We report x-ray photoelectron spectroscopy experimental results on band offsets at Ge/Si(100)2 x 1 interfaces grown by hydrogen and Sb-surfactant mediated epitaxy. For Ge deposited at 400 degrees C in Si(100)2 x 1, the valence band discontinuity was of 0.72 +/- 0.07 eV. Using atomic hydrogen and a Sb-monolayer mediated growth, we obtained values of 0.75 +/- 0.07 and 0.69 +/- 0.07 eV. Our data show that the surfactant Ge layer strain induced effects on the modification of band offsets are surprisingly negligible.
Andras Kis, Dumitru Dumcenco, Olivier Renault, Dmitrii Unuchek, Hokwon Kim, Nicolas Chevalier
Alfredo Pasquarello, Igor Reshetnyak, Thomas Bischoff