ABSTRACT
This chapter discusses the processes of the electron and hole injection into the i-region of graphene-layer and multiple graphene-layer p-i-n structures at the forward bias voltages. It calculates the band edge profile, the spatial distributions of the quasi-Fermi energies, carrier density and velocity, and the current-voltage characteristics by using analytical and numerical solutions of the equations of the model. The chapter demonstrates that the electron and hole collisions can strongly affect these distributions. It develops a model for the graphene-layer and multiple-graphene-layer forward biased p-i-n structures which accounts for relatively strong recombination and consider its effect on the characteristics which can be important for realization of infrared/terahertz injection lasers. The model in question assumes that the recombination of electrons and holes in the i-region and the leakage thermionic and tunneling currents at the p-i and i-n interfaces are relatively small.
