Scalable preparation of broadband ultrablack graphite nanoneedle surfaces through self-masked etching

• Ultrablack materials play an essential role in astronomical observation and many thermal applications. Many material systems such as vertically aligned carbon nanotubes have produced extraordinarily high absorption, but require complicated fabrication. Here we report a single step self-masked etching process performed on compressed-coal graphite plates on a silicon substrate, which produces an ultrablack material with 0.7% hemispherical reflectance in the visible region and specular reflectance below 0.7% between 850 nm and 10 µm. Nanoscopic pieces of silicon are ripped off the substrate and deposit on the graphite resulting in carbon nanoneedle structures, which grow linearly with etching time reaching a height of 5.7 µm after 60 minutes.

Subject headings

NATURVETENSKAP  -- Kemi -- Materialkemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Materials Chemistry (hsv//eng)

Keyword

Graphite

Nanoneedles

Reflection

Substrates

Astronomical observation

Carbon nanoneedles

Hemispherical reflectance

Material systems

Silicon substrates

Specular reflectance

Thermal applications

Vertically aligned carbon nanotube

Etching

Publication and Content Type

ref (subject category)

art (subject category)