Because of atomic thickness and non-zero band gap, two-dimensional (2D) transition-metal dichalcogenides (TMDCs) have become promising candidates for post-silicon nanoelectronic materials. In the process of realizing 2D electronic devices for scaling down modern integrated circuitry, contact engineering suitable for large-scale manufacturing is crucial, but it remains elusive. Here, we demonstrated the large-scale chemical assembly of van der Waals heterostructures, with metallic 1T′-MoTe₂ on top of semiconducting 2H-MoTe₂, via a spatial-controlled phase-engineered growth method. Based on the heterophase structure, a large-scale field-effect transistor (FET) array was fabricated, in which 1T′-MoTe₂ was used as the contact electrode and 2H-MoTe₂ was used as the semiconducting channel. The vertical nanosheet-based heterophase FET exhibits ohmic contact behavior with distinctively low contact resistance. A total of 120 FETs were measured, and the measured average field-effect mobility was as high as 15 cm² V^–1 s^–1 (comparable to that of exfoliated single-crystalline 2H-MoTe₂). The superior electrical properties are attributed to the atomic clean interface that leads to an ideal contact between top 1T′- and bottom 2H-MoTe_2. This spatially controlled large-scale chemical assembly of vertical 2D metal–semiconductor heterostructures with low contact resistance provides a new route toward the practical application of high-performance electronic and optoelectronic devices based on the atomically thin TMDCs.

中文翻译：

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用于低接触电阻晶体管的大规模垂直1T′/ 2H MoTe ₂纳米片基异质结构

由于原子厚度和非零带隙，二维（2D）过渡金属二卤化金属（TMDC）已成为后硅纳米电子材料的有希望的候选者。在实现用于缩小现代集成电路规模的2D电子设备的过程中，适合大规模生产的接触工程至关重要，但仍然难以捉摸。在这里，我们通过空间控制的相工程生长方法，证明了范德华异质结构的大规模化学组装，其中金属1T'-MoTe ₂位于半导体2H-MoTe _2的顶部。基于异相结构，制备了大规模场效应晶体管（FET）阵列，其中1T'-MoTe ₂被用作接触电极，而2H-MoTe ₂被用作接触电极。被用作半导体通道。垂直的基于纳米片的异相FET表现出欧姆接触行为，且接触电阻极低。总共测量了120个FET，测得的平均场效应迁移率高达15 cm ² V ^–1 s ^–1（与片状单晶2H-MoTe _2相比）。优异的电性能归因于原子清洁界面，可在顶部1T'-和底部2H-MoTe ₂之间实现理想的接触_。 具有低接触电阻的垂直二维金属-半导体异质结构的空间控制大规模化学组装为基于原子薄TMDC的高性能电子和光电器件的实际应用提供了一条新途径。