Indirect adatom interactions via sp-hybrid semiconductors

The Anderson-Newns model is used to study substrate-mediated interactions b etween adatoms on sp-hybrid semiconductors. The Dyson-equation technique is employed to obtain the adatom Green function and density of states in term s of Chebyshev polynomials. Expressions for the chemisorption and interacti on energies, plus charge transfer, as functions of adatom separation, d, ar e derived in a self-consistent manner. Results are provided for H-H adsorpt ion on the (100) and (111) faces of Si and Ge. The H-H indirect interaction is shown to obey a d(2) [or d(-3)] law for the (100) [or (111)] faces. (C) 2000 Elsevier Science B.V. All rights reserved.