Near perfect thin film flexible broadband optical absorber with high thermal/electrical conductivity

Abstract

Flexible ultra-black absorber with high thermal/electrical conductivity finds huge applications in the field of stray light attenuation, solar collectors, flexible electronics, and electronic thermal management systems. In this work, we report the fabrication of ultrablack absorber consists of vertically aligned carbon nanotubes (VACNT) in Polydimethylsiloxane (PDMS) having an absorption capacity of more than 98% in UV-Vis wavelength and more than 94% in NIR wavelength range. It is observed that the PDMS-VACNT composite shows ultra-high absorption capacity due to enhanced impedance matching and multiple scattering. In addition to this, the PDMS-VACNT composite shows an emissivity of 0.94 along with a 118% increase in thermal conductivity. Moreover, with the infiltration of VACNT in PDMS, the sheet resistance decrease drastically to 0.08 KΩ/sq, which signify the possible use of ultrablack absorber in electronic skin and flexible sensors etc.

Supreme-black levels enabled by touchproof microcavity surface texture on anti-backscatter matrix

“…2D), which is almost on a par with the world record (32), according to reports of appropriate reflectance measurements made using an integrating sphere system. The supreme-black sheet developed in this study is blacker than most as-grown VACNT blacks (10,31,43) and is one to two orders of magnitude blacker than previously developed touchproof superblack materials (11,12,20,21,30,50). Note that the combination of a spectrophotometer and integrating sphere optics, which we also mainly used in this study, is recognized as a standard instrument to evaluate spectral hemispherical reflectance; however, it certainly requires careful use for reliable results (31).…”

Flexible Graphite Nanoflake/Polydimethylsiloxane Nanocomposites with Promising Solar–Thermal Conversion Performance

“…In this regard, flexible polydimethylsiloxane (PDMS)-based nanocomposites integrating photothermal conversion media have evoked unprecedented interest as they can be fabricated as 3D porous structures and thin films or can be applied as coatings on various structural supports and complex geometries. − Due to superior absorption capabilities and their photostability, carbon-based photothermal materials such as graphite, CNT, graphene flakes, and carbon nanoparticles have been used to fabricate PDMS nanocomposites for various solar-powered applications. − ,, In particular, graphite is often the immediate choice because of its lost cost and ease of availability. − However, natural graphite has higher reflectance at the air–dielectric interface, limiting solar energy absorption. In addition, the absence of chemical functional groups on the graphite surface makes it less compatible with polymer structures.…”

Multiscale Structure Coordinated Poly(Ether Ether Ketone)‐Based Black Absorber with Wide‐Angle High Absorption Properties

“…Ideal black absorber has unique light absorption properties approximated to ideal blackbody, which can absorb all the light attached to surface without any reflection or transmission in widespectrum band . [1][2][3] High absorption property of black absorber makes it valuable for several application fields, covering from solar cells, [4][5][6] optical sensors, [7,8] photothermal conversion [9,10] to thermal detectors, etc. [11,12] Recently, these fields, especially in the field of space optics, have put forward requirements for DOI: 10.1002/admt.202300416 wide-angle high absorption of incident light by black absorbers, so as to improve the detecting precision of the optical payloads.…”