Temperature dependence of the radiative and non radiative recombination time in GaAs/AlGaAs quantum well structures

We report an experimental study of the photoluminescence (PL) properties, after both picosecond and continuous-wave excitation, of GaAs/Al(x)Ga(1-x)As quantum-well structures. The comparison between the PL decay time and the PL integrated intensity allows us to determine the temperature dependence of both the radiative and the nonradiative time constants. We find that the nonradiative processes play an important role and become dominant for T greater-than-or-equal-to 100 K. The radiative time constant turns out to be definitely higher than the measured PL decay time and increases by several orders of magnitude as the temperature is raised from T = 4 K to room temperature. The experimental results are finally compared with the theories existing in the literature.