Ejigu, Afrash2021-12-102023-11-092021-12-102023-11-091995-06http://10.90.10.223:4000/handle/123456789/29204In this thesis the excitation spectra of the 4TI ---+ 6 Al emission of Mn2 + in Znl . .Mr\Se crystals and their dependence on the crystal temperature, intensity of the exciting laser and manganese concentration (x $ 0.016) are investigated. Eventhougth some of the excitation spectra of these crystals were published in literature the origin of one of the excitation band ( M-band ) still remains unknown. The M-band is an excitation band of the 4TI ---+ 6AI emission of Mn2 + in Znl.MnxSe within the spectral range of bound excitons. Computer fitting techniques were used to determine some important parameters of the M-band and the bound exciton band (BE-band). F rom the comparison of the crystal temperature, exciting laser intensity and Mn concentration dependence of some of these fitting parameters of the M-band with that of the BE-band it is found that the M-band is built up of a multiple of bound excitons, which are different from that of the BE-band.enEnergy Transfer Between ExcitonsThesis