Photoluminescence dynamics in GaAs along an optically induced Mott transition

We present a detailed experimental study of the effects of the optically induced transition from the excitonic, insulating regime, to the plasma, metallic regime, on the spectra and on the photoluminescence dynamics of GaAs. The transition is rather abrupt and presents a Mott-like behavior. The critical temperature, of 49 K, corresponds to the exciton binding energy. Through the study of the characteristics of the photoluminescence dynamics, the critical density for the transition has been obtained with unprecedented resolution.