Articolo in rivista, 2023, ENG, 10.1063/5.0157327

Second spectrum of charge carrier density fluctuations in graphene due to trapping/detrapping processes

Francesco Pellegrino, Giuseppe Falci, Elisabetta Paladino

Dipartimento di Fisica e Astronomia "Ettore Majorana," Universita di Catania, Via S. Sofia 64, I-95123 Catania, Italy 2 INFN, Sez. Catania, I-95123 Catania, Italy 3 CNR-IMM, Via S. Sofia 64, I-95123 Catania, Italy

We investigate the second spectrum of charge carrier density fluctuations in graphene within the McWorther model, where noise is induced by electron traps in the substrate. Within this simple picture, we obtain a closed-form expression including both Gaussian and non-Gaussian fluctuations. We show that a very extended distribution of switching rates of the electron traps in the substrate leads to a carrier density power spectrum with a non-trivial structure on the scale of the measurement bandwidth. This explains the appearance of a 1=f component in the Gaussian part of the second spectrum, which adds up to the expected frequency-independent term. Finally, we find that the nonGaussian part of the second spectrum can become quantitatively relevant by approaching extremely low temperatures.

Applied physics letters

Keywords

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CNR authors

Falci Giuseppe, Paladino Elisabetta, Pellegrino Francesco Maria Dimitri

CNR institutes

IMM – Istituto per la microelettronica e microsistemi