What are the characteristics of graphene

　　Graphene is the thinnest and hardest nanomaterial known in the world. It is almost completely transparent and absorbs only 2.3% of light. The thermal conductivity is as high as 5300 W / m? K, which is higher than carbon nanotubes and diamond. Its electron mobility is more than 15000 cm2 / V? S, and it is higher than carbon nanotubes or silicon crystals, and its resistivity is only about 10-6 Ω? Cm, which is lower than that of copper or silver. Because of its extremely low resistivity and extremely fast electron migration, it is expected to be used to develop new generation electronic components or transistors that are thinner and more conductive. Because graphene is essentially a transparent and good conductor, it is also suitable for making transparent touch screens, light panels, and even solar cells.

As a new material, graphene has received great attention. In fact, graphene is a type of carbon that has ultra-high strength, lightness and extensibility, and will be able to change the appearance, feel and even the use form of digital products. Below, let's take a closer look at what are the characteristics of graphene and what are the advantages.

1, mechanical properties-harder than diamond

Graphene extracted from pencil graphite is actually harder than diamond and has a strength hundreds of times higher than the best steel in the world. This scientific discovery was published in the recent issue of Science. The authors are two graduate students of Columbia University , Wei Xiaoding from China and Li Yanco from Korean.

Data conversion analysis: Before the graphene sample particles began to fragment, the maximum pressure they could withstand every 100 nanometers distance reached about 2.9 micronewtons.

According to scientists' calculations, this result is equivalent to the pressure of 55 Newtons to break a 1 meter long graphene. If physicists can produce graphene (thickness of about 100 nanometers), which is equivalent to ordinary food plastic packaging bags, it will need to apply about 20,000 N of pressure to break it. In other words, if graphene is used to make bags, it will be able to withstand items weighing about two tons.

For example, the strength of a single layer of graphene is like adding the weight of an elephant to a pencil, so that you can use this pencil to pierce a single layer of graphene only as thick as a cling film.

2, excellent electrical properties-electronic transportation

The carbon atom has four valence electrons. In this way, each carbon atom contributes an unbonded π electron. These π electrons can form orbits in a direction perpendicular to the plane. The π electrons can move freely in the crystal and give graphene good electrical conductivity. Sex. Carrier migration is approximately equal to the speed of light.

In addition, graphene has a band structure with zero band gap. 10-8Ω · m resistivity, lower than copper / silver resistivity