WO2015166120A1 - Organic thermoelectric device, thermoelectric system, method for producing the device, coating for enclosure, enclosure and hybrid solar thermoelectric system - Google Patents

Abstract

The invention relates to a device comprising: a substrate (S); long and flat elements (E) consisting of organic semiconductor polymer that conducts a single type of carrier, and arranged on the substrate (S) in a coplanar manner, the ends thereof being arranged on two respective opposite ends of the substrate (S), and respectively forming a cold part (F) and a hot part (C), or being connected or arranged adjacently to same; connection elements (T) which interconnect in series to the elements (E) made of organic semiconductor polymers; and a first (U1) and a second (U2) electrode. The thermoelectric system includes two or more thermoelectric devices (D). The method is suitable for producing the device. The coating and the hybrid system are provided with at least one thermoelectric device (D), and the enclosure is provided with the coating.

Description

 Organic thermoelectric device, thermoelectric system, method for manufacturing the device, cladding for enclosure, enclosure and thermoelectric solar hybrid system Technical sector

 The present invention concerns, in general, in a first aspect, an organic thermoelectric device, formed by conductive organic semiconductor polymer elements of a single type of carriers arranged on a substrate, and more particularly a planar configuration device with their hot and cold faces arranged, respectively, at opposite ends of the semiconductor polymer elements, which are elongated.

 A second aspect of the invention concerns a thermoelectric system that includes two or more devices such as those of the first aspect.

 In a third aspect, the present invention concerns a method for manufacturing the device.

 A fourth aspect of the invention concerns a cladding covering comprising the device of the first aspect.

 A fifth aspect of the present invention concerns an enclosure that includes the coating of the fourth aspect.

 A sixth aspect of the present invention concerns a thermoelectric solar hybrid system, comprising a solar panel and, associated therewith, the device of the first aspect.

 The present invention is particularly applicable to the production of energy in large-scale applications, being implemented in large areas, such as windows and building walls or solar panels.

Prior art

 There are currently commercial B¡3Te2-based devices called Peltier modules used in refrigeration systems. The use of these devices for applications in large areas is completely unfeasible.

There are also certain organic prototypes that use nyp-type organic semiconductors, arranged alternately. Such is the case of the device proposed in patent application US20130042899, which includes two substrates that constitute, respectively, the cold and hot faces of the device, and which includes pairs of semiconductor members of different dopings trapped between both substrates, and which apply for example by means of an injection printer on the facing faces of both substrates. The distance between the cold and hot faces of such a device is very small.

 Many of these devices have serious drawbacks, such as their low efficiency and low viability when scaling large areas.

 In the application US20110094556 a thermoelectric device is described with a planar configuration in its thermoelectric elements constituted by short thermoelectric tracks arranged on a rigid substrate, alternating elements of material of type n with elements of material of type p, which are not organic materials. The substrate is trapped, together with another series of elements and layers of insulating materials, between an upper and a lower layer that constitute the hot and cold faces of the device, or vice versa. The application of the device proposed in US20110094556 in large areas is unfeasible (due to the high cost that it would entail), its planar configuration with such short thermoelectric tracks prevents the device from being used with large temperature differences since it would be very difficult to maintain a difference large temperature Such devices need to dissipate heat from the cold face, as the distance between the cold and hot faces is very small.

 International application WO2012101312A1 describes a micrometric scale thermoelectric device (microgenerator), which is not suitable for applications on large surfaces. The device proposed in said application can only be constituted by silicon nanowires as thermoelectric elements, being necessary, in particular, the use of n-type and p-type silicon nanowires, not considering the use of organic materials.

Although the device described in WO2012101312A1 has a planar configuration of its thermoelectric elements, the temperature difference must be from the center of the device to the ends, which, taking into account the reduced size of the device (about 5x5 mm ² ), It makes it difficult to achieve a very large temperature difference.

 The device proposed in WO2012101312A1 is not flexible and is obviously not feasible for large-scale applications.

On the other hand, in the International application WO2013065856A1 a thermoelectric conversion device is described that does use a single type of organic semiconductor, type p in this case, using semiconductor polymers, such as PEDOT, PAÑI, Polypyrrole, etc., with the possibility of incorporating a flexible substrate, and that meets the characteristics of the preamble of claim 1 of the present invention. In the device proposed in WO2013065856A1, the semiconductor polymer elements have a vertical conformation, as can be seen in Figure 1, such elements being arranged on the substrate in a substantially perpendicular direction, with one of its ends fixed to the substrate and its opposite ends fixed to an insulating layer, thus adopting a sandwich structure that traps, between the substrate and the insulating layer, the semiconductor polymer elements, where the substrate and the insulating layer constitute, respectively, the hot and cold faces of the device, or vice versa. As can be seen in Figure 2, the difference in temperature to be converted into voltage must occur between said hot and cold faces, which are separated from each other by a short distance, which makes it always necessary to dissipate heat in the cold face to maintain an acceptable temperature difference. Such heat dissipation of the cold face is even more necessary if one takes into account that the semiconductor polymer elements used are of a single type of doping, which means that the electrical connections between them are made from the cold face to the hot face, and as the metal used in such electrical joints is much better conductor of heat than the thermoelectric semiconductor, and has a very small length, such metal quickly heats the cold part, due to a better heat transmission between the cold part and hot, so much efficiency is lost.

 Thermoelectric materials in the device proposed in

WO2013065856A1 are prepared by mechanical coating methods, and the manufacturing process contains numerous stages that make it complicated, which translates into a considerable increase in the processing cost of the device. Explanation of the invention.

 It is necessary to offer an alternative to the state of the art that covers the gaps found therein, providing a thermoelectric device that, among others, improves the efficiency of the known, allows keeping cold and hot parts far enough away so as not to have the need of dissipating heat from the cold part, and is suitable for large-scale applications.

 To this end, the present invention concerns an organic thermoelectric device, comprising:

 - a substrate,

- elements of conductive organic semiconductor polymer of a single type of carriers, type not, preferably, type p, and which are arranged on said substrate; - connection elements, electricity conductors, which interconnect in series to said organic semiconductor polymer elements; Y

 - a first and a second electrode connected, respectively, with two of said organic semiconductor polymer elements;

 where first and a few second ends of the organic semiconductor polymer elements constitute, respectively, a cold part and a hot part of the device, or are attached or arranged adjacent thereto.

 Unlike the known proposals, in particular unlike the proposed device WO2013065856A1, in the device proposed by the first aspect of the invention the organic semiconductor polymer elements have a planar conformation, are elongated in one direction and are arranged coplanarly on the substrate , according to an arrangement in which the first and second ends of the organic semiconductor polymer elements are located on two respective opposite ends of the substrate.

 In the device proposed by the first aspect of the present invention, in general, the hot and cold parts are constituted by the portions of the substrate itself where the ends of the elongate elements or tracks of organic semiconductor polymer are arranged.

 For a preferred embodiment, the substrate is flexible, and for another less preferred embodiment, it is rigid.

 Preferably, the aforementioned two organic semiconductor polymer elements with which the first and second electrodes are respectively connected are the two end elements of the series constituting said serial connection of organic semiconductor polymer elements, although obviously if they are connected the first and second electrodes in other elements of the series other than the two extreme elements the device also works, although obtaining a smaller voltage difference than that existing between the two external elements, so this last less efficient connection is also contemplated as a less preferred embodiment of the device proposed by the present invention.

 With even greater preference, the first and second electrodes are connected to the free ends of said end elements of the series, since this is where a greater voltage difference will occur.

The mentioned first and second electrodes are constituted, according to an embodiment example, by at least some respective portions of two of the connecting elements. According to another embodiment, the first and second electrodes are additional connection elements to said connection elements.

 According to an embodiment, the elongated organic semiconductor polymer elements have rectangular shapes.

 According to an embodiment, the directions in which the organic semiconductor polymer elements are elongated are parallel to each other.

 According to an exemplary embodiment, the elongated organic semiconductor polymer elements are equally spaced apart in a transverse direction.

 According to other exemplary embodiments, said elongated organic semiconductor polymer elements are transverse spaced apart, varying distances.

 In general, the width of the organic semiconductor polymer elements is within a range from one or several nanometers to one or several centimeters, and as regards the length and width values of such polymer elements, and the relationship between the two, these may be considered appropriate for the desired application, although taking into account that the preferred application is related to large-scale surfaces, longitudinal distances of one or several meters is preferred.

 Because the distance between the cold part and the hot part is, in general, considerable (for example of the order of several meters), the electrical connections, that is to say the aforementioned connection elements, which interconnect in series the elements of Organic semiconductor polymers, from the hot to the cold part, are long enough to dissipate the heat on their own during the journey, thus heat is not transmitted to the cold part. Similarly, the polymer elements are also very long, so they also do not transmit heat from the hot part to the cold part. Therefore, it is not necessary to use a heat sink in the cold part.

 Advantageously, the device also includes a protective and sealing layer above at least the elements arranged on the substrate, for protection and isolation against adverse environmental conditions.

A second aspect of the invention concerns a thermoelectric system that includes two or more devices such as those of the first aspect, electrically connected in series or in parallel and with their substrates physically mounted one above the other, so that a higher voltage is generated. output than with a single device. In a third aspect, the present invention concerns a method for manufacturing the device of the first aspect by performing the following steps:

 a) deposit on the substrate a layer of metal or electrically conductive compound (such as Gold, Steel, ITO or Graphite) that is not electrochemically active, following a predetermined pattern,

 b) synthesizing said conductive organic semiconductor polymer from a single type of carriers, by electropolymerization, on said metal or electrically conductive compound constituting said organic semiconductor polymer elements, following said predetermined pattern, and then eliminating the metal or electrically conductive compound layer ; Y

 c) providing said connection elements in such a way that they interconnect in series the organic semiconductor polymer elements, by means of a good conductor or component, such as any electrical conductor metal, such as Copper, silver, gold, indium , aluminum etc.

 Because such interconnecting elements connect the ends of the organic semiconductor polymer elements arranged in the cold part with those arranged in the hot part, it is of interest that the heat of the hot part does not propagate to the cold part, whereby, for this purpose, it is desirable to make such connecting elements, generally formed in the form of tracks, as long as possible so that the heat dissipates during the path from one part to the other, so that the transmission is not transmitted heat from the hot part to the cold part and, therefore, a temperature difference is always generated between the hot and cold parts.

 Optionally, the method comprises performing, after said step c), an optimization step of the doped semiconductor polymer of the conductive organic semiconductor polymer elements, by reduction or oxidation of the semiconductor using chemical methods, that is by treatment with an oxidizing agent or reducer, or by electrochemical methods, that is, by using an electrochemical cell.

 According to an example of embodiment, the method comprises, after stage c) or after the stage of optimization of the doping, if necessary, the realization of a stage d) of elimination of excess material of semiconductor of organic semiconductor polymer, leaving only arranged on the substrate the elongated organic semiconductor polymer elements and the connection elements.

As regards the application of the aforementioned protective and sealing layer, this is carried out using any polymer solution. suitable, such as PMMA (Polymethylmethacrylate), which can be applied, for example, by spray, such as by means of an insulation sealant spray.

 As regards the deposition of step a), this is carried out by thermal evaporation or by any other method that deposits a metal on a substrate.

 According to a preferred embodiment, the substrate is flexible, made for example of at least one of the following materials: Polyethelene Terephthalate (PET), polyurethane, polypropylene and polyethylene, or a combination thereof.

 For another embodiment, the substrate is rigid, made for example of at least one of the following materials: glass, quartz and thermoset polymeric resins, or a combination thereof.

Although this method could be used to manufacture a device that alternately combines elements of organic semiconductor polymer of type n with others of type p, the method of synthesis of the semiconductor tracks, that is of the elements of organic semiconductor polymer, and The manufacturing process of the device would be very complex, since so that the polymers of type n can be alternated with those of type p, those of one type would have to be synthesized first and then those of the other type. This at the time of manufacturing process would be very expensive compared to using semiconductors of the same type since all the tracks are synthesized at the same time.

 As indicated above, preferably the polymers used are of type p, since today n-type polymers are very unstable and very low efficiency, so it is not practical to implement them in devices. Obviously, if the stability and efficiency of type n increases considerably in the future, your choice will be as preferred as those of type p.

 A fourth aspect of the invention concerns a cladding covering comprising the device of the first aspect.

 For an exemplary embodiment, the coating comprises two or more thermoelectric devices electrically connected in series or in parallel.

 Depending on the exemplary embodiment, said cladding is: a sheet to be superimposed on one or more facades of a building (for example, by placing the hot part on a facade where the sun falls and the cold part on a shadow facade), a board, panel, etc.

A fifth aspect of the present invention concerns an enclosure that includes the coating of the fourth aspect. Depending on the exemplary embodiment, said enclosure is a wall, a panel, a window, a door, a curtain, etc.

 A sixth aspect of the present invention concerns a thermoelectric solar hybrid system, comprising a solar panel and, associated therewith, the device of the first aspect, providing the hot part in an area in contact with the panel and the cold part in a position away from the areas of the panel where the sun's rays affect, thus complementing, with the energy obtained by the thermoelectric device, the production of energy obtained by the solar panel.

 For an exemplary embodiment, the hybrid system comprises two or more thermoelectric devices electrically connected in series or in parallel.

 The present invention is particularly applicable to energy production in large-scale thermoelectric applications, since the proposed thermoelectric device, due to its low production cost, is ideal for energy production in large areas.

Brief description of the drawings

 The foregoing and other advantages and features will be more fully understood from the following detailed description of some embodiments with reference to the attached drawings, which should be taken by way of illustration and not limitation, in which:

 Figure 1 is a schematic representation, at a functional level, of the device proposed by the first aspect of the present invention;

 Figure 2 illustrates the manufacturing method proposed by the third aspect of the invention, according to an exemplary embodiment, representing the results of each of the steps of the method until the final product is achieved, that is the device of the first aspect of the present invention, as seen in view (d);

 Figure 3 is a graph showing the experimental measurements obtained, relating voltage generated as a function of temperature difference between hot part and cold part of a prototype constructed of the device proposed by the first aspect;

 Figure 4 illustrates, in perspective and schematically, the enclosure proposed by the fifth aspect of the present invention, for an exemplary embodiment; Y

Figure 5 illustrates, also in perspective and schematically, the thermoelectric solar hybrid system proposed by the sixth aspect of the present invention, according to an exemplary embodiment. Detailed description of some embodiments

 The operation of the device D proposed by the first aspect of the present invention is based on thermoelectric junctions of a pon-type organic semiconductor (such as PEDOT, PAÑI, polypyrrole, polycarbazole, etc.) of the cold and hot C ends of a series of polymer tracks E of a thickness of microns or nanometers, as shown in Figure 1, electrically connected in series by means of the connecting elements T, so that the current generated by the temperature difference flows through of the cold and hot ends C of the device, generating a voltage V between the electrodes U1 and U2. In principle, any polymer or material with thermoelectric properties that can be synthesized by electrochemical methods is likely to be used in the device.

 As written in a previous section, a third aspect of the invention concerns a manufacturing method of the device D. This manufacturing method consists of four stages, according to an embodiment example, as shown in Figure 2, which represents the different intermediate products (views (a), (b) and (c)) and final (view (d)), obtained after the application of each of the respective stages of the method.

 The first stage, or stage a), is the creation on a substrate S of the drawing that is to be coated with the conductive polymer. This particular drawing or pattern must be made of a metal or conductive compound that is not electrochemically active, such as steel or gold. In the manufacture of an experimental prototype, a layer of GL gold consisting of 16 gold tracks of a thickness of 2 mm separated 2 mm from each other has been deposited by metallic evaporation, although in Figure 2 (a) 6 gold tracks have been illustrated only as a schematic representation.

 In the second stage, or stage b), the organic conductor semiconductor polymer PS of a single type of carriers is synthesized, by electropolymerization, on the metal or electrical conductor compound GL, following said predetermined pattern, and after that the layer of metal or electrical conductor compound GL, that is, in this case, the gold layer.

To carry out said electropolymerization of the semiconductor polymer PS, the substrate S is used as the working electrode in the second stage. For the manufacture of the experimental prototype, a three electrode cell has been used: a working electrode, consisting of the substrate with the gold pattern, an auxiliary electrode with a mesh of platinum, an Ag / AgCI reference electrode and a potentiostat. The electrochemical solution was composed of the monomer of the conductive polymer, in this case ethylenedioxythiophene (EDOT) and 1-Butyl-3-methylimdazole hexafluorophosphate in acetonitrile. The electropolymerization is carried out at -3 mA so that the gold pattern is coated by the polymer being synthesized, in the case of the experimental prototype, PEDOT: PF6. As previously mentioned, the gold layer is subsequently removed, in this case with royal water, so that only the conductive polymer PS remains on the PET substrate S as shown in Figure 2 (b).

 The third stage, or stage c) (see Figure 2 (c)), consists in making the contacts between the semiconductor polymer tracks (hot and cold part junctions), that is, providing the connecting elements T so that Connect in series the elements of organic semiconductor polymers E, by means of an element or compound that is a good conductor of electricity. For this case you can use any compound that conducts electricity as a metal, although it should be configured so that it is not a very good thermal conductor (constituting them in the form of long tracks), in the case of the experimental prototype gold has been used although It can be perfectly aluminum.

 As an optional step, the method comprises performing, after step c), an optimization step of the dopedness of the PS semiconductor polymer of the conductive organic semiconductor polymer elements, by reduction or oxidation of the semiconductor using chemical or electrochemical methods.

 The last stage, or stage d), consists in the elimination of the excess material of organic semiconductor polymer PS, only the elongated organic semiconductor polymer elements E and the connection elements T being arranged on the substrate S, as can be seen in Figure 2 (d), thus the device D being formed.

 The hot and cold parts (indicated respectively as F and C in Figure 1), are constituted, for the exemplary embodiment of Figure 2, by the portions of the substrate S itself where the ends of the elements or tracks are arranged. elongated organic semiconductor polymer E.

 It can be seen in Figure 2 (d), how the first U1 and second U2 electrodes are arranged on the free ends of the elements E located at the ends of the series of elements E.

Although in the schematic representation of Figure 2 (d), the device has been illustrated comprising only six polymer tracks E, in the actual design of the Experimental prototype built, this consists of 16 PEDOT E tracks linked by T gold tracks.

 Depending on the manufacturing process, multiple geometries and sizes can be adopted, in addition, the width and number of polymer tracks E can be changed.

 By means of lithographic techniques, a substrate S can be made with conductive tracks of a width of microns or even nanometers, which leads to an increase in the number of polymer tracks per unit area. This increase in the number of tracks per unit area will increase the voltage produced per unit temperature difference (Seebeck voltage). Several devices can also be mounted in series, one on top of the other, so that the power generated will be multiplied.

The voltage generated by the device as a function of temperature has been characterized, as shown in Figure 3. Experimental measurements have been made on the prototype built before and after subjecting the semiconductor polymer to an optimization treatment. of the thermoelectric parameters by chemical reduction with hydrazine, according to a study that the present inventors have made, starting from a semiconductor polymer with a Seebeck coefficient of 413 μν / ν until obtaining an optimized semiconductor polymer with a Seebeck coefficient of 91 μν / Κ The results are encouraging because, as shown in Figure 3, about 25 mV have been achieved (for the case of the optimized polymer) with a temperature difference of 60 ° C with only one device layer and only 16 tracks of conductive polymer

 Volt values can be reached by decreasing the width of the polymer tracks, so that they fit more per unit area and overlapping several layers of devices, that is, by the system proposed by the second aspect of the invention. The coating proposed by the fourth aspect of the invention comprises, according to an exemplary embodiment, the device D as illustrated in Figure 2 (d) or, advantageously, with a greater number of polymer track elements E and with dimensions appropriate to the support on which it is intended to be arranged.

The enclosure proposed by the fifth aspect of the invention is illustrated in Figure 4, for an exemplary embodiment for which it comprises a wall J on which the lining of the fourth aspect constituted by the device D. For clarity, the different elements that form the device D have not been illustrated although, obviously, these are as illustrated in Figure 2 (d), in greater or lesser number and with greater or lesser dimensions.

 Finally, Figure 5 illustrates the thermoelectric solar hybrid system proposed by the sixth aspect of the present invention, for which it comprises a solar panel K (in general a photovoltaic panel) on which solar rays R, and, associated therewith, the thermoelectric device D, to complement the energy production of the solar panel K, the hot face C of the device D being in contact with the solar panel K, and the cold face F in a shaded area, in this case behind panel K, so that between both sides C, F there is a temperature difference ΔΤ sufficient for the thermoelectric device D to generate an appreciable voltage.

 For another embodiment (not illustrated), the hybrid system comprises two or more thermoelectric devices D electrically connected in series or in parallel.

 A person skilled in the art could introduce changes and modifications in the described embodiments without departing from the scope of the invention as defined in the appended claims.

Claims

Claims 1. - Organic thermoelectric device, comprising: - a substrate (S), - conductive organic semiconductor polymer elements (E) with a single type of carriers and which are arranged on said substrate (S); - connection elements (T), electrical conductors, which interconnect in series said organic semiconducting polymer elements (E); and - a first (U1) and a second (U2) electrodes connected, respectively, with two of said organic semiconductor polymer elements (E); where first and second ends of the organic semiconductor polymer elements (E) constitute, respectively, a cold part (F) and a hot part (C) of the device, or are attached or arranged adjacent thereto; the device being characterized in that said organic semiconductor polymer elements (E) have a planar conformation, are elongated in one direction and are arranged coplanarly on said substrate (S), according to an arrangement in which said first and second ends of the elements of organic semiconductor polymer (E) are located on two respective opposite ends of the substrate (S). 2. - Device according to claim 1, characterized in that said substrate (S) is flexible. 3. - Device according to any one of the preceding claims, characterized in that said elongated organic semiconductor polymer elements (E) have rectangular shapes. 4. - Device according to any one of the previous claims, characterized in that the directions in which the organic semiconductor polymer elements (E) are elongated are parallel to each other. 5. - Device according to claim 4, characterized in that said elongated organic semiconductor polymer elements (E) are equally spaced from each other, in a transverse direction. 6. - Device according to claim 4, characterized in that said elongated organic semiconductor polymer elements (E) are separated from each other, transversely, by variable distances. 7. Device according to any one of the preceding claims, characterized in that said two organic semiconductor polymer elements (E) with which said first (U1) and second (U2) electrodes are respectively connected are the two extreme elements of the series that constitutes said series connection of elements of organic semiconductor polymers (E). 8. - Device according to claim 7, characterized in that the first (U1) and second (U2) electrodes are connected to the free ends of said end elements of the series. 9. - Device according to any one of the preceding claims, characterized in that the width of said organic semiconductor polymer elements (E) is within a range ranging from one or several nanometers to one or several centimeters. 10. - Device according to any one of the preceding claims, characterized in that said first (U1) and second (U2) electrodes are constituted by at least respective portions of two of said connection elements (T). 1. - Thermoelectric system comprising at least two devices (D) according to any one of the previous claims electrically connected in series or in parallel and with their substrates physically mounted on top of each other. 12. - Method for the manufacture of an organic thermoelectric device, which comprises manufacturing the device according to any one of claims 1 to 10 by carrying out the following steps: a) deposit on said substrate (S) a layer of metal or electrically conductive compound (GL) that is not electrochemically active, following a predetermined pattern, b) synthesizing said conductive organic semiconductor polymer (PS) of a single type of carriers, by electropolymeration, on said metal or electrically conductive compound (GL) constituting said organic semiconductor polymer elements (E), following said predetermined pattern, and thereafter remove the layer of metal or electrically conductive compound (GL); and c) providing said connection elements (T) so that they interconnect in series the organic semiconducting polymer elements (E), using a good electrically conductive element or compound. 13. - Method according to claim 12, characterized in that it comprises carrying out, after said step c), a step of optimizing the doping of the semiconductor polymer of the conductive organic semiconductor polymer elements, by reduction or oxidation of the semiconductor using chemical or electrochemical methods. 14. - Method according to claim 12 or 13, characterized in that it comprises, after said stage c) or after said doping optimization stage, carrying out a stage d) of elimination of excess organic semiconductor polymer (PS) material, leaving Only the elongated organic semiconductor polymer elements (E) and the connection elements (T) are arranged on the substrate (S). 15. - Method according to claim 12, 13 or 14, characterized in that said deposition of said step a) is carried out by thermal evaporation. 16. - Method according to any one of claims 12 to 15, characterized in that said substrate (S) is flexible. 17.- Method according to claim 16, characterized in that said flexible substrate (S) is made of at least one of the following materials: Polyethylene Terephthalate (PET), polyurethane, polypropylene and polyethylene, or a combination thereof. 18.- Method according to any one of claims 12 to 15, characterized in that said substrate (S) is rigid. 19.- Method according to claim 18, characterized in that said rigid substrate (S) is made of at least one of the following materials: glass, quartz and thermostable polymer resins, or a combination thereof. 20.- Enclosure covering comprising at least one thermoelectric device (D) according to any one of claims 1 to 10. 21.- Coating according to claim 20, characterized in that it comprises at least two thermoelectric devices (D) according to any one of claims 1 to 10 electrically connected in series or parallel. 22. - Enclosure that includes the covering of claim 20 or 21. 23. - Solar thermoelectric hybrid system, comprising a solar panel and, associated therewith, at least one thermoelectric device (D) according to any one of claims 1 to 10. 24. - Hybrid system according to claim 23, characterized in that it comprises at least two thermoelectric devices (D) according to any one of claims 1 to 10 electrically connected in series or parallel.