1202.4980 (Jingzhe Chen et al.)

First-principles Analysis of Photo-current in Graphene PN Junctions    [PDF]

Jingzhe Chen, Yibin Hu, Hong Guo

We report a first principles investigation of photocurrent generation by
graphene PN junctions. The junctions are formed by either chemically doping
with nitrogen and boron atoms, or by controlling gate voltages. Non-equilibrium
Green's function (NEGF) formalism combined with density functional theory (DFT)
is applied to calculate the photo-response function. The graphene PN junctions
show a broad band photo-response including the terahertz range. The dependence
of the response on the angle between the light polarization vector and the PN
interface is determined. Its variation against photon energy $E_{ph}$ is
calculated in the visible range. The essential properties of chemically doped
and gate-controlled PN junctions are similar, but the former shows fingerprints
of dopant distribution.

View original: http://arxiv.org/abs/1202.4980