DE102009002386A1 - Fluorescence Conversion Solar Cell - Injection Molding Production - Google Patents

Abstract

The invention relates to a combination of fluorescence conversion dyes in plastic moldings of polymethyl (meth) acrylate, which are used to convert the natural solar radiation in usable for the solar cell light. The plastic moldings are produced by injection molding.

Description

Field of the invention

The The invention relates to a combination of fluorescence conversion dyes in plastic moldings of polymethyl (meth) acrylate, the to be used, the natural sunlight convert into usable for the solar cells light. The Plastic moldings are polymerized by injection molding.

State of the art

photovoltaic cells The irradiated sunlight can only partially into usable convert electrical energy, a large part of the energy is lost in the form of heat. So, for example a silicon solar cell absorb all the photons that have an energy above the band edge of 1.1 eV of the crystalline silicon. This corresponds to a wavelength <1,100 nm. The excess Energy of the absorbed photons is converted into heat and leads to a heating of the photocell, the efficiency the photocell is lowered.

The structure and effect of fluorescence conversion solar cells is known from US 4,110,123 (Fraunhofer) or out Appl. Phys. 14, 123 ff. (1977) known.

WO 2007/031446 (BASF AG) describes fluorescence conversion solar cells composed of one or more glass plates or polymer plates coated with a fluorescent dye. As the fluorescent dye, dyes based on terrylenecarboxylic acid derivatives or combinations of these dyes with other fluorescent dyes are used. The disadvantage here is the separately required step of coating the glass plates with the formulation containing the dye.

Concentrator systems with lenses or mirrors

Optical systems based on lenses or mirrors for the concentration of light on the solar cells are known, concentration factors of up to 1,000 times are achieved. A disadvantage of the optical solutions, however, is that the entire electromagnetic spectrum of the light is concentrated, so that not only the effective light is concentrated, but also the photovoltaically ineffective light. This leads to an undesirable thermal load on the solar cells and a reduction in the efficiency. In order not to let the temperatures get too high, you can actively or passively cool the solar cells. In addition, the lenses or the lens systems must be tracked consuming mechanically the position of the sun, they also can only reflect the directly incident light. Diffused light contributes little or no energy. (please refer U.S. Patent 5,489,297 )

task

• • diffuses Licht zu nutzen und daher ohne aufwendige Nachführmechanik auskommen,
• • ein auf das Absorptionsspektrum der verwendeten Solarzelle (beispielsweise Si oder GaAs) abgestimmtes Licht zu liefern,
• • einen den optischen Konzentratoren vergleichbaren Konzentrationsgrad zu erzielen,
• • einfach und preiswert hergestellt zu werden,
• • die Wärmebelastung der Solarzellen und den damit verbundenen Wirkungsgradverlust zu verringern,
• • die aktive Solarzellenfläche zu verringern,
• • beständig gegen Witterungseinflüsse zu sein und im Laufe des Betriebs die optischen Eigenschaften praktisch nicht verändern,

In the light of the prior art discussed above, it has been the object to develop concentration paths for the optical radiation of the sun that are capable of

• • to use diffused light and therefore manage without complicated tracking mechanism,
• To provide a light tuned to the absorption spectrum of the solar cell used (for example Si or GaAs),
• • achieve a concentration level comparable to the optical concentrators,
• • easy and inexpensive to manufacture
• • reduce the heat load on the solar cells and the associated loss of efficiency,
• • reduce the active solar cell area,
• • be resistant to the effects of the weather and practically do not change the optical properties during operation,

solution

The Solution of the above object is achieved by a use of different fluorescence conversion dyes in Plastic moldings whose spectra are so coordinated are that the incident light targeted with such wavelengths is emitted, which are matched to the respective solar cell.

The Solution further comprises the solution of the dyes or the dye mixtures in a monomer mixture, which subsequently is polymerized to a plastic molding.

The plastic molded body can be constructed in one or more layers and comprise layers which contain the same or different dyes or dye mixtures. The individual layers can z. B. by gluing or by multilayer injection molding together. This can be z. B. by the method described in the applications DE 10233684 and DE 10254276 are described done.

The Layering can also be achieved by loose stacking each other Plastic moldings done.

• – Das eingestrahlte Sonnenlicht wird in für Silizium-Photovoltaikzellen optimale Wellenlängen umgewandelt,
• – Die Herstellung der Fluoreszenzkonversionssolarzellen kann nach bekannten Verfahren erfolgen,
• – Die Solarzellen werden vor Vandalismus geschützt,
• – die Konversionsraten sind überraschend hoch,
• – der Kunststoffformkörper ist einfach an die geometrischen und statischen Erfordernisse der Solarzelle anpassbar,
• – der Kunststoffformkörper ist leichter als eine vergleichbare Anordnung aus Mineralglas,
• – der Kunststoffformkörper kann schlagzäh ausgerüstet sein, so dass die Solarzellenanordnung gegen Hagel geschützt ist.

The solution according to the invention offers the following advantages:

• The irradiated sunlight is converted into optimal wavelengths for silicon photovoltaic cells,
• The preparation of the fluorescence conversion solar cells can be carried out by known methods,
• - The solar cells are protected against vandalism,
• - the conversion rates are surprisingly high,
• The plastic molding is easily adaptable to the geometric and static requirements of the solar cell,
• The plastic molding is lighter than a comparable arrangement of mineral glass,
• - The plastic molding can be equipped impact resistant, so that the solar cell array is protected against hail.

The production of the plastic molding

The monomers

The (meth) acrylates

A Particularly preferred group of monomers are (meth) acrylates The term (meth) acrylates includes methacrylates and acrylates as well as mixtures of both.

These Monomers are well known. These belong to other (meth) acrylates that are derived from saturated alcohols such as methyl (meth) acrylate, ethyl (meth) acrylate, Propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, tert-butyl (meth) acrylate, butoxymethyl (meth) acrylate, pentyl (meth) acrylate, Hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, Isodecyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, cyclohexyl (meth) acrylate and 2-ethylhexyl (meth) acrylate; (Meth) acrylates other than unsaturated Derive alcohols such as oleyl (meth) acrylate, 2-propynyl (meth) acrylate, Allyl (meth) acrylate, vinyl (meth) acrylate; Aryl (meth) acrylates, such as for example, benzyl (meth) acrylate or phenyl (meth) acrylate, wherein the aryl radicals are each unsubstituted or substituted up to four times could be; Cycloalkyl (meth) acrylates, such as 3-vinylcyclohexyl (meth) acrylate, bornyl (meth) acrylate; Isobornyl (meth) acrylate, Hydroxyalkyl (meth) acrylates such as 3-hydroxypropyl (meth) acrylate, 3,4-dihydroxybutyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate; Glycol di (meth) acrylates such as 1,4-butanediol (meth) acrylate, (Meth) acrylates of ether alcohols, such as, for example, tetrahydrofurfuryl (meth) acrylate, Vinyloxyethoxyethyl (meth) acrylate; Amides and nitriles of (meth) acrylic acid, such as N- (3-dimethylaminopropyl) (meth) acrylamide, N- (diethylphosphono) (meth) acrylamide, 1-Methacryloylamido-2-methyl-2-propanol; Sulfur-containing methacrylates, such as ethylsulfinylethyl (meth) acrylate, 4-thiocyanatobutyl (meth) acrylate, ethylsulfonylethyl (meth) acrylate, Thiocyanatomethyl (meth) acrylate, methylsulfinylmethyl (meth) acrylate, sulfide bis ((meth) acryloyloxyethyl); polyvalent (meth) acrylates, such as for example trimethyloylpropane tri (meth) acrylate.

These Monomers may be used singly or as a mixture. Mixtures are particularly preferred here, the methacrylates and Acrylic acid ester included.

The radical formers

The polymerization is generally started with known free-radical initiators. Among the preferred initiators include the azo initiators well known in the art, such as AIBN and 1,1-azobiscyclohexanecarbonitrile, and peroxy compounds such as methyl ethyl ketone peroxide, acetylacetone peroxide, dilauryl peroxide, tert-butyl per-2-ethylhexanoate, ketone peroxide, methyl isobutyl ketone peroxide, cyclohexa nonperoxide, dibenzoyl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxyisopropyl carbonate, 2,5-bis (2-ethylhexanoylperoxy) -2,5-dimethylhexane, tert-butylperoxy-2-ethylhexanoate, tert-butylperoxy-3,5,5 trimethylhexanoate, dicumyl peroxide, 1,1-bis (tert-butylperoxy) cyclohexane, 1,1-bis (tert-butylperoxy) 3,3,5-trimethylcyclohexane, cumyl hydroperoxide, tert-butyl hydroperoxide, bis (4-tert. Butylcyclohexyl) peroxydicarbonate, mixtures of two or more of the aforementioned compounds with one another and mixtures of the abovementioned compounds with unspecified compounds which can also form radicals.

These Compounds are commonly found in an amount of 0.01 to 1.0 wt .-%, preferably from 0.05 to 0.3 wt .-%, based on the Weight of the monomers used.

The impact modifiers

According to a particular aspect of the present invention, the molding composition can optionally be equipped mechanically stably by an impact modifier. Such impact modifiers for polymethacrylate plastics are well known, so are the production and the structure of impact-modified polymethacrylate molding compositions, inter alia in EP-A 0 113 924 . EP-A 0 522 351 . EP-A 0 465 049 and EP-A 0 683 028 described.

preferred impact-resistant molding compositions have 70-99 wt .-% polymethyl (meth) acrylates on. These polymethyl (meth) acrylates have been previously described.

According to a particular aspect of the present invention, the polymethyl (meth) acrylates used for the preparation of impact-modified molding compositions are obtained by free-radical polymerization of mixtures which comprise 80% by weight to 100% by weight, preferably 90% by weight to 98% by weight. %, Methyl methacrylate and optionally 0% by weight to 20% by weight, preferably 2% by weight to 10% by weight, of further free-radically polymerizable comonomers which have likewise been listed above. Particularly preferred comonomers include C ₁ to C ₄ alkyl (meth) acrylates, in particular methyl acrylate, ethyl acrylate or butyl methacrylate.

Preferably the average molecular weight Mw of the polymethyl (meth) acrylates for producing particularly impact-resistant molding compounds in the field from 90,000 g / mol to 200,000 g / mol, in particular 100,000 g / mol to 150,000 g / mol.

preferred impact-resistant molding compositions contain 1% by weight to 60% by weight, preferably from 2% by weight to 50% by weight, more preferably from 3% by weight to 45 wt .-%, in particular 5 wt .-% to 42 wt .-% of an impact modifier, which is an elastomeric phase of crosslinked polymer particles.

The Impact modifier can be known in per se Way by bead polymerization or by emulsion polymerization to be obtained.

preferred Impact modifiers provide crosslinked particles having a mean particle size in the range of 50 to 1000 nm, preferably 60 to 500 nm and more preferably 80 to 450 nm.

such Particles, for example, by the radical polymerization of mixtures which are generally at least 40% by weight, preferably 50% to 70% by weight of methyl methacrylate, 20% by weight to 50 wt .-%, preferably 25 wt .-% to 45 wt .-% butyl acrylate and 0.1 wt .-% to 2 wt .-%, preferably 0.5 wt .-% to 1 wt .-% of a crosslinking monomers, e.g. B. a polyfunctional (meth) acrylate, such as As allyl methacrylate and comonomers containing the previously mentioned vinyl compounds can be copolymerized.

Among the preferred comonomers include C ₁ -C ₄ alkyl (meth) acrylates, such as ethyl acrylate or butyl methacrylate, preferably methyl acrylate, or other vinylically polymerizable monomers such. Styrene. The mixtures for the preparation of the aforementioned particles may preferably comprise 0 wt .-% to 30 wt .-%, preferably 0.5 wt .-% to 15 wt .-% comonomers.

Particularly preferred toughening modifiers are polymerizate particles which have a two-layer, particularly preferably a three-layer core-shell structure. Such core-shell polymers are, inter alia, in EP-A 0 113 924 . EP-A 0 522 351 . EP-A 0 465 049 and EP-A 0 683 028 described.

Particularly preferred impact modifiers based on acrylate rubber have fol following structure: Core: Polymer having a methyl methacrylate content of at least 90% by weight, based on the weight of the core. Bowl 1: Polymer having a butyl acrylate content of at least 80% by weight, based on the weight of the first shell. Bowl 2: Polymer having a methyl methacrylate content of at least 90 wt .-%, based on the weight of the second shell.

Of the Core and the shells can in addition to the monomers mentioned each contain additional monomers.

For example, a preferred acrylate rubber modifier may have the following structure: Core: Copolymer of methyl methacrylate (95.7% by weight), ethyl acrylate (4% by weight) and allyl methacrylate (0.3% by weight) S1: Copolymer of butyl acrylate (81.2% by weight), styrene (17.5% by weight) and allyl methacrylate (1.3% by weight) S2: Copolymer of methyl methacrylate (96% by weight) and ethyl acrylate (4% by weight)

The Ratio of core to shell (s) of the acrylate rubber modifier can vary widely. Preferably, the weight ratio is Core to shell K / S in the range of 20:80 to 80:20, preferably from 30:70 to 70:30 to Modifiern with a shell or the ratio from core to shell 1 to shell 2 K / S1 / S2 in the range of 10:80:10 to 40:20:40, more preferably from 20:60:20 to 30:40:30 at Modifiers with two bowls.

The Particle size of the core-shell modifier is common in the range of 50 to 1,000 nm, preferably 100 to 500 nm and more preferably from 150 to 450 nm, without thereby causing a Restriction is to take place.

Such impact modifiers are commercially available from the Fa. Mitsubishi under the trade name METABLEN ^® IR 441.. In addition, impact-modified molding compositions can also be obtained. These include ACRYLITE PLUS ^® from the manufacturer CYRO Industries.

Of the Plastic moldings can also be made of polycarbonate (PC), polystyrene (PS), polyamide (PA), polyester (PE), thermoplastic polyurethane (PU), polyethersulfone, polysulfones, vinyl polymers, such as Polyvinyl chloride (PVC), be constructed.

Light stabilizers

As a light stabilizer UV-A and / or UV-B absorbers are used. Examples of classes of substances which can be used are the HALS compounds. HALS compounds are understood as meaning sterically hindered amines, as described, for example, in US Pat JP 0347856 are described. These "hindered amine light stabilizers" capture the radicals that form when exposed to radiation. In the trade, these products are made by Ciba under the trade name TINUVIN ^® 123, Tinuvin ^® 571, Tinuvin ^® 770 and Tinuvin ^® 622nd

Furthermore, light stabilizers based on benzophenone derivatives can be used. These products are marketed by BASF under the brand UVINUL ^® 5411.

Benzotriazole based light stabilizers can also be used. In the trade, these products are made by Cytec under the brand CYASORB ^® UV 5411 or Ciba under the trade name TINUVIN ^® P, Tinuvin ^® 571 and Tinuvin ^® 234th

Antioxidants

As an antioxidant sterically hindered phenols or phosphites or phosphonites can be used. In the trade, these products are made by Ciba under the trademarks Irganox ^® and Irgafos ^®.

Furthermore, the molding composition may contain other polymers to modify the properties. These include, but are not limited to, polyacrylonitriles, polystyrenes, polyethers, polyesters, polycarbonates and polyvinyl chlorides. These polymers can be used singly or as a mixture, and copolymers which are derivable from the abovementioned polymers can also be used.

The Weight average molecular weight Mw in the molding compound too used homo- and / or copolymers can in wide ranges vary, the molecular weight usually on the Matched purpose and the processing of the molding material becomes. In general, however, it is in the range between 20,000 and 1,000,000 g / mol, preferably 50,000 to 500,000 g / mol, and more preferably 80,000 to 300,000 g / mol, without any limitation should be done.

The Molding compounds for the production of the molding may be conventional Additives / additives of all kinds included. These include including dyes, antistatic agents, antioxidants, mold release agents, Flame retardants, lubricants, flow improvers, fillers, Light stabilizers and organic phosphorus compounds, such as phosphites or phosphonates, pigments, weathering agents and plasticizers. However, the amount of additives is limited to the purpose of use. So should the photoconductive property of the molding compound and their Transparency is not overly affected by additives become.

According to one particular embodiment of the present invention the molding composition at least 70, preferably at least 80 and especially preferably at least 90% by weight, based on the weight of the molding composition, Polymethyl (meth) acrylate on.

The injection molding process

The injection molding technique used in the present invention for processing thermoplastic molding compositions is known to the person skilled in the art. Overviews are z. To find in:
W. Mink, Basics of injection molding, 1st edition, Zechner & Hüthig Verlag, Speyer, 1966 ; and
Saechtling, Kunststofftaschenbuch, 26th Edition, Carl Hanser Verlag, 1995 ,
F. Johannaber / W. Michaeli, Instruction Manual Injection Molding, 2nd ed. Carl Hanser Verlag, 2004

The Injection molding of molded parts can be done both with the hot runner technique as well as with the cold runner technique. The hot runner technology offers over the cold runner technology some advantages, such as B. the realization of long flow paths, so you can put the bleed in the optimal place, a lossless work by avoiding sprue waste, the Possibility of a longer reprint, since the Material in the sprue does not freeze and the feasibility of shorter Cycle times. The disadvantage is u. a. the higher tooling costs by a more complex construction, the higher susceptibility to interference and the more difficult maintenance.

Preferred plastic substrates can be obtained from Evonik Röhm GmbH commercially under the trade name PLEXIGLAS ^®, further, the polymers for the preparation of molding compositions under the tradename ACRYLITE ^® from the manufacturer CYRO Industries are commercially available.

The injection molding process for the production of moldings of high optical quality is preferably carried out in the manner described below:
The temperature of the molten molding compound in the injection molding process is preferably 210 ° C-270 ° C, and more preferably 240 ° C-250 ° C, without any limitation thereto.

Of another is the temperature of the injection molding preferably 230 ° C-270 ° C, even more preferred 240 ° C-250 ° C, and the temperature of the injection mold is preferably 40 ° C-80 ° C and more preferably 50 ° C-60 ° C.

The Temperature of the injection molding cylinder is preferably 220 ° C-260 ° C and even more preferably 230 ° C-250 ° C.

The Molding composition is in the process of the invention with a pressure in the range of 50 bar to 1,000 bar in the tool injected. In this case, the pressure in a particular embodiment and is 50 bar in the first stage and in the second stage 400 bar.

Also, the injection rate may be stepped and in the first stage is in the range of 0.01 m / s to 0.1 m / s in the second stage in the range of 0.1 m / s to 1 m / s and in one possible third stage in the range of 0.05 m / s to 0.5 m / s. The metering path is preferably 1 to 4 times the snow ckendurchmessers.

Farther offers the variant injection-compression known to those skilled Advantages regarding the closing force requirement of Machine and voltage free of the product. This will be better obtained optical properties of the products, in particular lower Birefringence.

The Dimensions of the plastic substrates are, for example, up to 1 m in length and width, plates are preferred with a Length and width of 0.1 m-0.5 m.

The dyes used

Fluorescent dyes

As dyes dyes of the types perylene, terylene and rylene derivatives can be prepared from the Lumogen ^® - BASF, rhodamines, LDS ^® row - number of exciton, substituted pyrans (. E.g. DCM), coumarins (for example, Coumarin 30. Coumarin 1, coumarin 102, etc.) oxazines (eg, Nile Blue or also called Nile Blue A), pyridines, styryl derivatives, dioxazines, naphthalimides, thiazines, stilbenes, and cyanines (e.g., DODCI) of e.g. B. Lambdachrome ^® and Exciton ^® can be used. The types of perylene, terylene and Rylenderivate dyes are in the WO 2007/031446 described.

Also complex compounds of lanthanides and nanoscopic semiconductor structures, so-called quantum dots, z. B. based on cadmium selenide, cadmium sulfide, zinc sulfide, lead selenide, lead sulfide and others are suitable. Production and use of Quantum Dots are in US 2007/0132052 . US 2007/0174939 . WO 0229140 . WO 2004022637 . WO 2006065054 and WO 2007073467 described.

Complex compounds of lanthanides are in CA 20072589575 . EP 0767912 and in WO 9839822 as in Appl. Phys. Lett. 91, 051903 (2007), 23rd European Photovoltaic Solar Energy Conference, Valencia, 700 (2008), Am. Chem. Soc. (2007), DOI 10.1021 / ja070058e described.

The photonic layer

The photonic layer is arranged on the plastic molding, so that the sunlight must first penetrate this layer before the fluorescent dyes in the plastic molding for fluorescence can be stimulated.

As a photonic layer or wavelength-dependent mirror z. As interference filter (stack filter, rugate filter, notch filter, etc.), which may be constructed as a bandpass filter or edge filter known. These are z. B. prepared by depositing a plurality of thin dielectric layers having different refractive indices on a substrate. (S. Olaf Stenzel, "The Physics of Thin Film Optical Spectra", Springer-Verlag ) and ( N. Kaiser, HK Pulker, "Optical Interference Coatings", Springer-Verlag ).

The Layer thickness of the individual layer is usually smaller as the wavelength of light.

Another possibility is the use of photonic crystals which are described in the following applications ( DE 10024466 . DE 10204338 . DE 10227071 . DE 10228228 . DE 10 2004 055 303 . US 6,863,847 . WO 0244301 . DE 10357681 . DE 10 2004 009 569 . DE 10 2004 032 120 . WO 2006045567 . DE 10245848 . DE 10 2006 017 163 )

there it is a small transparent spherical inorganic or organic bodies in the densest sphere are arranged. Depending on the size and distance of the Spheres reflect this light in a defined bandwidth and leave the remaining light almost completely through this layer. It can also be hollow spherical Structures are used. Then these are inverse opals. The single spherical or hollow spherical Structures have the diameter of about 1/3 of the to be reflected Wavelength of light (depending on the angle of incidence the light and the distance of the balls).

The reflector

Under the plastic molding may optionally increase the yield nor an optically reflective molded body, for. B. a Mirror or a white foil or a plate arranged be.

The solar cells

• • Siliziumsolarzellen Monokristallines Silizium (c-Si), multikristallines Silizium (mc-Si), amorphes Silizium (a-Si), ebenso Tandemzellen aus multikristallinem und amorphem Silizium
• • III-V-Halbleiter Solarzellen Galliumarsenid (GaAs), Gallium-Indium-Phosphid (GaInP), Gallium-Indium-Arsenid (GaInAs), Gallium-Indium-Arsen-Phosphid (GaInAsP), Gallium-Indium-Phosphid (GaInP), Galliumantimonid (GaSb) Ebenso Tandemzellen (Mehrfachsolarzelle) aus Gallium-Indium-Phosphid und Galliumarsenid, aus Gallium-Indium-Arsenid und Gallium-Indium-Arsen-Phosphid, aus Gallium-Indium-Phosphid und Gallium-Indium-Arsenid, aus Galliumarsenid und Galliumantimonid oder aus Gallium-Arsenid und Germanium bzw. Tripelzellen (3-fach Solarzelle) aus Gallium-Indium-Phosphid, Galliumarsenid und Germanium oder aus Gallium-Indium-Phosphid, Gallium-Indium-Arsenid und Galliumantimonid
• • II-VI-Halbleiter Solarzellen Cadmiumtellurid (CdTe), Cadmiumsulfid (CdS)
• • I-III-V-Halbleiter Solarzellen CIS-Zellen: Kupfer-Indium-Diselenid (CuInSe2) bzw. Kupfer-Indium-Disulfid (CuInS2) CIGS-Zellen: Kupfer-Indium-Gallium-Diselenid (CuInGaSe2) Kupfer-Gallium-Diselenid (CuGaSe2), Kupfer-Gallium-Disulfid (CuGaS2)
• • Außerdem gibt es noch neuere Entwicklungen von Solarzellen auf der Basis vor organischen Werkstoffen.

The solar cell can be constructed of the usual materials, such as

• • Silicon solar cells Monocrystalline silicon (c-Si), multicrystalline silicon (mc-Si), amorphous silicon (a-Si), as well as tandem cells made of multicrystalline and amorphous silicon
• • III-V semiconductor solar cells gallium arsenide (GaAs), gallium indium phosphide (GaInP), gallium indium arsenide (GaInAs), gallium indium arsenic phosphide (GaInAsP), gallium indium phosphide (GaInP), Gallium antimonide (GaSb) Also called tandem cells (multiple solar cell) of gallium indium phosphide and gallium arsenide, of gallium indium arsenide and gallium indium arsenic phosphide, of gallium indium phosphide and gallium indium arsenide, of gallium arsenide and gallium antimonide or gallium arsenide and germanium or triple cells (gallium solar cell) of gallium indium phosphide, gallium arsenide and germanium or of gallium indium phosphide, gallium indium arsenide and gallium antimonide
• • II-VI Semiconductors Solar Cells Cadmium Telluride (CdTe), Cadmium Sulfide (CdS)
• • I-III-V semiconductor solar cells CIS cells: copper indium diselenide (CuInSe2) or copper indium disulfide (CuInS2) CIGS cells: copper indium gallium diselenide (CuInGaSe2) copper gallium diselenide (CuGaSe2), copper gallium disulfide (CuGaS2)
• • There are also recent developments of solar cells based on organic materials.

The following table shows some examples of semiconductors for solar cells. The specified wavelength corresponds to the wavelength of the light which provides the energy equal to the energy of the energy gap of the semiconductor, ie with this light, the semiconductor works most effectively as a solar cell (the fluorescence conversion cell is tuned to this wavelength). cell material Energy gap [eV] Wavelength [nm] Ge 0.66 1879 GaSb 0.73 1708 CuInSe2 1.0 1240 Si 1.12 1107 GaInAs 1.24 to 1.39 998 - 891 GaAs 1.42 873 CuInS2 1.55 800 CdTe 1.56 795 GaInP 1.64 to 1.81 756 - 687 CuGaSe2 1.68 738 a-Si: H 1.7 729 CuGaS2 2.30 539 CdS 2.42 512

Implementation of the invention

Examples

Single-component injection molding with PLEXIGLAS ^® 7N or 8N

Table: Setting parameters for the injection molding of the molding compounds (injection molding machine DEMAG D 150). Temperatures [° C] melt 245 cylinder 230; 235; 240; 245 Tool 55 Hot runner (nozzle, channel) 246; 246 metering path 26 mm Injection speed (stepped) Level 1 (23 mm - 20 mm) 13 Stage 2 (20 mm - 15 mm) 16 Level 3 (15 mm - 0 mm) 13 Reprint (graded) switching to holding pressure path-dependent at 5 mm screw path Level 1 (18 s) 82 Level 2 (8 s) 75

und Mehrkomponenten-Verbund (Overmoulding-/Mehrschichtverfahren)Multi-component bodies can be produced by the following process variants:
Multi-component injection molding / injection molding is the sequential bringing together of several plastic melts. A distinction is made here between sandwich methods (see graphic from Manual Injection Molding)

and multi-component composite (overmoulding / multilayer process)

Multilayer moldings can be achieved by using several plasticizing units Use of turntable tool technology, sliding table tools or manufactured by transfer technology with rotating index plate become. All processes are in injection molding and injection-compression molding applicable. In this case, both the cold runner and the hot runner technique come into use.

Description of the production of luminescent solar concentrators

Example 1: Preparation of a homogeneous colored injection-molded part

In
940 parts by weight of methyl methacrylate and
60 parts by weight of methyl acrylate
0.35 parts by weight of dilauroyl peroxide and
4.5 parts by weight of 2-ethylhexyl thioglycolate dissolved.

Subsequently, a mixture consisting of
0.15 parts by weight of Lumogen Yellow 083 (BASF)
0.16 parts by weight of Lumogen Orange 240 (BASF)
0.40 parts by weight of Lumogen Red 305 (BASF)
added.

Of the The batch is stirred intensively, in a bag made of polyester film filled, sealed and in a water bath for 24 hours Polymerized at 60 ° C. The final polymerization takes place in a tempering cabinet at 120 ° C for about 10 hours. Subsequently the material obtained is granulated in a mill.

Out The granules obtained become a test specimen in the dimensions 50 × 50 mm and 10 mm thickness produced by injection molding.

you obtains a homogeneous red fluorescent plate of 10 mm thickness.

Example 2: Production of a device with three layers by injection molding

Green granules:

In
940 parts by weight of methyl methacrylate and
60 parts by weight of methyl acrylate
0.35 parts by weight of dilauroyl peroxide and
4.5 parts by weight of 2-ethylhexyl thioglycolate dissolved.

Then be
0.15 parts by weight of Lumogen Yellow 083 (BASF)
added.

Of the The batch is stirred intensively, in a bag made of polyester film filled, sealed and in a water bath for 24 hours Polymerized at 60 ° C. The final polymerization takes place in a tempering cabinet at 120 ° C for about 10 hours. Subsequently the material obtained is granulated in a mill.

Red granules:

In
940 parts by weight of methyl methacrylate and
60 parts by weight of methyl acrylate
0.35 parts by weight of dilauroyl peroxide and
4.5 parts by weight of 2-ethylhexyl thioglycolate dissolved.

Then be
0.40 parts by weight Lumogen Red 305 (BASF)
added.

Of the The batch is stirred intensively, in a bag made of polyester film filled, sealed and in a water bath for 24 hours Polymerized at 60 ° C. The final polymerization takes place in a tempering cabinet at 120 ° C for about 10 hours. Subsequently the material obtained is granulated in a mill.

Orange granules:

In
940 parts by weight of methyl methacrylate and
60 parts by weight of methyl acrylate
0.35 parts by weight of dilauroyl peroxide and
4.5 parts by weight of 2-ethylhexyl thioglycolate dissolved.

Then be
0.16 parts by weight of Lumogen Orange 240 (BASF)
added.

Of the The batch is stirred intensively, in a bag made of polyester film filled, sealed and in a water bath for 24 hours Polymerized at 60 ° C. The final polymerization takes place in a tempering cabinet at 120 ° C for about 10 hours.

Subsequently the material obtained is granulated in a mill.

Out the green, red and orange granules will over a multi-component injection molding process a multi-layer test specimen made in the dimensions 50 × 50 mm. The fat every single color layer is 3 mm. Outside are the red or green layer, the inner layer is orange.

you receives a three-layered fluorescent plate with the Total thickness 9 mm.

Result

From In the experiments according to Ex. 1 and 2, the samples were at all edges polished. Subsequently, the fluorescence intensity became on a fluorescence spectrophotometer LS-55 (Perkin Elmer). The excitation was a daylight-like xenon light source used.

The maximum intensities and the associated wavelengths are recorded in Tab. Table 1 attempt Wavelength in nm Rel. Intensity Example 1 632 54 Example 2 577 487

Of the Example 2 shows a significantly higher intensity.

1

photonic layer

2

homogeneously colored luminescent fluorescence collector

21 22, 23

multilayered colored luminescent fluorescence collector

3

Reflector, z. Mirror or white plate

4, 41, 42, 43

at Fluorescence collector adapted solar cells

3.1

light source

3.2

surface the sample

3.3

edge the sample

3.4

detector

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

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Claims (25)

Plastic moldings of polymethyl (meth) acrylate, characterized in that it is colored with at least one fluorescent dye. Multilayer plastic molded body Polymethyl (meth) acrylate, characterized in that it contains at least dyed a fluorescent dye. Plastic moldings of polymethyl (meth) acrylate according to claim 2, characterized in that it consists of several individual Plastic moldings containing at least one fluorescent dye are colored, built up. Plastic moldings of polymethyl (meth) acrylate according to claim 2, characterized in that it glued from individual Plastic moldings containing at least one fluorescent dye are colored, built up. Plastic molding of polymethyl (meth) acrylate according to claim 1, characterized in that it according to the method injection molding or injection compression molding is. Plastic molding of polymethyl (meth) acrylate according to claim 2, characterized in that it according to one of the methods Sandwich injection molding, sandwich injection molding, multi-component composite injection molding or multi-component composite injection-compression molding is produced. Plastic moldings of polymethyl (meth) acrylate according to one of the preceding claims, characterized that he stained with at least one organic fluorescent dye is. Plastic moldings of polymethyl (meth) acrylate according to one of the preceding claims, characterized that it contains at least one organic fluorescent dye dyed the base of rylene, perylene, terylene and / or quaterylene is. Plastic moldings of polymethyl (meth) acrylate according to one of the preceding claims, characterized that it contains at least one dye based on complex lanthanoid compounds is colored. Plastic moldings of polymethyl (meth) acrylate according to one of the preceding claims, characterized that he uses at least one dye based on nanoscopic Semiconductor structures (Quantum Dots) is colored. Process for producing a plastic molding Polymethyl (meth) acrylate according to claim 1, characterized, that it is produced by injection molding, which comprises the following steps: solution of the dyes or the dye mixture in a monomer mixture of the monomer mixture in a foil bag, polymerize by increasing the temperature and then granulating the resulting polymer, The granules are injection-molded or injection-molded further processed. Arrangement of a plastic molded body according to claim 2 and a solar cell. Arrangement according to claim 3 to 6, characterized that a photonic layer on the plastic molding is arranged. Arrangement according to claim 3 to 6, characterized that a photonic layer of a dielectric interference filter is arranged. Arrangement according to claim 3 to 6, characterized that a photonic layer of a dielectric interference filter, which is designed as an edge filter is arranged Arrangement according to claim 3 to 6, characterized that a photonic layer of a dielectric interference filter, which is designed as a bandpass filter, is arranged Arrangement according to claim 3 to 6, characterized in that a photonic layer consisting of composed of photonic crystals is arranged. Arrangement according to claim 3 to 6, characterized that a photonic layer formed as an inverse opal is, is arranged. Arrangement according to claim 3 to 6, characterized that a flat reflector under the plastic molding is arranged. Arrangement according to claim 3 to 6, characterized that as a reflector, a mirror under the plastic molding is arranged. Arrangement according to claim 3 to 6, characterized that as a reflector a white foil or plate under the Plastic molding is arranged. Arrangement according to claim 3 to 6, characterized that a photonic layer on the plastic molding and a reflector disposed under the plastic molding are. Arrangement according to claim 3 to 6, characterized that a photonic layer according to claim 13 to 18 on the plastic molding and a reflector according to claim 19 to 21 under the plastic molding are arranged. Use of a plastic molding according to one of the claims 1 to 10 for the production of Solar collectors. Use of an arrangement according to one of the claims 12 to 23 for the production of solar collectors.