Geometrical and electronic properties of nanosize semiconductor Pt2Sin (n=10-20) material: A density functional theory investigation

Growth-pattern behaviors, relative stabilities, geometrical and electronic properties of nanosize Pt2Sin (n = 10-20) semiconductor material are investigated by using density functional methods. Optimized geometries exhibit that transition metal Pt-2 is doped on small-size opened cage-like silicon frame with n = 10-15 while Pt-2 is encapsulated into close cage-like Si frame with n = 16-20; Based upon the calculated relative stabilities, the particular stable Pt2Si16 unit is discovered. Furthermore, the dominant growth patterns of Pt2Sin (n = 10-20) are based upon the stable pentagonal prism PtSi10 unit. Interestingly, the critical size of geometry transition with bimetal atoms being completely encapsulated into silicon frame is determined to be 15. The calculated natural population analysis shows that charges are transferred from Si-n frames to Pt-2 atoms. Additionally, Pt2Si19 cluster has the smallest HOMO-LUMO gap and the strongest chemical activity.