Evidence of the absence of the clear electron spin-resonance signal from Ge dangling bonds (DBs) at Ge/GeO2 interfaces is explored by means of first-principles electronic-structure calculations. Comparing the electronic structures of the DBs at Si/SiO2 and Ge/GeO2 interfaces, we found that the electronic structure of the Ge-DB is markedly different from that of the Si-DB; the Ge-DB states does not position in the energy band gap of the Ge/GeO2 interface while the Si-DB states clearly appears. In addition, the charge density distribution of the Ge-DB state spreads more widely than that of the Si-DB state. These features are explained by considering the metallic properties of the bonding network of the Ge/GeO2 interface and the structural deformation of the Ge bulk at the Ge/GeO2 interface due to the lattice-constant mismatch.
@article{arxiv.0911.5608,
title = {First-principles electronic-structure calculation of dangling bonds at Si/SiO$_2$ and Ge/GeO$_2$ interfaces},
author = {Tomoya Ono and Shoichiro Saito},
journal= {arXiv preprint arXiv:0911.5608},
year = {2010}
}