Absorption measurements at high pressure on AlAs-AlxGa1−xAs-GaAs superlattices

Absorption data (300 K) are presented on AlxGa1−xAs-GaAs and AlAs-GaAs superlattices subjected to hydrostatic pressure (0–10 kbar). These data show that the confined-particle transitions, which partition and ’’label’’ the Γ energy band high above the band edge (as high as 400 meV or well above the L minima), all move with the same pressure coefficient (11.5 meV/kbar). A weaker effect of the L than the X indirect minima on the absorption is observed.