Clustering in ZnBVI-rich SrxZn1−xOyBVI1−y (BVI = S, Se, Te) highly mismatched alloys

Abstract

Abstract The clustering properties of dilute highly mismatched semiconductor alloys attract considerable interest recently. Non-homogeneity of clusters and strong internal strains are the main disadvantages of such alloys. 4O10Sr clustering in ZnBVI-rich SrxZn1−xOyBVI1−y (BVI = S, Se, Te) up to 800 °C are presented. Reduction of the internal strains is a cause of the cluster formation. The cohesive energies, stiffness coefficients, bond stretching and bond bending elastic constants of zinc blende SrS and SrSe are estimated. All or almost all oxygen atoms should be in 4O10Sr clusters up to 800 °C in SrxZn1−xOyS(Se)1−y if alloy content is y > 1 × 10−3 (5 × 10−4) and x > 4y. SrxZn1−xOyTe1−y are completely 4O10Sr cluster ordered with contents from the ultra dilute limit (x > 1 × 10−4, y = 1 × 10−4) up to 800 °C. The densities of 4O10Sr clusters were calculated by minimization of the free energy. The binding energy of the electron bound to the oxygen tetrahedron in ZnTe:O at RT is estimated. The obtained results demonstrate that SrxZn1−xOyBVI1−y are promising semiconductors with the reduced internal strains and identical polyatomic clusters containing oxygen tetrahedrons.