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New organic thin-film tunnel transistors for wearable and other small electronics

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New organic thin-film tunnel transistors for wearable and other small electronics


Circuit diagram of the PPG sensor interface prepared using our OTFTT to enhance weak sensory signals under illumination (wavelength, 650 nm). Credit: Nature Electronics (2025). DOI: 10.1038/s41928-025-01462-7

To meet the growing demands of flexible and wearable electronic systems, such as smart watches and biomedical sensors, electronics engineers are seeking high-performance transistors that can efficiently modulate electrical current while maintaining mechanical flexibility.

Thin-film transistors (TFTs), which are comprised of thin layers of conducting, semiconducting and insulating materials, have proved to be particularly promising for large-area flexible and wearable electronics, while also enabling the creation of thinner displays and advanced sensors.

Despite their potential, the energy-efficiency with which these transistors can switch has proved difficult to improve. This is due to the so-called thermionic limit, a theoretical threshold that delineates the lowest possible voltage required for a transistor to boost electrical current by a factor of 10 at room temperature when switching between “off” and “on” states.

Researchers at Soochow University and other institutes have developed a new TFT based on organic materials that could bypass this limitation, as it operates below the thermionic limit. The transistor, introduced in a paper published in Nature Electronics, was found to amplify signals with remarkable efficiency.

“Our work was driven by a fundamental challenge in wearable electronics and Internet of Things (IoT): the pursuit of high-performance devices with ultra-low-power consumption,” Jiansheng Jie, senior author of the paper, told Tech Xplore.

“Conventional organic thin-film transistors (OTFTs) are inherently limited by the thermionic emission mechanism, which sets a theoretical minimum for the subthreshold swing (SS)—a key metric that determines how efficiently a transistor can switch—of 60 mV dec-1 at room temperature. This inherent limitation results in excessive power dissipation during switching operations, posing a major barrier to energy-efficient operation.”

This recent study builds on recent works that highlighted the promise of so-called tunnel field-effect transistors (TFETs) based on inorganic semiconductors. These transistors were found to overcome the limitations of conventional transistors, leveraging a quantum mechanical process known as band-to-band tunneling.

“We sought to translate these advantages into the field of organic electronics,” said Jie. “Our central objective was to develop organic thin-film tunnel transistors (OTFTTs) capable of sub-60 mV dec-1 performance, thereby breaking the fundamental thermionic limit that has long governed conventional OTFTs.

“By demonstrating such behavior in a solution-processable, flexible organic platform, our research addresses a critical gap in the technological evolution of organic electronics and paves the way toward low-voltage, highly efficient flexible circuits for next-generation wearable and IoT applications.”

The new OTFTT developed by the researchers replaces the thermionic injection mechanism that drives the operation of conventional TFTs with band-to-band tunneling. This process allows to pass through the energy barrier directly and at extremely low voltages, significantly boosting the devices’ switching efficiency.

“The key innovation lies in the design of a hybrid inorganic-organic source-channel heterojunction,” explained Jie.

“We combined molybdenum trioxide (MoO3), an inorganic metal oxide with a deep-conduction-band, with the 2,7-dioctyl[1]-benzothieno[3,2-b][1]benzothiophene (C8-BTBT) single-crystalline thin film, which has a relatively low highest occupied molecular orbital (HOMO) energy level. This creates a ‘broken-gap’ alignment, where the HOMO of C8-BTBT lies above the conduction band (CB) of MoO3.”

New organic thin-film tunnel transistors for wearable and other small electronics
Cross-sectional schematic of the deposited MoO3 on top of C8-BTBT, where the bombardment of high-energy MoO3 clusters creates damage to the C8-BTBT, producing defects, interface diffusion and molecular stacking disorder. Credit: Nature Electronics (2025). DOI: 10.1038/s41928-025-01462-7

The configuration of the team’s transistor prompts the thermally excited tail of carriers originating from the MoO3 source to be sharply truncated. This in turn effectively suppresses classical thermionic emission processes, making band-to-band tunneling the dominant carrier injection mechanism.

“Meanwhile, by introducing a molecular decoupling layer (BPE-PDCTI) at the heterojunction interface, the Fermi-level pinning effect was effectively alleviated and the tunneling barrier height was further reduced,” said Jie.

“This strategic design enables the device to trigger charge band-to-band tunneling at an extremely low supply voltage. As a result, our OTFTTs overcame the 60 mV dec-1 thermionic limit on SS, achieving the lowest SS of 24.2 ± 5.6 mV dec-1 among the existing thin-film transistor technologies, alongside the record-high signal amplification efficiency of 101.2 ± 28.3 S A-1.”

The ultra-low SS yielded by the newly developed transistor is highly favorable for the development of low-power signal amplification circuits. In initial tests, circuits based on the transistor were found to achieve a gain in amplification of over 537 V V−1 at an ultra-low power consumption below 0.8 nW.

“Our OTFTTs break the fundamental thermionic limit—a long-standing theoretical ceiling on SS (60 mV dec⁻¹ at room temperature) that has constrained the energy efficiency of conventional for decades,” said Jie.

“This breakthrough not only redefines the performance boundaries of organic electronics but also enables a new class of ultra-low-power devices. The practical implications are substantial. Our OTFTTs are ideally suited for energy-constrained applications such as wearable health monitors, implantable biosensors, and self-powered IoT nodes.”

Notably, the OTFTT developed by Jie and his colleagues is compatible with existing processing and electronics fabrication strategies. In the future, it could be improved further and used to develop a wide range of high precision sensing devices, including trackers for the diagnosis or monitoring of specific medical conditions, environmental sensing systems and neuromorphic (brain-inspired) computing hardware.

“In bridging the gap between the intrinsic physical limitations of organic semiconductors and the stringent efficiency demands of next-generation technologies, this work represents a critical step toward intelligent, pervasive, and environmentally benign electronic systems,” said Jie.

Other researchers could soon build on the team’s design and set out to develop similar OTFTTs. Meanwhile, Jie and his colleagues plan to continue improving their device, for instance, by optimizing its performance via the careful engineering of energy levels at the interface between the organic materials it is based on.

To do this, they will select organic semiconductors with reduced bandgaps and lower carrier effective mass, while also creating high-conductivity interfacial decoupling layers that could enhance the transistor’s tunneling efficiency and performance.

“We will also expand the technology to n-type OTFTTs to enable all-organic tunneling logic circuits, addressing the current gap in low-power organic logic applications,” added Jie.

“Moreover, we plan to deploy OTFTTs in high-precision biomedical signal amplification (e.g., EEG, EMG), ultra-sensitive environmental sensing (e.g., trace gas detection, low-light imaging), and low-power IoT signal processing.

“Finally, we will continue developing scalable integration techniques for the large-scale fabrication of the OTFTTs on flexible substrates, aiming to accelerate the industrial adoption of high-performance, energy-efficient organic electronic systems.”

Written for you by our author Ingrid Fadelli, edited by Sadie Harley, and fact-checked and reviewed by Robert Egan—this article is the result of careful human work. We rely on readers like you to keep independent science journalism alive.
If this reporting matters to you,
please consider a donation (especially monthly).
You’ll get an ad-free account as a thank-you.

More information:
Wei Deng et al, Organic thin-film tunnel transistors, Nature Electronics (2025). DOI: 10.1038/s41928-025-01462-7.

© 2025 Science X Network

Citation:
New organic thin-film tunnel transistors for wearable and other small electronics (2025, October 22)
retrieved 22 October 2025
from https://techxplore.com/news/2025-10-thin-tunnel-transistors-wearable-small.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.





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How Data Centers Actually Work

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How Data Centers Actually Work


Lauren Goode: Well, they’re all interested in growing more. Who among us, Mike? But the hyperscalers refers to this class of major tech companies or cloud service providers. So Meta, Amazon, Microsoft, Google, they’re all in that category.

Molly Taft: Yeah, and I think it’s important to remember that these companies have so much money and they have an ability to raise capital like nobody’s business. So they’re able to do some really crazy stuff to build quick and to build-out really, really big. And they’re getting pretty creative, because their goals right now are to build these things quickly and get them up and running so they can basically use this physical infrastructure to compete with each other.

Lauren Goode: I think that’s right, Molly. I think there’s a lot of frenemy building happening right now, and I would just love to be a part of their group chats when all of these announcements are being made.

Michael Calore: Yeah, and speaking of frenemies, the other sphere of influence that these companies are operating in is the political sphere. Obviously, in order to build a giant data center somewhere, you need to have the political will to do it, which means you need buy-in from the local residents, the local government, the state, the country. So what’s happening in the political sphere with folks who want to build more data centers and people who oppose it, regulation? How is that playing out?

Molly Taft: That’s a great question, and I think if you look at the national conversation, it’s quite different than what’s happening on the local level. You have Washington, you obviously have an administration that is very friendly to the idea of an American AI empire. Importantly for the energy conversation, the way that the Trump administration has approached this support has been through support of fossil fuels. They would really like for all data centers to be powered with oil and gas, a little bit of nuclear and coal. And this works out great for those industries as well. If you’re going to have this massive expansion of power demand, it’s really cool to be in the middle of that and be the one that everyone wants to turn to for energy resourcing. And then on the other side, there has been this influx of local opposition to these data centers for a variety of reasons, be it the water use, be it fears about rising electricity rates, be it noise, and some of the really big struggles have catapulted this issue to national conversation. I’m thinking about xAI in Memphis. When Elon Musk wanted to get xAI up and running, he installed a bunch of unpermitted gas turbines in order to get xAI working that he installed in a majority Black community in Memphis that already had severe issues with air pollution and asthma. And those folks made themselves known. Earlier this year, there was an attempt in DC to impose a moratorium on any state regulation around AI at all. It was an incredibly broad inclusion in the Big Beautiful Bill that ultimately didn’t succeed. But one of the people who opposed it publicly was Marjorie Taylor Greene, who actually mentioned data centers in her opposition, and she compared AI to Skynet, the fictional AI from the Terminator movie franchise. So, this is getting some strange bedfellows in league with each other, I think this kind of contrast between what the administration is trying to push forward and some very powerful energy companies that stand to gain from it, versus some truly grassroots local movements and people concerned about the impacts of what these things are going to do in their communities.



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Isotropic MOF coating reduces side reactions to boost stability of solid-state Na batteries

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Isotropic MOF coating reduces side reactions to boost stability of solid-state Na batteries


An illustration summarizing the LSV–GCMS technique. Credit: Liu et al. (Nature Energy, 2025).

In recent years, energy engineers have been trying to design new reliable batteries that can store more energy and allow electronics to operate for longer periods of time before they need to be charged. Some of the most promising among these newly developed batteries are solid-state batteries, which contain solid electrolytes instead of liquid ones.

Compared to batteries with liquid electrolytes that are widely used today, solid-state batteries could exhibit higher energy densities (i.e., could store more energy) and longer lifetimes. However, many of these batteries have been found to be unstable, due to unwanted chemical reactions that occur between their high-voltage cathodes (i.e., positive electrodes) and solid electrolytes, which can speed up the degradation of the batteries’ performance over time.

These undesirable side reactions are particularly common in sodium-ion (Na+) solid-state batteries, which use Na+ ions to store and release electrical energy. This is because while Na is more abundant and cheaper than lithium, Na-ion batteries are inherently more chemically reactive than Li-ion batteries.

Researchers at the Chinese Academy of Sciences recently introduced a promising strategy to increase the durability and performance of solid-state Na-based solid-state batteries, by minimizing side reactions between their underlying cathodes and solid electrolytes. This strategy, outlined in a paper published in Nature Energy, entails the growth of a dense metal-organic framework (MOF) layer on the surface of high-voltage cathodes, which could prevent them from reacting with .

“Side reactions between high-voltage cathodes and electrolytes remain a critical obstacle to the advancement of solid-state batteries—particularly for Na-ion systems—due to the higher Na+/Na redox potential,” wrote Yuan Liu, Huican Mao and their colleagues in their paper.

“Despite recent extensive efforts, achieving a long cycle life is still challenging at the 4.2 V cut-off (versus Na+/Na). We design a room-temperature isotropic epitaxial growth to achieve a relatively uniform and dense metal–organic framework epilayer on Na3V2O2(PO4)2F surfaces.”

To assess the potential of their approach, the researchers grew a uniform MOF coating on Na₃V₂O₂(PO₄)₂F cathodes via a process known as room-temperature isotropic epitaxial growth. They then created a solid-state battery, pairing this coated electrode with a solid electrolyte based on the polymer polyethylene oxide.

“Despite using polyethylene oxide, a typical ether-based solid polymer electrolyte, the cathode with isotropic epilayer exhibits enhanced cycling performance at the 4.2 V cut-off (retaining up to 77.9% of its initial capacity after 1,500 cycles),” wrote the authors.

“Combining experimental measurements and theoretical analyses, the key factor governing isotropic epitaxial growth behavior is explicitly elucidated. Furthermore, we develop a self-designed high-sensitivity characterization method, in situ linear sweep voltammetry coupled with , to elucidate the failure mechanism of polyethylene oxide on Na3V2O2(PO4)2F surfaces and to reveal the excellent electrochemical stability of the isotropic epilayer.”

In initial tests, solid-state batteries based on the team’s coated cathode material were found to perform remarkably well, exhibiting significantly fewer side reactions between the and electrolyte. Notably, the strategy they employed could also be applied to other cathodes and batteries with different compositions.

Other researchers could soon draw inspiration from this study and employ similar strategies to stabilize other Na-based solid-state batteries. In the future, the isotropic epitaxial method developed by Liu, Mao and their colleagues could ultimately contribute to the large-scale deployment of durable and reliable with high-energy densities.

Written for you by our author Ingrid Fadelli, edited by Gaby Clark, and fact-checked and reviewed by Robert Egan—this article is the result of careful human work. We rely on readers like you to keep independent science journalism alive.
If this reporting matters to you,
please consider a donation (especially monthly).
You’ll get an ad-free account as a thank-you.

More information:
Yuan Liu et al, Designing an isotropic epilayer for stable 4.2 V solid-state Na batteries, Nature Energy (2025). DOI: 10.1038/s41560-025-01857-y.

© 2025 Science X Network

Citation:
Isotropic MOF coating reduces side reactions to boost stability of solid-state Na batteries (2025, October 24)
retrieved 24 October 2025
from https://techxplore.com/news/2025-10-isotropic-mof-coating-side-reactions.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.





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How Prankster Oobah Butler Convinced Venture Capitalists to Give Him Over $1 Million

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How Prankster Oobah Butler Convinced Venture Capitalists to Give Him Over  Million


Not long into his new documentary, Oobah Butler tells the cofounder of his newly minted company, Drops, that they should create a piece of luxury luggage that “looks like a bomb” and will sell for $200,000.

Immediately, I’m thinking his quest to get £1 million in 90 days might have come to an early end.

But I’m wrong.

Butler is a British prankster documentarian who is known for his stunts, like managing to get Amazon to sell its drivers’ urine as energy drinks or creating a fake restaurant called the Shed and gaming TripAdvisor to make it the top-rated London restaurant on the platform. His latest documentary, made for the UK’s Channel 4, is called How I Made £1 Million in 90 Days. Set in London and New York, it takes on the worlds of startups, venture capital, crypto, and what ultimately comes across as a lot of bullshitting, in the name of striking it rich quick.

Butler opens the film by saying, as someone who didn’t grow up with money and isn’t particularly motivated by it, he’s fascinated by the fact that people “idolize” wealthy entrepreneurs.

“It came from a place of wanting to understand why … everyone is so obsessed with money in this way,” he tells WIRED. “And I’m not talking about survival. I’m not talking about affording to exist. I’m talking about … being addicted to the making of money.”

His only rules for getting £1 million ($1.3 million USD) are that he’s not allowed to break the law and whatever costs he incurs trying to make it are his to bear. He employs several strategies to rack up the cash, including simply asking rich people for it (this doesn’t go well) and creating hype for crypto company UNFK by doing things like tricking bankers into committing crimes on camera. He also creates Drops, a company that makes news for its controversial stunts and then tries to capitalize on the attention by selling “very overpriced” items.

Butler seeks the advice of Venmo cofounder Iqram Magdon-Ismail, who quickly declares himself Butler’s cofounder on Drops and seems very enthusiastic at first, musing that the company is already “worth at least $10 million” just because the two of them are attached to it, and that they might be able sell out Madison Square Garden in a year’s time to tell their story. Their brainstorming session includes schemes for buying the first piece of land on Mars and selling the opportunity to name the “first branded species.” But after Butler suggests the bomb-like suitcase and a pair of “real life ad blocking sunglasses” that remove the wearer’s vision entirely, Magdon-Ismail temporarily ghosts him.

Butler then embarks on a memecoin adventure that goes south, before coming back to Drops and launching the “first legal child sweatshop in Britain in over a century.” He finds a loophole to avoid paying the child workers, reasoning that because he is filming the kids for the documentary, they are technically performers. His underage staff help him come up with marketing ideas to sell bespoke soccer jerseys featuring a fake religious cigarette brand called Holy Smokes. Though the clothing line gets coverage in GQ, Butler doesn’t sell anything close to £1 million worth of jerseys.



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