Band edge offset in strained InxGa1-xAs/GaAs quantum wells measured by high-excitation photoluminescence
A new method is presented for direct and reliable determination of the band edge offset in quantum well (QW) semiconductor heterostructures. It is based on luminescence measurements at various filling levels of the valence and conduction band quantum wells. Magnetoluminescence measurements were made to independently determine the effective masses. The conduction band offset to energy gap ratio for strained InxGa1-xAs QWS in an unstrained GaAs matrix was determined to be 0.79+or-0.05 for x=0.18 and 0.28.