Graphene Coated Absorbers
Graphene-coated absorbers, or other two-dimensional materials such as molybdenum disulfide or hexagonal boron nitride, are becoming an increasingly popular method for efficient absorption of electromagnetic radiation. Graphene-coated absorbers are generally composed of graphene, a two-dimensional sheet of carbon atoms arranged in a honeycomb pattern, and an underlying conductive layer or substrate. The graphene-coated absorber is typically stacked on top of a frequency selective surface (FSS), a device used to selectively reflect, transmit, and absorb specific frequencies of radiation.
Graphene is a relatively new material, having been discovered just over a decade ago. It has unique properties, such as its high electrical conductivity, that make it an ideal material for use in absorbers. It is also extremely thin, which allows it to have a higher absorption rate compared to other materials with the same conductivity. Additionally, its honeycomb lattice structure allows it to have high surface area, effectively extending the range of absorbed wavelengths.
Graphene-coated absorbers can be tailored to a variety of applications. They are ideal for antenna designs and can be used for radiofrequency (RF) applications, as well as for microwave applications. They can also be used for infrared applications such as night-vision systems and stealth technology. Graphene-coated absorbers are very efficient at absorbing incident energy, but can also be designed to allow some energy to pass through. This can be beneficial for certain applications, such as some imaging or radar systems, in which a certain amount of reflected energy can be useful.
Graphene-coated absorbers are relatively simple to manufacture and require minimal additional components. The absorber is typically composed of only graphene and a conductive substrate, such as aluminum. The graphene is coated onto the conductive substrate, which can be either flat or textured. Generally, the thickness of the graphene layers is between 1 and 100 nm and can be customized depending on the application. Additionally, other components such as a dielectric layer can be added to enhance the efficiency of the absorber.
Graphene-coated absorbers have proven to be highly efficient at absorbing incident energy and have many potential uses in a variety of different applications. They are relatively simple to manufacture and require minimal additional components. Furthermore, their thin and lightweight design makes them ideal for a range of different applications from radiofrequency to infrared.
