Magnetophotoluminescence of negatively charged excitons in narrow quantum wells - art. no. 125331

We present the results of photoluminescence experiments on the negatively c harged exciton X- in GaAs/AlxGa1-xAs quantum wells (QW) in high magnetic fi elds (less than or equal to 50 T). Three different QW widths are used here: 100, 120, and 150 Angstrom. All optically allowed transitions of X- are ob served, enabling us to experimentally verify its energy-level diagram. All samples behave consistently with this diagram. We have determined the bindi ng energy E-b of the singlet and triplet state of X- between 23 and 50 T fo r the 120 and 150 Angstrom QW, while only the triplet E-b is observed for t he 100 Angstrom QW. A detailed comparison with recent theoretical calculati ons shows an agreement for all samples across this entire field range.