Surface polarity and symmetry in semiconducting compounds

The polarity of the crystallographic surfaces of semiconducting compounds with the sphalerite and wurtzite structures results in gross differences in macroscopic chemical, mechanical and crystal growth behaviour which are reviewed. The asymmetry of the orthogonal 1 1 0 directions in {100} surfaces of sphalerite structure materials is manifested in phenomena arising from {1 1 1}A-B differences. To treat these phenomena the surface polarity index and the singular surface polyhedra for sphalerite- and wurtzite-structure semconducting compounds are introduced.