- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Percolation Effects in Electrolytically-Gated WS <sub/>2</sub> /Graphene Nano:Nano Composites
摘要： Mixed networks of conducting and non-conducting nanoparticles show promise in a range of applications where fast charge transport is important. While the dependence of network conductivity on the conductive mass fraction (Mf) is well understood, little is known about the Mf-dependence of mobility and carrier density. This is particularly important as the addition of graphene might lead to increases in the mobility of semiconducting nanosheet-network transistors. Here, we use electrolytic gating to investigate the transport properties of spray-coated composite networks of graphene and WS2 nanosheets. As the graphene Mf is increased, we find both conductivity and carrier density to increase in line with percolation theory with percolation thresholds (~8 vol%) and exponents (~2.5) consistent with previous reporting. Perhaps surprisingly, we find the mobility increases modestly from ~0.1 cm2/Vs (for a WS2 network) to ~0.3 cm2/Vs (for a graphene network) which we attribute to the similarity between WS2-WS2 and graphene-graphene junction resistances. In addition, we find both the transistor on- and off-currents to scale with Mf according to percolation theory, changing sharply at the percolation threshold. Through fitting, we show that only the current in the WS2 network changes significantly upon gating. As a result, the on-off ratio falls sharply at the percolation threshold from ~104 to ~2 at higher Mf. Reflecting on these results, we conclude that the addition of graphene to a semiconducting network is not a viable strategy to improve transistor performance as it reduces the on:off ratio far more than it improves the mobility.
关键词： graphene,ionic liquid,thin film transistor,WS2,carrier density,composite,mobility,Printed electronics
更新于2025-10-22 19:40:53
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Ultrathin Fully Printed Light-Emitting Electrochemical Cells with Arbitrary Designs on Biocompatible Substrates
摘要： Organic electronic devices are often highlighted in terms of cost-efficient solution processing and potential printability. However, few studies are reporting truly full-solution-processed devices taking into account the electrodes as well as all other layers. This results in a production method that only partially benefits from the cost efficiency of solution processing and that still depends on costly and elaborate techniques like evaporation and/or lithography. This lack of knowledge is addressed by presenting a truly fully printed light-emitting electrochemical cell on ultraflexible parylene C substrates usable for conformable electronics. All device parts are fabricated by industrial relevant printing-techniques under ambient atmosphere. Inkjet printing is used for the structuring of the device layout and is therefore able to implement and create arbitrary designs. Further layers are produced by blade coating which is well suited for the coating of large areas. The devices show stable operation at a luminance higher than 100 cd m?2 for 8.8 h, can reach a maximum brightness of 918 cd m?2, and exhibit a turn-on time of 40 s to reach 100 cd m?2. Moreover, biocompatible and biodegradable materials are utilized to allow potential applications in life science and bioelectronics.
关键词： fully printed electronics,light-emitting electrochemical cells,parylene,inkjet,bioelectronics,digital printing,conformable electronics
更新于2025-09-23 15:23:52
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Implementing Inkjet-Printed Transparent Conductive Electrodes in Solution-Processed Organic Electronics
摘要： Through the use of solution-based materials, the field of printed organic electronics has not only made new devices accessible, but also allows the process of manufacture to move toward a high throughput industrial scale. However, while solution-based active layer materials in these systems have been studied quite intensely, the printed electrodes and specifically the transparent conductive anode have only relatively recently been investigated. In this progress report, the use of metal nanoparticles within printed organic electronic devices is highlighted, specifically their use as replacement of the commonly used indium tin oxide transparent conductive electrode within organic photovoltaics (OPVs) and organic light emitting diodes (OLEDs). A cross fertilization between the applications is expected since an OPV device is essentially an inversely operated OLED. This report aims to highlight the use of inkjet-printed nanoparticles as cost-effective electrodes for printed optoelectronic applications and discusses methods to improve the conductive and interfacial properties. Finally, in an outlook, the use of these types of metal nanoparticle inks to manipulate light management properties, such as outcoupling, in the device is investigated.
关键词： embedded silver and copper grid,metal nanoparticle ink,inkjet-printed electronics,transparent electrode,solution-processed optoelectronics
更新于2025-09-23 15:23:52
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[IEEE 2018 13th International Congress Molded Interconnect Devices (MID) - Wu?rzburg (2018.9.25-2018.9.26)] 2018 13th International Congress Molded Interconnect Devices (MID) - Generation of 3D Functional Structures for High- Frequency Applications by Printing Technologies
摘要： Mechatronic Integrated Devices (MID) offer a high level of functional integration, miniaturization and allow a reduction of utilized components. Due to these benefits, the MID technology is constantly pushing forward into new application fields, e.g. for internet of things products. Most smart devices are equipped with sensors and have wireless capabilities to send and receive data. As the market requires faster transmission rates and higher frequencies, microwave technology is gaining more and more significance. One promising technology in order to enable highly integrated products is printed electronics. In this work, the suitability of a novel aerosol-based printing system is evaluated by generating microstrip lines. The created structures are characterized geometrically with a laser scan microscope and electrically with a network analyzer.
关键词： Microwave Technology,Additive Manufacturing,Printed Electronics
更新于2025-09-23 15:23:52
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Facile preparation of stable reactive silver ink for highly conductive and flexible electrodes
摘要： Stability of conductive ink and mechanical ?exibility of conductive pattern are essential for ?exible printed electronics. In this work, we reported a stable reactive silver ink for the facile fabrication of ?exible electrodes. The ink was mainly composed of silver-isopropanolamine (IPA) complex, formic acid reductant, and hydroxyethyl cellulose (HEC) adhesive agent, and it displayed good chemical stability. The ?exible electrodes on polyimide (PI) substrates were achieved by mask-printing and thermal sintering of the ink, and the e?ects of sintering parameters and HEC adhesive agent content on the electrical and ?exible properties and microstructure evolutions of silver layer were systematically investigated. Consequently, the silver layer sintered at 110 °C yields low electrical resistivity of 12.1 μΩ·cm, which is only eight times higher than that of bulk silver. Furthermore, the sintered silver layer still presents excellent ?exibility and low relative resistances after the bending, twisting, and folding tests. These results demonstrate that the stable reactive silver ink provides a promising and low cost opportunity for low temperature design and fabrication of high performance ?exible printed electronics.
关键词： Reactive silver ink,High conductivity,Silver layer,Flexibility,Printed electronics
更新于2025-09-23 15:23:52
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Nano-rheology printing of sub-0.2 <i>μ</i> m channel length oxide thin-film transistors
摘要： Down-scaling of the channel length of a fully solution-processed oxide thin-film transistor (TFT) to the nanometer-scale is the key to accessing next-generation devices for Internet-of-Things technology. In this work, we report on the fabrication of an oxide TFT with a channel length of 160 nm, which is far less than those obtained by the current direct-printing techniques, by a newly developed nano-rheology printing (nRP) method. The device had an on/off current ratio, subthreshold voltage, hysteresis, and field-effect mobility of approximately 107, 1.7 V, 0 V, and 0.16 cm2 V s-1, respectively. The key to achieving the sub-micron channel printed TFT is the introduction of a new amorphous La–Ru–O material, which exhibits relatively good conductivity and excellent nRP properties at the nanoscale, for source/drain electrode patterns. Such a short-channel TFT would never be achieved with conventional printing methods, and hence, this approach is highly important for accessing next-generation low-cost, large-area and environmentally friendly printed electronics.
关键词： nano-rheology printing,thermal-imprinting,printed electronics,solution process,oxide thin-film transistor
更新于2025-09-23 15:23:52
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[IEEE 2018 International Flexible Electronics Technology Conference (IFETC) - Ottawa, ON, Canada (2018.8.7-2018.8.9)] 2018 International Flexible Electronics Technology Conference (IFETC) - Flexible Printed Organic Thin-Film Transistor Devices and Integrated Circuit Applications
摘要： The latest developments in flexible and printed electronics technology based on organic thin-film transistor (OTFT) devices as well as printable electronic materials are briefly reported on in this paper. The successful fabrication and operation of printed OTFT devices and a variety of integrated circuit applications such as flip-flop logic gates and operational amplifiers will be demonstrated.
关键词： Organic electronics,Flexible electronics,Organic thin-film transistor,Printed electronics
更新于2025-09-23 15:22:29
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[IEEE 2018 International Flexible Electronics Technology Conference (IFETC) - Ottawa, ON, Canada (2018.8.7-2018.8.9)] 2018 International Flexible Electronics Technology Conference (IFETC) - Screen Printed Vias for a Flexible Energy Harvesting and Storage Module
摘要： This case study evaluates a highly flexible screen printed through-hole-via using silver microparticle inks for applications in energy harvesting and storage modules. The printed vias fabrication and reliability are evaluated by means of a double sided screen-printing method and repetitive (cyclic) bending tests. Vias, in 125 μm thick PET, were laser cut (50, 100, 150, and 200 μm nominal diameter) then filled, and simultaneously connected to adjacent vias, by screen printing. To investigate the use of the printed via in a monolithic energy module, the vias were used for the fabrication of a flexible printed supercapacitor (aqueous electrolyte and carbon electrode). The results indicate that the lower viscosity silver ink (DuPont 5064H) does not fill the via as effectively as the higher viscosity ink (Asahi LS411AW), and only the sidewall of the via Conversely, the Asahi silver paste fills the via more thoroughly and exhibited a 100 % yield (1010 vias; 100 μm nominal via diameter) with the 2-step direct screen-printing method. The bending test showed no signs of via specific breakdown after 30 000 cycles. The results indicate that this via filling process is likely compatible with roll-to-roll screen printing to enable multi-layered printed electronics devices.
关键词： flexible and printed electronics,screen printing,printed vias,bending reliability,energy module
更新于2025-09-23 15:22:29
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Universal Testing Apparatus Implementing Various Repetitive Mechanical Deformations to Evaluate the Reliability of Flexible Electronic Devices
摘要： A requirement of flexible electronic devices is that they maintain their electrical performance during and after repetitive mechanical deformation. Accordingly, in this study, a universal test apparatus is developed for in-situ electrical conductivity measurements for flexible electrodes that are capable of applying various mechanical deformations such as bending, twisting, shearing, sliding, stretching, and complex modes consisting of two simultaneous deformations. A novel method of deforming the specimen in an arc to induce uniform bending stress in single and alternating directions is also proposed with a mathematically derived control method. As an example of the arc bending method, the changes in the resistance of the printed radio frequency identification (RFID) tag antennas were measured by applying repetitive inner bending, outer bending, and alternating inner-outer bending. After 5000 cycles, the increases in resistance of the specimens that were subjected to inner or outer bending only were under 30%; however, specimens that were subjected to alternating inner-outer bending showed an increase of 135% in resistance. It is critical that the reliability of flexible electronic devices under various mechanical deformations be determined before they can be commercialized. The proposed testing apparatus can readily provide various deformations that will be useful to inform the design of device shapes and structures to accommodate deformations during use.
关键词： mechanical deformation,printed electronics,reliability,test apparatus,flexible electronics
更新于2025-09-23 15:22:29
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Three-dimensional monolithic integration in flexible printed organic transistors
摘要： Direct printing of thin-film transistors has enormous potential for ubiquitous and lightweight wearable electronic applications. However, advances in printed integrated circuits remain very rare. Here we present a three-dimensional (3D) integration approach to achieve technology scaling in printed transistor density, analogous to Moore’s law driven by lithography, as well as enhancing device performance. To provide a proof of principle for the approach, we demonstrate the scalable 3D integration of dual-gate organic transistors on plastic foil by printing with high yield, uniformity, and year-long stability. In addition, the 3D stacking of three complementary transistors enables us to propose a programmable 3D logic array as a new route to design printed flexible digital circuitry essential for the emerging applications. The 3D monolithic integration strategy demonstrated here is applicable to other emerging printable materials, such as carbon nanotubes, oxide semiconductors and 2D semiconducting materials.
关键词： printed electronics,organic transistors,3D integration,dual-gate transistors,flexible circuits
更新于2025-09-23 15:22:29