Xinming Zhuang https://orcid.org/0000-0001-6348-7539, Joon-Seok Kim, Wei Huang [email protected], Yao Chen, Gang Wang, Jianhua Chen, Yao Yao https://orcid.org/0000-0003-3068-766X, Zhi Wang [email protected], Fengjing Liu, Junsheng Yu, Yuhua Cheng, Zaixing Which https://orcid.org/0000-0002-9040-8805 [email protected], Lincoln J. I swear [email protected], Tobin J. Marks https://orcid.org/0000-0001-8771-0141 [email protected]and Antonio Facchetti https://orcid.org/0000-0002-8175-7958 [email protected]Authors Info & Affiliations
Contributed by Tobin J. Marks; received October 6, 2022; accepted December 9, 2022; reviewed by Thomas E. Mallouk, Ralph G. Nuzzo,and Peidong Yang
January 11, 2023
120 (3) e2216672120
Significance
Source-gated transistors (SGTs) exhibit high intrinsic gain, immunity to bias instability, low-power consumption, and tolerance to short-channel effects, and thus are attractive candidates for wearable devices. However, few studies have addressed the potential of metal oxide semiconductor (MO)-based SGTs. Here we demonstrate solution-processed MO SGTs based on a semiconductor homojunction, comprised of solution-processed In2O3 and In2O3:PEI polymer blend layers of controlled doping, exhibiting low saturation voltage, low-power consumption, and high intrinsic gain. Furthermore, electrooculographic signal monitoring is demonstrated using an SGT inverter, which provides a voltage gain of over 300 and is readily suitable for applications in wearable medical sensing.
Abstract
Cost-effective fabrication of mechanically flexible low-power electronics is important for emerging applications including wearable electronics, artificial intelligence, and the Internet of Things. Here, solution-processed source-gated transistors (SGTs) with an unprecedented intrinsic gain of ~2,000, low saturation voltage of +0.8 ± 0.1 V, and a ~25.6 μW power consumption are realized using an indium oxide In2O3/In2O3:polyethylenimine (PEI) blend homojunction with Au contacts on Si/SiO2. Kelvin probe force microscopy confirms source-controlled operation of the SGT and reveals that PEI doping leads to more effective depletion of the reverse-biased Schottky contact source region. Furthermore, using a fluoride-doped AlOx gate dielectric, rigid (on a Si substrate) and flexible (on a polyimide substrate) SGTs were fabricated. These devices exhibit a low driving voltage of +2 V and power consumption of ~11.5 μW, yielding inverters with an outstanding voltage gain of>5,000. Furthermore, electrooculographic (EOG) signal monitoring can now be demonstrated using an SGT inverter, where a ~1.0 mV EOG signal is amplified to over 300 mV, indicating significant potential for applications in wearable medical sensing and human–computer interfacing.
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Data, Materials, and Software Availability
All study data are included in the article and/or SI Appendix.
Acknowledgments
This work was supported by the NSF MRSEC program (grant DMR-1720139) and by AFOSR (grants FA9550-18-1-0320 and FA9550-22-1-0423). This work made use of the Northwestern University Micro/Nano Fabrication Facility (NUFAB), and EPIC facility of Northwestern University’s NUANCE Center, which has received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-1542205); the MRSEC program (NSF DMR-1720139) at the Materials Research Center; the International Institute for Nanotechnology (IIN); the Keck Foundation; and the State of Illinois, through the IIN. X.Z. thanks the National Natural Science Foundation of China (NSFC) (Grant Nos. U21A20492 & 62104133); Natural Science Foundation of Shandong Province (ZR2021QA011); China Postdoctoral Science Foundation (2021M701976); Postdoctoral Program for Innovative Talents of Shandong Province (SDBX2021002). We also gratefully acknowledge Q. Zhang’s kind help in drawing the eye diagram.
Author contributions
X.Z., J.-S.K., W.H., L.J.L., T.J.M., and A.F. designed research; X.Z., J.-S.K., and W.H. performed research; X.Z., J.-S.K., W.H., Y.C. (Northwestern), G.W., J.C., Y.Y., Z.W., F.L., J.Y., Y.C. (UESTC), Z.Y., and L.J.L. analyzed data; X.Z., W.H., T.J.M., and A.F. led the project.; Y.C. (Northwestern), G.W., J.C., Y.Y., Z.W., F.L., J.Y., Y.C. (UESTC), and Z.Y. discussed the results and commented on the manuscript; and X.Z., J.-S.K., W.H., L.J.L., T.J.M., and A.F. wrote the paper.
Competing interest
The authors declare no competing interest.
Supporting Information
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Information & Authors
Information
Published in
Proceedings of the National Academy of Sciences
Vol. 120 | No. 3
January 17, 2023
Classifications
Copyright
Data, Materials, and Software Availability
All study data are included in the article and/or SI Appendix.
Submission history
Received: October 6, 2022
Accepted: December 9, 2022
Published online: January 11, 2023
Published in issue: January 17, 2023
Keywords
- source-gated transistor (SGT)
- solution processing
- metal oxide–polymer blend material
- EOG monitoring
- Kelvin probe force microscopy
Acknowledgments
This work was supported by the NSF MRSEC program (grant DMR-1720139) and by AFOSR (grants FA9550-18-1-0320 and FA9550-22-1-0423). This work made use of the Northwestern University Micro/Nano Fabrication Facility (NUFAB), and EPIC facility of Northwestern University’s NUANCE Center, which has received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-1542205); the MRSEC program (NSF DMR-1720139) at the Materials Research Center; the International Institute for Nanotechnology (IIN); the Keck Foundation; and the State of Illinois, through the IIN. X.Z. thanks the National Natural Science Foundation of China (NSFC) (Grant Nos. U21A20492 & 62104133); Natural Science Foundation of Shandong Province (ZR2021QA011); China Postdoctoral Science Foundation (2021M701976); Postdoctoral Program for Innovative Talents of Shandong Province (SDBX2021002). We also gratefully acknowledge Q. Zhang’s kind help in drawing the eye diagram.
Author Contributions
X.Z., J.-S.K., W.H., L.J.L., T.J.M., and A.F. designed research; X.Z., J.-S.K., and W.H. performed research; X.Z., J.-S.K., W.H., Y.C. (Northwestern), G.W., J.C., Y.Y., Z.W., F.L., J.Y., Y.C. (UESTC), Z.Y., and L.J.L. analyzed data; X.Z., W.H., T.J.M., and A.F. led the project.; Y.C. (Northwestern), G.W., J.C., Y.Y., Z.W., F.L., J.Y., Y.C. (UESTC), and Z.Y. discussed the results and commented on the manuscript; and X.Z., J.-S.K., W.H., L.J.L., T.J.M., and A.F. wrote the paper.
Competing Interest
The authors declare no competing interest.
Notes
Reviewers: T.E.M., University of Pennsylvania; R.G.N., University of Illinois at Urbana-Champaign; and P.Y., University of California Berkeley University Health Services.
Authors
Affiliations
School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, P. R. China
Department of Chemistry, Northwestern University, Evanston, IL 60208
Materials Research Center, Northwestern University, Evanston, IL 60208
State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China
Joon-Seok Kim1
Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208
Department of Chemistry, Northwestern University, Evanston, IL 60208
School of Automation Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan 611731, China
Yao Chen
Department of Chemistry, Northwestern University, Evanston, IL 60208
Materials Research Center, Northwestern University, Evanston, IL 60208
Gang Wang
Department of Chemistry, Northwestern University, Evanston, IL 60208
Materials Research Center, Northwestern University, Evanston, IL 60208
Jianhua Chen
Department of Chemistry, Northwestern University, Evanston, IL 60208
Materials Research Center, Northwestern University, Evanston, IL 60208
Department of Chemistry, Northwestern University, Evanston, IL 60208
Materials Research Center, Northwestern University, Evanston, IL 60208
Department of Chemistry, Northwestern University, Evanston, IL 60208
Materials Research Center, Northwestern University, Evanston, IL 60208
Fengjing Liu
School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, P. R. China
Junsheng Yu
State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China
Yuhua Cheng
School of Automation Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan 611731, China
School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, P. R. China
Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208
Department of Chemistry, Northwestern University, Evanston, IL 60208
Materials Research Center, Northwestern University, Evanston, IL 60208
Department of Chemistry, Northwestern University, Evanston, IL 60208
Materials Research Center, Northwestern University, Evanston, IL 60208
Flexterra Corporation, Skokie, IL 60077
Notes
1X.Z. and J.-S.K. contributed equally to this work.
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