Dissociation energy of positively charged excitons in semimagnetic CdMnTe quantum wells

We present a transmission study of the energies of neutral and positively c harged excitons in modulation doped Cd1-xMnxTe quantum wells with variable concentration of the hole gas. Application of the semimagnetic semiconducto r as the QW material gives the opportunity to control independently the tot al hole concentration and its distribution between the two spin subbands (b y a small magnetic field). The positively charged exciton dissociation ener gy is found to be a linear function of the concentration in only one hole s pin subband (the one with the spin opposite to that of photocreated hole). This can be seen as a consequence of the fact that a charged exciton is not simply a three particle complex, but it consists of an exciton interacting with many holes.