CHARACTERIZATION OF ZNMGSSE ZNSE QUANTUM-WELLS GROWN BY MOVPE/

ZnMgSSe/ZnSe quantum wells grown by metalorganic vapour phase epitaxy (MOVPE) were investigated by photoluminescence (PL), photoluminescence excitation (PLE), reflection and X-ray diffraction spectroscopy. The binding energy of confined excitons in the wells was calculated with t he fractional dimension model. In a 4 nm quantum well with 3.318 eV Zn MgSSe barriers, the exciton binding energy was 1.7 times the bulk valu e of ZnSe. From comparison of the calculated and measured transition e nergies in the ZnMgSSe/ZnSe quantum wells we could identify the e(1)hh (1) and e(1)lh(1) transitions. The e(1)hh(1) transition dominates in t he PL spectrum whereas both e(1)hh(1) and e(1)lh(1) transitions appear in the PLE spectrum. The relative ratios of the conduction band disco ntinuities and the band-gap differences (Delta E-g) were between 23 an d 17% for Delta E-g between 222 and 515 meV. (C) 1998 Elsevier Science B.V. All rights reserved.