QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: sitangshu on February 26, 2013, 06:10

Title: Graphene Sheet Carrier Degeneracy
Post by: sitangshu on February 26, 2013, 06:10

Hi,

Can we call a single layer graphene sheet with electron density as high as 10^16 m^-2 at 300 K as a degenerate one?. The intrinsic carrier concentration at 300 K is about 9 X 10^14 m^-2.

Thanks!

Title: Re: Graphene Sheet Carrier Degeneracy
Post by: zh on February 26, 2013, 08:52

I think that you can estimate the Fermi energy for the graphene at a given carrier density according to the relationship between Fermi energy (E_F) and the carrier (or electron) density for a two-dimensional system. The relationship can be found in the textbook of solid state physics. According to the order of k_B * 300 K and E_F, then you can easily judge whether it is a degenerate  one or not.

Title: Re: Graphene Sheet Carrier Degeneracy
Post by: sitangshu on February 26, 2013, 10:33

The Fermi energy is about 50 meV, while KbT = 26 meV. Does this mean that the SLG system is degenerate?

Thanks!

Title: Re: Graphene Sheet Carrier Degeneracy
Post by: zh on February 26, 2013, 12:36

Your data already gives your answer. Yes, you can think that.