The charge-carrier trapping effect on 1/f noise in monolayer graphene

TL;DR

This paper investigates how charge carrier trapping by impurities affects the 1/f noise frequency exponent in graphene-boron nitride heterostructures, explaining multiple extrema observed experimentally.

Contribution

It introduces a kinetic model incorporating trapping and phonon interactions, providing a theoretical explanation for the extrema in the noise frequency exponent.

Findings

Frequency exponent exhibits multiple minima and maxima due to trapping effects.

The trapping probability's width and energy threshold influence the extrema.

Model aligns well with experimental data, estimating trapping parameters.

Abstract

The frequency exponent of 1/f noise in graphene-boron nitride heterostructures is known to have multiple extrema in its dependence on the charge carrier concentration. This behavior is explained in the present paper as a result of the charge carrier trapping by impurities in the boron nitride. A kinetic equation for the charge carriers subject to trapping and interacting with acoustic phonons is derived. This equation is solved numerically, and the equilibrium solutions are used to evaluate the frequency exponent according to the quantum theory of 1/f noise. It is found that the frequency exponent does develop several minima and maxima, provided that the trapping probability is sufficiently wide and has a threshold with respect to the charge carrier energy. A detailed comparison with the experimental data is made, and the results are used to estimate the energy threshold and the trapping cross-section.