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23 novembre 2011 3 23 /11 /novembre /2011 02:14

Solar panel and applications

Polycrystalline silicon is also a key component of solar panel construction. Growth of the photovoltaic solar industry was limited by the supply of the polysilicon material.Sony VGP-BPL12 Battery

For the first time, in 2006, over half of the world's supply of polysilicon was being used for production of renewable electricity solar power panels. Only twelve factories were known to produce solar-grade polysilicon in 2008. Monocrystalline silicon was higher priced and more efficient than multicrystalline. Sony VGP-BPS12 Battery

This however changed and, in 2011, there was a large excess of production capacity of polysilicon.

Deposition methods

Polysilicon deposition, or the process of depositing a layer of polycrystalline silicon on a semiconductor wafer, is achieved by pyrolyzing silane (SiH4) at 580 to 650 °C. This pyrolysis process releases hydrogen.Sony VGP-BPL13 Battery

Polysilicon layers can be deposited using 100% silane at a pressure of 25–130 Pa (0.2 to 1.0 Torr) or with 20–30% silane (diluted in nitrogen) at the same total pressure. Both of these processes can deposit polysilicon on 10–200 wafers per run, at a rate of 10–20 nm/min and with thickness uniformities of ±5%. Sony VGP-BPS13 Battery

Critical process variables for polysilicon deposition include temperature, pressure, silane concentration, and dopant concentration. Wafer spacing and load size have been shown to have only minor effects on the deposition process. The rate of polysilicon deposition increases rapidly with temperature, since it follows Arrheniusbehavior, Sony VGP-BPS13/B Battery

that is deposition rate = A·exp(–qEa/kT) where q is electron charge and k is the Boltzmann constant. The activation energy (Ea) for polysilicon deposition is about 1.7 eV. Based on this equation, the rate of polysilicon deposition increases as the deposition temperature increases. Sony VGP-BPS13/S Battery

There will be a minimum temperature, however, wherein the rate of deposition becomes faster than the rate at which unreacted silane arrives at the surface. Beyond this temperature, the deposition rate can no longer increase with temperature, since it is now being hampered by lack of silane from which the polysilicon will be generated. Sony VGP-BPS13/S Battery

Such a reaction is then said to be 'mass-transport-limited.' When a polysilicon deposition process becomes mass-transport-limited, the reaction rate becomes dependent primarily on reactant concentration, reactor geometry, and gas flow.

When the rate at which polysilicon deposition occurs is slower than the rate at which unreacted silane arrives, then it is said to be surface-reaction-limited. Sony VGP-BPS13A/B Battery

A deposition process that is surface-reaction-limited is primarily dependent on reactant concentration and reaction temperature. Deposition processes must be surface-reaction-limited because they result in excellent thickness uniformity and step coverage.Sony VGP-BPS13A/S Battery

A plot of the logarithm of the deposition rate against the reciprocal of the absolute temperature in the surface-reaction-limited region results in a straight line whose slope is equal to –qEa/k.

At reduced pressure levels for VLSI manufacturing, polysilicon deposition rate below 575 °C is too slow to be practical. Sony VGP-BPS13AS Battery

Above 650 °C, poor deposition uniformity and excessive roughness will be encountered due to unwanted gas-phase reactions and silane depletion. Pressure can be varied inside a low-pressure reactor either by changing the pumping speed or changing the inlet gas flow into the reactor. Sony VGP-BPS13B/B Battery

If the inlet gas is composed of both silane and nitrogen, the inlet gas flow, and hence the reactor pressure, may be varied either by changing the nitrogen flow at constant silane flow, or changing both the nitrogen and silane flow to change the total gas flow while keeping the gas ratio constant.Sony VGP-BPS13B/Q Battery

Polysilicon doping, if needed, is also done during the deposition process, usually by adding phosphine, arsine, or diborane. Adding phosphine or arsine results in slower deposition, while adding diborane increases the deposition rate. The deposition thickness uniformity usually degrades when dopants are added during deposition.Sony VGP-BPS13B/S Battery

Upgraded metallurgical-grade silicon

Upgraded metallurgical-grade (UMG) silicon (also known as UMG-Si) solar cell is being produced as a low cost alternative to polysilicon created by the Siemens process. UMG greatly reduces impurities in a variety of ways that require less equipment and energy than the Siemens process.Sony VGP-BPS13Q Battery

UMG is about 99% pure which is three or more orders of magnitude less pure and about 10 times less expensive than polysilicon ($1.70 to $3.20 per kg from 2005 to 2008 compared to $40 to $400 per kg for polysilicon). It has the potential to provide nearly-as-good solar cell efficiency at 1/5 the capital expenditure, half the energy requirements, and less than $15/kg.Sony VGP-BPS13S Battery

In 2008 several companies were touting the potential of UMG in 2010, but the credit crisis greatly lowered the cost of polysilicon and several UMG producers put plans on hold. The Siemens process will remain the dominant form of production for years to come due to more efficiently implementing the Siemens process.Sony VGP-BPL7 Battery

GT Solar claims a new Siemens process can produce at $27/kg and may reach $20/kg in 5 years. GCL-Poly expects production costs to be $20/kg by end of 2011. Elkem Solar estimates their UMG costs to be $25/kg, with a capacity of 6,000 tonnes by the end of 2010. Sony VGP-BPS7 Battery

Calisolar expects UMG technology to produce at $12/kg in 5 years with boron at 0.3 ppm and phosphorus at 0.6 ppm. At $50/kg and 7.5 g/W, module manufacturers spend $0.37/W for the polysilicon. For comparison, if a CdTe manufacturer pays spot price for tellurium ($420/kg in April 2010) and has a 3 micron thickness, their cost would be 10 times less, $0.037/Watt. At 0.1 g/W and $31/ozt for silver, polysilicon solar producers spend $0.10/W on silver. Sony VGP-BPL8 Battery

Q-Cells, Canadian Solar, and Calisolar have used Timminco UMG. Timminco is able to produce UMG-Si with 0.5 ppm boron for $21/kg but were sued by shareholders because they had expected $10/kg.[13] RSI and Dow Corning have also been in litigation over UMG-Si technology.Sony VGP-BPL8A Battery

Capacity

Polysilicon manufacturing market is in a very fast growth mode. According to Digitimes in July 2011, the total polysilicon production in 2010 was 209,000 tons and first-tier suppliers account for 64% of the market while China-based polysilicon firms have 30% of market share. Sony VGP-BPL8B Battery

The total production is likely to increase 37.4% to 281,000 tons by end of 2011. With high spot prices in 2008/2009 and lack of available material, many companies announced additional capacities for the coming years. Established producers (mentioned below) expand their capacities, additionally newcomers – especially from Asia – are moving into this market. Sony VGP-BPS8 Battery

Even long-time players in the field had difficulties recently to ramp-up new plants. It is yet unclear which companies will be able to produce at costs low enough to be profitable after the steep drop in spot-prices of the last months.  Leading producer capacities:Sony VGP-BPS8A Battery

Price

Prices of polysilicon are often divided into two categories, contract and spot prices. While in booming installation times, price rally occurs in polysilicon. Not only spot prices surpass contract prices in the market; but it is also hard to acquire enough polysilicon.Sony VGP-BPS8B Battery

Buyers will accept down payment and long term agreements to acquire a large enough volume of polysilicon. On the contrary, spot prices will be below contract prices once the solar PV installation is in a down trend. In late 2010, booming installation brought up the spot prices of polysilicon.Sony VGP-BPL9 Battery

In the first half of 2011, prices of polysilicon kept strong owing to the FIT policies of Italy. The solar PV price survey and market research firm, PVinsights,  reported that the prices of polysilicon might be dragged down by lack of installation in the second half of 2011.Sony VGP-BPS9 Battery

Covalent semiconductors are such solids as diamond, silicon, germanium, silicon carbide and silicon-germanium where atoms are linked by covalent bonds. Most of those materials, at least in their bulk form, are well studied and rarely hit the front pages of the top scientific journals in the last decade. Sony VGP-BPS9/B Battery

However, issue 23 of volume 93 (2004) of a major physics journal Physical Review Letters contained as many as 4 papers on diamond. Those papers were a reaction to a breakthrough discovery of superconductivity in synthetic diamond grown by high-pressure high-temperature (HPHT) method.Sony VGP-BPS9/S Battery

The discovery had no practical importance but surprised most scientists as superconductivity has not been considered seriously in covalent semiconductors.

Diamond

Superconductivity in diamond was achieved through heavy p-type doping by boron such that the individual doping atoms started interacting and formed an "impurity band".Sony VGP-BPS9A Battery

The superconductivity was of type-II with the critical temperature Tc = 4 K and critical magnetic field Hc = 4 T. Later, Tc ~ 11K has been achieved in homoepitaxial CVD films.

Regarding the origin of superconductivity in diamond, three alternative theories exist at the moment: Sony VGP-BPS9A/B Battery

conventional BCS theory based on phonon-mediated pairing, correlated impurity band theory and spin-flip-driven pairing of holes weakly localized in the vicinity of the Fermi level. Whereas there is no solid experimental support for either model, recent accurate measurements of isotopic shift of the transition temperature Tc upon boron and carbon isotopic substitutions favor the BCS theory.Sony VGP-BPS9A/S Battery

Silicon

It was suggested  that "Si and Ge, which also form in the diamond structure, may similarly exhibit superconductivity under the appropriate conditions", and indeed, discoveries of superconductivity in heavily boron doped Si (Si:B)[8] and SiC:B[9] have quickly followed. Sony VGP-BPS9B Battery

Similar to diamond, Si:B is type-II superconductor, but it has much smaller values of Tc = 0.4 K and Hc = 0.4 T. Superconductivity in Si:B was achieved by heavy doping (above 8 at.%), realized through a special non-equilibrium technique of gas immersion laser doping.Sony VGP-BPX11 Battery

Silicon carbide

Superconductivity in SiC was achieved by heavy doping with boron or aluminum. Both the cubic (3C-SiC) and hexagonal (6H-SiC) phases are superconducting and show a very similar Tc of 1.5 K. Sony VGP-BPL18 Battery

A crucial difference is however observed for the magnetic field behavior between aluminum and boron doping: SiC:Al is type-II, same as Si:B. On the contrary, SiC:B is type-I. In attempt to explain this difference, it was noted that Si sites are more important than carbon sites for superconductivity in SiC.Sony VGP-BPS18 Battery

Whereas boron substitutes carbon in SiC, Al substitutes Si sites. Therefore, Al and B "see" different environment that might explain different properties of SiC:Al and SiC:B.

Carbon nanotubes

Superconductivity in carbon nanotubes has been observed experimentally in 2001.Sony VGP-BPL20 Battery

Note however a crucial difference between nanotubes and diamond: Although nanotubes contain covalently bonded carbon atoms, they are closer in properties to graphite than diamond, and can be metallic without doping. Meanwhile, undoped diamond is an insulator.Sony VGP-BPS20/B Battery

The priority of many discoveries in science is vigorously disputed (see, e.g., Nobel Prize controversies). Another example, afterSumio Iijima has "discovered" carbon nanotubes in 1991, many scientists have pointed out that carbon nanofibers were actually observed decades earlier. Sony VGP-BPS20/S Battery

The same could be said about superconductivity in covalent semiconductors. Superconductivity ingermanium and silicon-germanium was predicted theoretically as early as in the 1960s. Shortly after, superconductivity was experimentally detected ingermanium telluride.Sony VGP-BPL21 Battery

In 1976, superconductivity with Tc = 3.5 K was observed experimentally in germanium implanted with copper ions; it was experimentally demonstrated that amorphization was essential for the superconductivity (in Ge), and the superconductivity was assigned to Ge itself, not copper.Sony VGP-BPS21 Battery

Monocrystalline silicon or single-crystal Si, or mono-Si is the base material of the electronic industry. It consists of silicon in which the crystal lattice of the entire solid is continuous, unbroken (with no grain boundaries) to its edges. Sony VGP-BPS21/S Battery

It can be prepared intrinsic, i.e. made of exceedingly pure silicon alone, or doped, containing very small quantities of other elements added to change in a controlled manner its semiconducting properties. Most silicon monocrystals are grown by the Czochralski process, in the shape of cylinders up to 2 m long and 30 cm in diameter (figure on the left), which, cut in thin slices, give thewafers onto which the microcircuits will be fabricated.Sony VGP-BPS21A Battery

Single-crystal silicon is perhaps the most important technological material of the last decades (the "silicon era"),[1] because its availability at an affordable cost has been essential for the development of the electronic devices on which the present day electronic and informatic revolution is based.Sony VGP-BPS21A/B Battery

Monocrystalline is opposed to amorphous silicon, in which the atomic order is limited to short range order only. In between the two extremes there is polycrystalline silicon, which is made up of small crystals, known as crystallites.Sony VGP-BPS21B Battery

Mono-Si in electronics

The monocrystalline form is used in the semiconductor device fabrication since grain boundaries would bring discontinuities and favor imperfections in the microstructure of silicon, such as impurities and crystallographic defects, which can have significant effects on the local electronic properties of the material.Sony VGP-BPL22 Battery

On the scale that devices operate on, these imperfections would have a significant impact on the functionality and reliability of the devices. Without the crystalline perfection, it would be virtually impossible to build Very Large-Scale Integration (VLSI) devices (figure at right), in which millions (up to billions, circa 2005) of transistor-based circuits, Sony VGP-BPS22 Battery

all of which must reliably be working, are combined into a single chip to get e.g. a microprocessor. Therefore, electronic industry has invested heavily in facilities to produce large single crystals of silicon.

Mono-Si in solar cells

Monocrystalline silicon is also used in the manufacturing of high performance solar cells. Sony VGP-BPS22/A Battery

Since, however, solar cells are less demanding than microelectronics for as concerns structural imperfections, monocrystaline solar grade (Sog-Si) is often used, single crystal is also often replaced by the cheaper polycrystalline or multicrystalline silicon.Sony VGP-BPS22A Battery

Monocrystalline solar cells can achieve 17% efficiency  whereas other types of less expensive cells including thin film and polycrystalline are only capable of achieving around 10% efficiency.

Few solar charger companies use monocrystalline solar panels because of the higher cost to produce the solar cells, although these higher efficiency products are starting to pop up as consumers demand more efficient products. Sony VGP-BPL23 Battery

The 2010 Consumer Electronics Showshowcased one of these high-efficiency monocrystalline chargers known as the JOOS Orange and awarded it the 2010 Best of Innovations Award. The charger is manufactured by SolarJOOS, a Silicon Valley based solar company.Sony VGP-BPS23 Battery

Printed electronics is a set of printing methods used to create electrical devices on various substrates. Printing typically uses common printing equipment or other low-cost equipment suitable for defining patterns on material, such as screen printing, flexography, gravure, offset lithography and inkjet.Sony VGP-BPS23/B Battery

Electrically functional electronic or optical inks are deposited on the substrate, creating active or passive devices, such as thin film transistors or resistors. Printed electronics is expected to facilitate widespread, very low-cost, low-performance electronics for applications such as flexible displays, smart labels, decorative and animated posters, and active clothing that do not require high performance.Sony VGP-BPS23/D Battery

The term printed electronics is related to organic electronics or plastic electronics, in which one or more inks are composed of carbon-based compounds. These other terms refer to the ink material, which can be deposited by solution-based, vacuum-based or some other method.Sony VGP-BPS23/G Battery

Printed electronics, in contrast, specifies the process, and can utilize any solution-based material, including organic semiconductors, inorganic semiconductors, metallic conductors, nanoparticles, nanotubes, etc.

For the preparation of printed electronics nearly all industrial printing methods are employed. Sony VGP-BPS23/P Battery

Similar to conventional printing, printed electronics applies ink layers one atop another. so that the coherent development of printing methods and ink materials are the field's essential tasks.

The most important benefit of printing is low-cost volume fabrication. The lower cost enables use in more applications.Sony VGP-BPS23/W Battery

An example is RFID-systems, which enable contactless identification in trade and transport. In some domains, such as light-emitting diodes printing does not impact performance. Printing on flexible substrates allows electronics to be placed on curved surfaces, for example, putting solar cells on vehicle roofs.Sony Limited Edition 007 Battery

More typically, conventional semiconductors justify their much higher costs by providing much higher performance.

Resolution, registration, thickness, holes, materials

The maximum required resolution of structures in conventional printing is determined by the human eye. Sony VAIO VGC-LB15 Battery

Feature sizes smaller than approximately 20 µm cannot be distinguished by the human eye and consequently exceed the capabilities of conventional printing processes. In contrast, higher resolution and smaller structures are necessary in electronics printing, because they directly affect circuit density and functionality (especially transistors). Sony VGN-AR Series Battery

A similar requirement holds for the precision with which layers are printed on top of each other (layer to layer registration).

Control of thickness, holes, and material compatibility (wetting, adhesion, solvation) are essential, but matter in conventional printing only if the eye can detect them. Conversely, the visual impression is irrelevant.Sony VGN-CR Series Battery

Printing technologies

The attraction of printing technology for the fabrication of electronics mainly results from the possibility to prepare stacks of micro-structured layers (and thereby thin-film devices) in a much more simple and cost-effective way compared to conventional electronics.Sony VIAO VGN-G Series Battery

Beside this, also the possibility to implement new or improved functionalities (e.g. mechanical flexibility) plays a role. The selection of used printing methods is determined by requirements concerning printed layers, by properties of printed materials as well as economic and technical considerations in terms of printed products.Sony VIAO VGN-G118 Battery

Printing technologies divide between sheet-based and roll-to-roll-based approaches. Sheet-based techniques, such as inkjet and screen printing are best for low-volume, high-precision work. Gravure, offset and flexographic printing are more common for high-volume production, such as solar cells, reaching 10.000 square meters per hour (m²/h).Sony VIAO VGN-G118CN/B Battery

While offset and flexographic printing are mainly used for inorganic and organic   conductors (the latter also for dielectrics), gravure printing is especially suitable for quality-sensitive layers like organic semiconductors and semiconductor/dielectric-interfaces in transistors, due to high layer quality.Sony VIAO VGN-G118CN/T Battery

In connection with high resolution, is also suitable for inorganic[12] and organic [13] conductors. Organic field-effect transistors and integrated circuits can be prepared completely by means of mass-printing methods.[11]

Inkjets are flexible and versatile, and can be set up with relatively low effort. Sony VIAO VGN-G218 Battery

Inkjets are probably the most commonly used method.[14] However, inkjets offer lower througput of around 100 m2/h and lower resolution (ca. 50 µm).[4] It is well suited for low-viscosity, soluble materials like organic semiconductors. With high-viscosity materials, Sony VGN-TZ121 Battery

like organic dielectrics, and dispersed particles, like inorganic metal inks, difficulties due to nozzle clogging occur. Because ink is deposited via droplets, thickness and dispersion homogeneity is reduced. Simultaneously using many nozzles and pre-structuring the substrate allows improvements in productivity and resolution, respectively.Sony VGN-TZ13 Battery

However, in the latter case non-printing methods must be employed for the actual patterning step.[15] Inkjet printing is preferable for organic semiconductors in organic field-effect transistors (OFETs) and organic light-emitting diodes (OLEDs), but also OFETs completely prepared by this method have been demonstrated.Sony VGN-TZ131 Battery

Frontplanes[17] and backplanes[18] of OLED-displays, integrated circuits,[19] organic photovoltaic cells (OPVCs) [20] and other devices can be prepared with inkjets.

Screen printing is appropriate for fabricating electrics and electronics on industrial scales due to its ability to produce thick layers from paste-like materials. Sony VGN-TZ132N Battery

This method can produce conducting lines from inorganic materials (e.g. for circuit boards and antennas), but also insulating and passivating layers, whereby layer thickness is more important than high resolution. Its 50 m²/h throughput and 100 µm resolution are similar to inkjets.Sony VGN-TZ132/N Battery

This versatile and comparatively simple method is used mainly for conductive and dielectric layers, but also organic semiconductors, e.g. for OPVCs, and even complete OFETs can be printed.

Other methods with similarities to printing, among them micro-contact printing and nano-imprint lithography are of interest.Sony VGN-TZ17N Battery

Here, µm- and nm-sized layers, respectively, are prepared by methods similar to stamping with soft and hard forms, respectively. Often the actual structures are prepared subtractively, e.g. by deposition of etch masks or by lift-off processes. For example electrodes for OFETs can be prepared Sporadically pad printing is used in a similar manner.Sony VGN-TZ16N Battery

Occasionally so-called transfer methods, where solid layers are transferred from a carrier to the substrate, are considered printed electronics. Electrophotography is currently not used in printed electronics.

Materials

Both organic and inorganic materials are used for printed electronics. Sony VGN-TZ18N Battery

Ink materials must be available in liquid form, for solution, dispersion or suspension. They must function as conductors, semiconductors, dielectrics, or insulators. Material costs must be fit the application.

Electronic functionality and printability can interfere with each other, mandating careful optimization.Sony VAIO VGN-AR47G/E1 Battery

For example, a higher molecular weight in polymers enhances conductivity, but diminishes solubility. For printing, viscosity, surface tension and solid content must be tightly controlled. Cross-layer interactions such as wetting, adhesion, and solubility as well as post-deposition drying procedures affect the outcome. Sony VAIO VGN-AR520E Battery

Additives often used in conventional printing inks are unavailable, because they often defeat electronic functionality.

Material properties largely determine the differences between printed and conventional electronics. Printable materials provide decisive advantages beside printability, such as mechanical flexibility and functional adjustment by chemical modification (e.g. light color in OLEDs). Sony VAIO VGN-AR53DB Battery

Printed conductors offer lower conductivity and charge carrier mobility.

With a few exceptions, inorganic ink materials are dispersions of metallic micro- and nano-particles.

PMOS but not CMOS is possible in printed electronics.Sony VAIO VGN-AR54DB Battery

Organic materials

Organic printed electronics integrates knowledge and developments from printing, electronics, chemistry, and materials science, especially from organic and polymer chemistry. Organic materials in part differ from conventional electronics in terms of structure, operation and functionality, which influences device and circuit design and optimization as well as fabrication method.Sony VAIO VGN-AR550E Battery

The discovery of conjugated polymers and their development into soluble materials provided the first organic ink materials. Materials from this class of polymers variously possess conducting, semiconducting, electroluminescent, photovoltaic and other properties. Other polymers are used mostly as insulators and dielectrics.Sony VAIO VGN-AR55DB Battery

In most organic materials, hole transport is favored over electron transport. Recent studies indicate that this is a specific feature of organic semiconductor/dielectric-interfaces, which play a major role in OFETs. Therefore p-type devices should dominate over n-type devices. Durability (resistance to dispersion) and lifetime is less than conventional materials.Sony VAIO VGN-AR630E Battery

Organic semiconductors include the conductive polymers poly(3,4-ethylene dioxitiophene), doped with poly(styrene sulfonate), (PEDOT:PSS) and poly(aniline) (PANI). Both polymers are commercially available in different formulations and have been printed using inkjet,screen and offset printing or screen, flexo and gravure  printing, respectively.Sony VAIO VGN-AR64DB Battery

Polymer semiconductors are processed using inkjet printing, such as poly(thiopene)s like poly(3-hexylthiophene) (P3HT) and poly(9,9-dioctylfluorene co-bithiophen) (F8T2). The latter material has also been gravure printed. Different electroluminescent polymers are used with inkjet printing,Sony VAIO VGN-AR65DB Battery

as well as active materials for photovoltaics (e.g. blends of P3HT with fullerene derivatives), which in part also can be deposited using screen printing (e.g. blends ofpoly(phenylene vinylene) with fullerene derivatives).

Printable organic and inorganic insulators and dielectrics exist, which can be processed with different printing methods.Sony VAIO VGN-AR660U Battery

Inorganic materials

Inorganic electronics provides highly ordered layers and interfaces that organic and polymer materials cannot provide.

Silver nanoparticles are used with flexo,[8] offset [42] and inkjet.[43] Gold particles are used with inkjet.Sony VAIO VGN-AR690U Battery

A.C. electroluminescent (EL) multi-color displays can cover many tens of square meters, or be incorporated in watch faces and instrument displays. They involve six to eight printed inorganic layers, including a copper doped phosphor, on a plastic film substrate. Sony VAIO VGN-AR71ZU Battery

CIGS cells can be printed directly onto molybdenum coated glass sheets.

A printed gallium arsenide germanium solar cell demonstrated 40.7% conversion efficiency, eight times that of the best organic cells, approaching the best performance of heavy silicon.Sony VAIO VGN-AR730E/B Battery

Substrates

Printed electronics allows the use of flexible substrates, which lowers production costs and allows fabrication of mechanically flexible circuits. While inkjet and screen printing typically imprint rigid substrates like glass and silicon, mass-printing methods nearly exclusively use flexible foil and paper.Sony VAIO VGN-AR73DB Battery

Poly(ethylene terephthalate)-foil (PET) is a common choice, due to its low cost and higher temperature stability. Poly(ethylene naphthalate)- (PEN) and poly(imide)-foil (PI) are alternatives. Paper's low costs and manifold applications make it an attractive substrate, however, its high roughness and large absorbency make it problematic for electronics.Sony VAIO VGN-AR74DB Battery

Other important substrate criteria are low roughness and suitable wettability, which can be tuned pre-treatment (coating, corona). In contrast to conventional printing, high absorbency is usually disadvantageous.

Applications

Printed electronics are in use or under consideration for: Sony VAIO VGN-AR75UDB Battery

Standards development and activities

Technical standards and roadmapping initiatives are intended to facilitate value chain development (for sharing of product specifications, characterizationstandards, etc.) This strategy of standards development mirrors the approach used by silicon-based electronics over the past 50 years.Sony VAIO VGN-AR820E Battery

Initiatives include:

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Installing Solar Power For Homes 29/08/2017 09:18

Great pleasure reading your post.Its full of information, thanks for sharing.