Evidence for interface defect states in amorphous Fe–ZnSe heterostructures

Electrical transport measurements on bilayers of Fe and amorphous ZnSe are performed. The samples are grown at low temperatures in order to achieve amorphous layers. The annealing behavior observed with the temperature dependence of the conductivity reveals localized electron states to be present at the interfaces between Fe and ZnSe. The density of interface defect states is found to be N(EF)≈1013 eV−1 cm2. These interface states disappear upon annealing at 250 K.