Dong Yuhang, Hu Han, Xu Xiaobao, Gu Yu, Chueh Chu-Chen, Cai Bo, Yu Dejian, Shen Yalong, Zou Yousheng, Zeng Haibo
Key Laboratory of Advanced Display Materials and Devices, Ministry of Industry and Information Technology, Institute of Optoelectronics & Nanomaterials, College of Materials Science and Engineering , Nanjing University of Science and Technology , Nanjing 210094 , China.
Department of Chemical Engineering , National Taiwan University , Taipei 10617 , Taiwan.
J Phys Chem Lett. 2019 Aug 1;10(15):4149-4156. doi: 10.1021/acs.jpclett.9b01673. Epub 2019 Jul 11.
Benefiting from morphology-/size-tunable optical features, nanocrystals have been considered promising candidates for display or lighting applications. To achieve selective characteristic emission, precise control in size and morphology is thus a prerequisite. Herein, we report that the nanosecond-pulsed laser irradiation induces CsPbBr reshaping, yielding precise control of size and morphology. Under 532 and 355 nm laser irradiation, polydisperse CsPbBr nanocrystals or raw micron powders can be reshaped into uniform sizes of 12 and 6 nm, respectively. Moreover, by tuning ligand composition, the morphology of reshaped nanocrystals can be manipulated, such as nanocubes, nanorods, or nanosheets. Results reveal that the reshaping process relies on striving for a delicate balance between energy deposition and heat dissipation under irradiation. A low dissipation rate leads to temperature rising and lattice breaking, which turn out to be the driving forces for reshaping. This feasible method provides a reliable, and scalable route toward preparation of perovskite functional nanocrystals.
受益于形态和尺寸可调的光学特性，纳米晶体被认为是显示或照明应用的有前途的候选材料。因此，为了实现选择性特征发射，精确控制尺寸和形态是一个先决条件。在此，我们报告纳秒脉冲激光辐照诱导CsPbBr重塑，从而实现对尺寸和形态的精确控制。在532和355 nm激光辐照下，多分散的CsPbBr纳米晶体或原始微米粉末可分别重塑为12和6 nm的均匀尺寸。此外，通过调整配体组成，可以操纵重塑纳米晶体的形态，如纳米立方体、纳米棒或纳米片。结果表明，重塑过程依赖于在辐照下在能量沉积和散热之间寻求微妙的平衡。低耗散率导致温度升高和晶格破裂，这反过来成为重塑的驱动力。这种可行的方法为制备钙钛矿功能纳米晶体提供了一条可靠且可扩展的途径。
