Subband tuning in semiconductor quantum wells using narrow barriers

摘要

A method for controlling the intersubband spacing in GaAs/AlGaAs quantum wells by incorporating a thin AlAs barrier at the well center has been investigated using reflectance and photoluminescence spectroscopy. Two structures with 5.7 and 11.3 Aring; AlAs barriers were studied. The predicted exciton sequence for the first sample (5.7 Aring; barrier) isE1hle;E1lle;E2hle;E2l, whereas for the second structure (11.3 Aring; barrier), the predicted sequence isE1hle;E2hle;E1lle;E2l. This work verifies that the sequence reversal, predicted for the 11.3 Aring; sample, occurs by performing polarization excitation luminescence measurements on these samples.