GW approximation is used to systematically revisit the image-potential band-gap narrowing at metal/semiconductor interfaces proposed by Inkson in the 1970's. Here we have questioned how the narrowing as calculated from quasi-particle energy spectra for the jellium/Si interface depends on rs of the jellium. The gap narrowing is found to only weakly depend on rs (i.e., narrowing ≃0.3 eV even for a large rs=6). Hence we can turn to smaller polarizability in the semiconductor side as an important factor in looking for larger narrowing.
@article{arxiv.cond-mat/0108412,
title = {Image-potential band-gap narrowing at a metal/semiconductor interface},
author = {Ryotaro Arita and Yoshiaki Tanida and Kazuhiko Kuroki and Hideo Aoki},
journal= {arXiv preprint arXiv:cond-mat/0108412},
year = {2009}
}