标题： 零偶极肖特基接触：二维半导体的同系金属接触 显示英文标题

标题： Zero-Dipole Schottky Contact: Homologous Metal Contact to 2D Semiconductor

摘要： 金属接触与二维半导体的能带对齐通常由于界面偶极子的形成和金属诱导间隙态（MIGS）等非理想因素而偏离理想的肖特基-莫特（SM）规则。 尽管可以通过范德华（vdW）接触工程技术强烈抑制MIGS，但由于两种接触材料的电负性差异，界面偶极子很难消除。 在这里，我们展示了当二维半导体MoSi$_2$N$_4$与同源金属对比物MoSi$_2$N$_4$(MoN)$_n$ ($n = 1-4$) 接触时，界面偶极子可以被实际消除。 SiN外层同时存在于MoSi$_2$N$_4$和 MoSi$_2$N$_4$(MoN)$_n$中，在接触界面产生几乎相等的电荷“推回”效应。这种几乎对称的电荷重新分布导致界面处没有净电子转移，从而形成\emph{零偶极子}接触。 有趣的是，我们证明即使在极端近距离接触的情况下，当MoSi$_2$N$_4$（MoN）被任意推向MoSi$_2$N$_4$，且层间距离极小，界面偶极子仍几乎为零。 这种\emph{零偶极子}肖特基接触是一个特殊的情况，其中通常仅在非相互作用状态下出现的SM规则，在MoSi$_2$N$_4$/MoSi$_2$N$_4$(MoN)$_n$范德华异质结中表现出来，尽管组成单层之间存在强烈的相互作用。 基于改变MoSi$_2$N$_4$/MoSi$_2$N$_4$(MoN) vdWH中的层间距离，提出了一个压力传感模型。 显示英文摘要

摘要： Band alignment of metal contacts to 2D semiconductors often deviate from the ideal Shottky-Mott (SM) rule due to the non-ideal factors such as the formation of interface dipole and metal-induced gap states (MIGS). Although MIGS can be strongly suppressed using van der Waals (vdW) contact engineering, the interface dipole is hard to eliminate due to the electronegativity difference of the two contacting materials. Here we show that interface dipole can be practically eliminated in 2D semiconducting MoSi$_2$N$_4$ when contacted by its homologous metallic counterpart MoSi$_2$N$_4$(MoN)$_n$ ($n = 1-4$). The SiN outer sublayers, simultaneously present in both MoSi$_2$N$_4$ and MoSi$_2$N$_4$(MoN)$_n$, creates nearly equal charge `push-back' effect at the contact interface. This nearly symmetrical charge redistribution leads to zero net electron transfer across the interface, resulting in a \emph{zero-dipole} contact. Intriguingly, we show that even in the extreme close-contact case where MoSi$_2$N$_4$(MoN) is arbitrarily pushed towards MoSi$_2$N$_4$ with extremely small interlayer distance, the interface dipole remains practically zero. Such \emph{zero-dipole} Schottky contact represents a peculiar case where the SM rule, usually expected to occur only in the non-interacting regime, manifests in MoSi$_2$N$_4$/MoSi$_2$N$_4$(MoN)$_n$ vdWH even though the constituent monolayers interact strongly. A model for pressure sensing is then proposed based on changing the interlayer distance in MoSi$_2$N$_4$/MoSi$_2$N$_4$(MoN) vdWH.