Multifunctional thin film optically graded flexible absorber

Abstract

Flexible near perfect optical absorbers have many applications in the field of photovoltaic, energy harvesting and defence technologies. Even though flexible absorber coatings can be easily applied on the curved surfaces with complex geometry, the experimental realization of such absorbers having high absorption capacity in the broadband range is a challenging task. Here, we report the design and fabrication of a polydimethylsiloxane (PDMS) based optically graded thin (total thickness - 750 ȝP) aVVePbl\ Zhich VhRZV QeaU SeUfecW absorption (95%) in the wavelength range of 300 to 2000 nm. The observed high absorbing capacity may be attributed to the presence of multiscale feature size in optically graded assembly which leads to efficient light trapping and multiple scattering of incident beam. The multilayer assembly comprises layers of PDMS reinforced with iron, zinc oxide (ZnO) and carbon nanotubes (CNTs). In addition to this, detailed fracture mechanism of fabricated absorber is studied. Moreover, contact angle study of fabricated thin film structure reveals that it is not only a near perfect absorber but also hydrophobic in nature. The ease of fabrication process combined with the excellent properties shown by the multilayer flexible assembly makes it an attractive option for industrial applications.