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Published on: July 24, 2015
Ionic screening of charged-impurity scattering in graphene
Fang Chen1, Jilin Xia, Nongjian Tao
1Department of Electrical Engineering, Center for Bioelectronics and Biosensors, Biodesign Institute, Arizona State University, Tempe, Arizona 85287, USA.
Nano Letters
|March 24, 2009
Summary
Ionic screening significantly enhances charge transport in graphene field effect transistors. Increased ion concentration boosts carrier mobility and alters conductivity, supporting long-range Coulomb scattering theory.
Area of Science:
- Condensed Matter Physics
- Materials Science
Background:
- Graphene field effect transistors (GFETs) are crucial for electronic applications.
- Understanding charge transport mechanisms is key to optimizing GFET performance.
Purpose of the Study:
- To investigate the impact of ionic screening on GFET charge transport properties.
- To elucidate the relationship between ionic concentration and carrier mobility.
Main Methods:
- Experimental study of graphene field effect transistors.
- Systematic variation of ionic concentration.
- Measurement of charge transport parameters, including carrier mobility and conductivity.
Main Results:
- Dramatic increases in carrier mobilities observed with increasing ionic concentration.
- Systematic changes in minimum conductivity position, magnitude, and plateau width.
- Observed conductivity saturation and crossover from linear to constant conductivity regimes.
- Results support the theory of long-range Coulomb scattering.
Conclusions:
- Ionic screening is a dominant factor influencing charge transport in GFETs.
- The findings provide insights into optimizing GFETs for enhanced performance.
- The study validates theoretical models of scattering mechanisms in graphene.
