Mott transition versus Bose-Einstein condensation of excitons

We investigate the influence of many-body effects on both the chemical potentials of carriers, and the Mott transition of para-excitons in Cu2O over a wide range of temperatures and carrier densities, in order to determine the region where an excitonic fraction can exist. In contrast to simplified approximations used in the literature we consider full dynamical screening between carriers and find out that (i) the chemical potentials are much less decreased by the many-body effects, and (ii) for low temperatures the density, where the Mott transition appears, is one order of magnitude higher. This leads to an extension of the region of existence of excitons and, therefore, of a possible BEC, to higher temperatures.