Scientists have turned graphene into a universal sensor of infrared waves. Adding layers of arsenic and black phosphorus also allowed the determination of terahertz waves, according to a study by scientists from the Moscow Institute of Physics and Technology, published in the journal Optics Express.
Graphene is called one of the allotropic modifications of carbon, which is a flat sheet with a thickness of one atom, consisting of hexagonal cells. Graphene has many properties that are useful for modern materials science, for example, its superconductivity, the discovery of which Nature called the main sensation of 2018, or the possibility of converting heat to electricity.
At the same time, graphene in its pure form is not suitable for use in electronic devices, solar cells and lasers. For this, scientists add various impurities to it, which greatly change the properties of the material for the worse.
In a new work, researchers found a way around this limitation. Adding layers of arsenic and black phosphorus to graphene made it possible to strongly change the nature of the interaction of the material with light – this allowed the structure to absorb light in a very wide frequency range, including far infrared and terahertz radiation.
“If you apply the required voltage, the operating range of such receivers can be changed without loss of signal reception quality. We calculated the parameters of light-sensitive elements made on the basis of a graphene monolayer, which can capture far-infrared light. Such photodetectors can replace almost any infrared and terahertz radiation sensors used today”.
Viktor Ryzhiy, lead author of the study