Infrared photovoltaic device

Abstract

It provides thin layers that are solid, stable, and 100% reversible in their electrical properties without the need for heating to sintering temperatures. [Solution] An infrared photovoltaic device, wherein the PV layer sequence comprises a glass carrier, a first layer applied on top of the electrode layer, a second layer applied on top of the first layer as a partially basic glass-like layer comprising silicon-oxygen bridges in a glass-like network and partially comprising base-soluble aluminum particles as inorganic aggregates, and a transparent coated electrode applied on top of the second layer and having a contact electrode, wherein a framework of conductively interconnected Al flakes is provided between the electrode layer and the transparent coated electrode via contact points and short electrolyte bridges, and the PV activity in the visible light region is weak or nonexistent, and the PV layer sequence uses extremely long waves in the far IR range with wavelengths greater than 5 micrometers.

Description

Technical Field

[0001] The present invention can generally be classified in the field of electro-technical thin layers. The technical field is usually outlined in German Patent No. 102015102801, in which the inventors were involved. Well-known means, features and methods can be recognized from the present application and the prior art cited therein. Layers of the type in question, which have a thickness in the micrometer range and can be flexibly supported on movable, foldable and flexible carriers, are generally known. Thus, BASF Corp.'s AT 36002 E, publication number 0119051B2, discloses a suitable acrylate-based coating that can be used as a cover for flexible substrates. Typical constituents, properties and means for producing such layers can be recognized from this document.

[0002] The present invention relates to a method for producing electro-technical thin layers in a specific electro-technical PV layer sequence.

Background Art

[0003] PV layer sequences have long been the subject of research and development. Monocrystalline and polycrystalline Si cells, which are properly welded and packaged, in contact and aligned outdoors in solar parks, are established product examples in the relevant technical field. The problem is that these classical cells are rigid and not flexible. Regionally extending panels always have to be oriented horizontally with respect to the sun in order to guarantee optimal yield. Here, a flexible thin layer system that provides support for electro-technical thin layers from the conductive layer and switching layer, through the PV layer, to the coating layer and protective layer, is useful. The applicant is active in this specific field and the present application claims a method for producing such layers, as well as layer composites and layer sequences obtained by this method.

[0004] The layer of problem types and the protective and conductive layers of the PV layer sequence are inherently conductive and / or flexible. Suitable conductive and protective layers are disclosed, for example, in German Patent No. 19815291 B4 and the prior art cited therein.

[0005] A method for producing an established PV conductive layer and such a PV layer composite is disclosed in German Patent Application Publication No. 19946712 A1. The disadvantage is that the presence of solvents and sintering-reactive substances requires a temperature of 150 °C or higher so that they can be completely removed during the final hot consolidation. In practical product examples, the final hot consolidation is carried out at 450 °C.

[0006] Taking these problems into account, European Patent No. 2119747 B1 proposes a conductive silver composition that can be sintered via over-reactive metal nanoparticles at about 100 °C to obtain a continuous conductor track. However, even with this means, it is impossible to produce an electro-technical thin layer, especially a PV layer sequence, on a substrate without performing a sintering step, and the step of heating the printed thin layer to a sintering temperature of about 100 °C, 130 °C in an exemplary embodiment, is always necessary.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] Accordingly, the problem addressed by the present invention is to overcome the disadvantages of the prior art and to provide a method that can provide thin layers that are solid, stable, and exhibit virtually 100% reversibility in their electrical-technical properties without the need to heat up to the sintering temperature, despite industrial process regimes and large surface area manufacturing, and an electrical-technical thin layer according to this method.

Means for Solving the Problem

[0009] The solution to this problem is provided according to the features of the independent claims. Advantageous embodiments can be recognized from the dependent claims and the following description.

[0010] According to the present invention, a method for manufacturing an electrical-technical thin layer at room temperature, in which conductive and / or semiconductive inorganic aggregates are regionally provided in a dispersion and cured to obtain a layer, is defined by the fact that the curing is carried out at room temperature and the curing is promoted by exposure to at least one reagent.

[0011] An electrical-technical thin layer sequence obtained according to this method and obtained as a PV layer sequence comprises a thin layer sequence comprising a glass carrier, an electrode layer applied on top of the glass carrier, a first layer applied on top of the electrode layer and comprising aluminum particles in a plastic matrix, a second layer applied on top of the first layer and comprising at least a glassy layer that is at least partially basic, comprising at least silicon-oxygen cross-links in a glassy network, and comprising at least partially base-soluble aluminum particles as inorganic aggregates, and a transparent coated electrode applied on top of the second layer and having a contact electrode. Next, the PV layer sequence thus prepared is characterized by exhibiting a photovoltaic effect in the range of long-wave and very long-wave infrared.

[0012] Details and Advantageous Features of the Present Invention According to the present invention, a method for producing an electro-technical thin layer at room temperature, in which conductive and / or semiconductive inorganic aggregates are provided regionally in a dispersion and cured to obtain a layer, is characterized in that the curing is carried out at room temperature and the curing is promoted by exposure to at least one reagent.

[0013] The method is preferably characterized in that a PV layer sequence is formed.

[0014] The method preferably applies, as at least one base layer, a layer comprising at least one metal or metal compound, and the at least one metal or its compound is selected from the group consisting of steel, zinc, tin, silver, copper, aluminum, nickel, lead, iron.

[0015] The method preferably applies, as a conductive base layer, at least one metal conductive and / or semiconductive layer and is at least partially cured.

[0016] The method preferably uses a material web that extends regionally as a carrier, and the material web is selected from the group of materials consisting of glass, plastic, polycarbonate, plastic film, metal alloy, motor block alloy, heat exchanger tube alloy, heat exchanger alloy, heat exchanger welding alloy, ceramic, industrial ceramic, natural stone, marble, clay ceramic, roof tile ceramic, laminated wood material, floorboard material, aluminum, staircase aluminum alloy, printed circuit board composite, integrated circuit housing material, processor housing compound.

[0017] The method preferably has the inorganic aggregates of the first layer being a metal or metal compound distributed in a plastic matrix, and the metal type of the metal or metal compound is selected from the group consisting of beryllium, boron, aluminum, gallium, indium, silicon, germanium, tin, lead, arsenic, antimony, selenium, tellurium, copper, silver, gold, zinc, iron, chromium, manganese, titanium, zirconium.

[0018] This method preferably has the inorganic aggregates of the second layer being a metal or metal compound that is at least partially aligned and distributed in the inorganic matrix, and the metal type of the above metal or metal compound being selected from the group consisting of beryllium, boron, aluminum, gallium, indium, silicon, germanium, tin, lead, arsenic, antimony, selenium, tellurium, copper, silver, gold, zinc, iron, chromium, manganese, titanium, zirconium.

[0019] This method preferably uses, as the inorganic matrix in the layer, a matrix comprising at least one chain-forming or modifying element as a glassy oxide matrix, and the above element being selected from the group consisting of boron, phosphorus, silicon, arsenic, sulfur, selenium, tellurium, amorphous carbon, graphite-modified carbon, carbon in the form of carbon nanotubes, carbon in the form of multi-walled carbon nanotubes, carbon in the form of buckminsterfullerene, calcium, sodium, aluminum, lead, magnesium, barium, potassium, manganese, zinc, tin, antimony, cerium, zirconium, titanium, strontium, lanthanum, thorium, yttrium, fluorine, chlorine, bromine, iodine.

[0020] This method preferably - A conductive electrode layer is applied on top of the carrier, - A metal or metal compound distributed in the plastic matrix is applied on top of the electrode layer as inorganic aggregates in the first layer, - A second layer of inorganic metal aggregates in at least a partially strongly basic or strongly acidic oxide matrix is applied on top of the first layer, - During application and curing, the metal aggregates react with the strongly acidic or basic matrix, and then the matrix reacts with the metal aggregates of the first layer, - During curing and reaction, a photoactive junction is formed, - A transparent coating electrode and / or a contact electrode are provided on the second layer, and - The layer sequence that is photo - electrochemically active is appropriately in contact with the PV layer sequence and is welded and packaged.

[0021] The drawings are described with reference to sketches in principle.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Figure 4a

Figure 4b

Modes for Carrying Out the Invention

[0023] In an advantageous embodiment, the electro - technical thin - layer sequence obtained as a PV layer sequence by the method according to the invention is such that the thin - layer sequence - comprises a glass carrier, - comprises an electrode layer applied on top of the glass carrier and comprising silver, - comprises a first layer applied on top of the electrode layer and comprising aluminum particles in a plastic matrix. - As a glass-like layer that is at least partially basic, comprising at least silicon-oxygen cross-links in a glass-like network and at least partially containing basic-soluble aluminum particles as inorganic aggregates, and comprising a second layer applied on top of the first layer, - Applied on top of the second layer and comprising a transparent coated electrode having a contact electrode, and then, - The PV layer sequence prepared in this way is characterized by exhibiting a photovoltaic effect in the long-wave and far-infrared ranges.

[0024] In a further advantageous embodiment, an acrylate-based paint for the outer part is mixed with aluminum flakes (pigment addition in the paint industry for paints with a silver appearance), homogenized, and the first layer is deposited on a glass carrier having an area of about 10 cm × 10 cm pre-coated with a translucent conductive metal layer. The acrylate-based layer comprising aluminum flakes is pre-cured in air at room temperature for 5 minutes. Thereafter, a second mixture of the same acrylate-based paint is made from aluminum flakes, mixed with silica sol, and adjusted to a basic pH with an aqueous sodium hydroxide solution in a cooled stirrer and homogenized. The still reactive mixture is applied as a second layer on top of the first pre-cured layer and distributed evenly and so as to coat. A parallel reaction in which aluminum is at least partially solubilized promotes the final curing of both layers. The layer composite thus obtained is provided, at its top, with finger electrodes made from room-temperature conductive silver from Busch. As shown in the scanning electron microscope image (SEM) of FIG. 1, the layer thus obtained is characterized, at its top, by a plastic matrix in which the base-soluble water glass provides a siloxane moiety. The Al flakes carried in the matrix are soluble and surely fuse into the plastic matrix. As taught by FIG. 2, the Al flakes pass through the plastic layer to the surface and enable direct electrical contact of a framework made from Al flakes conductively interconnected via contact points and short electrolyte crosslinks. Separation of the flexible segments of the plastic bilayer using a scalpel showed that the bilayer exists as a flexible solid removable composite. The removed segments were tested on their bottom side by SEM. As shown by the SEM image of FIG. 3, also at the bottom a very large number of Al flakes are present and contact and enable electrical contact with the phase interface of the translucent electrode.

[0025] The upper part of the bilayer is provided with finger electrodes made of room-temperature conductive silver from Busch and is additionally in regional contact with a transparent adherable ITO film. Subsequently, the coated electrode and the bottom electrode are brought into contact, and the cell was investigated with regard to PV activity. The bilayer was first investigated with regard to PV activity using a cold light LED light source with visible light. The photovoltaic current was weak or non-existent. After a short heating phase of 1 - 4 seconds, a clear photovoltaic potential difference exceeding 100 mV was measured upon irradiation with a halogen lamp. It was possible to tap a certain load for operating an LED bicycle lamp. The question arises as to whether this is attributable to the Peltier effect. To test this, thermocouples welded and packaged in a water-impermeable vacuum bag, with contact lines introduced at the top and bottom of the all-contact cell and completely immersed in 10 liters of hot water, were provided. After a heating time of about 5 minutes, the temperature of all thermocouples was the same. The photovoltaic potential difference between the coated electrode and the bottom electrode was significant and depended on the cell temperature, which decreased slowly relative to the water temperature. The starting value, final value, and intermediate value fluctuations were recorded digitally and reproduced in the figure of FIG. 4. As shown by FIG. 4a, the measurement of the photovoltaically tapable potential from the PV bilayer shows a relative dependence on the water temperature decreasing from 46 °C to 31 °C, i.e., the lower the temperature, the lower the tapable potential. However, in the Peltier element, the temperature gradient that would then be required for the measurable Seebeck effect is certainly not measured by the surrounding water. The temperature of the cell completely surrounded by uniformly heated water shows no gradient.

[0026] In a pizza oven, verification of the cell removed and taken out of the packaging surprisingly showed that up to 50 °C, at the distance of the cell from the heating wall of the pizza oven, sufficient thermal radiation does not reach the cell. As shown by FIG. 4b, the well-known optical absorption maximum of H2O as a function of wavelength in air is significant in the wavelength range of 5 - 10 micrometers.

[0027] The inventors believe that, in particular, hot water emits in this wavelength range and thus provides photons of appropriate energy with the highest efficiency in the selected experimental setup. The measured results clearly show an available bandgap at long wavelengths up to the far-IR range beyond 5 micrometers. However, this also conversely means that at high thermal incidence, sufficient thermal radiation would be required to penetrate the thin air layer around the cell and be able to generate an electric current. This was confirmed as follows. In a pizza oven at 80 °C, with a 2 cm air gap between the heated oven stone and the bilayer, manufactured as described above and contacting bilayer delivers a clearly measurable electric current that drops again relative to the temperature during cooling and retreats at about 60 °C. The bilayer sequence manufactured according to the present invention enables the advantageous utilization of long-wavelength photovoltaic power up to the far-IR irradiation, a wavelength range that was previously disadvantageously ignored and not investigated in the prior art. When the cell described above is connected to a voltmeter and heated by a flat hand placed thereon, a potential difference is established that is relative to each measurable surface temperature. Industrial waste heat and / or body heat can be effectively and efficiently utilized, especially with the PV layer sequence manufactured according to the present invention.

Industrial Applicability

[0028] It is a problem of the prior art methods that these always require a high-temperature sintering step. A further problem is that flexible thin layers, especially PV layers, often do not show resistance to such temperatures and furthermore do not allow the utilization of industrial waste heat and / or long-wavelength photons.

[0029] Solutions to these problems can be provided by a method in which an additional reaction during curing promotes and improves the curing. This particularly enables a double-layer sequence which advantageously enables, in particular, a PV layer sequence to be produced in which metal particles are present overall and the upper layer comprises a plastic matrix in which a base-solubilizable siloxane moiety and metal particles are present, and by means of mutual final curing during base solubilization industrial waste heat and / or long-wave IR irradiation can be made available by means of a photovoltaic means. The effective utilization of industrial waste heat / heat / body heat provides clear economic advantages in a very large number of fields.

Claims

1. An infrared photovoltaic device comprising a PV layer sequence formed at room temperature, wherein the PV layer sequence comprises: - a glass carrier, - an electrode layer applied on top of the glass carrier and comprising silver, - a first layer applied on top of the electrode layer and comprising aluminum particles in a plastic matrix, - a second layer applied on top of the first layer and comprising at least a silicate-oxygen crosslink in a glassy network as at least a partially basic glassy layer and at least partially basic soluble aluminum particles as inorganic aggregates, - a transparent coated electrode applied on top of the second layer and having a contact electrode, wherein a cured framework of Al flakes conductively interconnected through contact points and short electrolyte crosslinks is provided between the electrode layer and the transparent coated electrode, wherein the PV activity in the visible light region is weak or absent, wherein the PV layer sequence uses very long waves in the far IR range with a wavelength greater than 5 micrometers, characterized infrared photovoltaic device.

2. The infrared photovoltaic device according to claim 1, which converts electromagnetic radiation generated from industrial waste heat into electrical energy. ​

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