Optimizing Charge Injection across Transition Metal Dichalcogenide Heterojunctions: Theory and Experiment.
In search of an improved strategy to form low-resistance contacts to semiconducting transition metal dichalcogenides, we combine ab initio density functional electronic structure calculations for an NbSe2/WSe2interface with quantum transport measurements of the corresponding heterojunction between a few-layer WSe2semiconductor and a metallic NbSe2layer. Our theoretical results suggest that, besides a rigid band shift associated with charge transfer, the presence of NbSe2does not modify the electronic structure of WSe2. Since the two transition metal dichalcogenides are structurally similar and display only a small lattice mismatch, their heterojunction can efficiently transfer charge across the interface. These findings are supported by transport measurements for WSe2field-effect transistors with NbSe2contacts, which exhibit nearly ohmic behavior and phonon-limited mobility in the hole channel, indicating that the contacts to WSe2are highly transparent.
Physics and Astronomy Department, Michigan State University , East Lansing, Michigan 48824, United States.
Jie
J
Guan
Physics and Astronomy Department, Wayne State University , Detroit, Michigan 48201, United States.
Hsun-Jen
HJ
Chuang
Physics and Astronomy Department, Wayne State University , Detroit, Michigan 48201, United States.
Zhixian
Z
Zhou
Physics and Astronomy Department, Michigan State University , East Lansing, Michigan 48824, United States.
David
0000-0003-1131-4788
D
Tománek
ab initio calculations; contacts; electronic structure; heterojunctions; transition metal dichalcogenides