Wood-based superblack

Area of Science:

• Materials Science
• Nanotechnology
• Optics

Background:

• Light's detrimental effects on optical devices necessitate materials with near-zero light reflectance (superblack).
• Superblack materials are crucial for advancing light-centered technologies.
• Current superblack materials often involve complex fabrication or microfabrication.

Purpose of the Study:

• To develop a simple, robust, and sustainable superblack material using a top-down approach.
• To investigate wood delignification and carbonization as a method for creating superblack surfaces.
• To evaluate the performance of the wood-derived superblack material compared to existing technologies.

Main Methods:

• A metal-free top-down strategy involving wood delignification and high-temperature carbonization (1500°C).
• Computational methods guided the material development process.
• Characterization of the resulting material's structure and optical properties, including reflectance across various incidence angles.

Main Results:

• Vertically aligned carbon microfiber arrays (~100 µm thickness) were formed from subwavelength severed cells.
• Achieved ultra-low light reflectance of 0.36%, independent of the incidence angle.
• Demonstrated lower laser beam reflectivity compared to commercial light stoppers.

Conclusions:

• A simple, sustainable, and robust superblack material can be fabricated from wood.
• The material's properties are rationalized by delignification, lignin content, carbonization temperature, and wood density.
• Wood-derived superblack material serves as a viable, mechanically robust alternative to microfabricated carbon nanotube arrays.