Graphene-Based Field-Effect Transistor Technologies

Graphene-based field-effect transistors (GFETs) represent a transformative class of devices in which a two-dimensional carbon lattice serves as the active channel for charge transport. Owing to graphene’s exceptional carrier mobility, atomic thinness and ambipolar conduction, GFETs offer unique advantages over conventional silicon-based transistors, particularly in high-frequency and analogue applications. The absence of a bandgap in pristine graphene poses challenges for digital switching, yet its linear energy–momentum relation enables rapid electronic response and low noise performance. Engineering strategies such as dielectric deposition, substrate selection and dual-gating have been developed to improve current saturation, enhance transconductance and tailor the electrostatic control of the channel. Hybrid structures combining graphene with semiconductors or insulators can introduce tunable bandgaps or enhance interface quality. Collectively, these efforts have led to GFETs capable of operating at millimetre-wave frequencies, performing novel radio-frequency functions such as frequency multiplication and demonstrating potential in sensing, bioelectronics and high-speed communications.

Research from Nature Portfolio

High-gain GFETs have been realised by integrating a thin aluminium oxide top-gate dielectric, achieving record voltage gains in the tens of decibels and maximum oscillation frequencies that outstrip earlier graphene devices. This advance was enabled by careful interface engineering to reduce parasitic capacitances and improve current saturation under ambient conditions. In a separate effort, monolithic integrated circuits based on epitaxial graphene have demonstrated reliable operation at 80–100 GHz, encoding and decoding multi-gigabit-per-second data streams. High-quality wafer-scale growth and process scalability were key to unlocking millimetre-wave performance. Furthermore, dual-gated GFETs have been exploited as compact frequency multipliers, utilising the material’s ambipolar transfer characteristics to produce efficient frequency doubling, tripling and quadrupling with substantial output power concentration at the target harmonic. These circuits exemplify the potential of graphene for analogue signal processing without resorting to complex complementary device architectures.

Research from all publishers

A hybrid graphene-on-silicon field-effect transistor has been developed for bioelectronic applications, in which an overlying graphene sheet electrostatically shields and couples to an underlying silicon channel. This configuration yields a unique subthreshold response mediated by two coupled carrier populations and offers routes to integrated sensing platforms. In the domain of microwave and millimetre-wave systems, comprehensive reviews have charted methods for large-area graphene growth, device fabrication and circuit integration, highlighting both the promise of ultrahigh carrier mobility and the limitations imposed by interface trap densities and contact resistances. These surveys outline strategies for embedding GFETs and graphene diodes into amplifiers, mixers and oscillators, emphasising compatibility with existing fabrication technologies. Concurrently, advanced transport modelling of bottom-gated GFETs on boron nitride substrates has elucidated the impact of velocity saturation by phonon scattering and Dirac-pinch-off effects, predicting intrinsic cut-off frequencies into the sub-THz range. Such theoretical insights guide the optimisation of channel geometry and dielectric environment for next-generation high-speed graphene electronics.

Graphene-Based Field-Effect Transistor Technologies publication trend

The graph below shows the total number of articles in graphene-based field-effect transistor technologies across all publications each year (not limited to Nature Index journals).

Technical terms

Field-effect transistor (FET): A three-terminal device in which an electric field controls the conductivity of a semiconducting or semimetallic channel.

Carrier mobility: The velocity of charge carriers per unit electric field, indicating how rapidly electrons or holes traverse the channel.

Transconductance: The change in output current per unit change in gate voltage, a measure of the device’s amplification capability.

Ambipolar conduction: The ability of a material to conduct both electrons and holes, typically modulated by gate bias.

Dirac point: The energy at which the density of states in graphene vanishes and electron and hole populations are equal, corresponding to minimum conductivity.

References

1. Graphene‐on‐Silicon Hybrid Field‐Effect Transistors. Advanced Electronic Materials (2023).
2. High-Gain Graphene Transistors with a Thin AlOx Top-Gate Oxide. Scientific Reports (2017).
3. Graphene‐Based Microwave Circuits: A Review. Advanced Materials (2022).
4. Wafer scale millimeter-wave integrated circuits based on epitaxial graphene in high data rate communication. Scientific Reports (2017).
5. A graphene based frequency quadrupler. Scientific Reports (2017).
6. High-Frequency Limits of Graphene Field-Effect Transistors with Velocity Saturation. Applied Sciences (2020).