Evidence for type I band alignment in GaNAs/GaAs quantum structures by optical spectroscopies

Type I band line-up in GaNxAs1−x/GaAs multiple quantum wells (MQW) with x⩽3% is concluded based on the following experimental results: (i) a comparable radiative decay time of the GaNAs-related photoluminescence (PL) measured from single GaNAs epilayers and the GaNAs/GaAs MQW structures, (ii) the observed PL polarization, and (iii) the spatial confinement of photoexcited holes within the GaNAs layers under resonant excitation of the GaNAs MQW.