Illumination as a tool to investigate the quantum mobility of the two-dimensional electron gas in a Si δ-doped ${\mathrm{G}\mathrm{a}\mathrm{A}\mathrm{s}/\mathrm{I}\mathrm{n}}_{0.15}{\mathrm{Ga}}_{0.85}\mathrm{A}\mathrm{s}/\mathrm{G}\mathrm{a}\mathrm{A}\mathrm{s}$ quantum well

A systematic investigation of the transport properties of a GaAs/InGaAs quantum well electronically coupled to a silicon delta-doped layer was carried out as a function of the illumination time of the sample. Shubnikov–de Haas measurements allowed the determination of the quantum mobility of each occupied subband that could be accurately analyzed from the dark condition up to the continuous-illumination regime. The origin of the persistent-photoconductivity effect observed in the sample could be unambiguously determined and was confirmed by self-consistent calculations.