Effect of Screening by Two-Dimensional Charge Carriers on the Binding Energy of Excitonic States in GaAs/AlGaAs Quantum Wells.

The spectrum of excitonic excited states in GaAs/AlGaAs quantum wells of different width is studied together with its change due to the screening of electron–hole interaction by two-dimensional electrons. The exciton binding energy decreases sharply with an increase in the concentration of two-dimensional electrons. The temperature dependence of screening parameters is studied for the ground and excited excitonic states down to ultralow temperatures T = 50 mK. © 2002 MAIK “Nauka / Interperiodica”. [ABSTRACT FROM AUTHOR]