The electronic structure of metallic thin films grown on a semi-infinite substrate is investigated within the framework of a tight-binding model by the Green-function-matching method. An exact expression for the full Green function of the complete system is derived. It includes accurately the reduced dimensionality of the system and yields the complete description of the electronic properties: quantum-well states, resonances, and continuous substrate bands. Ag/Au(001), Co/Cu(001), and their complementary structures are selected as model systems. The calculation shows the existence of both sp and d derived quantum-well states, which are spin and symmetry dependent. The confining potential arises from the energy mismatch between thin-film overlayer and substrate bands with the same spin and symmetry. The thickness dependence of the quantum-well states’ binding energy provides a mechanism to tailor the density of states at the Fermi level. © 1996 The American Physical Society.

• Received 28 July 1995

DOI:https://doi.org/10.1103/PhysRevB.53.13583