Graphene is a one-atom thick sheet of carbon atoms arranged in a honeycomb lattice structure. It is the thinnest material possible and is very strong and flexible. In 2004, Geim and Novoselov discovered graphene by peeling layers of graphite with Scotch tape. Graphene has excellent electrical and thermal conductivity and is transparent, making it promising for applications like batteries, touchscreens, solar cells, LEDs, and ultracapacitors.