Determination of wurtzite GaN lattice polarity based on surface reconstruction

Abstract

We identify two categories of reconstructions occurring on wurtzite GaN surfaces, the first associated with the N face, (0001̄), and the second associated with the Ga face, (0001). Not only do these two categories of reconstructions have completely different symmetries, but they also have different temperature dependence. It is thus demonstrated that surface reconstructions can be used to identify lattice polarity. Confirmation of the polarity assignment is provided by polarity-selective wet chemical etching of these surfaces.