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. Although optic ally inactive, the dark levels are important because they contribute s tates available to the excitons. A general formalism is presented for the treatment of excitons, photon modes, and biexcitons in resonating microcavities. Scattering by disorder and phonons is also considered. Results for the biexciton binding energy, radius, and damping are disc ussed in the physically relevant cases. The cavity biexciton photolumi nescence spectra are also investigated; they are found to be qualitati vely different depending on the relative magnitudes of the exciton-cav ity detuning, the biexciton binding energy, the exciton-photon couplin g, and the damping. (C) 1998 Optical Society of America.