Interface corrugation effect on the polarization anisotropy of photoluminescence from (311)A GaAs/AlAs short-period superlattices

Studying GaAs/AlAs superlattices containing a quantum-well-wire array revealed photoluminescence polarization anisotropy for samples with GaAs layers less than 21 Å thick. It was found that polarization for a thickness of more than 40 Å was mainly due to valence band anisotropy, whereas polarization for a thickness of less than 21 Å was equally attributable to both valence band anisotropy and anisotropy associated with interface corrugation. For a GaAs layer thickness of less than 21 Å, a blueshift of the Γ electron-Γ heavy hole transition was observed. In this transition, the position of the peak of photoluminescence from the GaAs/AlAs (311)A superlattices containing a quantum-well-wire array is shifted toward higher energies compared to the (311)B and (100) superlattices containing no quantum-well wire with the same GaAs layer thickness. The conclusion was made that a blueshift is observed in GaAs/AlAs superlattices with GaAs layers less than 21 Å thick and a red-shift is observed when the thickness is larger than 43 Å.