SELF-CONSISTENT CALCULATIONS OF WORK FUNCTION, SHOTTKY BARRIER HEIGHTS AND SURFACE ENERGY OF METAL NANOFILMS IN DIELECTRIC CONFINEMENT

Abstract

We suggest a method for the self-consistent calculations of characteristics of metal films indielectric environment. Within a modified Kohn-Sham method and stabilized jellium model, themost interesting case of asymmetric metal-dielectric sandwiches is considered, for which dielectricmedia are different from the two sides of the film. As an example, we focus on Na, Aland Pb. We calculate the spectrum, electron work function, and surface energy of polycrystallineand crystalline films placed into passive isolators. We find that a dielectric environmentgenerally leads to the decrease of both the electron work function and surface energy. It isrevealed that the change of the work function is determined only by the average of dielectricconstants from both sides of the film. We introduced the position of a conductivity band in thedielectric as a parameter in the self-consistency procedure and performed calculations, usingimage potential, for the aluminum film with ideal interfaces vacuum/Al(111)/SiO 2 ,vacuum/Al(111)/AlO and sandwiches SiO/Al(111)/AlO. As a result, effective potential profilesand the Schottky barrier heights were calculated.