Band alignments in InxGa1-xP/GaAs heterostructures investigated by pressure experiments

InxGa1-xP/GaAs (x = 0.541 and 0.427) heterostructures, grown by Atomic Laye r Molecular Beam Epitaxy (ALMBE) on low temperature substrates, have been c haracterised by pressure-dependent and time-resolved photoluminescence expe riments. The excitonic optical transitions and recombination dynamics are b oth influenced by the particular band alignments of these systems. The vale nce band offset has been found to have approximately the same absolute valu e (Delta E-VB approximate to 380 meV), independent of the In content of the alloy in the barrier, whereas the conduction band offset varies appreciabl y depending on the alloy band gap. The huge valence band offset implies a s trong asymmetry in the confinement of carriers, affecting the exciton recom bination dynamics in the quantum wells.