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  • Low-Temperature 2D/2D Ohmic Contacts in WSe 2 Field-Effect Transistors as a Platform for the 2D Metal–Insulator Transition
Title: Low-Temperature 2D/2D Ohmic Contacts in WSe 2 Field-Effect Transistors as a Platform for the 2D Metal–Insulator Transition
We report the fabrication of hexagonal-boron-nitride (hBN) encapsulated multi-terminal WSe_2 Hall bars with 2D/2D low-temperature Ohmic contacts as a platform for investigating the two-dimensional (2D) metal-insulator transition. We demonstrate that the WSe_2 devices exhibit Ohmic behavior down to 0.25 K and at low enough excitation voltages to avoid current-heating effects. Additionally, the high-quality hBN-encapsulated WSe_2 devices in ideal Hall-bar geometry enable us to accurately determine the carrier density. Measurements of the temperature (T) and density (n_s) dependence of the conductivity \sigma(T,n_s) demonstrate scaling behavior consistent with a metal-insulator quantum phase transition driven by electron-electron interactions, but where disorder-induced local magnetic moments are also present. Our findings pave the way for further studies of the fundamental quantum mechanical properties of 2D transition metal dichalcogenides using the same contact engineering.  more » « less
Award ID(s):
1707785 1307075 2004445
PAR ID:
10215944
Author(s) / Creator(s):
; ; ; ; ; ;
Date Published:
Journal Name:
ACS Applied Materials & Interfaces
ISSN:
1944-8244
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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