title: Experimental observation of an extremely dark material made by a low-density nanotube array.
abstract: An ideal black material absorbs light perfectly at all angles and over all wavelengths. Here, we show that low-density vertically aligned carbon nanotube arrays can be engineered to have an extremely low index of refraction, as predicted recently by theory [Garcia-Vidal, F. J.; Pitarke, J. M.; Pendry, J. B. Phys. Rev. Lett. 1997, 78, 4289-4292] and, combined with the nanoscale surface roughness of the arrays, can produce a near-perfect optical absorption material. An ultralow diffused reflectance of 1 x 10(-7) measured from such arrays is an order-of-magnitude lower compared to commercial low-reflectance standard carbon. The corresponding integrated total reflectance of 0.045% from the nanotube arrays is three times lower than the lowest-ever reported values of optical reflectance from any material, making it the darkest man-made material ever.
authors.affiliation: The Future Chips Constellation & Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180, USA.
authors.forename: Zu-Po
authors.initials: ZP
authors.lastname: Yang
authors.forename: Lijie
authors.initials: L
authors.lastname: Ci
authors.forename: James A
authors.initials: JA
authors.lastname: Bur
authors.forename: Shawn-Yu
authors.initials: SY
authors.lastname: Lin
authors.forename: Pulickel M
authors.initials: PM
authors.lastname: Ajayan
mesh_terms: D003116:Color; D003460:Crystallization / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D036103:Nanotechnology / Q000379:methods*; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D010783:Photometry; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D037742:Nanotubes, Carbon