| Super high frequency (SHF) acoustic measurement realizes the piezoelectric characterization in semiconducting material without the effect of electrical conducting. We have proposed the method for measuring shear and extensional electromechanical coupling coefficient k15 and k33 in a semiconducting crystal simultaneously, using Brillouin scattering method. In ZnO crystal, k15 value measured from measured acoustic velocities was in good accordance with the previously reported constant. We also have found large variety in effective piezoelectricity, implying variety of resistivity in the ZnO crystal. |