The properties of metal/semiconductor interfaces are generally described by the metal-induced gap states (MIGS) model. However, rare-earth (RE) arsenide interfaces are found not to follow the MIGS model in having very different Schottky barrier heights (SBHs) for the Ga- or As-terminations of polar (100) or (111) RE-As/GaAs interfaces. Density function supercell calculations find this effect is due to localized defect interface states located on the mis-coordinated atoms of these interfaces that pin their SBHs at very different energies for each termination as determined by the anion sublattice bonding. Band offsets of semiconducting ScN/GaN interfaces also depend on their termination as determined by the same defect interface states. This pinning mechanism dominates any MIGS mechanism when it arises. Nonpolar (110) interfaces have little change in bonding, so they have no defect interface states, and we find their SBH is pinned by MIGS at the charge neutrality level. Hence, traditional MIGS models should be extended to include such interface states in a more general description.

中文翻译：

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稀土砷化物/GaAs 界面处费米能级钉扎的终止依赖性

金属/半导体界面的特性通常由金属诱导间隙态 (MIGS) 模型描述。然而，发现稀土 (RE) 砷化物界面不遵循 MIGS 模型，对于极性 (100) 或 (111) RE-As/GaAs 的 Ga 或 As 终端具有非常不同的肖特基势垒高度 (SBH)接口。密度函数超晶胞计算发现这种效应是由于位于这些界面的错配原子上的局部缺陷界面状态，这些界面状态将它们的 SBH 固定在每个终止的非常不同的能量上，由阴离子亚晶格键合决定。半导体 ScN/GaN 界面的带偏移也取决于它们的终止，这是由相同的缺陷界面状态决定的。这种固定机制在任何 MIGS 机制出现时都占主导地位。非极性 (110) 界面的键合变化很小，因此它们没有缺陷界面状态，我们发现它们的 SBH 被 MIGS 固定在电荷中性水平。因此，应扩展传统 MIGS 模型以在更一般的描述中包含此类界面状态。