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Title: Quasi-2D Model to Predict Solid Microstructure in Drying Thin Films
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 of Pe and Bi, 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 modified Bi and well defined coating regimes, which may be generalized for any solution processed thin film coating systems.  more » « less
Award ID(s):
1933819
PAR ID:
10491926
Author(s) / Creator(s):
; ; ; ;
Publisher / Repository:
ACS
Date Published:
Journal Name:
Langmuir
Volume:
39
Issue:
46
ISSN:
0743-7463
Page Range / eLocation ID:
16231 to 16243
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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