Photoemission and theoretical studies of GaAs(111) and (1-bar 1-bar 1-bar) surfaces: Vacancy models.

Abstract

Experimental and theoretical results for the Ga- and As-terminated GaAs(111) 2\ifmmode\times\else\texttimes\fi{}2 reconstructed surfaces are presented. For the Ga-terminated (111) surface, tight-binding calculations of total density of electronic states for the vacancy model are in good agreement with results from angle-integrated photoemission measurements. Comparison of experiment and theory also demonstrates that the vacancy model is not suitable for the As-terminated (1\ifmmode\bar\else\textasciimacron\fi{} 1\ifmmode\bar\else\textasciimacron\fi{} 1\ifmmode\bar\else\textasciimacron\fi{}) surface. This is in agreement with the prediction that vacancy formation is energetically unfavorable at this surface.