WO2010128461A1

WO2010128461A1 - Therminal contacts photovoltaic modules

Info

Publication number: WO2010128461A1
Application number: PCT/IB2010/051967
Authority: WO
Inventors: Fabio Renato Cappelli; Stefano Segato; Antonio Maroscia
Original assignee: SOLARGENIUS Srl
Current assignee: SOLARGENIUS Srl
Priority date: 2009-05-07
Filing date: 2010-05-05
Publication date: 2010-11-11
Anticipated expiration: 2011-11-07
Also published as: SM200900035A; KR20120020156A; BRPI1007677A2; SM200900035B

Abstract

A method of making a photovoltaic electric energy generating apparatus, comprising at least the successive steps of a) providing a support (T) with a surface (E) susceptible of being oriented toward a light source (S), b) providing at least one electrode layer (2) of an electrically conductive material with a first predetermined electronic potential, c) providing at least one active layer (3) of an optoelectronic material susceptible of absorbing photons and release electrons, d) providing at least one counter-electrode layer (4) of an electrically conductive material with a second electronic potential different from the first. The method includes a step of e) depositing a first connection layer (1) of a first electrically conductive material on the surface (E), which layer is in electric contact with at least one portion of the electrode layer (2) and a step of f) depositing a second connection layer (5) of a second electrically conductive material on at least one portion of the counter-electrode layer (4). The first and second connection layers (1, 5) are arranged to be operably connected to an electric and/or electronic circuit (6) for electric current generation.

Description

THERMINAL CONTACTS FOR PHOTOVOLTAIC MODULES

Field of the invention

The present invention finds application in the field of renewable energy, and particularly relates to a method of making a photovoltaic electric energy generating apparatus.

The invention also relates to a photovoltaic electric energy generating apparatus that can be obtained by this method.

Background art

From US-B-6013871 , in the name of Lawrence, a photovoltaic device is known which is made of layers of paint or metal oxides, embedded in a polymer matrix and coated with a layer of clear material to allow the passage of light.

From the international application WO2008/018030 in the name of the inventors a multilayer photovoltaic paint is known for absorption and conversion of light radiation into electric energy, which is composed of at least one first layer designed to adhere to the surface of the support, a second layer of an electrically conductive material designed to form an electrode, a third optoelectronically active layer designed to convert photons into electrons, a fourth layer of an electrically conductive material designed to form a counter-electrode.

A peculiar feature of this prior art paint is that it includes a base layer that is formed of a substantially homogeneous and continuous base material, which is electronically, chemically and mechanically inert to the other layers to define a universal anchoring base adaptable to surfaces of any shape and size. The materials of the various layers are initially in a liquid or pasty state, allowing the use of very simple deposition techniques, i.e. injection, paintbrush, palette-knife painting techniques or the like.

The process for application of said multilayer paint includes the steps of depositing the layer of base material onto the outer surface of the support, to form an anchoring surface, and later successively depositing the remaining layers.

Thanks to this process photovoltaic devices can be formed on surfaces of any type and size, in an easy manner and at low cost.

While this application method affords considerable advantages and is conceptually simple, it still requires the base layer to be deposited over the whole surface of the support that is designed to receive the remaining layers.

It frequently happens that the surface on which the paint is to be coated is electrically and chemically inert per se, i.e. has been coated with an insulating or dielectric layer beforehand. In these cases, the deposition of a base layer would be useless and costly, and would generally affect the cost-effectiveness and usefulness of the method of making the apparatus.

Furthermore, connection of the apparatus to an external user circuit requires connection of the electrode and counter-electrode layers to an external user circuit by means of electric terminals that essentially consist of traditional metal conductors or wires, using difficult and complex welding processes, which does not always ensure safe and reliable results.

Also, the above process involves considerable increases in the times and costs for making and connecting the terminals, and hence for making the device as a whole, as well as poor reliability and operating continuity of the assembly.

Disclosure of the invention

A primary object of the present invention is to obviate the above mentioned drawbacks by providing a method of making a photovoltaic electric energy generating apparatus by coating the surface of a support with a multilayer photovoltaic paint, which method may avoid any preliminary deposition of a base layer of material that is electrically and chemically inert to the remaining layers.

A particular object is to provide a method that allows simple, safe and easily automatable connection of the electrode and counter-electrode layers with an external electric circuit.

Yet another object is to conceive a photovoltaic electric energy generating apparatus that can be directly obtained by the above method.

These objects are fulfilled by a method of making a photovoltaic electric energy generating apparatus as defined in claim 1.

In a further aspect of the invention, the intended objects are fulfilled by a photovoltaic electric energy generating apparatus that can be obtained by the above method, as defined in claim 14.

Brief description of the figures

Further features and advantages of the invention will be more apparent upon reading of the description of a few exemplary embodiments of the method and apparatus of the invention, which are described by way of example and without limitation with the help of the annexed drawings, in which: FIG. 1 shows a cross sectional view of a first embodiment of a photovoltaic apparatus of the invention;

FIG. 2 shows a cross sectional view of a second embodiment of a photovoltaic apparatus of the invention; FIG. 3 shows a cross sectional view of a second embodiment of a photovoltaic apparatus of the invention;

FIG. 4 shows a block diagram of the method of making a photovoltaic apparatus of the type depicted in FIGS. 1 , 2 and 3 by application of a multilayer photovoltaic paint in accordance with the invention.

Description of the preferred embodiments

Referring to FIG. 1 , a photovoltaic apparatus of the invention is schematically shown.

The apparatus may be applied to a movable or stationary support T made of a rigid, semirigid or flexible material, but not in the liquid or pasty state.

The support T has an outer surface E susceptible of being oriented toward a light source S.

Suitably, the outer surface E is selected to at least partially have electrically insulating and/or dielectric properties. Thus, the next layers of the photovoltaic paints may be deposited onto the surface E without a base or intermediate substrate to adhere to the support T.

In the first embodiment of the apparatus 100 as shown in FIG. 1 , the support T or at least the surface E is one of the components of the apparatus 100. The surface E is selected to at least partially have dielectric and/o insulating properties. The apparatus 100 has at least three intermediate layers comprising an electrode layer 2 of a material having a first predetermined electronic potential, e.g. of about 3eV, an active layer 3 of an optoelectronic material susceptible of converting photons into electrons and generating electric charges, and a counter-electrode layer 4 of a material with a second electronic potential different from the first, e.g. of about 4eV.

The base materials that form the layers 2, 3, 4 may be those as described in the above mentioned international application WO2008/018030.

According to the invention, at least one first connection layer 1 is provided, which is made of a first electrically conductive material, at least partially overlapping the surface E and at least partially contacting the electrode layer 2.

A second connection layer 5 is further provided, which is made of a second electrically conductive material and is at least partially in contact with the counter-electrode layer 4.

The base materials for these layers are polymeric materials that are initially in the liquid or pasty state and can be later conveniently cured, containing metal oxides with superior conductive properties, such as iron, copper, zinc, titanium, gold and silver.

The first connection layer 1 and the second connection layer 5 are arranged to be connected to an electric and/or electronic circuit 6 for powering a suitable external load either local or grid network. The support T is at least partially composed of a non electrically conductive material.

In the first embodiment as shown in FIG. 1 , in which the apparatus is generally designated by numeral 100, the support T may consist of a film 7 made of an electrically insulating or dielectric polymer material. Advantageously, the first connection layer 1 may be at least partially embedded and/or integrated in the support T or the polymeric film 7.

In the second embodiment as shown in FIG. 2, in which the apparatus is generally designated by numeral 200, the support T consists of at least one layer 8 of an electrically insulating or dielectric fibrous material.

Alternatively, the outer surface E of the fibrous layer 8 is impregnated with an insulating and/or dielectric material.

Conveniently, a cover layer 9 made of an optically transparent polymeric material is laid on the layers 1-5 for covering, sealing and protecting the layers from external agents and particularly from oxygen and external radiation, particularly UV rays.

In the third embodiment of the apparatus 300, as shown in FIG. 3, the support T comprises at least one first plate 10 made of an at least partially transparent or opaque plastic of glass support material, which has a top face 11 adapted to define the support surface E for a first series of layers 1- 5.

Furthermore, the apparatus comprises at least one second plate 12 made of an at least partially transparent, preferably highly transparent plastic or glass material, having a bottom face 13 substantially parallel to and spaced from the top face 11 of the first plate 10 by a distance D equal to or larger than the maximum thickness of the first series of layers 1-5. Such second plate 12 may replace the protective layer 9 of the second embodiment, with the additional improvement of also protecting the layers 1-5 from impacts, scratches and weather agents.

Preferably, the at least two facing plates 10, 12 have surfaces of substantially identical sizes and are mutually joined at their facing peripheral edges by a suitable seal and/or suitable sealing compounds, like in double glazing panel, to define a substantially hermetically sealed chamber. The chamber 14 will be preferably maintained under vacuum and/or filled with an inert gas, such as nitrogen or argon. This will further increase protection of the layers 1-5, extend the life of the apparatus as a whole, and improve its effectiveness with time.

Of course, appropriate means have been provided to connect the connection layers 1 , 5 with conductors and terminals outside the apparatus, not shown.

In one alternative embodiment, not shown, a second series of layers 1-5 similar to the first series may be provided on the bottom face 13 of the second plastic of glass plate 12. In this case, the distance D between the facing plates 10, 12, i.e. the maximum thickness of the chamber 14 will be at least equal to the sum of the thicknesses of both sets of layers 1-5. Thanks to the at least partial transparence of this second set of layers 1-5, part of the photons may pass through it and also reach the first set of layers 1-5, thereby doubling or at least increasing the overall efficiency of the apparatus per unit surface area.

In another embodiment, also not shown, more than two plates may be provided, each having a series of layers 1-5 at least at one inner surface, which layers are connected to external terminals or conductors .

Conveniently, each of the intermediate layers 2-4 may have an appropriate shape, e.g. to define photovoltaic cells mutually connected in series and/or parallel by the connection layers 1 and 5.

Referring to FIG. 4, a method of making the photovoltaic apparatus 100 is shown. The method comprises the steps of: a) providing a support T having a surface E susceptible of being oriented toward a light source S; b) providing at least one electrode layer 2 of an electrically conductive material with a first predetermined electronic potential; c) providing at least one active layer 3 of an optoelectronic material susceptible of absorbing photons and releasing electrons; d) providing at least one counter-electrode layer 4 of an electrically conductive material with a second electronic potential, different from the first.

The surface E is selected to at least partially have dielectric and/or insulating properties, and a step is provided of e) depositing a first connection layer 1 of a first electrically conductive material on the surface E, which layer is designed to be in electric contact with at least one portion of the electrode layer 2, and a step of f) depositing a second connection layer 5 of a second electrically conductive material on at least one portion of the counter-electrode layer 4.

The first and second connection layers 1 , 5 are arranged to be operatively connected to an electric and/or electronic circuit 6 for powering an external local or network user unit, schematically designated by numeral 6.

The materials of all the layers 1-5 are polymeric compounds initially in liquid or pasty state.

Once the polymeric compounds of the layers 1-5 have been deposited, they undergo a curing step g), to define differentiated cured layers.

In an alternative embodiment, the electrode layer 2, the active layer 3 and the counter-electrode layer 4 may be obtained by controlled layering of a substantially homogeneous mixture M of the base materials that form said intermediate layers 2, 3, 4.

The mixture M may be evenly applied to the surface E to be evenly in contact with the first connection layer 1 and the second connection layer 5 and undergoes a controlled layering and curing step h) to promote the formation of the above mentioned cured and physically differentiated intermediate layers 2, 3, 4.

Suitably, the base materials of the electrode layer 2 and counter-electrode layer 5 are electronically differentiated.

Similarly, the base materials of the first and second connection layers 1 , 5 are electrically differentiated.

Suitably, each of the intermediate layers 2, 3, 4 has an appropriate shape, to define photovoltaic cells mutually connected in series and/or parallel by the connection layers 1 and 5.

With this method, all the layers, and particularly also the connection layers 1 , 5 may be easily deposited by automated, industrial-scale process, for instance using silk screens or inkjet printers.

The above description clearly shows that the invention fulfils the intended objects and particularly the object of providing a photovoltaic electric energy generating apparatus by application of a multilayer photovoltaic paint that can reduce the number of layers to be deposited and the need for a base layer that is inert to the others.

The apparatus and method of the invention are susceptible to a number of changes or variants, within the inventive concept disclosed in the annexed claims. All the details thereof may be replaced by other technically equivalent parts, and the materials may vary depending on different needs, without departure from the scope of the invention.

While the apparatus and method have been described with particular reference to the accompanying figures, the numerals referred to in the disclosure and claims are only used for the sake of a better intelligibility of the invention and shall not be intended to limit the claimed scope in any manner.

Claims

1. A method of making a photovoltaic electric energy generating apparatus (100, 200, 300), comprising at least the following steps: a) providing a support (T) having a surface (E) susceptible of being oriented toward a light source (S); b) providing at least one electrode layer (2) of an electrically conductive material with a first predetermined electronic potential; c) providing at least one active layer (3) of an optoelectronic material susceptible of absorbing photons and releasing electrons; d) providing at least one counter-electrode layer (4) of an electrically conductive material with a second electronic potential, that is different from the first one; wherein said surface (E) is selected to at least partially have dielectric and/or insulating properties, there being provided a step of e) depositing a first connection layer (1) of a first electrically conductive material on said surface (E), which connection layer is designed to be in electric contact with at least one portion of said electrode layer (2) and a step of f) depositing a second connection layer (5) of a second electrically conductive material on at least one portion of said counter-electrode layer

(4), said first and said second connection layers (1 , 5) being designed to be operatively connected to an electric and/or electronic circuit (6) for the generation of an electric current.

2. Method as claimed in claim 1 , wherein the materials of said layers (1- 5) are polymeric compounds which are initially in the liquid or pasty state.

3. Method as claimed in claim 1, wherein said polymeric compounds undergo a curing step after deposition to define differentiated cured layers.

4. Method as claimed in one or more of the preceding claims, wherein at least said electrode (2), active (3) and counter-electrode (4) intermediate layers are obtained by controlled layering of a substantially homogeneous mixture (M) of the materials of said layers (2, 3, 4).

5. Method as claimed in claim 4, wherein said mixture (M) is evenly applied to said surface (E) to be in contact with said first (1) and said second (5) connection layers and undergoes a controlled layering (h) and full curing step to promote the formation of said cured and physically differentiated layers (2, 3, 4).

6. Method as claimed in claim 1 , wherein the base materials of said electrode layer (2) and said counter-electrode layer (4) are electronically differentiated.

7. Method as claimed in claim 1 , wherein the base materials of said first electric connection layer (1) and said second electric connection layer (5) are electrically differentiated.

8. Method as claimed in claim 1 , wherein said support (T) is at least partially made from an electrically insulating and/or dielectric material.

9. Method as claimed in claim 1 , wherein said support (T) has a surface (E) at least partially covered with an electrically insulating and/or dielectric material (9).

10. Method as claimed in claim 1 , wherein said at least one first connection layer (1) is at least partially integrated in the surface (E) of said support (T).

11. Method as claimed in one or more of the preceding claims, wherein a step is provided of depositing at least one cover layer (9) of an optically transparent polymeric material on said layers (1-5), to seal and protect them from external agents, particularly oxygen, and from external radiation.

12. Method as claimed in one or more of the preceding claims, wherein said optically transparent polymeric material is selected from the group comprising vinyl compounds.

13. Method as claimed in claim 1, wherein said layers (1-5) are successively deposited on the surface (E) of said support (T) which consists of a film (7) of an electrically insulating and/or dielectric polymeric material.

14. Method as claimed in claim 1 , wherein said layers (1-5) are successively deposited on the surface (E) of said support (T) which consists of at least one layer (8) of a fibrous material.

15. Method as claimed in claim 1 , wherein said support (T) comprises at least one first plastic or glass plate (10) which is at least partially transparent, with a top surface (11) on which said layers (5) are deposited.

16. Method as claimed in claim 15, wherein a second at least partially transparent plastic or glass plate (12) is provided, with a bottom surface (13) substantially parallel to and spaced from the first plate by a distance (D) larger than the maximum thickness (R) of said layers (1-5).

17. Method as claimed in claim 16, wherein said first plate (10) and said second plate (12) have substantially identical surface areas, with facing peripheral edges that are joined to define a substantially hermetic chamber (14) which can be held under vacuum and filled with an inert gas.

18. Method as claimed in claim 16, wherein a second set of layers (1-5) similar to the first is laid on the bottom surface of said second plate (12), to allow light to pass therethrough and at least partially reach said first set of layers (1-5).

19. Method as claimed in claim 1 , wherein said layers (1-5) are all formed by automated deposition of the corresponding materials, such as by screen printing or inkjet printing or the like.

20. A photovoltaic apparatus (100, 200, 300) that can be obtained by the method as claimed in one or more of claims 1 to 15, comprising:

- at least one support (T) having a surface (E) susceptible of being oriented toward a light source (S);

- at least one electrode layer (2) of a material with a first predetermined electronic potential;

- at least one active layer (3) of an optoelectronic material susceptible of absorbing photons and releasing electrons, which is placed in electric contact with at least one portion of said at least one electrode layer (2); - at least one counter-electrode layer (4) of a material with a second electronic potential, different from the first, which is placed in electric contact with at least one portion of said at least one active layer (3); wherein at least one connection layer (1) of a first electrically conductive material is provided, which at least partially overlaps said surface (E) and is at least partially in contact with said at least one electrode layer (2), at least one second connection layer (5) of a second electrically conductive material is provided which is placed at least partially in contact with said counter-electrode layer (4), said first (1) and said second (5) connection layers being designed to be connected to an electric and/or electronic circuit (6) for generating an electric current.

21. Apparatus as claimed in claim 20, wherein said layers are made of initially liquid or pasty polymeric compounds to be appropriately cured.

22. Apparatus as claimed in claim 20, wherein said support (T) is at least partially made from an electrically insulating and/or dielectric material.

23. Apparatus as claimed in claim 20, wherein said support (T) consists of a film (7) made of an electrically insulating or dielectric material.

24. Apparatus as claimed in one or more of claims 20 to 23, wherein said at least one first connection layer (1) is at least partially embedded and/or integrated in said support (T) or said film (7) of polymeric material.

25. Apparatus as claimed in claim 20, wherein said support (T) consists of at least one layer of a fibrous material (8).

26. Apparatus as claimed in claim 25, wherein said fibrous material (8) that forms said support (T) is made of an electrically insulating and/or dielectric material.

27. Apparatus as claimed in claim 26, wherein the outer surface (E) of said fibrous layer (8) is impregnated with an insulating and/or dielectric material, selected from those comprising vinyl compounds.

28. Apparatus as claimed in one or more of claims 20 to 27, wherein a cover layer (9) is provided, which is made of an optically transparent polymeric material adapted to cover, seal and protect said layers (1-5) from external agents, particularly oxygen, and from external radiation.

29. Apparatus as claimed in claim 20, wherein said support (T) comprises at least one first plastic or glass plate (10) which is at least partially transparent, said first plate (10) having a first face (11) defining said support surface (E) for said layers (1-5).

30. Apparatus as claimed in claim 29, wherein said support (T) further comprises at least one second plastic or glass plate (12) which is at least partially transparent, said second plate (12) having a second face (13) opposite to the first face (11) and adapted to cover and protect said layers (1-5).

31. Apparatus as claimed in claim 30, wherein said at least one first (10) and at least one second (12) plates have substantially the same size and shape, with facing peripheral edges, joined and sealed together by a seal and/or sealing compounds, to define a substantially hermetically sealed chamber (14) therebetween.

32. Apparatus as claimed in claim 31 , wherein said hermetically sealed chamber (14) is maintained under vacuum or filled with an inert gas.

33. Apparatus as claimed in claim 31 , wherein said second plate (12) has a bottom surface (13) with a second set of layers (1-5) laid thereon, which is similar to the first and at least partially transparent to allow light to pass therethrough and at least partially reach said first set of layer (1-5).

34. Apparatus as claimed in claim 31 , wherein said connection layers (1 , 5) are connected to terminals outside said chamber (14).

35. Apparatus as claimed in claim 30, wherein more than two mutually facing plates are provided, each having a set of layers (1-5) on at least one inner and/or outer surface thereof.

36. Apparatus as claimed in one or more of claims 24 to 35, wherein each of said intermediate layers (2-4) has an appropriate shape, to define photovoltaic cells mutually connected in series and/or parallel by said connection layers (1 , 5).