MoS2 Transistors with Low Schottky Barrier Contact by Optimizing the Interfacial Layer Thickness

作者：Cheng, Jinbing^*; He, Junbao; Pu, Chunying; Liu, Congbin^*; Huang, Xiaoyu; Zhang, Deyang; Yan, Hailong; Chu, Paul K.

来源：Energies, 2022, 15(17): 6169.

DOI：10.3390/en15176169

• MoS2
• TiO2
• Schottky barrier
• contact resistance

Molybdenum disulfide (MoS2) has attracted great attention from researchers because of its large band gap, good mechanical toughness and stable physical properties; it has become the ideal material for the next-generation optoelectronic devices. However, the large Schottky barrier height (phi(B)) and contact resistance are obstacles hampering the fabrication of high-power MoS2 transistors. The electronic transport characteristics of MoS2 transistors with two different contact structures are investigated in detail, including a copper (Cu) metal-MoS2 channel and copper (Cu) metal-TiO2-MoS2 channel. Contact optimization is conducted by adjusting the thickness of the TiO2 interlayer between the metal and MoS2. The metal-interlayer-semiconductor (MIS) structure with a 1.5 nm thick TiO2 layer has a smaller Schottky barrier of 22 meV. The results provide insights into the engineering of MIS contacts and interfaces to improve transistor characteristics.