Persistent IR photoconductivity in InAs/GaAs structures with QD layers

Persistent IR photoconductivity in InAs/GaAs structures with layers of QDs with a p-and n-type conductivity was studied. At the initial stage, after the illumination is switched off, the relaxation of photoconductivity follows a logarithmic law. The relaxation time depends on temperature; it decreases as temperature increases. A simple model of photoconductivity relaxation, based on thermal activation of carriers from the QD layer, is proposed. The model is consistent with the experimental data.