New surface phases for potassium adatoms on cleaved Si(111)

[摘要] In a previous study (B. Reihl and K.O. Magnusson, Phys. Rev. B 42 (1990) 11839) no change was observed in the LEED pattern from the 2x1 pattern of the clean Si(lll) surface upon potassium adsorption, In contrast to this paper, we observe six surface phases during room temperature dosing of K on the cleaved Si(lll) surface. In addition, Ne observe a 3x1 pattern on the cleaved K/Si(111) surface upon annealing. This paper will provide photographs of the new phases observed with LEED. It also will set limits on the K coverage required far these phases using results from photoemission and secondary electron cutoff measurements. Tentative models for these surfaces will be proposed. These new LEED results show a more complex interaction between K and the cleaved Si(111) surface than previously thought and hopefully will encourage further exploration of adsorption on the cleaved Si(lll) surface. (C) 1997 Elsevier Science B.V.

[发布日期] 1997-05-15

[关键词] alkali metals;low energy electron diffraction (LEED);low index single crystal surfaces;metal-semiconductor interfaces;silicon;surface thermodynamics (including phase transitions);work function measurements