Reuters reports that researchers have made a substance that is so dark it absorbs more than 99.9 percent of light. It is being called the blackest black. The photo shows a National Institute of Standards and Technology reflectance standard (top), a sample of the new darkest material (center) and a piece of glassy carbon (bottom).
The substance has a total reflective index of 0.045 percent - which is more than three times darker than the nickel-phosphorus alloy that now holds the record as the world's darkest material.
Basic black paint, by comparison, has a reflective index of 5 percent to 10 percent.
The researchers are seeking a "world's darkest material" designation by Guinness World Records. But their work will likely yield more than just bragging rights.
Ajayan said the material could be used in solar energy conversion. "You could think of a material that basically collects all the light that falls into it," he said.
Pulickel Ajayan, who led the research team at Rice University in Houston, provided Reuters with these facts about the new material.
It is composed of carbon nanotubes, tiny tubes of tightly rolled carbon that are 400 times smaller than the diameter of a strand of hair. The carbon helps absorb some of the light.
These tubes are standing on end, much like a patch of grass. This arrangement traps light in the tiny gaps between the "blades."
The researchers have also made the surface of this carbon nanotube carpet irregular and rough to cut down on reflectivity.
Photo: Shawn-Yu Lin/Rensselaer Polytechnic Institute
Reuters 
