Tunnel Field-Effect Transistors for the Future of Low-Power Electronics

By Ankit SinghReviewed by Frances BriggsAug 12 2025

Shrinking chips are hitting a wall. Traditional transistors, the workhorses of modern electronics, are struggling to switch faster without guzzling power. A rival design, the tunnel field-effect transistor, sidesteps the problem by exploiting quantum tunnelling rather than heat-driven electron flow.

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With the right mix of materials, TFETs promise cooler, smaller, and more efficient circuits for everything from the Internet of Things to brain-inspired computers. But before they can leave the lab, engineers must overcome finicky fabrication and fickle performance.

Operating Principles: Quantum Tunneling versus Thermionic Emission

TFETs operate differently from traditional metal-oxide semiconductor field-effect transistors. Traditional transistors control current by thermionic emission: electrons must gain enough thermal energy to leap over a barrier between the source and channel.

This method is limited by available thermal energy, which means you can’t make the current switch more sharply than 60 millivolts of gate change for every tenfold change in current at room temperature.¹

What is the problem with this 60 mV limit?

When designing traditional metal-oxide semiconductor field-effect transistors, this number is a ceiling. At room temperature, physics says you can’t make the transistor’s current switch faster than that using heat-driven electrons. Try to run at lower voltages and the “off” state leaks, the “on” state weakens, and logic levels blur. The result: wasted power or sluggish performance. Increasing voltage to circumvent this means wasted power. 

TFETs use quantum tunneling to sidestep this issue. In a TFET, the source and drain are heavily doped and create a steep p-i-n structure. The gate voltage shifts the energy bands, and when they align, a narrow tunnel barrier opens. Electrons then slip directly from the source’s valence band into the channel’s conduction band, driven by quantum mechanics rather than heat.

This mechanism enables TFETs to achieve subthreshold swings lower than the traditional thermionic limit. It also allows better control over ON and OFF states at lower voltages, reducing static and dynamic power consumption.¹

Materials for TFET Fabrication

The choice of semiconductor material is critical. To achieve sharp subthreshold characteristics and high on-current, the tunneling probability needs to be optimized. A high tunnelling probability demands a low band gap and a small effective mass, so many TFET prototypes use compounds such as indium arsenide, gallium antimonide, or indium gallium arsenide. They have small direct band gaps and low effective masses, which outperform silicon's tunneling efficiency.²

Two-dimensional materials also come into play here. Molybdenum disulfide, tungsten diselenide, and molybdenum ditelluride combine direct band gaps with strong electrostatic control, useful for compact TFET designs.^2,3

A recent study in Nano Letters combined multilayer graphene, hexagonal boron nitride (hBN), and bilayer graphene to create a highly sensitive TFET-based quantum detector. Graphene’s exceptional conductivity and hBN’s insulating, atomically smooth surface made it possible to form extremely clean lateral tunnel junctions.

By tuning the band gaps in the layered structure, the device could detect electromagnetic waves in the terahertz range (a tricky frequency band between microwaves and infrared) with both high sensitivity and a wide dynamic range. This meant it could pick up extremely weak to very strong signals without losing accuracy.

Researchers are also exploring phosphorus-based materials to improve TFETs by creating a dopingless heterojunction TFET (DL-HTDET) to enhance performance for future low-power electronics.^4,5

Advantages of TFETs

TFETs have three key advantages over other transistors. First, their ultra-low subthreshold swing makes for faster, more efficient switching. Second, their low supply voltages and minimal leakage cut standby power use, ideal for always-on sensors and mobile gadgets. Third, they scale well: short-channel effects that plague tiny metal-oxide semiconductor field-effect transistors are less of a problem when electrons tunnel, rather than hop, over barriers.^3,6

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Current Research Directions

TFETs are ideal for low-power operation in IoT devices due to their low subthreshold swing and reduced leakage, which help increase battery life in sensor nodes and edge devices. Their ability to integrate with high-density circuits supports the large number of devices needed in IoT networks.³

Neuromorphic computing is another area where TFETs are making an impact. Their ability to mimic the sharp spikes of biological neurons makes them attractive for this hardware, along with their energy efficiency.

Flexible and wearable electronics have also made the most of this technology, with 2D TFETs being used to create more efficient circuits than advanced silicon technologies.^7,8

Challenges in Fabrication, Reliability, and Variability

Despite the advantages, TFETs still face substantial hurdles that hinder their commercial adoption.

Manufacturing TFETs requires exacting control of material properties and device interfaces. Achieving the desired band alignments demands precise doping and deposition techniques, especially when working with heterostructures or atomically thin 2D layers. Processing variations during fabrication can lead to inconsistent junction profiles or unintended defects, which impact tunneling efficiency and device yield.⁹

Because TFET conduction depends sensitively on the atomic-scale alignment of energy bands, any irregularities or defects can cause significant variability between devices. Trap-assisted tunneling, interface traps, and other non-idealities can increase leakage currents or lower the on/off current ratio. This susceptibility imposes reliability concerns for circuits intended for large-scale or safety-critical applications.¹⁰

Material Innovations Addressing Challenges

To tame these issues, researchers are fine-tuning the small scale. For instance, the engineering of heterostructure band alignment between different 2D materials or III-V compounds aims to maximize tunneling probability and minimize ambipolar conduction. Isoelectronic trap (IET) technology in silicon TFETs enhances tunneling currents while taking advantage of the established processing capabilities of silicon. Defect engineering in materials like MoS₂ and other 2D substances aims to create channels with controlled electronic properties while reducing variability and leakage pathways.^11,12

Conclusion

These TFETs sit at the intersection of quantum physics, materials science, and chip engineering. Though not yet ready to roll off production lines in volume, progress in their materials and fabrication is steady. If those efforts pay off, these quantum-powered switches could underpin the next wave of low-power computing, from smart sensors to brain-like processors and bendable electronics.

References and Further Reading

1. Kumar Kumawat, P., Birla, S., & Singh, N. (2023). Tunnel field effect transistor device structures: A comprehensive review. Materials Today: Proceedings, 79, 292-296. DOI:10.1016/j.matpr.2022.11.203. https://www.sciencedirect.com/science/article/abs/pii/S2214785322070535
2. Marin, E. G. et al. (2020). Lateral Heterostructure Field-Effect Transistors Based on Two-Dimensional Material Stacks with Varying Thickness and Energy Filtering Source. ACS Nano, 14(2), 1982. DOI:10.1021/acsnano.9b08489. https://pubs.acs.org/doi/10.1021/acsnano.9b08489
3. Kanungo, S. et al. (2022). 2D materials-based nanoscale tunneling field effect transistors: Current developments and future prospects. Npj 2D Materials and Applications, 6(1), 1-29. DOI:10.1038/s41699-022-00352-2. https://www.nature.com/articles/s41699-022-00352-2
4. Viti, L. et al. (2025). Quantum Sensitive, Record Dynamic Range Terahertz Tunnel Field-Effect Transistor Detectors Exploiting Multilayer Graphene/hBN/Bilayer Graphene/hBN Heterostructures. Nano Lett. 2025, 25, 15, 6005–6012. DOI:10.1021/acs.nanolett.4c04934. https://pubs.acs.org/doi/full/10.1021/acs.nanolett.4c04934
5. Khodabakhsh, A., Amini, A., & Afzal, A. (2025). Phosphorus-based heterojunction tunnel field-effect transistor: from atomic insights to circuit renovations. Physical Chemistry Chemical Physics. DOI:10.1039/d4cp04121f. https://pubs.rsc.org/en/content/articlelanding/2025/cp/d4cp04121f/
6. Why Tunnel FETs? (2019). ESD Association, Inc. https://www.esda.org/news/why-tunnel-fets/
7. Pal, A. et al. (2024). An ultra energy-efficient hardware platform for neuromorphic computing enabled by 2D-TMD tunnel-FETs. Nature Communications, 15(1), 1-10. DOI:10.1038/s41467-024-46397-3. https://www.nature.com/articles/s41467-024-46397-3
8. He, Y. et al. (2024). Evolution of Tribotronics: From Fundamental Concepts to Potential Uses. Micromachines, 15(10), 1259. DOI:10.3390/mi15101259. https://www.mdpi.com/2072-666X/15/10/1259
9. What are Tunnel Field-Effect Transistors (TFETs)? (2024). Invention Patent Drawings / Illustrations. https://rightpatents.com/tunnel-field-effect-transistors-tfets/
10. Chandan, B. V., Nigam, K. K., & Tanveer, A. (2025). Performance and Reliability Investigation of Mg2Si based Tunnel FET under Temperature Variations for High-Sensitivity Applications. Micro and Nanostructures, 200, 208084. DOI:10.1016/j.micrna.2025.208084. https://www.sciencedirect.com/science/article/abs/pii/S2773012325000135
11. Mori, T., Iizuka, S. & Nakayama, T. (2017). Material engineering for silicon tunnel field-effect transistors: isoelectronic trap technology. MRS Communications 7, 541–550. DOI:10.1557/mrc.2017.63. https://link.springer.com/article/10.1557/mrc.2017.63
12. Lyu, J., Gong, J., & Li, H. (2022). Harnessing defects for high-performance MoS₂ tunneling field-effect transistors. Materials Research Letters, 11(4), 266–273. DOI:10.1080/21663831.2022.2145921. https://www.tandfonline.com/doi/full/10.1080/21663831.2022.2145921

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