[paper] OTFTs in Mechanical Sensors

Organic Thin Film Transistors in Mechanical Sensors 

Zachary A. Lamport, Marco Roberto Cavallari^2,3, Kevin A. Kam, 

Christine K. McGinn, Caroline Yu, and Ioannis Kymissis

DOI: 10.1002/adfm.202004700

¹Department of Electrical Engineering, Columbia University, USA
²Departamento de Engenharia de Sistemas Eletrônicos, EPU de São Paulo, Brazil
³Department of Renewable Energies. UNILA, Brazil

Abstract: The marriage of organic thin-film transistors (OTFTs) and flexible mechanical sensors has enabled previously restricted applications to become a reality. Counterintuitively, the addition of an OTFT at each sensing element can reduce the overall complexity so that large-area, low-noise sensors can be fabricated. The best-performing instance of this is the active matrix, used in display applications for many of the same reasons, and nearly any type of flexible mechanical sensor can be incorporated into these structures. In this Progress Report, some of the flexible sensor devices that have taken advantage of these mechanical properties are highlighted, examining the advantages that OTFTs offer in the hybrid integration of local amplification and switching. In particular, the current research on resistive pressure sensors, capacitive pressure sensors, resistive or piezoresistive strain sensors, and piezoelectric sensors is identified and enumerated.

Fig: Suspended-gate FET: a) Schematic illustration of device geometry; b) electrical equivalent circuit; c) pressure response of ID at constant VDS = VGS = −60 V

Acknowledgements C.M. received funding from the National Science Foundation Graduate Research Fellowship Program (DGE—1644869). Z.L. thanks Corning and the NSF under STTR 1914013 for financial support.

OFETs Compact Modeling

Advances in Compact Modeling of Organic Field-Effect Transistors

Sungyeop Jung¹, Member, IEEE, Yvan Bonnassieux², Gilles Horowitz², Sungjune Jung¹, Member, IEEE, Benjamin Iñiguez³, Fellow, IEEE, and Chang-Hyun Kim⁴, Senior Member, IEEE

IEEE J-EDS (Early Access)

DOI: 10.1109/JEDS.2020.3020312

¹Future IT Innovation Laboratory and Department of Creative IT Engineering, Pohang University of Science and Technology, Pohang 37673, South Korea.
²LPICM, Ecole Polytechinque, CNRS, 91128 Palaiseau, France.

³DEEEA, Universitat Rovira i Virgili, Tarragona 43007, Spain.

⁴Department of Electronic Engineering, Gachon University, Seongnam 13120, South Korea

Abstract: In this review, recent advances in compact modeling of organic field-effect transistors (OFETs) are presented. Despite the inherent strength for printed flexible electronics and the extremely aggressive research conducted over more than three decades, the OFET technology still seems to remain at a relatively low technological readiness level. Among various possible reasons for that, the lack of a standard compact model, which effectively bridges the device- and system-level development, is clearly one of the most critical issues. This paper broadly discusses the essential requirements, up-to-date progresses, and imminent challenges for the OFET compact device modeling toward a universal, physically valid, and applicable description of this fast-developing technology.

Figure (a) Cross-sectional illustration and (b) circuit diagram with multi-component overlap capacitances of the printed 3-D organic complementary inverter, and (c) measured and simulated transient output voltage of an 11-stage ring oscillator.

Compact DC Modeling of Organic Field-Effect Transistors: Review and Perspectives

In spite of impressive improvements achieved for organic field-effect transistors (OFETs), there is still a lack of theoretical understanding of their behaviors. Furthermore, it is challenging to develop a universal model that would cover a huge variety of materials and device structures available for state-of-the-art OFETs. Nonetheless, currently there is a strong need for specific OFET compact models when device-to-system integration is an important issue. We briefly describe the most fundamental characters of organic semiconductors and OFETs, which set the bottom line dictating the requirement of an original model different from that of conventional inorganic devices. Along with an introduction to the principles of compact modeling for circuit simulation, a comparative analysis of the reported models is presented with an emphasis on their primary assumptions and applicability aspects. Critical points for advancing OFET compact models are discussed in consideration of the recent understanding of device physics.

[1] Kim, C.-H.; Bonnassieux, Y.; Horowitz, G., "Compact DC Modeling of Organic Field-Effect Transistors: Review and Perspectives," Electron Devices, IEEE Transactions on , vol.61, no.2, pp.278,287, Feb. 2014
doi: 10.1109/TED.2013.2281054
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