Relationship between deposition techniques and nanoparticle dispersions for flexible and printed electronics

Reverse micelles composed of polystyrene-b-poly(2-vinylpyiridine) have been used to synthesize nanoparticles composed of a wide range of materials, including metals, metal oxides, dielectrics, semiconductors perovskites, and core–shell nanoparticles. In this contribution, we examine the effect of deposition parameters on two-dimensional nanoparticle arrangements from colloidal solutions created using spin coating, dip coating, slot-die coating, and electrospray deposition. Despite the importance of achieving uniform coatings of ordered arrays of colloidal particles, previous studies have not thoroughly addressed this challenge. We show that the adjustability of interparticle distance depends on the deposition technique used and only occurs within the stable defect-free operating window of the deposition parameters. Establishing the specific operating window for each technique for a model system, we propose general guidelines that can be used for ensuring uniform coatings regardless of precursor loading and provide a guide for adjusting the deposition conditions when coating defects occur. We introduces a novel application of ellipsometry to evaluate interparticle spacing in nanoparticle arrays, enhancing our ability to assess film uniformity, allowing for quick and easy tuning of nanoparticle dispersion. Comparisons between spin, dip, and slot-die coating techniques reveal insights into the correlation between interparticle spacing and ordering, highlighting the importance of fitting relationships for various coating samples. This comprehensive comparison and discussion provide a roadmap for future research, outlining current challenges and trends and offering insights into achievable spacings and ordering in coating processes. This allows the classification of various deposition techniques with respect to their suitability for tailored applications.