Molecular cluster of InP (001)-(2x1)

     It has been assumed that the surface reconstructions of InP (001) are the same as those on GaAs (001).  We have found that this is incorrect.  The striking difference between these two surfaces is best exemplified by the anion-rich reconstructions.  For GaAs (001), the stable As-rich surface exhibits a (2x4) unit cell, which is formed by two adjacent rows of dimers separated by trenches.  On this surface, each arsenic dangling bond is filled with a pair of electrons, while the gallium dangling bond is empty.  Conversely, we have discovered that phosphorous-rich InP (001) reconstructs into a (2x1) unit cell. This reconstruction is composed of a complete layer of buckled phosphorous dimers. We have also calculated the properties of a phosphorous-dimer cluster using density function theory.  This result is shown on the left.  The translucent contour represents the distribution of electron spin densities.  Compared with the arsenic dimer, the phosphorous dimer is buckled!  Furthermore, We have found that the dangling bond of the bucked-up atom is filled with a pair of electrons (green color), while the buckled-down atom is populated with only one electron (orange color). 
 

Copyright 1996-2007, R. F. Hicks, Semiconductor Material Chemistry and Plasma Processing Laboratory, University of California, Los Angeles.

For information, please contact Professor Robert F. Hicks
Last Modified May 21, 2007 05:58 PM