Electronic properties of metal-induced gap states formed at alkali-halide/metal interfaces

TL;DR

This study investigates the spatial distribution and decay length of metal-induced gap states at alkali-halide/metal interfaces using NEXAFS, revealing dependence on the alkali halide's band gap and localization at anion sites.

Contribution

It provides new insights into how the decay length of MIGS varies with alkali halide properties and demonstrates site localization of MIGS at anion sites.

Findings

Decay length depends on alkali halide, larger for smaller band gaps.

MIGS localize at anion sites, confirmed by NEXAFS comparison.

Decay length is more influenced by the alkali halide than the metal.

Abstract

The spatial distribution and site- distribution of metal induced gap states (MIGS) are studied by thickness dependent near edge x-ray absorption fine structure (NEXAFS) and comparing the cation and anion edge NEXAFS. The thickness dependent NEXAFS shows that the decay length of MIGS depends on rather an alkali halide than a metal, and it is larger for alkali halides with smaller band gap energy. By comparing the Cl edge and K edge NEXAFS for KCl/Cu(001), MIGS are found to be states localizing at anion sites.