Metal halide perovskites are one of the most investigated materials in optoelectronics, with their lead-based counterparts being renowned for their enhanced optoelectronic performance. The 3D CsPbX₃ structure has set the standard with many studies currently attempting to substitute lead with other metals while retaining the properties of this material. This effort has led to the fabrication of metal halides with lower dimensionality, wherein particular 2D layered perovskite structures have captured attention as inspiration for the next generation of colloidal semiconductors. Here we report the synthesis of the Ruddlesden–Popper Cs₂CdCl₄:Sb³⁺ phase as colloidal nanoplatelets (NPs) using a facile hot injection approach under atmospheric conditions. Through strict adjustment of the synthesis parameters with emphasis on the ligand ratio, we obtained NPs with a relatively uniform size and good morphological control. The particles were characterized through transmission electron microscopy, synchrotron X-ray diffraction, and pair distribution function analysis. The spectroscopic characterization revealed most strikingly an intense cyan emission under UV excitation with a measured PLQY of ∼20%. The emission was attributed to the Sb³⁺-doping within the structure.

中文翻译：

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二维胶体 Cs2CdCl4:Sb3+ Ruddlesden–Popper 相纳米片中的青色发射

金属卤化物钙钛矿是光电领域研究最多的材料之一，其铅基同类材料以其增强的光电性能而闻名。3D CsPbX ₃结构为目前许多试图用其他金属替代铅的研究设定了标准，同时保留了这种材料的特性。这一努力导致了低维金属卤化物的制造，其中特定的 2D 层状钙钛矿结构作为下一代胶体半导体的灵感而受到关注。在这里，我们报告了 Ruddlesden–Popper Cs ₂ CdCl ₄ :Sb ³⁺的合成在大气条件下使用简便的热注射方法将相作为胶体纳米片 (NPs)。通过以配体比例为重点的合成参数的严格调整，我们获得了尺寸相对均匀且形态控制良好的纳米颗粒。通过透射电子显微镜、同步加速器 X 射线衍射和对分布函数分析对颗粒进行了表征。光谱表征最显着地揭示了在紫外激发下强烈的青色发射，测得的 PLQY 为~20%。发射归因于结构内的Sb ³⁺掺杂。