Author/Authors :
Faezinia, Hamid Department of Electronic Engineering, Tabriz Branch, Islamic Azad University, Tabriz, Iran. , Zavvari, Mahdi Department of Electronic Engineering, Urmia Branch, Islamic Azad University, Urmia, Iran.
Abstract :
Graphene based optical devices are highly recommended and interested for
integrated optical circuits. As a main component of an optical link, a photodetector based
on graphene nano-ribbons is proposed and studied. A quantum transport model is
presented for simulation of a graphene nano-ribbon (GNR) -based photo-transistor based
on non-equilibrium Green’s function method. In the proposed model a self-energy matrix
is introduced which takes the effect of optical absorption in GNR channel into account.
The self-energy matrix is treated as a scattering matrix which leads to creation of carriers.
The transition matrix element is calculated for optical absorption in graphene channel and
is used to obtain the optical interaction self-energy. The resulting self-energy matrix is
added to retarded Green’s function and is used in transport equations for calculation of
current flow in the photo-transistor. By considering the effect of optical radiation, the
dark and photocurrent of detector are calculated and results are used for calculation of
responsivity.
Keywords :
Non-equilibrium Green’s function , Graphene nano-ribbon , Photo-transistor , Selfenergy
