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Title: Field-effect conductivity scaling for two-dimensional materials with tunable impurity density
Abstract A scaling law is demonstrated in the conductivity of gated two-dimensional (2D) materials with tunable concentrations of ionized impurity scatterers. Experimental data is shown to collapse onto a single 2D conductivity scaling (2DCS) curve when the mobility is scaled by r , the relative impurity-induced scattering, and the gate voltage is shifted by V s , a consequence of impurity-induced doping. This 2DCS analysis is demonstrated first in an encapsulated 2D black phosphorus multilayer at T = 100 K with charge trap densities programmed by a gate bias upon cooldown, and next in a Bi 2 Se 3 2D monolayer at room temperature exposed to varying concentrations of gas adsorbates. The observed scaling can be explained using a conductivity model with screened ionized impurity scatterers. The slope of the r  vs.  V s plot defines a disorder-charge specific scattering rate Γ q = d r / d V s equivalent to a scattering strength per unit impurity charge density: Γ q > 0 indicates a preponderance of positively charged impurities with Γ q < 0 for negatively charged. This 2DCS analysis is expected to be applicable in arbitrary 2D materials systems with tunable impurity density, which will advance 2D more » materials characterization and improve performance of 2D sensors and transistors. « less
Authors:
; ; ; ; ; ; ; ;
Award ID(s):
1729016
Publication Date:
NSF-PAR ID:
10403251
Journal Name:
2D Materials
Volume:
9
Issue:
3
Page Range or eLocation-ID:
031002
ISSN:
2053-1583
Sponsoring Org:
National Science Foundation
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