Rapid Fabrication of Graphene Field-Effect Transistors with Liquid-metal Interconnects and Electrolytic Gate Dielectric Made of Honey

Abstract

Historically, graphene-based transistor fabrication has been time-consuming due to the high demand for carefully controlled Raman spectroscopy, physical vapor deposition, and lift-off processes. For the first time in a three-terminal graphene field-effect transistor embodiment, we introduce a rapid fabrication technique that implements non-toxic eutectic liquid-metal Galinstan interconnects and an electrolytic gate dielectric comprised of honey. The goal is to minimize cost and turnaround time between fabrication runs; thereby, allowing researchers to focus on the characterization of graphene phenomena that drives innovation rather than a lengthy device fabrication process that hinders it. We demonstrate characteristic Dirac peaks for a single-gate graphene field-effect transistor embodiment that exhibits hole and electron mobilities of 213 ± 15 and 166 ± 5 cm 2/V·s respectively. We discuss how our methods can be used for the rapid determination of graphene quality and can complement Raman Spectroscopy techniques. Lastly, we explore a PN junction embodiment which further validates that our fabrication techniques can rapidly adapt to alternative device architectures and greatly broaden the research applicability.

Polar Organic Gate Dielectrics for Graphene Field-Effect Transistor-Based Sensor Technology

“…To verify the quality of the monolayer graphene sample, 514.5 nm Raman spectroscopy measurements were conducted with a Renishaw Invia Micro-Raman System. It is important to note, the G-Band and the 2D band for monolayer graphene on PET are difficult to measure as there are strong polymeric vibrational modes that are sensitive to Raman scattering near the G-Band of graphene [ 5 ], see Figure 3 a. Therefore to get an accurate measurement of the graphene Raman peaks on PET, one needs to operate the Raman spectroscopy system in a static mode to improve the resolution, see Figure 3 b,c.…”

“…Recent research in flexible electronics has explored the utilization of two-dimensional graphene in thin-film devices due to its high carrier mobility, high tensile strength, and broadband sensing capability [ 3 , 4 ]. Graphene is defined as a monolayer of carbon atoms arranged in a hexagonal lattice with a bond length of 1.42 Å and a lattice constant of 2.46 Å [ 5 ]. The unique atomic structure of graphene gives rise to its exceptional electrical and mechanical properties that enable a plethora of potential applications for next-generation wearable devices, transducers, and sensors.…”

“…The unique atomic structure of graphene gives rise to its exceptional electrical and mechanical properties that enable a plethora of potential applications for next-generation wearable devices, transducers, and sensors. However, due to the lack of flexible materials for gate dielectrics, graphene field-effect transistors (GFETs) have been constrained by limitations similar to that of traditional flexible FETs [ 5 ]. As flexible devices become a trademark in the commercial sector, there is a need for flexible gate dielectric materials in order realize robust wearable devices with flexible GFETs.…”

Electric Double Layer Field Effect Transistor Using SnS Thin Film as Semiconductor Channel Layer and Honey Gate Dieletric

“…Honey was reported to possess the ability to produces high on-current and low voltage operation while forming an ionic gel-like solution similar to ionic gels which consist of ionic liguids. It has recently shown ideal transistor performance as a electrolytic gate dielectrics in Graphene field effect transistors using liquid metal interconnects [8].…”

Channel length scaling and electrical characterization of graphene field effect transistor (GFET)

“…The current carrying channel is in direct contact with surrounding and this provides better control on surface charge [9]. Therefore, GFET biosensors are favorable and more sensitive as it able to directly translate interactions of biomolecules on its surface into readable electrical signals [10]- [12]. Hence, device parameters especially conducting channel length plays vital role in determining the effective performance of GFET for biosensing applications.…”