Nonequilibrium Green's function modelling of quantum well solar cells

We present a microscopic model of the photocurrent in $GaAs-AlGaAs$ quantum well solar cells (QWSC), based on the nonequilibrium Green's function formalism (NEGF) for a multiband tight binding Hamiltonian. The quantum kinetic equations of motion are selfconsistently coupled to Poisson's equation. Relaxation and broadening mechanisms are considered by the inclusion of acoustic and optical electron-phonon interaction in a self consistent Born approximation of the scattering selfenergies. The model is applied to different multi-quantum-well sytems to investigate the role of device geometry and coupling between the wells.