Resonance capture of holes in modulation-doped n-AlGaAs/GaAs quantum well structures

摘要

A study was conducted to clarify the effect of the theoretically predicted oscillations of efficiency of capture of photoexcited carriers on the spectral characteristics of photoluminescence (PL) of the modulation-doped n-AlGaAs/GaAs structures. The structures were grown by molecular-beam epitaxy on semi-insulating GaAs substrates with (001) orientation. A sample was placed in an optical cryostat allowing measurements from room to liquid nitrogen temperature. It was found that broadening of the temperature range considerably increased the informativity of the PL method in diagnostics of quantum wells. It was revealed that that the energy of the transition between the lower quantum levels 1e-1hh of electrons and holes was determined with high accuracy at low temperatures and between the levels with higher energies at high temperatures.