Amorphous Si/Ge heterojunctions: Band discontinuities and local order studied by photoemission spectroscopy

We present a study of the heterojunctions formed when Ge is deposited onto a variety of atomically clean Si-based amorphous substrates. With the use of synchrotron-radiation photoemission spectroscopy we are able to measure the valence-band discontinuities and also probe the local order at the interface. We find that linear theories of band discontinuities are valid to an accuracy of 0.2 eV for these materials. © 1988 The American Physical Society.