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[[Vol. 79]Insight into Organic Antiambipolar Transistors_ WPI-MANA.pdf](https://mdr.nims.go.jp/filesets/d610db50-4b12-41bf-b864-befd732be082/download)

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International Center for Materials Nanoarchitectonics (WPI-MANA)

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[[Research Highlights Vol.79] Insight into Organic Antiambipolar Transistors](https://mdr.nims.go.jp/datasets/aaadb325-8f21-40b3-89bf-77c162e3beae)

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2022/11/07 8:52 Insight into Organic Antiambipolar Transistors| MANAhttps://www.nims.go.jp/mana/research/highlights/vol79.html 1/2Previous  Index  Nextesearch Highlights[Vol. 79]Insight into Organic Antiambipolar Transistors25 Oct, 2022WPI-MANA researchers have elucidated the mechanism behind organic antiambipolartransistors (OAATs), a new class of transistors with possible applications in artificialintelligence and neuromorphic devices.Transistors are one of the basic building blocks of modern technology and electronics. The emergenceof artificial intelligence and brain-like devices has brought about a need for multiple logic gateoperations to be conducted on the same transistor chip. Even the gold standard, complementarymetal-oxide semiconductor (CMOS) transistors, cannot handle such a large load of operations. Hence,the search is on for technologies that can.Researchers from WPI-MANA, led by Dr. Ryoma Hayakawa, have been investigating a new class oftransistors, OAATs. OAATs can support multiple logic gate operations owing to a unique propertycalled negative differential transconductance (NDT). The research team’s extensive work, directed byDr. Yutaka Wakayama, has looked to first elucidate the charge-carrier mechanism in these devices,and then also apply them to multiple logic gate operations. "We needed to know how OAATs work sothat they could then be improved upon. So, we directly visualized the electron flow in an OAAT, usinga technique called operando photoemission electron microscopy (PEEM). We were then able tounderstand where the transistor junction gets its exciting switchable property," explains Wakayama.The PEEM experiments showed that a depletion layer is formed at the lateral p-n interface; thisgenerates a large potential difference, enhancing electron conduction in the transistor. Armed withhttps://www.nims.go.jp/mana/research/highlights/vol78.htmlhttps://www.nims.go.jp/mana/research/highlights/index.htmlhttps://www.nims.go.jp/mana/research/highlights/vol80.html2022/11/07 8:52 Insight into Organic Antiambipolar Transistors| MANAhttps://www.nims.go.jp/mana/research/highlights/vol79.html 2/2this knowledge, the research team looked at its applicability. "By adjusting input voltages acrossOAATs, we could achieve five different logic gate operations on the same device. We could evenswitch between two logic gates with a given set of inputs," explains Wakayama.OAATs are stable and reliable, operating for months. They can surpass CMOS devices for manyapplications. Keeping this in mind, the work done at WPI-MANA could lead to a massive reduction inthe number of transistors required in current integrated circuits and improve their processing ability,enabling the development of more advanced technology that can handle large amounts of operations.Reference“Carrier-Transport Mechanism in Organic Antiambipolar Transistors Unveiled by OperandoPhotoemission Electron Microscopy”Ryoma Hayakawa, Soichiro Takeiri, Yoichi Yamada, Yutaka Wakayama, and Keiki Fukumoto.Journal: Advanced Materials, 2022, 34, 2201277 (June 19 2022)DOI : 10.1002/adma.202201277“Electrically Reconfigurable Organic Logic Gates: A Promising Perspective on a Dual-GateAntiambipolar Transistor”Ryoma Hayakawa, Kosuke Honma, Shu Nakaharai, Kaname Kanai, and Yutaka Wakayama.Journal: Advanced Materials, 2022, 34, 2109491 (February 27 2022)DOI : 10.1002/adma.202109491AffiliationsInternational Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for MaterialsScience (NIMS), Namiki 1-1, Tsukuba, Ibaraki 305-0044, JapanContact informationInternational Center for Materials Nanoarchitectonics(WPI-MANA)National Institute for Materials Science1-1 Namiki, Tsukuba, Ibaraki 305-0044 JapanPhone: +81-29-860-4710E-mail: mana-pr[AT]ml.nims.go.jpTo receive our e-mail newsletter “MANA Research Highlights”, please send an e-mail with "MANA ResearchHighlights request” in the subject line or main text to the following address: mana-pr_at_ml.nims.go.jp *Please change "_at_ " in the email address to @.https://samurai.nims.go.jp/profiles/hayakawa_ryoma?locale=enhttps://samurai.nims.go.jp/profiles/wakayama_yutaka?locale=enhttps://doi.org/10.1002/adma.202201277https://samurai.nims.go.jp/profiles/hayakawa_ryoma?locale=enhttps://samurai.nims.go.jp/profiles/nakaharai_shu?locale=enhttps://samurai.nims.go.jp/profiles/wakayama_yutaka?locale=enhttps://doi.org/10.1002/adma.202109491