ESR and ODMR of ZincVacancy‐Associated Defects in ZnSe

ESR and ODMR of halogen‐free and iodine‐doped ZnSe single crystals are investigated. In the case of the halogen‐free samples four distinct associated centres are detected by ESR. The iodine‐doped crystals contain only one type of acceptor centres attributed to a zinc vacancy associated with an iodine ion. The g‐tensor components of this centre are g1 = 1.955, g2 = 2.192, g3 = 2.221 with a tilting angle of 2°. The g‐values and tiltings of the acceptor centres are discussed in a model previously developed for similar centres in ZnS, although this model cannot account for the finer structures. From the close similarity of the ESR and ODMR anisotropies and from the conformity of emission, ODMR acceptor, and ODMR donor resonance in their dependence on optical energy the participation of these centres in the donor‐acceptor emission process is concluded. The 77Se hyperfine splitting is observed, and in addition for the first time a ligand hyperfine structure of a selfactivated centre in ZnSe is identified (of 127I). Finally, arguments are given for the existence of a deep iodine‐associated donor complex.