P-Type ohmic contact to MoS2via binary compound electrodes. Issue 8 (15th February 2023)

• Record Type: Journal Article
• Authors: Ren, Yin-Ti; Chen, Yuan-Tao; Hu, Liang; Wang, Jiang-Long; Gong, Peng-Lai; Zhang, Hu; Huang, Li; Shi, Xing-Qiang
• Is Part Of: Journal of materials chemistry. Volume 11:Issue 8(2023)
• Page Start: 3119
• Page End: 3126
• Publication Date: 2023-02-15
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d2tc05088a
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : Both n- and p-type ohmic contact to MoS2 can be obtained via different CuS surfaces, due to the weak metallicity and large work function variation of the CuS surfaces, and due to interface quasi-bonding between CuS and MoS2 . Abstract : Electronic contacts to two-dimensional (2D) semiconductors, e.g., MoS2, of both n- and p-type, are important for complementary metal-oxide–semiconductor logic circuitry. Here, via systematic first-principles density-functional theory calculations, we report that both n - and p-type ohmic contact to MoS2 can be obtained via different surfaces of the same material, the binary compound covellite (CuS). The weak metallicity is helpful to suppress the metal-induced gap states and hence suppress the Fermi-level pinning effect. Importantly, the work functions of different CuS surfaces varies a lot from 3.8 eV to 5.8 eV. The higher work function F(Cu–S) surface forms a p-type contact to MoS2, and the p-type Schottky barrier height (SBH) can be reduced by increasing the layer number of the MoS2 . The origin of the p-type SBH reduction can be attributed to quasi-bonding both at the F(Cu–S)/MoS2 interface and between MoS2 layers, which synergistically shifts the valence band edge up. Due to the large work function variation of CuS surfaces and interface quasi-bonding, p-type ohmic contact to monolayer MoS2 can be obtained with the P(S) surface. Additionally, the P(Cu)/monolayer MoS2 junction forms an n-type ohmic contact because of the large work function variation. The widely tunable SBH and contact types of the binary compound CuS/MoS2 junctions make them promising for high-efficiency electronic and optoelectronic devices.