- High-performance flexible nanoscale transistors based on transition metal dichalcogenides NATURE ELECTRONICS 2021
Uncovering the Effects of Metal Contacts on Monolayer MoS2.
Metal contacts are a key limiter to the electronic performance of two-dimensional (2D) semiconductor devices. Here, we present a comprehensive study of contact interfaces between seven metals (Y, Sc, Ag, Al, Ti, Au, Ni, with work functions from 3.1 to 5.2 eV) and monolayer MoS2 grown by chemical vapor deposition. We evaporate thin metal films onto MoS2 and study the interfaces by Raman spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, transmission electron microscopy, and electrical characterization. We uncover that (1) ultrathin oxidized Al dopes MoS2n-type (>2 × 1012 cm-2) without degrading its mobility, (2) Ag, Au, and Ni deposition causes varying levels of damage to MoS2 (e.g. broadening Raman E' peak from <3 to >6 cm-1), and (3) Ti, Sc, and Y react with MoS2. Reactive metals must be avoided in contacts to monolayer MoS2, but control studies reveal the reaction is mostly limited to the top layer of multilayer films. Finally, we find that (4) thin metals do not significantly strain MoS2, as confirmed by X-ray diffraction. These are important findings for metal contacts to MoS2 and broadly applicable to many other 2D semiconductors.
View details for DOI 10.1021/acsnano.0c03515
View details for PubMedID 32905703
- Temperature-Dependent Contact Resistance to Nonvolatile Memory Materials IEEE TRANSACTIONS ON ELECTRON DEVICES 2019; 66 (9): 3816–21
3D Heterogeneous Integration with 2D Materials
IEEE. 2019: 89–90
View details for Web of Science ID 000501001400043