CARRIER EFFECTIVE MASSES IN SYMMETRICALLY STRAINED (GAIN)AS GA(PAS) MULTIPLE-QUANTUM-WELL STRUCTURES/

The carrier effective masses in symmetrically strained (GaIn)As/Ga(PAs ) multiple-quantum-well heterostructures have been determined as a fun ction of the incorporated compressive strain in the (GaIn)As quantum-w ell layer by applying magneto-optical studies. The precise structural parameters, i.e., individual layer thicknesses, strain values, and cry stalline perfection, have been determined independently by high-resolu tion x-ray diffraction and transmission electron microscopy. By analyz ing both the allowed and forbidden optical transitions as a function o f the magnetic field, detected by polarization-dependent magnetophotol uminescence excitation spectroscopy, the exciton binding energy as wel l as the effective in-plane electron and heavy-hole masses have been d etermined quantitatively as a function of strain. The theoretically pr edicted significant decrease of the in-plane heavy-hole mass with incr easing strain has been observed. The obtained results are discussed an d compared with the contradictory results reported in the literature.