Dissertation
Modeling agglomeration and deposition of organic nanoparticles during solution processing of thin films
Doctor of Philosophy (PhD), Washington State University
01/2016
Handle:
https://hdl.handle.net/2376/108316
Abstract
Solution-processing of electron acceptor nanoparticles such as fullerenes and carbon nanotubes is a cost-effective technique to fabricate thin nano-composite films, which is of critical relevance to a range of organic electronic devices, such as organic photovoltaics, perovskite solar cells and supercapacitors. The most critical fabrication parameters for these processes include the choice of solvent, processing temperature and concentration of nanoparticles. The scientific literature lacks detailed study of the effect of these parameters on the morphology of the resulting thin nanocomposite films, which typically comprises distributed crystalline and amorphous domains of constituent species. The structure of the thin film is ultimately determined by the structure of the nanoparticle agglomerates that grow in solvents and on substrates during solution processing. To gain fundamental insight into the agglomeration of nanoparticles in varied chemical environments of interest to solution-processing techniques, molecular dynamics (MD) simulations were conducted for a range of systems that comprised fullerene derivative-solvent, fullerene derivative-polymer and carbon nanotube-solvent. The simulations provided mechanistic insights that would help in selecting favorable processing parameters. However, conclusive prediction can only be attained by analyzing systems of length scales relevant to the specific device, which is often not accessible to state-of-the-art MD simulations. In an effort to bridge this existing gap, we developed multi-scale models, based on MD and kinetic Monte Carlo (kMC), to study the growth of nanoparticle agglomerates in solutions and on substrates. The model can be applied to a multitude of systems where agglomeration and deposition of molecules and molecular aggregates is of importance. In particular, we investigated the agglomeration of nanoparticles during the processing of thin films for electron transport layer in perovskite solar cells. The results indicate that the model is able to predict nucleation, extent of surface coverage, growth rate and nature of defects in thin films grown at various processing conditions. Based on these demonstrated capabilities, the model will aid to design solution-processing of thin films with tailored morphologies that could immensely benefit a range of electronic devices.
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Details
- Title
- Modeling agglomeration and deposition of organic nanoparticles during solution processing of thin films
- Creators
- S. M. Golam Mortuza
- Contributors
- Soumik Banerjee (Advisor)Hussein M Zbib (Committee Member)Weihong Zhong (Committee Member)John McCloy (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Mechanical and Materials Engineering, School of
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Number of pages
- 261
- Identifiers
- 99900581523001842
- Language
- English
- Resource Type
- Dissertation