Morphology Control by Pulsed Laser in Chemical Deposition Illustrated in ZnO Crystal Growth
Morphology Control by Pulsed Laser in Chemical Deposition Illustrated in ZnO Crystal Growth
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DOI：
10.1021/acs.cgd.9b00133
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发表时间：
2019-05-01
影响因子：
3.8
通讯作者：
Liu, C. Richard
中科院分区：
文献类型：
--
作者：
Liu, Siyu;Liu, C. Richard
研究了脉冲激光诱导沉积过程中ZnO晶化的控制。在不同的脉冲激光照射条件下，晶体的取向，形貌和生长速率进行了观察。利用脉冲激光输入能级的阶跃变化和相应的材料状态观测，确定了成核和晶体生长过程中的不同能垒。因此，通过精确调节脉冲激光能量，克服了特定的能量障碍，ZnO晶体具有所需的取向和形貌可以在无籽衬底上在无催化剂的环境中获得。不同形貌的晶体在激光诱导生长中表现出不同的行为，生长速率比其他水热反应高出几个数量级。通过分析反应/扩散限制区的晶体生长特性，定义了一组调整ZnO晶体尺寸的准则。激光诱导晶体生长将通过提供一种实用的工具来以精确和有效的方式调整纳米材料的形态而有益于纳米制造，并且它将使人们更深入地了解水热反应中的热力学和动力学机制。
The control of pulsed-laser-induced deposition was studied with the case of ZnO crystallization in a hydrothermal reaction. Crystal orientation, morphologies, and growth rate were observed to vary under different pulsed-laser irradiation conditions. Different energy barriers during nucleation and crystal growth processes were determined by stepped changes of input energy levels of a pulsed laser with the corresponding observations of the states of the material. Therefore, by precisely adjusting the pulsed laser energy that overcomes a particular energy barrier, ZnO crystals with desired orientation and morphology could be obtained on a seedless substrate in a catalyst-free environment. Crystals varied in morphologies showed different behavior in laser-induced growth, and growth rates were orders of magnitude higher than those of other hydrothermal reactions. By analyzing crystal growth characteristics in the reaction/diffusion-limited region, a set of guidelines were defined to tune the dimensions of ZnO crystals. Laser-induced crystal growth will benefit nanomanufacturing by providing a practical tool to tune the morphology of nanomaterials in a precise and effective manner, and it will bring deeper insight into the thermodynamic and kinetic mechanisms in hydrothermal reactions.