RECOMBINATION OF CORRELATED ELECTRON-HOLE PAIRS IN 2-DIMENSIONAL SEMICONDUCTORS

The Coulomb interaction of electrons and holes in a two-dimensional semiconductor is shown to affect radiative and nonradiative recombination processes strongly. Our detailed calculations based on a many-body theory give the Coulomb correlation factors for a wide range of carrier densities and temperatures. For radiative recombination, a continuous transition between an excitonlike and a free-carrier-like behavior is revealed, which strongly influences the temperature dependence of the radiative lifetime. Auger recombination is strongly enhanced and its kinetic behavior is modified to look like classical radiative recombination up to fairly high temperatures.