Hefei National Laboratory for Physical Sciences at the Microscale, CAS Centre for Excellence Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China , Hefei, Anhui 230026, China.
Langmuir. 2018 Feb 27;34(8):2647-2653. doi: 10.1021/acs.langmuir.7b03801. Epub 2018 Feb 15.
Using first-principles calculations, we perform a comprehensive study of representative metal (Al, Sc, Pd, Ag, Pt, and Au) contacts with monolayer (ML) and bilayer (BL) CN, which is a low-cost and easily synthesized two-dimensional metal-free semiconductor. Through analyzing the geometries, electronic structures, and Fermi level pinning effects of CN-metal interfaces, we find metals Al and Sc top contact with ML CN are Ohmic, which can be ascribed to the strong interactions and large orbital overlaps. Besides, owing to weak van der Waals interactions at interfaces and low work functions of metallic materials, Ohmic contacts can also be realized in ML/BL CN-Ag and BL CN-Sc systems. Furthermore, it was also predicted that CN-Sc and CN-Ag systems still maintain Ohmic features along the edge contacts. Given the lower resistance of the Ag electrode, the CN-Ag electrode should be a more attractive electrode in practical applications. These predictions not only provide insights into the fundamental properties of the layered CN-metal interfaces but also pave way to design high-performance devices using low-cost layered CN.
利用第一性原理计算，我们对具有代表性的金属（Al、Sc、Pd、Ag、Pt 和 Au）与单层（ML）和双层（BL）CN 的接触进行了全面研究，这是一种低成本且易于合成的二维无金属半导体。通过分析 CN-金属界面的几何形状、电子结构和费米能级钉扎效应，我们发现金属 Al 和 Sc 与 ML CN 的顶接触是欧姆接触，这归因于强相互作用和大轨道重叠。此外，由于界面处的范德华相互作用较弱和金属材料的低功函数，ML/BL CN-Ag 和 BL CN-Sc 系统也可以实现欧姆接触。此外，还预测了 CN-Sc 和 CN-Ag 系统在边缘接触处仍保持欧姆特性。由于 Ag 电极的电阻较低，因此在实际应用中，CN-Ag 电极应该是更具吸引力的电极。这些预测不仅为层状 CN-金属界面的基本特性提供了深入的了解，而且为使用低成本层状 CN 设计高性能器件铺平了道路。
