Design and Fabrication of a Multifunctional Flexible Absorber (Flexorb) in the UV-Vis-NIR Wavelength Range

Synthesis of a near perfect absorber is required for many technologically challenging areas. Most of the existing super absorbers are rigid and usually exploit the light in the visible range only leaving a significant part of available energy in the solar spectrum unutilized. Here the synthesis of a multifunctional flexible absorber (flexorb) with an ultrahigh absorbing capacity of >99% in the whole UV-vis-NIR region is reported. Flexorb is fabricated by texturing the polydimethylsiloxane matrix reinforced by ZnO nanorods, Fe particles and carbon nanotubes (CNTs). The near perfect absorbing behavior of flexorb emanates from two factors: 1) the multiple scattering and subsequent trapping of incident light induced by texturing and fillers having varying geometries and aspect ratios and 2) reduced reflection losses at the flexorb/surrounding interface due to impedance matching provided by CNTs. The flexibility of flexorb ensures that it can be deformed in a variety of shapes without any damage or creasing failure and can be readily mounted on surfaces made of stainless steel, glass, or acrylic polymer. It is believed that the present work will trigger further research to develop flexible multifunctional absorbers for harnessing the solar energy in the broader spectrum for various applications.