Quantum-well thickness dependence of spin polarization of excitons

Abstract

The optical orientation of exciton spins in semiconductor quantum wells (SQWs) was investigated by observing the circular polarization of the photoluminescence (PL). The left/right circularly polarized PL in SQWs was measured. It was found that there is a difference between the two different polarization conditions, which is caused by spin-dependent phase-space filling. The PL polarization was estimated from the signals of the left and right circularly polarized PL and was found to depend on the well thickness of SQWs as well as on the sample temperature. The influence of an electric field on the PL polarization was studied.