BIEXCITONS AND DARK STATES IN SEMICONDUCTOR MICROCAVITIES

We analyze the formation of two-dimensional biexcitons and the role of exciton dark states decoupled from the cavity mode in semiconductor m icrocavities containing a few resonating quantum wells. A general form alism is presented for the treatment of excitons, photon modes and bie xcitons in resonating microcavities. Scattering by disorder is also co nsidered. The interface disorder seen by cavity polaritons is shown to be reduced by averaging along the cavity axis. The spectral narrowing of cavity polariton lines is discussed. Results for the biexciton bin ding energy, radius and damping are discussed in the physically releva nt cases. The cavity biexciton photoluminescence spectra are found to be qualitatively different depending on the relative magnitudes of the exciton-cavity detuning, the biexciton binding energy, the exciton-ph oton coupling and the damping. (C) 1998 Elsevier Science B.V. All righ ts reserved.