Electronic structure of the oxide-diluted magnetic semiconductorZn1−xMnxO

We have studied the electronic structure of ${\mathrm{Zn}}_{1-x}{\mathrm{Mn}}_x\mathrm{O}$ using photoemission spectroscopy measurements and configuration-interaction (CI) calculations on a ${\mathrm{MnO}}_4$ cluster model. It is shown that the CI calculation can give a consistent description of the photoemission and $d-d$ optical absorption spectra of ${\mathrm{Zn}}_{1-x}{\mathrm{Mn}}_x\mathrm{O}$ as well as those of other II-VI- and III-V-based diluted magnetic semiconductors such as ${\mathrm{Cd}}_{1-x}{\mathrm{Mn}}_x\mathrm{Te}$ and ${\mathrm{Ga}}_{1-x}{\mathrm{Mn}}_x\mathrm{As}.$ The CI approach predicts that the magnitude of the $p-d$ exchange constant in ${\mathrm{Zn}}_{1-x}{\mathrm{Mn}}_x\mathrm{O}$ is much larger than that in ${\mathrm{Ga}}_{1-x}{\mathrm{Mn}}_x\mathrm{As}.$