Abstract
X-ray photoelectron spectroscopy is used to measure the valence-band offset in situ for GaAs/AlAs(100) heterojunctions grown by molecular-beam epitaxy. and core-level to valence-band-edge binding-energy differences are measured in GaAs(100) and AlAs(100) samples, respectively, and the to core-level binding-energy difference is measured in GaAs-AlAs(100) and AlAs-GaAs(100) heterojunctions. (Note that GaAs-AlAs indicates a heterojunction with GaAs grown on top of AlAs; GaAs/AlAs refers collectively to both growth sequences.) Measurements of the to core-level energy separations indicate that the band offset for GaAs/AlAs(100) is commutative; the value we obtain is eV. Our observation of commutativity is believed to be a consequence of the high quality of our GaAs/AlAs(100) heterojunctions, and of the inherent commutativity of the band offset in this heterojunction system.
- Received 16 May 1988
DOI:https://doi.org/10.1103/PhysRevB.38.12764
©1988 American Physical Society