SURFACE-STRUCTURE, BONDING, AND DYNAMICS - UNIVERSALITY OF ZINC BLENDE (110) POTENTIAL-ENERGY SURFACES

Using a tight-binding, total energy (TBTE) model we examine the hypothesis that the potential energy surfaces (PES) describing the (110) cleavage faces of the tetrahedrally coordinated zinc blende structure compound semiconductors exhibit a common "universal" form if expressed in terms of suitably scaled parameters. TBTE calculations on both III-V and II-VI compounds reveal a linear scaling with bulk lattice constant of the geometric parameters of the reconstructed surfaces. This scaling is analogous to that found using low-energy, electron-diffraction surface-structure determination. The surface atomic force constants (found from a TBTE calculation) also scale monotonically with the lattice constant. Using TBTE models proposed previously for GaP, GaAs, GaSb, InP, InSb, and ZnSe, we find that the force constants scale as the inverse square of the bulk lattice constant. These results suggest that if distances are measured in units of the bulk lattice constant, the PES may be a universal function for the cleavage surfaces of zinc blende structure compound semiconductors, on average, with small fluctuations from this average occurring in individual materials.