FIRST-PRINCIPLES CALCULATION OF ELECTRON SURFACE-STATES OF THE ZINCBLENDE GAN(110) SURFACE

The surface electronic structure for an unrelaxed as well as relaxed z inc-blende GaN(110) surface has been investigated within the local den sity approximation of density functional theory, employing a first-pri nciples full-potential self-consistent linear muffin-tin orbital (LMTO ) method and a supercell approach. Intrinsic surface states appear in the fundamental energy gap for an unrelaxed surface. These intrinsic g ap surface states shift towards the bulk valence and the conduction ba nd region on considering the relaxation of the surface atoms. Orbitals characters of surface states at Gamma, X, M, X'' symmetry points have been identified. Several localized and resonance states are predicted for the first time in different energy regions. (C) 1998 Elsevier Sci ence B.V. All rights reserved.