Graphene/MoS2 Hybrid Technology for Large-Scale Two-Dimensional Electronics

• Published in: Nano letters Vol. 14; no. 6; pp. 3055 - 3063
• Main Authors: Yu, Lili, Lee, Yi-Hsien, Ling, Xi, Santos, Elton J. G, Shin, Yong Cheol, Lin, Yuxuan, Dubey, Madan, Kaxiras, Efthimios, Kong, Jing, Wang, Han, Palacios, Tomás
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 11.06.2014
• Subjects: Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Electron states; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Fullerenes and related materials; diamonds, graphite; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Methods of electronic structure calculations; Physics; Specific materials; Surface double layers, schottky barriers, and work functions; flexible and transparent; Molybdenum disulfide; field-effect transistor; integrated circuits; heterostructure; graphene; Work functions; Transport properties; Schottky barriers; Doping; Theoretical study; Boron nitride; Optical systems; Flexibility; AND circuit; CVD; Graphene; Transition elements; Transistor channel; Heterojunctions; Density functional method; Ohmic contacts; Barrier height; Electrostatics; Transparent material; Heterostructures
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl404795z

Two-dimensional (2D) materials have generated great interest in the past few years as a new toolbox for electronics. This family of materials includes, among others, metallic graphene, semiconducting transition metal dichalcogenides (such as MoS2), and insulating boron nitride. These materials and their heterostructures offer excellent mechanical flexibility, optical transparency, and favorable transport properties for realizing electronic, sensing, and optical systems on arbitrary surfaces. In this paper, we demonstrate a novel technology for constructing large-scale electronic systems based on graphene/molybdenum disulfide (MoS2) heterostructures grown by chemical vapor deposition. We have fabricated high-performance devices and circuits based on this heterostructure, where MoS2 is used as the transistor channel and graphene as contact electrodes and circuit interconnects. We provide a systematic comparison of the graphene/MoS2 heterojunction contact to more traditional MoS2-metal junctions, as well as a theoretical investigation, using density functional theory, of the origin of the Schottky barrier height. The tunability of the graphene work function with electrostatic doping significantly improves the ohmic contact to MoS2. These high-performance large-scale devices and circuits based on this 2D heterostructure pave the way for practical flexible transparent electronics.