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Low-frequency noise as a probe of microscopic disorder in CVD-grown graphene

Jagadis Prasad Nayak, Smrutirekha Sahoo, Shreya Barman, Gopi Nath Daptary

Abstract

We report a detailed investigation of low-frequency resistance fluctuations (1/f noise) in chemical vapor deposition (CVD) grown graphene. Systematic measurements reveal that the magnitude of 1/f noise in CVD-grown graphene is significantly higher by several orders of magnitude than that typically observed in exfoliated single-crystal graphene. This enhancement is attributed to structural imperfections such as grain boundaries and defect states within the polycrystalline film. Detailed analysis of the temperature dependence of the noise demonstrates that the resistance fluctuations arise from thermally activated dynamics of localized defects. These results provide key insights into the microscopic mechanism of noise in scalable graphene films and highlight the role of defect engineering in optimizing graphene for large-scale electronic applications. Our findings establish low-frequency noise as a sensitive probe of microscopic disorder in CVD graphene, providing a practical pathway for assessing material quality in scalable electronic technologies.

Low-frequency noise as a probe of microscopic disorder in CVD-grown graphene

Abstract

We report a detailed investigation of low-frequency resistance fluctuations (1/f noise) in chemical vapor deposition (CVD) grown graphene. Systematic measurements reveal that the magnitude of 1/f noise in CVD-grown graphene is significantly higher by several orders of magnitude than that typically observed in exfoliated single-crystal graphene. This enhancement is attributed to structural imperfections such as grain boundaries and defect states within the polycrystalline film. Detailed analysis of the temperature dependence of the noise demonstrates that the resistance fluctuations arise from thermally activated dynamics of localized defects. These results provide key insights into the microscopic mechanism of noise in scalable graphene films and highlight the role of defect engineering in optimizing graphene for large-scale electronic applications. Our findings establish low-frequency noise as a sensitive probe of microscopic disorder in CVD graphene, providing a practical pathway for assessing material quality in scalable electronic technologies.
Paper Structure (3 sections, 4 equations, 6 figures)

This paper contains 3 sections, 4 equations, 6 figures.

Table of Contents

  1. INTRODUCTION
  2. Results and Discussion
  3. Conclusion

Figures (6)

  • Figure 1: Schematic of the CVD-grown graphene device.
  • Figure 2: Characterization of CVD-grown graphene. (a) Optical microscope image and (b) SEM image of the graphene film. (c) and (d) Raman spectra measured at the grain boundary (location 1 in (b)) and within a single grain (location 2 in (b)), respectively, highlighting the variation in spectral features between the two regions
  • Figure 3: (a) Normalized sheet resistance of CVD-grown graphene as a function of gate voltage $(V_g - V_D)$ at $T = 80$ K. The Dirac point occurs at $V_D = 58$ V. (b) Temperature dependence of the sheet resistance measured at a fixed gate voltage $(V_g - V_D) = 10$ V.
  • Figure 4: (a) Time series of voltage fluctuations measured at different temperatures at $(V_g - V_D) = 10$ V. The traces are vertically offset for clarity (offset value $3\,\mu$V). (b) Power spectral density of voltage fluctuations as a function of frequency. The dashed line represents a typical $1/f$ dependence. The inset shows the variance at $T=100$ K as a function of $V^2$, demonstrating quadratic scaling.
  • Figure 5: Relative variance of resistance fluctuations $\langle \delta R^2 \rangle / \langle R^2 \rangle$ as a function of temperature at $(V_g - V_D) = 10$ V.
  • ...and 1 more figures