Density Functional Theory Study The Electrical And Optical Properties Of Graphene Doped With Pd

In this work we have studied the electrical and optical properties of graphene doped with Pd using Density Functional Theory (DFT) which is based on first principle calculations. For electrical properties, we mainly study the systems of graphene doped with one Pd atom, and graphene doped with two Pd atoms. Then we study oxidative gas O2and reducing gas CO adsorb on graphene doped with Pd system. Via calculating the systems’adsorption energy, charge transfer, energy bands and density of states (DOS), we find that graphene doped with Pd adsorb gas molecular which has higher adsorption energy and more charge transfer, at the same time, the interaction force between Pd doped graphene system and gas molecular strengthened, compare to intrinsic graphene adsorb O2and CO gas molecular. But there are some differences in the energy bands and DOS for Pd doped graphene adsorbing O2and CO. Intrinsic graphene adsorb O2, DOS near Fermi-level get more higher, after Pd doping, the DOS decrease, but sa2me phenomenon do not happen on adsorbing CO, the DOS almost keep unchanged. Two Pd atoms doped with graphene adsorb O2, interaction force get strong obviously, we can see that from the increasing adsorption energy, charge transfer and length of O-O, simultaneously, conduction characteristic of the system also get to be strengthened. While, two Pd atoms doped graphene adsorbing CO do not display much huge change comparing to one Pd atom doped graphene adsorbing CO. For optical properties, we mainly calculate the dielectric function, adsorption coefficient and energy loss coefficient of intrinsic graphene, one Pd atom doped graphene and two Pd atoms doped graphene. The calculation results show that intrinsic graphene can absorb10eV～25eV spectral region, while the region of below lOeV and above25eV almost cannot be absorbed, which illustrates that visible light is almost transparent for intrinsic graphene. However, grapehe dope with Pd which can change its low energy level light absorption character, and can absorb visible light in some extent, what is more, graphene doped with two Pd atoms owns better light absorption character than graphene doped with one Pd atom.