Parsons Lindsey E, Russ Brendan, Eisler Carissa N
Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, California 90095, United States.
ACS Nanosci Au. 2025 Jun 14;5(4):276-283. doi: 10.1021/acsnanoscienceau.5c00054. eCollection 2025 Aug 20.
Lead halide perovskite (LHP) nanocrystals have demonstrated a significant electronic response to their local environment due to their ionic lattice nature. Here, we demonstrated their tunable dipole alignment via solution-processed methods. We synthesized LHP nanocubes and nanoplates in air and characterized them by UV-vis spectrophotometry and transmission electron microscopy. Using atomic force microscopy, UV-vis spectrophotometry, and back focal plane fluorescence microscopy, we characterized thin films of nanocubes on untreated glass, nanoroughened glass, and polymer film (poly-(methyl methacrylate), PMMA), as well as a perovskite nanocubes-nanoplate binary film on etched glass. Most notably, the dipole orientation factor can be modulated from 0.47 to 0.59 (effective transition dipole moment angle from 47° to 40°) by using glass or PMMA, respectively. Understanding the tunable anisotropic transitions in these materials at the nanoscale is required to control light emission into specific modes, which will maximize efficiency in devices such as light-emitting diodes, photovoltaics, and quantum information technology.
卤化铅钙钛矿（LHP）纳米晶体由于其离子晶格性质，已表现出对其局部环境的显著电子响应。在此，我们通过溶液处理方法展示了它们可调节的偶极排列。我们在空气中合成了LHP纳米立方体和纳米片，并通过紫外-可见分光光度法和透射电子显微镜对其进行了表征。利用原子力显微镜、紫外-可见分光光度法和后焦平面荧光显微镜，我们对未处理玻璃、纳米粗糙化玻璃和聚合物薄膜（聚甲基丙烯酸甲酯，PMMA）上的纳米立方体薄膜，以及蚀刻玻璃上的钙钛矿纳米立方体-纳米片二元薄膜进行了表征。最值得注意的是，通过分别使用玻璃或PMMA，偶极取向因子可从0.47调节至0.59（有效跃迁偶极矩角从47°变为40°）。要控制光发射到特定模式，从而使发光二极管、光伏和量子信息技术等器件的效率最大化，就需要了解这些材料在纳米尺度上的可调谐各向异性跃迁。
