A theory of excitons in the presence and absence of disorder for spatially separated electrons and holes in nanostructures

We develop a theory of exciton formation in double layer semiconductor systems in which electrons and holes are spatially separated by a potential barrier. We include the effect of disorder which is present between the layers. The disorder within the electron and hole layers is mainly due to structural imperfections such as interface roughness and variations in the thickness of double layer structures. We use a lattice gas model to calculate electron, hole and exciton densities. Our theory predicts that disorder promotes the dissociation of excitons in double layer systems.