Semimetal/Substrate Cavities Enabling Industrial Materials for Structural Coloring

Area of Science:

• Materials Science
• Optics
• Nanotechnology

Background:

• Conventional color coatings (dyes and pigments) cause contamination and degrade.
• Structural coloring offers a sustainable, high-quality alternative using nanostructures.
• Existing structural coloring methods often require expensive noble metals or lithography.

Purpose of the Study:

• To develop a sustainable, scalable, and lightweight surface coloring method.
• To eliminate the need for metallic back-reflectors in structural coloring.
• To demonstrate functional coloration on industrial surfaces.

Main Methods:

• Designed and fabricated semimetal/substrate cavities (SSCs) with subwavelength thickness.
• Utilized ultrathin films of bismuth (Bi) and aluminum oxide (Al2O3).
• Deposited SSCs directly onto silicon and stainless steel substrates.

Main Results:

• Achieved vivid, well-defined structural colors with excellent angular stability.
• Demonstrated the feasibility of using industrial surfaces as active elements in color generation.
• Showcased a method independent of metallic mirrors.

Conclusions:

• The semimetal/substrate cavity (SSC) approach provides an efficient, sustainable solution for surface coloration.
• The design is adaptable to various semimetal/dielectric combinations.
• This method offers a lightweight, daylight-friendly option for industrial and everyday applications.