Résumé:

We report on high-pressure, low-temperature photoluminescence of Ga0.5In0.5P/GaAs single quantum wells grown by metalorganic-molecular-beam epitaxy. A type-I-type-II (and GAMMA-X) transition occurs at P=3.25+/-0.1 GPa for all well widths (from 10 to 70 angstrom), in contrast to what is observed in (Al,Ga)As/GaAs quantum wells. Using envelope-function calculations for the type-II transitions, a valence-band offset of 330+/-20 meV is deduced independent of pressure, within experimental precision. This is in good agreement with a previous photoreflectance study and with recent theoretical predictions on such heterostructures.