Detailed varied-parameter characterization of the GaAs/Al_xGa_1–xAs super-multiperiod superlattices by photoreflectance spectroscopy

Abstract

A room-temperature study of the optical transitions in GaAs/AlxGa1–xAs super-multiperiod superlattices (SMP-SLs) grown by molecular beam epitaxy was performed by photoreflectance spectroscopy. The development of devices based on high quality semiconductor SMP-SLs requires a comprehensive understanding of the energy miniband formation in the grown samples. Existing theoretical approaches to modeling the energy spectrum of SMP-SLs do not always correctly describe one in real structures due to the lack of correct information about the energy spectrum. The combination of the results of photoreflectance spectroscopy with the data obtained within the framework of the 8-band Kane theoretical model allows us to get a detailed interpretation of all optical transitions, that was confirmed by the results of the detailed study of GaAs/AlxGa1–xAs SMP-SL samples with different quantum wells and barriers widths.