SYNCHROTRON-RADIATION PHOTOEMISSION-STUDY OF GE ZNS(111) HETEROJUNCTION/

The band lineup at the Ge/ZnS(111) interface has been studied by synch rotron radiation photoemission spectroscopy. The experimental results indicate that the deposition of Ge films by evaporation is a two-dimen sional growth at the initial stage. With the growing of Ge overlayer, surface S atoms diffuse into Ge overlayer and react with Ge atoms at t he interface. We derive the valence band offsets of 1.94 +/- 0.1 eV an d 2.23 +/- 0.1 eV for Ge/ZnS heterojunctions grown at 200 degrees C an d room temperature, respectively. The results are in good agreement wi th theoretical predictions.