Flexible Textured Nanocomposite for Energy Harvesting Applications

The present study provides a method for designing and fabricating a multifunctional flexible absorber (flexorb) that can be used as a coating material for ultra-high absorption applications. Untextured nanocomposite (UNC) is synthesized by reinforcing 1 wt. % of nanofillers [carbon nanotubes (CNTs), zinc oxide nanorods and iron nanoparticles] in polydimethylsiloxane (PDMS). Homogeneous mixture of these nanoparticles led to an ultra-high absorption ≥ 96 % from 300-2000 nm. Subsequently, texturing on the surface of UNC, enhance the absorption ≥ 99 % in entire UV-Vis-NIR wavelength range. This increase in absorption is due to the multiple scattering of incident beam along with the surface texture. In addition to this CNTs reinforced in flexorb provides better impedance matching which results in lower reflection losses from flexorb/air interface. Moreover, the textured nanocomposite exhibited a better tensile, tear, shear and peel-off strength than pure PDMS and UNC. The flexorb has an advantage of flexibility which ensures that it can be deformed in variety of shapes without any damage or creasing failure. Such a ultra-black textured nanocomposite may find many applications such as suppression of stray light in telescopes, thermal imaging sensors, spectroscopy and energy harvesting.