The mechanical strength of bulk single crystal wurtzite ZnO was investigated at elevated temperatures by means of compressive deformation. The yield stress of

ZnO at 650 to 850C was found to be around 10 to 20MPa, i.e., much lower than that of GaN, a typical wide band-gap semiconductor. On the basis of the observed temperature dependence of yield stress, the activation energy for dislocation motion at elevated temperatures in ZnO was deduced to be 0.7 to 1.2eV, which follows the relation of activation energy for dislocation motion versus band-gap energy known in a variety of semiconductors.

High-Temperature Strength and Dislocation Mobility in the Wide Band-Gap ZnO: Comparison with Various Semiconductors. Yonenaga, I., Koizumi, H., Ohno, Y., Taishi, T.: Journal of Applied Physics, 2008, 103[9], 093502