Showing papers on "Flexible electronics published in 2007"

Inorganic semiconductors for flexible electronics

Abstract: This article reviews several classes of inorganic semiconductor materials that can be used to form high-performance thin-film transistors (TFTs) for large area, flexible electronics. Examples ranging from thin films of various forms of silicon to nanoparticles and nanowires of compound semiconductors are presented, with an emphasis on methods of depositing and integrating thin films of these materials into devices. Performance characteristics, including both electrical and mechanical behavior, for isolated transistors as well as circuits with various levels of complexity are reviewed. Collectively, the results suggest that flexible or printable inorganic materials may be attractive for a range of applications not only in flexible but also in large-area electronics, from existing devices such as flat-panel displays to more challenging (in terms of both cost and performance requirements) systems such as large area radiofrequency communication devices, structural health monitors, and conformal X-ray imagers.

All-inkjet-printed flexible electronics fabrication on a polymer substrate by low-temperature high-resolution selective laser sintering of metal nanoparticles

Abstract: All-printed electronics is the key technology to ultra-low-cost, large-area electronics. As a critical step in this direction, we demonstrate that laser sintering of inkjet-printed metal nanoparticles enables low-temperature metal deposition as well as high-resolution patterning to overcome the resolution limitation of the current inkjet direct writing processes. To demonstrate this process combined with the implementation of air-stable carboxylate-functionalized polythiophenes, high-resolution organic transistors were fabricated in ambient pressure and room temperature without utilizing any photolithographic steps or requiring a vacuum deposition process. Local thermal control of the laser sintering process could minimize the heat-affected zone and the thermal damage to the substrate and further enhance the resolution of the process. This local nanoparticle deposition and energy coupling enable an environmentally friendly and cost-effective process as well as a low-temperature manufacturing sequence to realize large-area, flexible electronics on polymer substrates.

Fabrication of fully transparent nanowire transistors for transparent and flexible electronics

Abstract: The development of optically transparent and mechanically flexible electronic circuitry is an essential step in the effort to develop next-generation display technologies, including 'see-through' and conformable products. Nanowire transistors (NWTs) are of particular interest for future display devices because of their high carrier mobilities compared with bulk or thin-film transistors made from the same materials, the prospect of processing at low temperatures compatible with plastic substrates, as well as their optical transparency and inherent mechanical flexibility. Here we report fully transparent In(2)O(3) and ZnO NWTs fabricated on both glass and flexible plastic substrates, exhibiting high-performance n-type transistor characteristics with approximately 82% optical transparency. These NWTs should be attractive as pixel-switching and driving transistors in active-matrix organic light-emitting diode (AMOLED) displays. The transparency of the entire pixel area should significantly enhance aperture ratio efficiency in active-matrix arrays and thus substantially decrease power consumption.

Downscaling of self-aligned, all-printed polymer thin-film transistors

Abstract: Printing is an emerging approach for low-cost, large-area manufacturing of electronic circuits, but it has the disadvantages of poor resolution, large overlap capacitances, and film thickness limitations, resulting in slow circuit speeds and high operating voltages. Here, we demonstrate a self-aligned printing approach that allows downscaling of printed organic thin-film transistors to channel lengths of 100–400 nm. The use of a crosslinkable polymer gate dielectric with 30–50 nm thickness ensures that basic scaling requirements are fulfilled and that operating voltages are below 5 V. The device architecture minimizes contact resistance effects, enabling clean scaling of transistor current with channel length. A self-aligned gate configuration minimizes parasitic overlap capacitance to values as low as 0.2–0.6 pF mm−1, and allows transition frequencies of fT = 1.6 MHz to be reached. Our self-aligned process provides a way to improve the performance of printed organic transistor circuits by downscaling, while remaining compatible with the requirements of large-area, flexible electronics manufacturing.

Nanotube electronics: a flexible approach to mobility.

Abstract: An innovative and scalable strategy for making high-density arrays of aligned nanotubes could lead to the mass-production of high-performance, high-power flexible electronics.

Latest advances in substrates for flexible electronics

Abstract: — Recent advances in both organic- and inorganic-based electronics processed on flexible substrates offer substantial rewards in terms of being able to develop displays that are thinner, lighter, robust, and conformable, and can be rolled away when not required. In addition, plastic-based substrates coupled with the recent developments in solution deposition and ink-jet printing for laying down OLED materials and active-matrix thin-film-transistor (TFT) arrays open up the possibility of cost-effective processing in high volumes using roll to roll (R2R) processing. To replace glass, however, a plastic substrate needs to be able to offer some or all of the properties of glass, i.e., clarity, dimensional stability, thermal stability, barrier, solvent resistance, and low coefficient of thermal expansion (CTE) coupled with a smooth surface. In addition, a conductive layer may be required. No plastic film offers all these properties so any plastic-based substrate will almost certainly be a multilayer composite structure. This paper will discuss the issues associated with selecting plastic materials, contrast the various options, and highlight how to gain optimum performance through process control. This will be illustrated with examples of film in use in flexible electronic applications.

Printed Graphene Circuits

Abstract: we have fabricated transparent electronic devices based on graphene materials with thickness down to one single atomic layer by the transfer printing method. The resulting printed graphene devices retain high field effect mobility and have low contact resistance. The results show that the transfer printing method is capable of high-quality transfer of graphene materials from silicon dioxide substrates, and the method thus will have wide applications in manipulating and delivering graphene materials to desired substrate and device geometries. Since the method is purely additive, it exposes graphene (or other functional materials) to no chemical preparation or lithographic steps, providing greater experimental control over device environment for reproducibility and for studies of fundamental transport mechanisms. Finally, the transport properties of the graphene devices on the PET substrate demonstrate the non-universality of minimum conductivity and the incompleteness of the current transport theory.

Microsolidics: Fabrication of Three‐Dimensional Metallic Microstructures in Poly(dimethylsiloxane)

Abstract: This Communication describes a method of fabricating complex metallic microstructures in 3D by injecting liquid solder into microfluidic channels, and allowing the solder to cool and solidify; after fabrication, the metallic structures can be flexed, bent, or twisted This method of fabrication—which we call microsolidics—takes advantage of the techniques that were developed for fabricating microfluidic channels in poly(dimethylsiloxane) (PDMS) in 2D and 3D, uses surface chemistry to control the interfacial free energy of the metal– PDMS interface, and uses techniques based on microfluidics, but ultimately generates solid metal structures This approach makes it possible to build flexible electronic circuits or connections between circuits, complex embedded or freestanding 3D metal microstructures, 3D electronic components, and hybrid electronic–microfluidic devices There are several techniques for making metal microstructures in 3D Electroplating and electroless deposition are routinely used to construct microstructures with metallic layers several nanometers to several microns thick in 2D or 3D [1–11] To generate solid replicas of 3D objects, several groups have developed a technique, referred to as “microcasting”, to form metals in order to fabricate microparts (eg, posts and gears) with features as small as 10 lm and aspect ratios as high as 10 from steel, zirconia, and alumina [12,13] Techniques based on LIGA (Lithographie, Galvanoformung, und Abformung) produce even more complicated metallic objects by depositing a metal onto a molded polymer template that is subsequently removed to yield an open structure (such as a honeycomb arrangement of cells) [14,15] In principle, these approaches can be used to pattern metals of any thickness to produce features with an aspect ratio that is larger than that produced using electroplating

Air stable high resolution organic transistors by selective laser sintering of ink-jet printed metal nanoparticles

Abstract: A high resolution organic field effect transistor (OFET) fabrication process has been developed based on the selective laser sintering of ink-jet printed nanoparticle inks and the recent development of an air stable carboxylate-functionalized polythiophene semiconducting polymer. The entire fabrication and device characterization are performed at room temperature, ambient pressure, and air environment without using complex lithographic methods. This low temperature OFET fabrication process based on nanoparticle laser sintering has great potential for realizing inexpensive, large area flexible electronics on heat sensitive polymer substrates.

Medical device with flexible printed circuit

Abstract: A catheter or lead having a flexible printed circuit for conveying signals and/or energy. Each trace may be in electrical connection with one or more external electrical contacts. More specifically, each trace is typically electrically connected to a single contact. The traces and contacts may assist in diagnosis and/or detection of bio-electrical signals emitted by organs, and may transmit such signals to a connector or diagnostic device affixed to the catheter. The external electrical contacts may detect bioelectric energy or may deliver electrical or thermal energy to a target site.

Fabrication of multilayer passive and active electric components on polymer using inkjet printing and low temperature laser processing

Abstract: The low temperature fabrication of passive (conductor, capacitor) and active (field effect transistor) electrical components on flexible polymer substrate is presented in this paper. A drop-on-demand (DOD) ink-jetting system was used to print gold nano-particles suspended in Alpha-Terpineol solvent, PVP (poly-4-vinylphenol) in PGMEA (propylene glycol monomethyl ether acetate) solvent, semiconductor polymer (modified polythiophene) in chloroform solution to fabricate passive and active electrical components on flexible polymer substrates. Short pulsed laser ablation enabled finer electrical components to overcome the resolution limitation of inkjet deposition. Continuous argon ion laser was irradiated locally to evaporate the carrier solvent as well as sinter gold nano-particles. In addition, selective ablation of multilayered gold nanoparticle film was demonstrated using the novel SPLA-DAT (selective pulsed laser ablation by different ablation threshold) scheme for sintered and non-sintered gold nanoparticles. Finally, selective ablation of multilayered film was used to define narrow FET (field effect transistor) channel. Semiconductor polymer solution was deposited on top of channel to complete OFET (organic field effect transistor) fabrication.

Nanoscale Patterning and Electronics on Flexible Substrate by Direct Nanoimprinting of Metallic Nanoparticles

Abstract: Recent years have witnessed an expanding interest in the application of flexible polymer materials (e.g., polyimide, polyester, etc.) as the substrates for electronic and display devices. These applications include flexible organic light-emitting displays, thin film transistors, sensors, and polymer MEMS. The advantages of polymer-based materials are their mechanical flexibility, light weight, enhanced durability, and low cost compared with rigid materials (such as silicon and quartz). However, it can be difficult to integrate polymers into an integrated circuit (IC) microfabrication process due to their low thermal stability (low melting and low glass transition temperatures) and solvent susceptibility. In practice, conventional IC fabrication processes are subject to limitations, in that they are multi-step, involve high processing temperatures, caustic baths and strong solvents. In order to address the current problems of microfabrication on flexible substrate, many alternative approaches to conventional photolithography-based process have been introduced by a number of researchers. These include microcontact printing (lCP) combined with metal etching, electroless plating, electropolymerization, and direct metal layer transfer for the microscale metal patterning on flexible substrates. Stencil lithography was mainly applied for dielectric layer patterning on polymer substrates for the formation of electrical capacitors due to its limited resolution. Inkjet printing was used for a drop-on-demand patterning of conductive polymer PEDOT and gold layers for drain-source and gate electrodes. However, its best resolution is 20–50 lm limited by the nozzle diameter, the statistical variation of the droplet flight, and spreading on the substrate. Organic semiconducting materials are being widely used as semiconducting layers in flexible electronics due to their costeffectiveness, mechanical flexibility, and ease of application via specific chemical modification. However, further channel size down-scaling is essential for better performance of organic field effect transistor due to the lower carrier mobility of the organic semiconducting materials. While the abovementioned methods cannot achieve ultrafine features (a few lm’s down to ∼ 100 nm) in high aerial density and good reproducibility, nanoimprinting lithography (NIL) allows easy fabrication of precise nanoscale structures. NIL has been applied for nanopatterning in various fields such as biological nanostructures, nanophotonic devices, organic electronics, and the patterning of magnetic materials. Especially, metal nanopatterning via nanoimprinting is widely employed in nanoscale electronics and biosensing platforms. However, metal nanoimprinting has been typically an indirect process where a polymer (e.g., PMMA) pattern is first created by nanoimprinting, and then used as a mask for metal film etching or metal lift-off process. This involves multiple and expensive process steps and its chemistry is harsh for the flexible substrates. Furthermore, flexible substrates are not resistant to high temperature and pressure during the imprinting process. Recently, imprint resists based on monomer or copolymer have been developed and used for low pressure/low temperature nanoimprinting process. However, these are also indirect methods for metal nanopatterning. Very few direct metal nanoimprinting processes have been demonstrated so far due to the high melting temperature of metals. As an alternative to metal direct nanoimprinting, solid state embossing methods based upon plastic deformation of metal thin films have been introduced. These approaches involved either deformation of a metal film under very high pressure or deformation of a metal thin film/polymer multilayer under relatively lower pressure. Evidently, they are not compatible with flexible substrate since its mechanical strength is not sufficient for such processes. Additionally, these methods do not allow the fabrication of isolated, arbitrary features, and always leave unwanted residual layers. To alleviate the limitations described in the fabrication processes above, the authors have recently developed a novel C O M M U N IC A IO N

Design of Metal Interconnects for Stretchable Electronic Circuits using Finite Element Analysis

Abstract: In this work, the design of flexible and stretchable interconnections is presented. These interconnections are done by embedding sinuous electroplated metallic wires in a stretchable substrate material. A silicone material was chosen as substrate because of its low stiffness and high elongation before break. Common metal conductors used in the electronic industry have very limited elastic ranges; therefore a metallization design is crucial to allow stretchability of the conductors going up to 100%. Different configurations were simulated and compared among them and based on these results, a horseshoe like shape was suggested. This design allows a large deformation with the minimum stress concentration. Moreover, the damage in the metal is significantly reduced by applying narrow metallization schemes. In this way, each conductor track has been split in four parallel lines of 15 mum and 15 mum space in order to improve the mechanical performance without limiting the electrical characteristics. Compared with the single copper or gold trace, the calculated stress was reduced up to 10 times.

Inorganic Semiconductors for Flexible Electronics

Abstract: This article reviews several classes of inorganic semiconductor materials that can be used to form high-performance thin-film transistors (TFTs) for large area, flexible electronics. Examples ranging from thin films of various forms of silicon to nanoparticles and nanowires of compound semiconductors are presented, with an emphasis on methods of depositing and integrating thin films of these materials into devices. Performance characteristics, including both electrical and mechanical behavior, for isolated transistors as well as circuits with various levels of complexity are reviewed. Collectively, the results suggest that flexible or printable inorganic materials may be attractive for a range of applications not only in flexible but also in large-area electronics, from existing devices such as flat-panel displays to more challenging (in terms of both cost and performance requirements) systems such as large area radiofrequency communication devices, structural health monitors, and conformal X-ray imagers.

Solution-deposited carbon nanotube layers for flexible display applications

Abstract: We have investigated two possible fields of application for carbon nanotube (CNT) networks in flexible displays. Transparent and conductive layers of CNTs were spray coated onto glass and plastic substrates. The spectral transmission of the produced layers is almost even for all wavelengths in the visible regime. A sheet resistance of 400 Ω/□ at a transmittance of 80% was achieved. Thin-film transistors (TFT) were created on silicon wafers and glass substrates using low-density CNT networks as a semiconducting layer. The process used for device fabrication on glass substrates is fully compatible to application on plastic foils. The transistors reach on/off ratios of more than five orders of magnitude and show device charge carrier mobilities in the order of 1 cm 2 /Vs. These values promise an application in active matrix liquid crystal displays (AMLCD). Issues that need to be addressed are the homogeneity and reproducibility of the device properties.

Transfer printing methods for the fabrication of flexible organic electronics

Abstract: A transfer printing method for fabricating organic electronics onto flexible substrates has been developed. The method relies primarily on differential adhesion for the transfer of a printable layer from a transfer substrate to a device substrate. The works of adhesion and cohesion for successful printing are discussed and developed for a model organic thin-film transistor device consisting of a polyethylene terephthalate (PET) substrate, gold (Au) gate and source/drain electrodes, a polymethylmethacrylate (PMMA) [or poly(4-vinylphenol)] dielectric layer, and a pentacene (Pn) organic semiconductor layer. The device components are sequentially printed onto the PET device substrate with no mixed processing steps performed on the device substrate. Optimum printing conditions for the Pn layer were determined to be 600psi and 120°C for 3min. A set of devices with a PMMA dielectric layer was measured as a function of channel length and exhibited a contact resistance corrected mobility of 0.237cm2∕Vs. This is la...

High-performance carbon nanotube field effect transistors with a thin gate dielectric based on a self-assembled monolayer.

Abstract: Individual single-walled carbon nanotube (SWCNT) field effect transistors (FETs) with a 2 nm thick silane-based organic self-assembled monolayer (SAM) gate dielectric have been manufactured. The FETs exhibit a unique combination of excellent device performance parameters. In particular, they operate with a gate−source voltage of only −1 V and exhibit good saturation, large transconductance, and small hysteresis (≤100 mV), as well as a very low subthreshold swing (60 mV/dec) under ambient conditions. The SAM-based gate dielectric opens the possibility of fabricating transistors operating at low voltages and constitutes a major step toward nanotube-based flexible electronics.

Improvements of Permeation Barrier Coatings Using Encapsulated Parylene Interlayers for Flexible Electronic Applications

Abstract: A multilayer barrier structure composed of silicon nitride, silicon oxide, and encapsulated parylene on a polycarbonate substrate has been investigated for flexible electronic applications. The organic buffer is commonly used as the smoothing, strengthening and defect-decoupling layer. However, a lateral leakage problem was observed in the organic interlayer, and resulted in increased permeation and poor adhesion between organic and inorganic layers. It was found that an encapsulated, thermal-treated parylene interlayer can be used to efficiently reduce the water vapor and oxygen permeation. After 75 d, the water vapor transmission rate (WVTR) can reach 2.5 x 10 -7 (g m 2 ) d -1 , as calculated by the calcium test. After being flexed for 5 000 times, the WVTR value almost keeps around 2.1×10 -6 (g.m -2 ) d -1 . The performance of the proposed multilayer barrier structure has a high potential for flexible solar cell and organic light-emitting diode applications.

Strong carbon-nanotube-polymer bonding by microwave irradiation

Abstract: The vigorous response of multiwalled carbon nanotubes (MWNTs) to microwave irradiation, leading to the release of a large amount of heat, is used to locally melt a plastic matrix adjacent to the nanotubes within a period of seconds This results in the intercalation of the MWNTs into the polymer matrix at room temperature without any physical damage to the polymer The so-called "microwave welding" approach creates a new paradigm for the formation of very strong MWNT-polymer bonds without the use of any adhesive, and represents a significant step forward for the fabrication of functional nanotube composites Here, we demonstrate the implications of the anisotropic alignment of MWNTs in polymers, patterned conductors/resistors for soft electronics, and high-strength composites, where the MWNTs are 'soldered' to flexible polymer substrates

High-Performance, Vertical-Type Organic Transistors with Built-In Nanotriode Arrays

Abstract: Organic transistors have attracted considerable interest because they are lightweight, flexible, inexpensive, and highly efficient over large areas. As a result of these characteristics, organic transistors are expected to find use in a variety of applications, including electronic barcodes, displays, and sensors. Until now, their performance has been inferior to inorganic transistors because of their lower mobility values (typical mobility ranges are 1–10 and 500–10 000 cm Vs for organic and inorganic semiconductors, respectively). Attempts to enhance the performance of organic transistors have relied on decreasing the length and increasing the cross-sectional area through which the charge carriers travel. In the case of an organic thin-film transistor (OTFT), which is the most popular type of organic transistor (Fig. 1a), it is necessary to decrease the channel length and increase the channel width by fine patterning the source and drain electrodes. Nanometer-scale devices can be fabricated if state-of-the-art lithographic techniques are used prior to organic-film growth. However, this type of process is not practical for fabricating low-cost, largescale flexible electronics. One approach to resolving this issue is to employ a verticaltype transistor (Fig. 1b). The carrier pathway in a verticaltype transistor is perpendicular to the substrate, and the current is dispersed over a wide area in the device. A static induction transistor (SIT), which is frequently referred to as a solidstate triode, is one of the simplest vertical-type transistors. SITs were first developed using inorganic semiconductors,

Flexible eddy current sensor array for proximity sensing

Abstract: This paper presents a new flexible eddy current sensor array and its measurement system that used for conformable proximity sensing, for instance, the gap between curved surfaces. The sensor probe, designed to consist of a forked coils array and a long flat cable, is manufactured on a thin flexible substrate by the flexible printed circuit board (FPCB) technology. The probe is very thin and flexible, so that it can conform to the surface geometries of the measured objects. Time division multiplexing (TDM) technology has been introduced to scan and sample all the sensing elements. Some reforms are also implemented to the conventional LC oscillator to solve the problem of the coils having a low Q-factor. Experimental results show that, to a steel target, the measurement accuracy of the sensor system can reach ±0.5% for a 2 mm full scale. The practice for real-time inspection of the small gaps between large curved surfaces is also considered.

Liquid Crystal Polymer (LCP): The ultimate solution for low-cost RF flexible electronics and antennas

Abstract: In this paper, solutions for developing low cost electronics for antenna transceivers that take advantage of the stable electrical properties of the organic substrate liquid crystal polymer (LCP) has been presented. Three important ingredients in RF wireless transceivers namely embedded passives, a dual band filter and a RFid antenna have been designed and fabricated on LCP. Test results of all 3 of the structures show good agreement between the simulated and measured results over their respective bandwidths, demonstrating stable performance of the LCP substrate.

Laser Direct-Write of Metallic Nanoparticle Inks

Abstract: The combination of nanoparticle inks with laser direct-write allows the laser printing of fine electrically-conductive patterns on substrates requiring extremely low processing temperatures (< 250 oC). Silver lines with widths under 20 microns and thicknesses under one micron have been laser printed (using a 355 nm laser direct-write system) on polyimide substrates. These features are equivalent to those seen in typical vapor deposited and lithographically patterned thin films. Electrical resistivities of these lines in the range of 5-10 times bulk silver have been demonstrated. The low processing temperature of the nanoparticle inks also allows the laser-curing of printed silver lines without damage to the sensitive substrate. A cw 532 nm laser was used to cure asdeposited silver lines with a resistivity similar to that achieved in oven-curing. This approach is ideally suited for the prototyping and short production runs of interconnects for flexible electronics, RFID antennas and OLED displays. This work will show how these nanoparticle inks are processed using laser direct-write, and will discuss the structure and electrical properties of these printed lines on polyimide substrates.

Photodetector arrays directly assembled onto polymer substrates from aqueous solution.

Abstract: We report a simple and inexpensive approach to directly assemble arrays of cadmium sulfide (CdS) semiconductors onto transparent flexible poly(ethylene terephthalate) (PET) sheets via a polymer-mediated selective nucleation and growth process from an aqueous solution. This strategy of assembling functional materials onto plastics utilizes the surface functional molecules of the UV photooxidation patterned polymer to direct the nucleation and growth of CdS. We demonstrated that such assembled structures are viable for flexible macroelectronics, as manifested by the fabrication of CdS photodetector arrays on PET that can withstand bending. The best devices exhibited a specific detectivity of 3 x 10(11) cm Hz(1/2) W(-1) at 514-nm excitation wavelength at a modulation frequency of 90 Hz at room temperature. This direct assembly strategy eliminates additional lithography and etching steps during the deposition of the active inorganic semiconductor layer, is general to other inorganic materials and plastic substrates, and can enable low-cost, wearable, and/or disposable flexible electronics.

Thin film battery on an integrated circuit or circuit board and method thereof

Abstract: The present invention relates to flexible thin film batteries on semiconducting surface or the conductive or insulating packaging surface of a semiconductor device and methods of constructing such batteries Electrochemical devices may be glued to a semiconducting surface or the conductive or insulating packaging surface of a semiconductor device or deposited directly thereon The invention also relates to flexible thin film batteries on flexible printed circuit boards where the electrochemical devices may also be glued or deposited on the flexible printed circuit board

Porous processing carrier for flexible substrates

Abstract: The present invention is directed to a substrate product (10) for use in the manufacture of active matrix liquid crystal display panels, flexible displays, or flexible electronics. The product includes a display substrate (20) suitable for use as a display panel. The display substrate has a thickness less than or equal to 0.4 mm. Trie product also includes at least one porous support substrate (30) removably attached to the display substrate by an adhesive layer (40).

Adhesion energy of Cu/polyimide interface in flexible printed circuits

Abstract: The adhesion strength of interfaces was evaluated for two Cu/polyimide laminates, which had the same interface but different polyimide film thickness A new technique was applied to evaluate the bond energy of the interface, where micro scale polyimide film blocks were scratched off from the interface-side surface of the copper film Energy consumed during plastic deformation was successfully calculated with the help of a numerical simulation for crack extension Contrary to the results of conventional peel tests which yielded 340 J/m2 and 580 J/m2, respectively for the two samples, the interfacial adhesion energy was obtained as 30 J/m2 and 25 J/m2 by the new technique

Method of Compensating for Crosstalk

Abstract: An apparatus and method for crosstalk compensation in a jack of a modular communications connector includes a flexible printed circuit board connected to jack contacts and to connections to a network cable. The flexible printed circuit board includes conductive traces arranged as one or more couplings to provide crosstalk compensation.

ZnO field-effect transistors prepared by aqueous solution-growth ZnO crystal thin film

Abstract: A ZnO thin-film transistor (TFT) with a channel layer formed via aqueous solution-growth at low temperature is demonstrated. This ZnO thin-film semiconductor has a well-controlled crystalline form, exhibiting n-channel, enhancement-mode behavior with a channel mobility as large as 0.56 cm2 V−1 s−1. Low-cost, superior transistor characteristics and low-temperature processing makes ZnO TFT attractive for flexible electronics on temperature sensitive substrates.