Bandgap energy of the O-rich ZnTexO1-x (0 < x ≤ 0.35)

Abstract

Model is set up to provide a depiction for the bandgap energy of the O-rich ZnTexO1-x with wurtzite structure. A better agreement between the result obtained by the model and the experimental data than the result reported in other reference can be found. It is also found that the equation with a bowing term should be modified when it is used to describe the bandgap energy of ZnTexO1-x. The weak composition dependence of the Γ VBM (valence band maximum) in the O-rich range is due to two factors. One is the localized effect of the Te level. The other is the weak anticrossing interaction between the Te level and the Γ VBM of ZnO. The influence of the localized effect of the O level on the Γ CBM (conduction band minimum) is weaker than that of the Te level on the Γ VBM in ZnTexO1-x. In addition, it is found that the Γ CBM of ZnTexO1-x depending on O content in the dilute oxygen range is much stronger than the Γ VBM of ZnTexO1-x depending on Te content in the dilute Te range because the impurity–host interaction in the dilute Te range is much weaker than that in the dilute O range.