Guo Yuxi, Kang Lixing, Zeng Qingsheng, Xu Manzhang, Li Lei, Wu Yao, Yang Jiefu, Zhang Yanni, Qi Xiaofei, Zhao Wu, Zhang Zhiyong, Liu Zheng
School of Information Science and Technology, Northwest University, Xi'an, Shaanxi 710127, People's Republic of China. School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
Nanotechnology. 2021 Mar 19;32(23):235204. doi: 10.1088/1361-6528/abe963.
The primary challenge for the widespread application of two-dimensional (2D) electronics is to achieve satisfactory electrical contacts because, during the traditional metal integration process, difficulties arise due to inevitable physical damage and selective doping. Two-dimensional metal-semiconductor junctions have attracted attention for the potential application to achieve reliable electrical contacts in future atomically thin electronics. Here we demonstrate the van der Waals epitaxial growth of 2D NiTe-MoS metal-semiconductor vertical junctions where the upper NiTe selectively nucleates at the edge of the underlying MoS. Optical microscopy (OM), scanning electron microscopy (SEM), atomic force microscopy (AFM), and scanning transmission electron microscope (STEM) studies confirmed that NiTe-MoS metal-semiconductor vertical junctions had been successfully synthesized. The electrical properties of the NiTe-contacted MoS field-effect transistors (FETs) showed higher field-effect mobilities (μ ) than those with deposited Cr/Au contacts. This study demonstrates an effective pathway to improved MoS transistor performance with metal-semiconductor junctions.
二维（2D）电子学广泛应用面临的主要挑战是实现令人满意的电接触，因为在传统的金属集成过程中，由于不可避免的物理损伤和选择性掺杂会出现困难。二维金属-半导体结因其在未来原子级薄电子学中实现可靠电接触的潜在应用而受到关注。在此，我们展示了二维NiTe-MoS金属-半导体垂直结的范德华外延生长，其中上层的NiTe在下层MoS的边缘选择性成核。光学显微镜（OM）、扫描电子显微镜（SEM）、原子力显微镜（AFM）和扫描透射电子显微镜（STEM）研究证实，NiTe-MoS金属-半导体垂直结已成功合成。与沉积Cr/Au接触的MoS场效应晶体管（FET）相比，NiTe接触的MoS场效应晶体管的电学性能表现出更高的场效应迁移率（μ）。这项研究展示了一种通过金属-半导体结提高MoS晶体管性能的有效途径。
