Graphene is frequently in news recently. What is its importance? 1) It is a two-dimensional material and has good electrical conductivity. 2) It is one of the thinnest but strongest materials tested so far. 3) It is entirely made of silicon and has high optical transparency. 4) It can be used as conducting electrodes required for touch screens, LCDs and organic LEDs. Which of the statements given above are correct?

Graphene is a single layer of carbon atoms arranged in a honeycomb (hexagonal) lattice, so it is one atom thick. That makes it a two-dimensional material. Its electrons move very fast with little resistance, which gives it excellent electrical conductivity. So statement 1 is correct.

Statement 2 is also correct. Lab tests (Columbia University, 2008) put its tensile strength at around 130 GPa, far above steel, and it is still one of the thinnest and strongest materials tested.

Statement 3 is wrong. Graphene is made of carbon, not silicon. Silicon is the base of conventional chips, and that is where the confusion comes from. Graphene is highly transparent, absorbing only about 2.3 percent of light per layer, but that does not make it silicon.

Statement 4 is correct. Because graphene is conducting and transparent, it is studied as a replacement for indium tin oxide in touch screens, LCDs and OLEDs. Indium is scarce, and that gives graphene a strong case in GS3 on critical materials and nanotechnology.

Trap: Students who see the words high transparency and conductivity often rush to mark statement 3 as correct, or forget that carbon is the element involved.