By using an in-house nonequilibrium Green’s function (NEGF)-based ab initio simulator, we investigate the physical mechanisms driving the Sb( ${01}\overline {{1}}{2}$ )–MoS2 system to exhibit the lowest reported contact resistance, ${R}_{C}={42} \Omega \cdot \mu \text{m}$ , to the 2-D semiconductor MoS2. We can find that the transport from the hybridized bands in the Sb–MoS2 heterojunction is quite ineffective and that the back-gate-induced doping of MoS2 in the contact region is crucial to explain the experiments. In fact, by accounting in our ab initio simulations for the presence of a back gate according to the experiments, it is possible to match the band structure of the MoS2 in the Sb–MoS2 heterojunction with that of the external MoS2 layer, which drastically increases the electronic transmission throughout the contact, and ultimately pushes ${R}_{C}$ close to the quantum limit. Furthermore, we extend the applicability of our previously demonstrated simulation methodology and thus investigate a field-effect transistors (FETs)-like device including an ab initio description of the carrier injection at the Sb–MoS2 contact.

中文翻译：

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通过从头算输运模拟重新解释 Sb–MoS2 欧姆接触中的低电阻

通过使用基于内部非平衡格林函数 (NEGF) 的从头算模拟器，我们研究了驱动 Sb( ${01}\上划线{{1}}{2}$ )–MoS2 系统表现出最低的接触电阻， ${R}_{C}={42} \Omega \cdot \mu \text{m}$ ，到二维半导体MoS2。我们可以发现，Sb-MoS2 异质结中杂化能带的传输非常无效，并且接触区域中背栅诱导的 MoS2 掺杂对于解释实验至关重要。事实上，根据实验，通过从头算模拟考虑背栅的存在，可以将 Sb-MoS2 异质结中 MoS2 的能带结构与外部 MoS2 层的能带结构相匹配，从而大大增加整个接触过程中的电子传输，并最终推动 ${R}_{C}$接近量子极限。此外，我们扩展了之前演示的模拟方法的适用性，从而研究了类似场效应晶体管（FET）的器件，包括 Sb-MoS2 接触处载流子注入的从头开始描述。