Heterostructures with ZnSe quantum wells and different barrier materials (Zn1-xMgxS1-ySey and Zn1-xBexSe) are investigated by means of photoluminescence and reflectivity in external magnetic fields up to 20 T. Up to four exciton excited states are well-resolved in the photoluminescence excitation spectra of undoped structures. Model calculations of the magneto-exciton fan chart are performed. In n-type modulation doped quantum wells negatively charged excitons associated with heavy-hole and light-hole excitonic states are found. (C) 1998 Elsevier Science B.V. All rights reserved.