Review on 1/f noise and its progress in two-dimensional material graphene

The noise is the signal. Low-frequency noise with a 1/f-type spectral density (1/f noise) has been observed in a wide variety of systems. There’s plenty of physical processes under the 1/f noise phenomenon. It is not only a useful tool for scientific research, but also a quantitative probe for the performance of electronic devices. From the general mathematical forms to physical processes, this paper summarizes the 1/f noise models. Based on Markov process and diffusion process, two general mathematical models of 1/f noise are introduced respectively. On this basis, tracing the development history, several typical physical models are described, including Mc Whorter model, Hooge model, Voss-Clarker model, Dutta-horn model, interference model and unified Hung model. The rise of the two-dimensional material graphene offers unique opportunities for the mechanism research on 1/f noise. In the fact of the cloudy and even contradictory conclusions from different reports, this paper combs the consensus accepted widely. An analysis model based on three-level classification for the graphene low-frequency noise study is built, which divides the noise into intrinsic background 1/f noise, 1/f-like noise and Lorentz-like noise. Typical research on the related mechanism at each level are analyzed, and the dominant mechanisms are summarized. Further we focus on the gate-modulated characteristic spectrum shape of 1/f noise from different reported experiments, which may be a key to the material internal scattering mechanism and charge distribution. The experimental measurements show that the characteristic shape is variable, and mainly exists in three forms: V-type, Ʌ-type and M-type. Through the comparative analysis of graphene cleanliness, bias current (voltage) and other experimental parameters, the possible causes of the complexity and variability of the characteristic shape are analyzed. It shows that the main reason may be that the experimental parameters are not strictly controlled, and the selection of measuring point is unreasonable. In order to capture accurate noise characteristics to clearly reveal the noise mechanism, this paper puts forward the standard 1/f noise measurement paradigm to guide the effective research on graphene 1/f noise and distinguishing the intrinsic and extrinsic noise. The standard paradigm includes three processes. Firstly, prepare suspended graphene samples. Then remove the surface contamination by methods such as current annealing, which is followed by the test of the relationship curve between the 1/f noise amplitude and the bias voltage or current. Based on this curve, suitable test point can be selected for different measurement scheme. The proposed standard intrinsic background 1/f noise measurement paradigm may hold the promise to clarify and reveal the characteristics of graphene 1/f noise.