Although hundreds of two-dimensional crystals exist, graphene is indisputably the most well-known. Why is it so famous? Certainly, due to its intrinsic characteristics. In fact, graphene is made of a layer of monatomic carbon, which has a mechanical resistance about 100 times higher than iron, thickness being equal, and moreover, it is flexible and stretchable. It has extraordinary thermal and electric conductivity, its current carrying capacity being higher than copper. In addition, it is optically transparent, has a huge surface area and is a virtually impermeable barrier against the vast majority of chemical elements.
Apart from graphene, there is a new 2-dimensional world to discover, with materials possessing properties that are complementary to those of the most famous crystal. Other two-dimensional crystals, in fact – such as Boron Nitride, Molybdenum Disulfide, Tungsten Disulfide, the already known Black Phosphorus, Gallium Sulfide, or, again, Tungsten Selenide, Niobium Selenide, Tantalum Selenide, just to mention a few -, are materials with innovative properties, capable of improving the characteristics and performance of already existing or newly developed objects and devices.