Abstract:
Lines $a$, $b$, $c$, $d$ and impurity absorption edge of ZnMnO for $\sigma$- and $\pi$-polarizations of light in temperature interval of 7–300 K were registered in this paper. Intensive lines $a_\pi$ and $a_\sigma$ are clearly observed in interval of 7–100 K, while other lines are observed only at low temperatures. For determination of type of optical transitions, to which excitonic lines $a$, $b$, $c$, $d$ are corresponding the calculation of oscillator strength of most intensive lines was made. Lines $a_\pi$ and $a_\sigma$ have Lorentz form, parameters of this form were calculated with OriginPro 9.1 program. The energy of impurity absorption edge was determined. Lines $a$, $b$, $c$ and $d$ were analyzed in model of Mn$^{2+}$–4O$^{2-}$ cluster. Optical transitions take place from antibonding $(p+d^5)^*$-states in forbidden gap to state, which is splitted from the bottom of conduction band of ZnMnO. Electron-hole pairs which are localized inside the cluster are called as local excitons.
Keywords:zinc oxide, localized excitons, antibonding states.
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