Ionization equilibrium and Mott transition in an excited semiconductor, phase diagram

The thermodynamic properties of an electron–hole plasma in a highly excited semiconductor are investigated. Special attention is directed to the influence of many‐particle effects like screening, lowering of the ionization energy, and Mott effect on the ionization equilibrium. In particular, the Mott effect limits the region of existence of excitons and, therefore, of a possible Bose–Einstein condensate at low temperatures. Results for the chemical potential and the degree of ionization are presented for cuprous oxide. A possible window for the occurrence of a BEC of excitons taking into account the Mott effect is shown. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)