Optical-absorption studies of wurtzite-phaseZn1−xMnxSe

Optical-absorption results on single-crystal samples of ${\mathrm{Zn}}_{1\mathrm{-}\mathrm{x}}$ ${\mathrm{Mn}}_{\mathrm{x}}$Se are presented. Dichroism associated with the fundamental edge is established for x≥0.35, consistent with the onset of the wurtzite phase. Up to four absorption bands associated with ${\mathrm{Mn}}^{2+}$ intraion transitions are seen at x∼0.50; the shifts of the three lowest transitions with x are analyzed with use of ligand-field theory applied to localized ${\mathrm{MnSe}}_4$ clusters. Consistent polarization in the Mn absorption spectrum occurs in the wurtzite region. Possible mechanisms leading to such polarizations are considered.