Growth of noble metal nanostructures on the Bi nanoline surface: A first-principles study

Recent experiments suggest that self-assembled Bi nanolines on the passivated Si(0 0 1) surface can be used as templates to grow one-dimensional arrays of noble-metal (Au, Ag) nanoclusters. In order to ascertain this template effect, the gold atom on the H-terminated Si(0 0 1) surface and that on the Bi line are examined by density-functional methods. The calculation indicates that the gold atom enters a Si dimer on the H-terminated surface and the BiSi backbonds of a Bi dimer on the Bi line. The gold atom is 0.6 eV more stable on the Bi line than on the H-terminated surface. This result suggests the preferential adsorption of gold on the Bi line and confirms its template effect.