Photon Green's functions for a consistent theory of absorption and emission in nanostructure-based solar cell devices

The light-matter interaction in planar nanostructures with applications in photovoltaic devices is investigated by means of a microscopic quantum-kinetic theory based on the non-equilibrium Green's function formalism. The Dyson and Keldysh equations for the Green's functions of photons are solved numerically. The result is used to couple the optical and electronic degrees of freedom via respective self-energies. The numerical approach for the solution of the optical problem is verified against a standard transfer-matrix formalism and applied to the computation of absorption and emission characteristics in ultra-thin-absorber solar cells.