Microscopic Mechanism of 1/f Noise in Graphene: Role of Energy Band Dispersion

Abstract

A distinctive feature of single-layer graphene is the linearly dispersive energy bands, which in the case of multilayer graphene become parabolic. A simple electrical transport-based probe to differentiate between these two band structures will be immensely valuable, particularly when quantum Hall measurements are difficult, such as in chemically synthesized graphene nanoribbons. Here we show that the flicker noise, or the 1/f noise, in electrical resistance is a sensitive and robust probe to the band structure of graphene. At low temperatures, the dependence of noise magnitude on the carrier density was found to be opposite for the linear and parabolic bands. We explain our data with a comprehensive theoretical model that clarifies several puzzling issues concerning the microscopic origin of flicker noise in graphene field-effect transistors (GraFET).

Nonequilibrium mesoscopic conductance fluctuations as the origin of 1/f noise in epitaxial graphene

“…Low-frequency noise, also referred to as flicker noise or 1/f noise, is a common phenomenon caused by various physical mechanisms and found in numerous systems [4,5], including electronic transport in graphene devices [6][7][8][9]. At low temperature, the noise properties of graphene are of particular interest for its application in metrology as a quantum Hall resistance [10][11][12][13] and impedance [14] standard.…”

Variability Effects in Graphene: Challenges and Opportunities for Device Engineering and Applications

“…From the metrology perspective, on the other hand, we demonstrate that variabilities in graphene can function as novel probing mechanisms [58,65,[71][72][73][74][75], where the 'signal fluctuations' can be useful for potential sensing applications. This role of graphene variabilities is of both fundamental and practical interest [76][77][78], extendable to other thin-films or nanomaterials [79][80][81][82], and may be employed in developing novel metrology applications.…”

“…Due to their large surface-to-volume ratio, graphene devices are sensitive to the interface traps close to the graphene surface [61,71,77]. They exist in the gate oxide or the substrate of non-suspended graphene devices, and can also be from the attached molecules or the surrounding environment [60-62, 70, 102].…”

“…For instance, suspended graphene devices show a 6-12 times lower LFN than those with a SiO 2 substrate, suggesting that the traps in SiO 2 substrate contribute significantly to LFN [118]. On the other hand, recent studies have suggested that the LFN in graphene depends on various scattering mechanisms, the environment near the graphene surface and the sample qualities [65,77,102,119]. For instance, Heller et al [102] have proposed that the LFN behavior in liquid-gated graphene devices can relate to the charge-induced local potential fluctuations near the graphene-electrolyte interface (i.e.…”

“…A low-level phase noise is a critical requirement for high-frequency applications of graphene [61,122]. LFN measurements are broadly used as a characterization technique to provide information about interface traps in graphene devices [60,61,63,65,77,123]. Figure 2b and 2c show a typical room-temperature LFN measurement of a back-gated single-layer graphene (SLG) device [65].…”