Magneto-optical Transitions of GaAs/AlGaAs Multiple Quantum Wells

Photoluminescence (PL) transitions of an undoped GaAs/Al0.33Ga0.67As multiple quantum well structure composed of four different well widths (3, 5, 7 and 10 nm) were investigated under pulsed magnetic fields to 50 T. At B = 0 T, four corresponding PL peaks were detected, which exhibit PL line broadening for narrow quantum wells (3 and 5 nm) due to the interface roughness. By comparing the PL peak transition energies with the calculated transition energies including the binding energy corrections, the exact quantum well widths can be determined. In the presence of a magnetic field, PL transitions undergo a diamagnetic shift. By fitting the diamagnetic shift, we were able to estimate the dimensionality parameters, diamagnetic coefficient and magnetic-to-Coulomb energy ratio.