Contact Effect of ReS 2 /Metal Interface

• Published in: ACS applied materials & interfaces Vol. 9; no. 31; pp. 26325 - 26332
• Main Authors: Park, Jae Young, Joe, Hang-Eun, Yoon, Hyong Seo, Yoo, SangHyuk, Kim, Taekyeong, Kang, Keonwook, Min, Byung-Kwon, Jun, Seong Chan
• Format: Journal Article
• Language: English
• Published: United States 09-08-2017
• Subjects: ReS2; contact resistance; rhenium disulfide; Kelvin probe force microscopy; density functional theory; field-effect transistor; Schottky diode; TMDc
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.7b06432

Rhenium disulfide (ReS
) has attracted immense interest as a promising two-dimensional material for optoelectronic devices owing to its outstanding photonic response based on its energy band gap's insensitivity to the layer thickness. Here, we theoretically calculated the electrical band structure of mono-, bi-, and trilayer ReS
and experimentally found the work function to be 4.8 eV, which was shown to be independent of the layer thickness. We also evaluated the contact resistance of a ReS
field-effect transistor using a Y-function method with various metal electrodes, including graphene. The ReS
channel is a strong n-type semiconductor, thus a lower work function than that of metals tends to lead to a lower contact resistance. Moreover, the graphene electrodes, which were not chemically or physically bonded to ReS
, showed the lowest contact resistance, regardless of the work function, suggesting a significant Fermi-level pinning effect at the ReS
/metal interface. In addition, an asymmetric Schottky diode device was demonstrated using Ti or graphene for ohmic contacts and Pt or Pd for Schottky contacts. The ReS
-based transistor used in this study on the work function of ReS
achieved the possibility of designing the next-generation nanologic devices.