The conduction-band offset in GaAs-AlxGa1-xAs quantum wells is determined with a new light scattering method. A value of Ec Eg=Qe=0.69 is found for x 0.06. The conduction-band discontinuity Ec is obtained from electronic light scattering in a photoexcited sample. The total gap discontinuity Eg is deduced from resonance Raman scattering by AlxGa1-xAs phonons in the same sample. The light scattering method is unique because Ec can be determined regardless of the valence-band structure or exciton binding energies. It also allows a direct measurement of Eg, so that an exact knowledge of the alloy composition in AlxGa1-xAs is no longer needed.
ASJC Scopus subject areas
- Condensed Matter Physics