A thin-film infrared absorber using CNT/nanodiamond nanocomposite

This paper reports on the fabrication and characterization of thin-film nanocomposites comprised of tangled carbon nanotubes in a polymer matrix. The density of nanotubes in the polymer was significantly increased using detonation nanodiamonds. Nanodiamonds reduce the surface forces between the polymer and the nanotubes and mitigate the agglomeration problem of nanotubes in polymer. This resulted in thinner, more uniform networks that serve as efficient absorbers of infrared energy over a broad spectrum, ranging from the visible to the mid-wavelength infrared. An infrared absorbance of 97 % was achieved for a 1.6 µm thick nanocomposite film across the spectral range of 714 nm to 5 µm. The films are electrically insulating, mechanically and thermally stable up to 300 ˚C, and can be integrated with microbolometers to enhance their responsivity