| 1. |
- Andersson Ersman, Peter, et al.
(författare)
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Monolithic integration of display driver circuits and displays manufactured by screen printing
- 2020
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Ingår i: Flexible and Printed Electronics. - : Institute of Physics Publishing. - 2058-8585. ; 5:2
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Tidskriftsartikel (refereegranskat)abstract
- Here, we report all-screen printed display driver circuits, based on organic electrochemical transistors (OECTs), and their monolithic integration with organic electrochromic displays (OECDs). Both OECTs and OECDs operate at low voltages and have similar device architectures, and, notably, they rely on the very same electroactive material as well as on the same electrochemical switching mechanism. This then allows us to manufacture OECT-OECD circuits in a concurrent manufacturing process entirely based on screen printing methods. By taking advantage of the high current throughput capability of OECTs, we further demonstrate their ability to control the light emission in traditional light-emitting diodes (LEDs), where the actual LED addressing is achieved by an OECT-based decoder circuit. The possibility to monolithically integrate all-screen printed OECTs and OECDs on flexible plastic foils paves the way for distributed smart sensor labels and similar Internet of Things applications.
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| 2. |
- Tran, Van Chinh, et al.
(författare)
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Electrical current modulation in wood electrochemical transistor
- 2023
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 120:118
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Tidskriftsartikel (refereegranskat)abstract
- The nature of mass transport in plants has recently inspired the development of low-cost and sustainable wood-based electronics. Herein, we report a wood electrochemical transistor (WECT) where all three electrodes are fully made of conductive wood (CW). The CW is prepared using a two-step strategy of wood delignification followed by wood amalgamation with a mixed electron-ion conducting polymer, poly(3,4-ethylenedioxythiophene)–polystyrene sulfonate (PEDOT:PSS). The modified wood has an electrical conductivity of up to 69 Sm−1 induced by the formation of PEDOT:PSS microstructures inside the wood 3D scaffold. CW is then used to fabricate the WECT, which is capable of modulating an electrical current in a porous and thick transistor channel (1 mm) with an on/off ratio of 50. The device shows a good response to gate voltage modulation and exhibits dynamic switching properties similar to those of an organic electrochemical transistor. This wood-based device and the proposed working principle demonstrate the possibility to incorporate active electronic functionality into the wood, suggesting different types of bio-based electronic devices.
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| 3. |
- Zabihipour, Marzieh, et al.
(författare)
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Designing Inverters Based on Screen Printed Organic Electrochemical Transistors Targeting Low-Voltage and High-Frequency Operation
- 2021
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Ingår i: Advanced Materials Technologies. - : John Wiley and Sons Inc. - 2365-709X. ; 6:12
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Tidskriftsartikel (refereegranskat)abstract
- Low-voltage operating organic electronic circuits with long-term stability characteristics are receiving increasing attention because of the growing demands for power efficient electronics in Internet of Things applications. To realize such circuits, inverters, the fundamental constituents of many circuits, with stable transfer characteristics should be designed to provide low-power consumption. Here, a rational inverter design, based on fully screen printed p-type organic electrochemical transistors with a channel size of 150 × 80 µm2, is explored for driving conditions with input voltage levels that differs of about 1 V. Further, three different inverter circuits are explored, including resistor ladders with resistor values ranging from tens of kΩ to a few MΩ. The performance of single inverters, 3-stage cascaded inverters and 3-stage ring oscillators are characterized with respect to output voltage levels, propagation delay, static power consumption, voltage gain, and operational frequency window. Depending on the application, the key performance parameters of the inverter can be optimized by the specific combination of the input voltage levels and the resistor ladder values. A few of the inverters are in fact fully functional up to 30 Hz, even when using input voltage levels as low as (0 V, 1 V). © 2021 The Authors.
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| 4. |
- Zabihipour, Marzieh, et al.
(författare)
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High-Gain Logic Inverters based on Multiple Screen-Printed Organic Electrochemical Transistors
- 2022
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Ingår i: Advanced Materials Technologies. - : John Wiley and Sons Inc. - 2365-709X. ; 7:10, s. 2101642-
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Tidskriftsartikel (refereegranskat)abstract
- Organic electronic circuits based on organic electrochemical transistors (OECTs) are attracting great attention due to their printability, flexibility, and low voltage operation. Inverters are the building blocks of digital logic circuits (e.g., NAND gates) and analog circuits (e.g., amplifiers). However, utilizing OECTs in electronic logic circuits is challenging due to the resulting low voltage gain and low output voltage levels. Hence, inverters capable of operating at relatively low supply voltages, yet offering high voltage gain and larger output voltage windows than the respective input voltage window are desired. Herein, inverters realized from poly(3,4-ethylenedioxythiophene):polystyrene sulfonate-based OECTs are designed and explored, resulting in logic inverters exhibiting high voltage gains, enlarged output voltage windows, and tunable switching points. The inverter designs are based on multiple screen-printed OECTs and a resistor ladder, where one OECT is the driving transistor while one or two additional OECTs are used as variable resistors in the resistor ladder. The inverters’ performances are investigated in terms of voltage gain, output voltage levels, and switching point. Inverters, operating at +/−2.5 V supply voltage and an input voltage window of 1 V, that can achieve an output voltage window with ∼110% increment and a voltage gain up to 42 are demonstrated. © 2022 The Authors.
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| 5. |
- Zabihipour, Marzieh, et al.
(författare)
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High yield manufacturing of fully screen-printed organic electrochemical transistors
- 2020
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Ingår i: npj Flexible Electronics. - : Nature Research. - 2397-4621. ; 4:1
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Tidskriftsartikel (refereegranskat)abstract
- The potential of the screen printing method for large-scale production of organic electrochemical transistors (OECTs), combining high production yield with low cost, is here demonstrated. Fully screen-printed OECTs of 1 mm2 area, based on poly(3,4-ethylenedioxythiophene) doped with poly(styrensulfonate) (PEDOT:PSS), have been manufactured on flexible polyethylene terephthalate (PET) substrates. The goal of this project effort has been to explore and develop the printing processing to enable high yield and stable transistor parameters, targeting miniaturized digital OECT circuits for large-scale integration (LSI). Of the 760 OECTs manufactured in one batch on a PET sheet, only two devices were found malfunctioning, thus achieving an overall manufacturing yield of 99.7%. A drain current ON/OFF ratio at least equal to 400 was applied as the strict exclusion principle for the yield, motivated by proper operation in LSI circuits. This consistent performance of low-footprint OECTs allows for the integration of PEDOT:PSS-based OECTs into complex logic circuits operating at high stability and accuracy. © 2020, The Author(s).
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| 6. |
- Zabihipour, Marzieh, 1985-
(författare)
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Organic Electrochemical Transistors for Printed Digital Circuits
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Organic electronics enables cost-effective production of flexible electronic devices with high throughput and easy processing compared to the conventional electronics. Organic electronics, therefore, has the potential to realize various innovative applications on a large scale, for example, flexible displays, smart windows, solar cells, electronic skin and implantable medical devices.Many of the materials employed in the field of organic electronics can be processed from chemical solutions. This allows for making various types of inks and hence the possibility to use the traditional high-volume printing methods such as screen printing, inkjet printing and gravure printing for fabricating organic electronic devices on different surfaces. Screen printing has advantages over the other methods in terms of the range of ink viscosity, resolution, and controllable thickness of dry ink film.For various applications envisioned for an integration of printed organic electronics with other technology platforms, a prolonged lifetime and low power consumption are desired. This requires an optimized design of the electronic components and circuits so that they can operate at reduced voltages to guarantee both the long lifetime and the low power consumption. This thesis focuses on designing fully screen printed vertically stacked organic electrochemical transistors (OECTs) and OECT-based circuits operating at low supply voltages and at the same time delivering high gain and low power consumption with long lifetime. The OECTs and OECT-based circuits employ poly(3,4-ethylenedioxythiophene) (PEDOT:PSS) as the organic polymer in their channel. The multi-layered OECTs have a small footprint with a high manufacturing yield and performance uniformity across the printed area, making them suitable for complex printed circuits. Furthermore, various inverter designs based on the reliable and reproducible OECTs are developed and explored to target circuits that can perform at relatively low supply voltages, yet offering improved performance.
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| 7. |
- Zabihipour, Marzieh, et al.
(författare)
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Organic electrochemical transistors manufactured by laser ablation and screen printing
- 2022
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Ingår i: Flexible and Printed Electronics. - : IOP Publishing Ltd. - 2058-8585. ; 7:3
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Tidskriftsartikel (refereegranskat)abstract
- The dimensions of the material serving as the channel in organic electrochemical transistors (OECTs) are important for the overall switching performance. Here, a laser ablation step is included in the OECT manufacturing process, in an attempt to shorten the channel length of the OECT. The source and drain electrodes are formed by laser ablation of a previously screen printed carbon-based rectangle, which in this study resulted in an average channel length equal to 25 mu m. All other processing steps rely on screen printing, allowing for large-area manufacturing of OECTs and OECT-based circuits on flexible substrates. This approach results in a manufacturing yield of 89%; 178 out of a total of 200 OECTs exhibited an ON/OFF ratio exceeding 1000 with a statistical mean value of 28 000 and reproducible switching performance. OECT-based circuits, here demonstrated by a logic inverter, provide a reasonably high voltage gain of 12. The results thus demonstrate another reliable OECT manufacturing process, based on the combination of laser ablation and screen printing.
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