Optical properties of a type-II GaAs/GaP strained-layer superlattice

摘要

We studied the optical properties of a type-II (GaAs)$- 6$//(GaP)$-6$/ strained layer superlattice grown by Atomic Layer Molecular Beam Epitaxy (ALMBE) on GaAs substrate. The evolution of the photoluminescence peaks as a function of the temperature and excitation power as well as the photoluminescence excitation spectra supported the assignment of the transition involved. For (GaAs)$-6$//(GaP)$-6$/, the lowest conduction band is the X level in GaP layers. The energy distance between the X level in GaP layers and the $Gamma level in GaAs layers is approximately 44 meV. This sample is spatially indirect (type-II) superlattice. We found that the temperature dependence of the photoluminescence spectra is different from other's results.