Band-Offset Analysis of Atomic Layer Deposition La₂O₃ on GaAs(111), (110), and (100) Surfaces for Epitaxial Growth

In this paper, we measured band offsets for La2O3 prepared by atomic layer deposition on GaAs(111), (110), and (100) surfaces. La2O3 grows epitaxially on GaAs(111) with very low interfacial defect density and exhibits a band offset that is predicted for defect-free interfaces by the metal-induced gap state theory. On the other hand, the polycrystalline La2O3 deposited on GaAs(110) and (100) shows band offsets close to the values predicted for Fermi-level pinning. In this way, band offsets can qualitatively estimate interfacial defect levels.