Angle-resolved photoemission from polar and nonpolar zinc oxide surfaces

We report the first angle-resolved photoemission spectra (ARPES) of polar and nonpolar surfaces of an ionic wurtzite-type compound semiconductor. We present experimental results obtained at photon energies between 20 and 80 eV on the polar zinc and oxygen and the nonpolar (101̄0) surfaces of ZnO and identify surface-induced features by comparison with recent theoretical calculations. Comparison between ARPES experiments and theory confirms the determination of the surface-atom geometry at ZnO(101̄0) by low-energy electron diffraction studies. © 1982 The American Physical Society.