Electrical properties of ZnO single crystals annealed in a zinc atmosphere

The electrical conductivity and the Hall coefficient of ZnO single crystals annealed in a zinc atmosphere after growth were measured in a temperature range from 77 K to 1000 K. The results are compared with those of ZnO crystals from the zinc rich phase boundary. A shallow level with an activation energy at about 15 meV dominates in both groups of samples. Its concentration was found to correlate directly with the degree of non-stoichiometry.