably, the much larger octahedra and {110}-bound rhombic dodecahedra show more blue-shifted absorption wavelengths than the {100}-bound nanocubes do, demonstrating the presence of optical facet effects. 10 nm CsPbI₃ nanocubes were also prepared and anion-exchanged to CsPbBr₃ nanocubes. Similarly, CsPbBr₃ rhombic dodecahedra were converted to rhombic dodecahedral CsPbI₃. For both compositions, the much larger rhombic dodecahedra still display more blue-shifted absorption and emission bands than those of the nanocubes, indicating very large optical band shifts are possible by tuning the crystal morphology or exposed surfaces.

中文翻译：

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CsPbBr3 和 CsPbI3 菱形十二面体和纳米立方体显示面相关的光学特性

CsPbBr ₃菱形十二面体、八面体和纳米立方体已使用典型试剂合成，但通过调整所用有机封端分子的量和反应温度。尽管已鉴定出一些 Cs ₄ PbBr ₆，但发现其存在不会影响光学性能检查。随着 CsPbBr ₃菱形十二面体的尺寸从 59 nm 增加到 168 nm，它们的带隙逐渐减小。值得注意的是，更大的八面体和 {110} 结合的菱形十二面体比 {100} 结合的纳米立方体显示出更多的蓝移吸收波长，证明了光学面效应的存在。还制备了10 nm CsPbI ₃纳米立方体并将阴离子交换为 CsPbBr ₃纳米立方体。类似地，CsPbBr ₃菱形十二面体被转化为菱形十二面体CsPbI ₃。对于这两种组合物，大得多的菱形十二面体仍然显示出比纳米立方体更多的蓝移吸收和发射带，表明通过调整晶体形态或暴露表面可以实现非常大的光带偏移。