Low-Frequency Noise in Two-Dimensional Materials

Low-frequency noise (LFN), often manifesting as a 1/f spectral signature, poses both a diagnostic tool and a limiting factor for electronic and optoelectronic devices built from atomically thin materials. In two-dimensional systems such as graphene, transition metal dichalcogenides and other van der Waals layers, the reduced dimensionality enhances the influence of surface adsorbates, interfacial trap states and contact interfaces on charge transport. Fluctuations in carrier number or mobility, driven by trapping–detrapping processes, impurity motion and electrostatic inhomogeneities, give rise to resistance and current noise that can degrade sensor resolution, transistor stability and coherence in quantum applications. Understanding the interplay between intrinsic material properties—such as band structure, screening length and defect density—and extrinsic factors—such as device architecture, dielectric environment and chemical doping—is essential for noise suppression. Recent advances in measurement methodologies, from cross-correlation spectrum analysis to nanoscale noise mapping, have revealed strategies to mitigate LFN through geometry optimisation, controlled doping and dynamic modulation of charge distributions. The global significance of this research lies in enabling low-noise two-dimensional platforms for high-precision sensing, low-power electronics and robust quantum circuits.

Research from Nature Portfolio

Recent studies have demonstrated that in high-mobility graphene configured in a Corbino geometry, an applied magnetic field can suppress 1/f noise by reducing anisotropic mobility fluctuations associated with impurity clustering dynamics. This work models the field-dependent noise suppression in terms of mobile impurity scattering and charge-density modulation, pointing to novel routes for noise control in two-dimensional conductors. Another advance employs nanoscale conductive-probe mapping of monolayer MoS₂ grains, revealing that regions of elevated sulphur-vacancy density act simultaneously as charge-hopping sites and trap centres. By correlating local photocurrent enhancement with trap-density maps, this approach highlights the dual role of atomic defects in photoconductive gain and noise generation, offering in situ guidance for defect engineering in layered semiconductors.

Low-Frequency Noise in Two-Dimensional Materials publication trend

The graph below shows the total number of articles in low-frequency noise in two-dimensional materials across all publications each year (not limited to Nature Index journals).

Technical terms

1/f noise (Pink noise): Slow, scale-invariant fluctuations in current or resistance whose power spectral density is inversely proportional to frequency.

Charge-carrier number fluctuation: Variations in the number of mobile charge carriers due to trapping and detrapping at defects or interfaces.

Mobility fluctuation: Changes in carrier mobility caused by dynamic scattering from moving impurities or phonons.

Contact resistance noise: Noise arising from time-dependent fluctuations at the metal–semiconductor interface in devices.

Corbino geometry: A circular conductor configuration with concentric electrodes that minimises edge scattering and separates contact noise from channel noise.

Ambipolar transport: The ability of a device to conduct both electrons and holes, often tuned by gate voltage or chemical doping.

References

1. Suppression of 1/f noise in graphene due to anisotropic mobility fluctuations induced by impurity motion. Communications Physics (2023).
2. Low-frequency noise of MoTe2 transistor: effects on ambipolar carrier transport and CYTOP doping. Discover Nano (2024).
3. 1 / f noise in van der Waals materials and hybrids. Advances in Physics X (2017).
4. Electrical Low-Frequency 1/f γ Noise Due to Surface Diffusion of Scatterers on an Ultra-low-Noise Graphene Platform. Nano Letters (2021).
5. Nanoscale enhancement of photoconductivity by localized charge traps in the grain structures of monolayer MoS2. Scientific Reports (2018).
6. Analysis of Low-Frequency 1/f Noise Characteristics for MoTe2 Ambipolar Field-Effect Transistors. Nanomaterials (2022).
7. A correlation noise spectrometer for flicker noise measurement in graphene samples. Measurement Science and Technology (2019).