Self-organised wires and antiwires on semiconductor surfaces

Identification of intermediate linear structure formed during Bi/Si(001) surface anneal

“…The physical height difference found from tightbinding and DFT simulations is about 70 pm. However, simulated STM of the Haiku and Miki models [13,15] find that at a simulated bias of À1.5 V, the apparent heights are 140 pm and 55 pm, respectively, a difference of 85 pm, which is larger than the physical height difference from modelling, but smaller than that found by STM at À2.3 V. Caution should be used in comparing experimental and theoretical results, especially in this system where the apparent height varies strongly with the sample bias voltage. However, the simulation does show that the Miki Fig.…”

“…The Naitoh model has been calculated to be considerably less stable than the (2 · n) overlayer [11,22] and is not expected to be present on the surface. However, the Miki model has continued to attract attention from theoretical groups, as a possible candidate for the Bi nanoline [9,[13][14][15]22]. While its incorrect registry with the substrate disqualifies it as a candidate structure for the nanoline, its low energy and the natural cooperative stress relief mechanism of the tensile 1DV and the compressive Bi dimers, suggest that it might be present on a mixed Bi:Si surface.…”

“…The structure of the Bi nanoline is rather complex, comprising five and seven membered rings of subsurface silicon, capped by a pair of Bi dimers [10] (This structure was named the Haiku model 2 ). However, while the structure of the Bi nanoline has been studied in some detail by several theoretical groups [9][10][11][12][13][14][15], the mechanism for nucleation and growth of this complex structure remains unknown. It has been suggested recently that nucleation occurs from rows of Bi dimers which fill in missing dimer trenches [16,17].…”