Symmetry of Wurtzite

Abstract

The symmetry analysis of wurtzite, performed originally by Dresselhaus at the origin of the Brillouin zone, is extended. A method is employed at the zone boundaries which is considerably simpler than the standard procedure. Optical selection rules for band-to-band transitions in the neighborhood of k=0 are re-examined. It is found that light polarized perpendicular to the $c$ axis should be absorbed more strongly than light polarized along the $c$ axis, independently of the symmetry types of the initial and final states, unless they have the same symmetry, which is unlikely. This result is in agreement with experiment for CdS and ZnS.