"2D" describes the freedom of the electrons. They can move in X and Y, but not Z. This restricted freedom causes all sorts of unique electronic behavior never s

"2D" describes the freedom of the electrons. They can move in X and Y, but not Z. This restricted freedom causes all sorts of unique electronic behavior never seen in 3D systems. You are certainly correct that graphene has height. Source: I am getting a PhD in 2D electron physics