Influence of random potential fluctuations on the interwell radiative recombination in biased double quantum well

A systematic study of the photoluminescence from double quantum well in p-i-n GaAs/AlGaAs/GaAs heterostructure under the influence of an external electric and magnetic field at different temperatures has been performed. The luminescence peak of the indirect recombination exhibits a dynamical narrowing when increasing the temperature from 10 to 20 K. This is explained by thermal delocalization of electrons and holes localized in the wells at low temperatures due to the random potential fluctuations. This explanation is supported by time-resolved photoluminescence measurements of the different components of the spectra