Low-cost, flexible and broadband terahertz absorber based on annealed carbonized sponge

Carbon-based functional materials, such as grapheme and MXenes, have been widely explored as Terahertz (THz) absorbers due to their broad structural-dependent properties, however, they usually suffer from high-cost, complex fabrication process and narrowband characteristics. Here, a broadband, low-cost and flexible THz absorber is realized based on annealed carbonized sponge (CS) that is obtained from a commercially available melamine sponge through a pyrolysis process conducted in an inert atmosphere. Due to the ultra-high porosity and good conductivity, the obtained CS shows excellent shielding and absorption performance with the maximum electromagnetic interference shielding effectiveness value of 49 dB and maximum reflection loss value of 47 dB, respectively, covering 100% qualified frequency bandwidth ranging from 0.25 to 3.5 THz, which far extends most reported materials. Furthermore, this obtained efficient THz absorber is demonstrated by THz transmission and reflection imagings, which demonstrate its potential applications in electromagnetic stealth, shielding, and beyond.

Automated summary

A broadband, low-cost, and flexible THz absorber is achieved using annealed carbonized sponge obtained from a commercially available melamine sponge through a pyrolysis process. The obtained CS shows excellent shielding and absorption performance covering a wide frequency bandwidth, far extending most reported materials. This efficient THz absorber has potential applications in electromagnetic stealth, shielding, and beyond, as demonstrated by THz transmission and reflection imagings.