Statistical Characterization of Self-Assembled Colloidal Crystals by Single-Step Vertical Deposition

TL;DR

This paper statistically analyzes the self-assembly of multi-layer polystyrene colloidal crystals via vertical deposition, demonstrating control over layer thickness and domain size with and without lithographic templates.

Contribution

It introduces a method for producing thick, multi-layer colloidal crystal films with controllable size and demonstrates enhanced domain sizes using lithographic templates.

Findings

Produced 30-40 layer thick colloidal films with 80-100 μm lateral size.

Achieved larger, crack-free domains with lithographic templates, up to 250 μm.

Validated statistical characterization of self-assembly parameters.

Abstract

We have statistically characterized the self-assembly of multi-layer polystyrene colloidal crystals, using the technique of vertical deposition, with parameters chosen to produce thick layers of self-assembled crystals in one deposition step. In addition, using a lithographically directed self-assembly method, we have shown that the size of multi-layer, continuous crack-free domains in lithographically defined areas can be many times larger than in the surrounding areas. In a single deposition step, we have produced continuous colloidal crystal films of 260 nm diameter polystyrene spheres approximately 30 -- 40 layers thick, with a controllable lateral size of 80 -- 100 $\upmu$m without lithography, and as high as 250 $\upmu$m with the lithographic template.