| AVS 60th International Symposium and Exhibition | |
| Graphene and Other 2D Materials Focus Topic | Monday Sessions |
| Session GR+EM+NS+SP+TF-MoA |
| Session: | Electronic Properties and Charge Transport in 2D Materials |
| Presenter: | A.A. Balandin, University of California, Riverside |
| Authors: | A.A. Balandin, University of California, Riverside S. Rumyantsev, Ioffe Institute, Russian Academy of Sciences M. Shur, Rensselaer Polytechnic Institute |
| Correspondent: | Click to Email |
Low-frequency current fluctuations with the spectral density S(f)~1/f (f is the frequency) is a ubiquitous phenomenon observed in a wide variety of electronic materials and devices. Low-frequency 1/f noise limits the sensitivity of sensors and makes the main contribution to the phase-noise of communication systems via its up-conversion. For this reason, practical applications of every new material system require a thorough investigation of specific features of the low-frequency noise in this material and developing methods for its reduction. It has already been demonstrated that the low-frequency current fluctuations in graphene [1-3] and thin films of van der Waals materials [4] reveal unusual gate bias dependence, which cannot be described with conventional Hooge parameter or McWhorter model. In this talk, I will review state-of-the-art in the 1/f noise field in graphene and van der Waals materials, and describe possibilities for deeper understanding of 1/f noise offered by availability of continuous atomically thin films. A long-standing question of importance for electronics is whether 1/f noise is generated on the surface of conductors or inside their volumes. Using graphene multilayers we were able to directly address this fundamental problem of the noise origin. Unlike the thickness of metal or semiconductor films, the thickness of graphene multilayers can be continuously and uniformly varied all the way down to a single atomic layer of graphene – the actual surface. We found that 1/f noise becomes dominated by the volume noise when the thickness exceeds ~7 atomic layers (~2.5 nm). The 1/f noise is the surface phenomenon below this thickness [5]. We investigated experimentally the effect of the electron-beam irradiation on the level of the low-frequency 1/f noise in graphene devices. It was found unexpectedly that 1/f noise in graphene reduces with increasing concentration of defects induced by irradiation [6]. The bombardment of graphene devices with 20-keV electrons reduced the noise spectral density by an order-of magnitude at the radiation dose of 104 m C/cm2. The noise reduction can be explained within the mobility fluctuation mechanism. The obtained results are important for the proposed applications of graphene and van der Waals materials in sensors and communications.
[1] G. Liu, et al., Appl. Phys. Lett., 95, 033103 (2009); [2] S. Rumyantsev, et al., J. Phys.: Cond. Matter, 22, 395302 (2010); [3] G. Liu, et al., Appl. Phys. Lett., 100, 033103 (2012); [4] M.Z. Hossain, et al., ACS Nano, 5, 2657 (2011); [5] G. Liu, et al., Appl. Phys. Lett., 102, 093111 (2013); [6] M. Z. Hossain, et al. Appl. Phys. Lett., 102, 153512 (2013).