Flicker Noise in Bilayer Graphene Transistors

TL;DR

This study investigates low-frequency flicker noise in bilayer graphene transistors, revealing that the noise originates from carrier fluctuations and is influenced by device contacts and ungated regions, with implications for graphene electronics.

Contribution

The paper provides the first experimental analysis of flicker noise in bilayer graphene transistors, identifying its origin and dependence on device structure.

Findings

Noise spectra follow 1/f behavior above 10-100 Hz

Carrier-number fluctuation is the main noise source

Hooge parameter estimated at 10E-4

Abstract

We present the results of the experimental investigation of the low - frequency noise in bilayer graphene transistors. The back - gated devices were fabricated using the electron beam lithography and evaporation. The charge neutrality point for the fabricated transistors was around 10 V. The noise spectra at frequencies above 10 - 100 Hz were of the 1/f - type with the spectral density on the order of 10E-23 - 10E-22 A2/Hz at the frequency of 1 kHz. The deviation from the 1/f spectrum at the frequencies below 10 -100 Hz indicates that the noise is of the carrier - number fluctuation origin due to the carrier trapping by defects. The Hooge parameter of 10E-4 was extracted for this type of devices. The gate dependence of the noise spectral density suggests that the noise is dominated by the contributions from the ungated part of the device channel and by the contacts. The obtained results are important for graphene electronic applications.