Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
Nanoscale. 2017 Dec 21;10(1):319-327. doi: 10.1039/c7nr07403d.
Tin(ii) monosulfide (SnS) is a layered, anisotropic material that is of interest as a two-dimensional semiconductor for opto-electronic, thermoelectric, and piezoelectric applications. In this study, the effect of work function on contact behavior was investigated. Ni/Au, Pd/Au, Cr/Au, and Ti/Au contacts were fabricated onto individual, solution-synthesized, p-type SnS nanoribbons. The lower work function metals (Cr and Ti) formed Schottky contacts, whereas the higher work function metals (Ni and Pd) formed ohmic or semi-ohmic contacts. Of the ohmic contacts, Ni was found to have a lower contact resistance (∼10 Ω cm or lower) than Pd (∼10 Ω cm or lower). Both the calculated Schottky barriers (0.39 and 0.50 eV) for Cr and Ti, respectively, and the ohmic behavior for Ni and Pd agree with behavior predicted by Schottky-Mott theory. The results indicate that high work function metals should be considered to form low resistance contacts to SnS multilayers.
二硫化锡（SnS）是一种具有层状各向异性的材料，作为二维半导体，在光电、热电和压电等领域具有应用前景。在这项研究中，研究了功函数对接触行为的影响。通过溶液合成法制备了 p 型 SnS 纳米带，并在其上制作了 Ni/Au、Pd/Au、Cr/Au 和 Ti/Au 接触。较低功函数的金属（Cr 和 Ti）形成肖特基接触，而较高功函数的金属（Ni 和 Pd）形成欧姆或半欧姆接触。对于欧姆接触，发现 Ni 的接触电阻（约 10 Ω cm 或更低）低于 Pd（约 10 Ω cm 或更低）。Cr 和 Ti 的计算肖特基势垒（分别为 0.39 和 0.50 eV）以及 Ni 和 Pd 的欧姆行为均与肖特基-莫特理论的预测一致。结果表明，应该考虑使用高功函数金属来形成 SnS 多层结构的低电阻接触。
