The manifestation of Coulomb gap in photoluminescence of GaAs/AlGaAs quantum wells with positively charged acceptors

We report results of photoluminescence and photoexcitation studies carried out on GaAs/AlGaAs quantum well structures with positively charged acceptors. We explain the observed spectral peculiarities by an appearance of the Coulomb gap. Another evidence of the Coulomb gap is an anomalously large Stocks shift which has been observed in our experiments.

► The sample with selectively beryllium doped GaAs/AlGaAs quantum wells was optically studied.
► A certain peculiarities in photoluminescence and photoexcitation spectrum were found.
► A simple qualitative scheme of optical excitation and re-combination in presence of Coulomb gap was described.
► The obtained experimental results are in agreement with proposed model.