Charge Inhomogeneity Mediated Low-Frequency noise in Encapsulated Monolayer and Bilayer Graphene Field-Effect Transistors

Among 2D materials family, semimetal graphene is the only material that has promise in designing high mobility field-effect transistors (FETs). One-dimensional (1D) edge contacts to graphene channels in heterostructure GFETs consisting hexagonal boron nitride (hBN) and graphene have recently demonstrated superior device transport properties.¹ Moreover, these devices have also demonstrated low transport noise, necessary for applications such as RF communications.² With low-frequency-noise (LFN) studies on hBN/graphene/hBN heterostructure GFETs showing ultra-low-noise in carrier-rich region, studies comparing LFN in such GFETs consisting single layer (SLG) and bilayer graphene (BLG) near charge neutrality point has not been compared and analyzed thoroughly. In this work, we systematically study temperature-dependent transport and LFN characteristics to model the channel characteristics in SLG and BLG, 1D edge-contacted 2D heterostructure GFETs. Our study shows a substantial difference in electron-hole puddle transport in these devices. As such, these high-performance 1D edge-contacted 2D heterostructure GFETs play a fundamental role to study electron-hole puddle physics.

[1] L. Wang et al., Science 342, 614-617 (2013)

[2] Behera et al., ACS Appl. Electron. Mater. 3, 4126-4134 (2021)