# Carrier mobility and scattering lifetime in electric double-layer gated few-layer graphene

## TL;DR

This study investigates the transport properties of few-layer graphene under high surface charge densities induced by electric double-layer gating, revealing asymmetries in carrier mobility and analyzing scattering mechanisms through experimental and theoretical approaches.

## Contribution

The paper combines experimental EDL-FET measurements with DFT calculations to analyze carrier mobility and scattering in few-layer graphene, highlighting electrolyte effects.

## Key findings

- Carrier mobility shows asymmetry between hole and electron doping.
- Scattering lifetime depends on carrier density and electrolyte properties.
- Large induced surface charge densities are achieved and studied.

## Abstract

We fabricate electric double-layer field-effect transistor (EDL-FET) devices on mechanically exfoliated few-layer graphene. We exploit the large capacitance of a polymeric electrolyte to study the transport properties of three, four and five-layer samples under a large induced surface charge density both above and below the glass transition temperature of the polymer. We find that the carrier mobility shows a strong asymmetry between the hole and electron doping regime. We then employ ab-initio density functional theory (DFT) calculations to determine the average scattering lifetime from the experimental data. We explain its peculiar dependence on the carrier density in terms of the specific properties of the electrolyte we used in our experiments.