Author/Authors :
Novikov، نويسنده , , A.V and Andreev، نويسنده , , B.A and Vostokov، نويسنده , , N.V and Drozdov، نويسنده , , Yu.N and Krasilnik، نويسنده , , Z.F and Lobanov، نويسنده , , D.N and Moldavskaya، نويسنده , , L.D and Yablonskiy، نويسنده , , A.N and Miura، نويسنده , , M and Usami، نويسنده , , N and Shiraki، نويسنده , , Y and Valakh، نويسنده , , M.Ya and Mestres، نويسنده , , N and Pascual، نويسنده , , J، نويسنده ,
Abstract :
The effect of strain-driven alloying on sizes, shape and the photoluminescence (PL) properties of Ge(Si)/Si(001) self-assembled islands was investigated for temperatures of Ge deposition above 550 °C using atomic force microscopy (AFM), X-ray analysis, Raman spectroscopy. We found out that strain-driven Si diffusion into Ge/Si(001) self-assembled islands causes formation of an alloy in islands at these growth temperatures. An increase in the Ge content in the islands with a lower growth temperature results in a decrease of the pyramid-islands volume at which they transform to dome-islands. The energy of the optical transition in the free-standing islands was calculated using the observed values of the islands composition and elastic strain. The discrepancy between the calculated energy and the data observed from photoluminescence spectra is related to the changes of composition and height of the islands during Si overgrowth.
