The differences of total energies of the ⟨110⟩ Si0.5Ge0.5 nanowires passivated by X (X = F, Cl, or H) as a function of the configurations. Si/Ge/X atoms are represented by yellow/pink/white balls. Potential energy profiles and transition state structures for (b) H desorption and (c) F desorption from SiGe nanowire. The insets show the bond length's variations of H–H, Si–H, F–F, and Si–F with the reaction coordinates. The nanowire with four unit cells is used in the calculation.
The variations of surface Si atoms ratio as a function of temperature, for X-passivated Si x Ge1-x nanowires: (a) Si0.125Ge0.875; (b) Si0.25Ge0.75; (c) Si0.375Ge0.625; (d) Si0. 5Ge0. 5. The black squares/red circles/blue triangles indicate the passivants of F, Cl, and H, respectively.
The distributions of Si ratio in a Si0.5Ge0.5 films as a function of temperature: (a) with H passivants; (b) with F passivants. The Si ratio of the layer 1, 2, 3, 5 as a function of temperature and passivants are shown in (c) and (d).
Stabilities of the ⟨110⟩ Si0.5Ge0.5 nanowires of various shape and diameter. (a) phase diagram of ground states for various μF; (b) the formation energies at μF = −3.4 eV, with the energies of SiGe bulk and corresponding SiF4/GeF4 molecules shown in blue and black lines, respectively.
Band structures and charge distributions of CBE and VBE of the stable Si x Ge1-x nanowires passivated by F atoms: (a) Si0.5Ge0.5; (b) Si0.375Ge0.625. All the valence bands maximums are shifted to zero.
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