The Polymer Society of Korea

Abstract

We present a spontaneous bottom-up strategy for photonic micropatterning based on spatially controlled heterogeneous nucleation during colloidal crystallization. Nucleation is suppressed on strongly charged glass substrates, whereas weakly charged photoresist surfaces promote localized crystallization via depletion-induced attractions. Lithographically defined photoresist patterns thereby enable spatially selective crystal growth in a single step without physical confinement. The resulting patterns show ordered crystalline grains with uniform orientation and strong structural colors. By tuning depletant and salt concentrations, an optimal interaction regime maximizing optical performance is identified, enabling full-spectrum color tuning through particle size variation. This nucleation-based approach extends to alternative patterning methods, such as vapor-phase masking and oil stamping, providing a versatile route for bottom-up fabrication of photonic micropatterns.