Quasi-2D Model to Predict Solid Microstructure in Drying Thin Films
Quasi-2D Model to Predict Solid Microstructure in Drying Thin Films
复制标题
预测干燥薄膜中固体微观结构的准二维模型
DOI：
10.1021/acs.langmuir.3c01469
复制
发表时间：
2023
期刊：
影响因子：
3.9
通讯作者：
Cairncross, Richard A.
中科院分区：
文献类型：
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作者：
Starger, Jesse L.;Fafarman, Aaron T.;Baxter, Jason B.;Alvarez, Nicolas J.;Cairncross, Richard A.
通过溶液加工产生的固体涂层的微观结构高度依赖于生长、溶质扩散和溶剂蒸发之间的耦合。在这里，使用耦合干燥和凝固的准二维数值模型来预测两个相邻核向彼此生长的瞬态横向生长。溶质和溶剂的横向梯度影响膜厚度和固体生长速率的演变。重要的工艺参数和溶剂性质由无量纲佩克莱特数 (Pe) 和比奥数 (Bi) 捕获，并通过由薄膜厚度和核之间距离定义的纵横比进行修改。通过 Pe 和 Bi 的变化，蒸发动力学和纵横比在很大程度上决定了涂层质量。这些发现应用于干燥结晶卤化物钙钛矿薄膜，展示了一个方便的流程图，用于捕获改性Bi和明确的涂层体系之间的关系，这可以推广到任何溶液处理的薄膜涂层系统。
The microstructure of solid coatings produced by solution processing is highly dependent on the coupling between growth, solute diffusion, and solvent evaporation. Here, a quasi-2D numerical model coupling drying and solidification is used to predict the transient lateral growth of two adjacent nuclei growing toward each other. Lateral gradients of the solute and solvent influence the evolution of film thickness and solid growth rate. The important process parameters and solvent properties are captured by the dimensionless Peclet number (Pe) and the Biot number (Bi), modified by an aspect ratio defined by the film thickness and distance between nuclei. By variation ofPeandBi, the evaporation dynamics and aspect ratio are shown to largely determine the coating quality. These findings are applied to drying thin films of crystallizing halide perovskites, demonstrating a convenient process map for capturing the relationship between the modifiedBiand well-defined coating regimes, which may be generalized for any solution-processed thin film coating systems.