PHOTOVOLTAIC DEVICES COMPRISING LUMINESCENT SOLAR CONCENTRATORS AND PEROVSKITE-BASED PHOTOVOLTAIC CELLS

Abstract

A photovoltaic device or solar device including at least one luminescent solar concentrator (LSC) having an upper surface, a lower surface and one or more external sides; at least one perovskite-based photovoltaic cell or solar cell positioned on the outside of at least one of the external sides of said luminescent solar concentrator (LSC), the perovskite being selected from organometal trihalides. The photovoltaic device or solar device may be used advantageously in various applications necessitating the production of electrical energy by utilising light energy, in particular solar radiation energy such as, for example: building integrated photovoltaic (BIPV) systems, photovoltaic windows, greenhouses, photobioreactors, noise barriers, lighting equipment, design, advertising, automotive industry. Moreover, the photovoltaic device or solar device can be used both in stand-alone mode and in modular systems.

Claims

1. A photovoltaic device or solar device comprising: at least one luminescent solar concentrator (LSC) having an upper surface, a lower surface and one or more external sides; at least one perovskite-based photovoltaic cell or solar cell, the photovoltaic cell or solar cell positioned outside of at least one of the external sides of the luminescent solar concentrator (LSC), wherein the perovskite is selected from organometal trihalides.

2. The photovoltaic device or solar device according to claim 1, wherein the luminescent solar concentrator (LSC) has an upper surface configured to receive photons, a lower surface configured to receive photons, wherein the upper surface is positioned closer to a photon source with respect to the lower surface, and four external sides that extend from the upper surface to the lower surface.

3. The photovoltaic device (or solar device) according to claim 1, wherein the luminescent solar concentrator (LSC) is a plate comprising a matrix in transparent material and at least one photoluminescent compound.

4. The photovoltaic device or solar device according to claim 3, wherein the transparent material is selected from the group consisting of: polymethyl methacrylate (PMMA), polycarbonate (PC), polyisobutyl methacrylate, polyethyl methacrylate, polyallyl diglycol carbonate, polymethacrylimide, polycarbonate ether, polyethylene terephthalate, polyvinyl butyral, ethylene-vinylacetate copolymers, ethylene-tetrafluoroethylene copolymers, polyimide, polyurethane, styrene-acrylonitrile copolymers, styrene-butadiene copolymers, polystyrene, methyl-methacrylate styrene copolymers, polyethersulfone, polysulfone, cellulose triacetate, transparent and impact-resistant crosslinked acrylic compositions, transparent glass and mixtures thereof; wherein the transparent material has a refractive index ranging from 1.30 to 1.70; wherein the transparent glass is selected from the group consisting of silica, quartz, alumina, titanium dioxide, and mixtures thereof; and wherein the transparent and impact-resistant crosslinked acrylic compositions consist of a fragile matrix (I) having a glass transition temperature (T.sub.g) above 0° C. and elastomeric domains having dimensions smaller than 100 nm that consist of macromolecular sequences (II) having a flexible nature with a glass transition temperature (T.sub.g) below 0° C. (PPMA-IR), or mixtures thereof.

5. The photovoltaic device or solar device according to claim 3, wherein the photoluminescent compound is selected from perylene compounds; acene compounds; benzothiadiazole compounds; compounds comprising a benzoheterodiazole group and at least one benzodithiophene group; disubstituted naphthathiadiazole compounds; benzoheterodiazole compounds disubstituted with benzodithiophene groups; disubstituted benzoheterodiazole compounds; disubstituted diaryloxybenzoheterodiazole compounds; and mixtures thereof.

6. The photovoltaic device or solar device according to claim 3, wherein the photoluminescent compound is present in the transparent matrix in a quantity ranging from 0.1 g per unit of surface area to 3 g per unit of surface area, wherein the unit of surface area being referred to the surface area of the matrix of transparent material expressed in m.sup.2.

7. The photovoltaic device or solar device according to claim 3, wherein the photoluminescent compound is selected from quantum dots (QDs) that can be composed of different elements selected from the elements belonging to groups 12-16, 13-15, 14-16, of a Periodic Table of the Elements or mixtures thereof.

8. The photovoltaic device or solar device, according to claim 7, wherein the photoluminescent compound selected from quantum dots (QDs) is present in the transparent matrix in a quantity ranging from 0.05 g per unit of surface area to 100 g per unit of surface area, wherein the unit of surface area being referred to is the surface area of the matrix of transparent material expressed in m.sup.2.

9. The photovoltaic device or solar device according to claim 1, wherein the luminescent solar concentrator (LSC) is a plate having a thickness ranging from 0.1 mm to 50 mm.

10. The photovoltaic device or solar device according to claim 1, wherein the perovskite is selected from organometal trihalides having a general formula ABX.sub.3, wherein: A represents an organic cation such as methylammonium (CH.sub.3NH.sub.3.sup.+), formamidinium [CH(NH.sub.2).sub.2.sup.+], n-butylammonium (C.sub.4H.sub.12N.sup.+), tetra-butylammonium (C.sub.16H.sub.36N.sup.+); B represents a metallic cation such as lead (Pb.sup.2+), tin (Sn.sup.2+); X represents a halogen ion such as iodine (I.sup.−), chlorine (Cl.sup.−), bromine (Br.sup.−).

11. The photovoltaic device or solar device according to claim 1, wherein the perovskite is selected from: methyl ammonium lead iodide (CH.sub.3NH.sub.3PbI.sub.3), methyl ammonium lead bromide (CH.sub.3NH.sub.3PbBr.sub.3), methyl ammonium lead chloride (CH.sub.3NH.sub.3PbCl.sub.3), methyl ammonium lead iodide bromide (CH.sub.3NH.sub.3PbI.sub.xBr.sub.3-x), methyl ammonium lead iodide chloride (CH.sub.3NH.sub.3PbI.sub.xCl.sub.3-x), formamidinium lead iodide [CH(NH.sub.2).sub.2PbI.sub.3], formamidinium lead bromide [CH(NH.sub.2).sub.2PbBr.sub.3], formamidinium lead chloride [CH(NH.sub.2).sub.2PbCl.sub.3], formamidinium lead iodide bromide [CH(NH.sub.2).sub.2PbI.sub.xBr.sub.3-x], formamidinium lead iodide chloride [CH(NH.sub.2).sub.2PbI.sub.xCl.sub.3-x], n-butyl ammonium lead iodide (C.sub.4H.sub.12NPbI.sub.3), tetra-butyl ammonium lead iodide (C.sub.16H.sub.36NPbI.sub.3), n-butyl ammonium lead bromide (C.sub.4H.sub.12NPbBr.sub.3), tetra-butyl ammonium lead bromide (C.sub.16H.sub.36NPbBr.sub.3), methyl ammonium tin iodide (CH.sub.3NH.sub.3SnI.sub.3), methyl ammonium tin bromide (CH.sub.3NH.sub.3SnBr.sub.3), methyl ammonium tin iodide bromide (CH.sub.3NH.sub.3SnI.sub.xBr.sub.3-x), formamidinium tin iodide [CH(NH.sub.2).sub.2SnI.sub.3], formamidinium tin iodide bromide [CH(NH.sub.2).sub.2SnI.sub.xBr.sub.3-x], n-butyl ammonium tin iodide (C.sub.4H.sub.12NSnI.sub.3), tetra-butyl ammonium tin iodide (C.sub.16H.sub.36NSnI.sub.3), n-butyl ammonium tin bromide (C.sub.4H.sub.12NSnBr.sub.3), tetra-butyl ammonium tin bromide (C.sub.16H.sub.36NSnBr.sub.3), methyl ammonium tin iodide (CH.sub.3NH.sub.3SnI.sub.3), or mixtures thereof.

12. The photovoltaic device or solar device according to claim 1, wherein the at least one perovskite-based photovoltaic cell or solar cell is coupled to at least one of the external sides of the luminescent solar concentrator (LSC) with use of a optical gel, wherein the optical gel is selected from the group consisting of transparent silicone oils and fats, and epoxy resins.

13. The photovoltaic device or solar device according to claim 1, wherein the electrical energy generated by the at least one perovskite-based photovoltaic cell or solar cell is transported using a wiring system that is connected to the photovoltaic device or solar device.

14. The photovoltaic device or solar device according to claim 1 wherein the photovoltaic device or solar device is used in applications selected from the group consisting of building integrated photovoltaic (BIPV) systems, photovoltaic windows, greenhouse, photobioreactors, noise barriers, lighting equipment, design, advertising, and automotive industry.

15. The photovoltaic device or solar device according to claim 1, wherein the perovskite is methyl ammonium lead iodide (CH.sub.3NH.sub.3PbI.sub.3).

16. The photovoltaic device or solar device according to claim 3, wherein the photoluminescent compound is selected from the group consisting of perylene compounds such as N,N′-bis(2′,6′-di-iso-propylphenyl)(1,6,7,12-tetraphenoxy)(3,4,9,10-perylene diimide (Lumogen® F Red 305—Basf), 9,10-diphenylanthracene (DPA), 4,7-di(thien-2′-yl)-2,1,3-benzothiadiazole (DTB), 5,6-diphenoxy-4,7-bis(2-thienyl)-2,1,3-benzothiadiazole (DTBOP), 5,6-diphenoxy-4,7-bis[5-(2,6-dimethylphenyl)-2-thienyl]benzo[c]1,2,5-thiadiazole (MPDTBOP), 5,6-diphenoxy-4,7-bis[5-(2,5-dimethylphenyl)-2-thienyl]benzo[c]1,2,5-thiadiazole (PPDTBOP), 4,7-bis[5-(2,6-dimethylphenyl)-2-thienyl]benzo[c]1,2,5-thiadiazole (MPDTB), 4,7-bis[5-(2,6-di-iso-propylphenyl)-2-thienyl]benzo[c]1,2,5-thiadiazole (IPPDTB), 4,7-bis[4,5-(2,6-dimethylphenyl)-2-thienyl]benzo[c]1,2,5-thiadiazole (2MPDTB) 4,7-bis(7′,8′-dibutylbenzo[1′,2′-b′:4′,3′-b″]dithien-5′-yl)-benzo[c] [1,2,5]thiadiazole (F500), 4,9-bis(7′,8′-dibutylbenzo[1′,2′-b′:4′,3′-b″]dithien-5′-yl)-naphtho[2,3-c][1,2,5]thiadiazole (F521), 4,7-bis(5-(thiophen-2-yl)thiophen-2-yl)benzo[c][1,2,5]thiadiazole (QTB), 4,9-bis(thien-2′-yl)-naphtho[2,3-c][1,2,5]thiadiazole (DTN), and mixtures thereof.

17. The photovoltaic device or solar device according to claim 3, wherein the photoluminescent compound is selected from the group consisting of perylene compounds such as 9,10-5,6-diphenoxy-4,7-bis[5-(2,6-dimethylphenyl)-2-thienyl]benzo[c]1,2,5-thiadiazole (MPDTBOP), 5,6-diphenoxy-4,7-bis[5-(2,5-dimethylphenyl)-2-thienyl]benzo[c]1,2,5-thiadiazole (PPDTBOP), N,N′-bis(2′,6′-di-iso-propylphenyl)(1,6,7,12-tetraphenoxy)(3,4,9,10-perylene diimide (Lumogen® F Red 305—Basf), and mixtures thereof.

18. The photovoltaic device or solar device according to claim 3, wherein the photoluminescent compound is present in the transparent matrix in a quantity ranging from 0.2 g per unit of surface area to 2.5 g per unit of surface area, and wherein the unit of surface area being referred to is the surface area of the matrix of transparent material expressed in m.sup.2.

19. The photovoltaic device or solar device according to claim 3, wherein the photoluminescent compound is selected from quantum dots (QDs) that can be composed of different elements selected the group consisting of lead sulphide (PbS), zinc sulphide (ZnS), cadmium sulphide (CdS, cadmium selenide (CdSe), cadmium telluride (CdTe), silver (Ag), gold (Au), aluminium (Al), and mixtures thereof.

20. The photovoltaic device or solar device according to claim 4, wherein the transparent material is selected from polymethylmethacrylate (PMMA), PMMA-IR, or mixtures thereof.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0069] The present invention will now be illustrated in greater detail by means of an embodiment with reference to FIGS. 1 and 2 below reported.

[0070] FIG. 1 is a sectional view with respect to plane (A) of FIG. 2, of a photovoltaic device or solar device.

[0071] FIG. 2 is a three-dimensional view of the photovoltaic device or solar device of FIG. 1.

[0072] FIG. 3 is a graph illustrating the external quantum efficciency of a solar cell.

DETAILED DESCRIPTION

[0073] In particular, FIG. 1 represents a sectional view with respect to plane (A) of FIG. 2, of a photovoltaic device (or solar device) (100) comprising: a luminescent solar concentrator (LSC) (110) including at least one photoluminescent compound (120) and a perovskite-based photovoltaic cell (or solar cell) (110a) comprising the following layers: a substrate of glass (140) coated with a layer of transparent and conductive oxide (TCO) (anode) (150); an electron transporter layer (Electron Transport Material—ETO) (160); a layer of perovskite (170); optionally, a scaffold of mesoporous titanium dioxide (TiO.sub.2) (not shown in FIG. 1) positioned between said electron transporter layer (Electron Transport Material—ETO) and said perovskite layer (170); a layer based on a hole transport material (Hole Transport Material—HTM) (180), a metallic contact know as a “back contact” (cathode) (190); optionally, a suitable optical gel (not shown in FIG. 1) positioned between said substrate layer of glass (140) and said luminescent solar concentrator (LSC) (110). In said FIG. 1, an incident photon (130) having a first wavelength enters the luminescent solar concentrator (LSC) (110) and is absorbed by the photoluminescent compound (120) and emitted at a second wavelength different from the first. The incident photons are internally reflected and refracted within the luminescent solar concentrator (LSC) until they reach the photovoltaic cell (or solar cell) (110a) and are converted into electrical energy.

[0074] FIG. 2 shows a three-dimensional view of a photovoltaic device (or solar device) (100) comprising a luminescent solar concentrator (LSC) (110) and a perovskite-based photovoltaic cell (or solar cell) (110a).

[0075] For the purpose of improving understanding of the present invention and putting it into practice, in what follows we present a number of illustrative and non-limiting examples thereof.

[0076] For greater simplicity, in the examples which follow the terms “solar cell” and “solar device” are used, which should be understood as having the same meaning as “photovoltaic cell” and “photovoltaic device”.

Example 1

Preparation of Plate 1 (Casting) (LSC1)

[0077] In a 4-litre flask were heated, with magnetic stirring, 2500 ml of methyl methacrylate (MMA) (Sigma-Aldrich), previously distilled in order to remove any inhibitors of polymerisation, bringing the temperature to 80° C., in 2 hours. The following were then added: 250 mg 2,2′-azo-bis[2-methylpropionamidine]dihydrochloride (AIBN) (initiator) dissolved in 250 ml of methyl methacrylate (MMA) (Sigma-Aldrich), previously distilled: the temperature of the mixture obtained falls by approximately 3° C.-4° C. Said mixture was heated, bringing the temperature to 94° C. in 1 hour: all this was left at said temperature for 2 minutes and then cooled in an ice bath, obtaining a pre-polymer syrup which, if not used immediately, may be stored for a few weeks in a refrigerator.

[0078] A mould was then prepared, assembled with two glass plates of dimensions 100×400×6 mm, separated by a seal in polyvinyl chloride (PVC) of larger diameter equal to 6 mm, held together with metal clamps.

[0079] Into a 4-litre glass flask were then added 2 litres of pre-polymer syrup obtained as described above, 120 mg of lauroyl peroxide (Sigma-Aldrich) dissolved in 1 litre of methyl methacrylate (MMA) (Sigma-Aldrich), previously distilled, a quantity of 5,6-diphenoxy-4,7-bis[5-(2,6-dimethylphenyl)-2-thienyl]benzo[c]1,2,5-thiadiazole (MPDTBOP) equal to 200 ppm, 5000 ppm Tinuvin® P (Basf) and 5000 ppm Tinuvin® 770 (Basf): the mixture obtained was maintained with magnetic stirring and under vacuum (10 mm Hg), for 45 minutes, at ambient temperature (25° C.), obtaining a degassed solution. The solution thus obtained was poured into the mould prepared as described above, which, after closing the seal aperture, was immersed in a bath of water at 55° C., for 48 hours. The mould was then placed in an oven at 95° C., for 24 hours (curing step), then removed from the oven and allowed to cool at ambient temperature (25° C.). The metal clamps and the seal were then removed, and the glass plates were separated by isolating plate 1 (LSC1) (the plate was cut to dimensions 75×300×6 mm).

Example 2

Preparation of Plate 2 (Casting) (LSC2)

[0080] Plate 2 (LSC2) was prepared by working as reported in Example 1, apart from the fact that instead of 5,6-diphenoxy-4,7-bis[5-(2,6-dimethylphenyl)-2-thienyl]benzo[c]1,2,5-thiadiazole (MPDTBOP), 5,6-diphenoxy-4,7-bis[5-(2,5-dimethylphenyl)-2-thienyl]benzo[c]1,2,5-thiadiazole (PPDTBOP) was used in a quantity equal to 200 ppm, obtaining plate 2 (LSC2) (dimensions 75×300×6 mm).

Example 3

Preparation of Plate 3 (Casting) (LSC3)

[0081] Plate 3 (LSC3) was prepared by working as reported in Example 1, apart from the fact that instead of 5,6-diphenoxy-4,7-bis[5-(2,6-dimethylphenyl)-2-thienyl]benzo[c]1,2,5-thiadiazole (MPDTBOP), N,N′-bis(2′,6′-di-iso-propylphenyl)(1,6,7,12-tetraphenoxy)(3,4,9,10-perilene diimide (Lumogen® F Red 305—Basf) was used in a quantity equal to 160 ppm, obtaining plate 3 (LSC3) (dimensions 75×300×6 mm).

Example 4

Preparation of Perovskite-Based Solar Cell

[0082] A perovskite-based solar cell was prepared by following, with a few modifications, the procedure described by Li G. et al., in Advanced Energy Materials (2015), 1401775, reported above.

[0083] To this end, a perovskite-based solar cell was prepared on a substrate of glass coated with FTO [tin oxide doped with fluorine (SnO.sub.2:F)—(Fluorinated Tin Oxide) (Hartford Glass), previously subjected to a cleaning procedure consisting of cleaning by hand, rubbing with a lint-free cloth soaked in a detergent diluted with distilled water. The substrate was then rinsed with distilled water. The substrate was then deep-cleaned using the following methods in sequence: ultrasound baths in (i) distilled water plus detergent (followed by drying by hand with a lint-free cloth; (ii) distilled water [followed by drying by hand with a lint-free cloth; (iii) acetone (Aldrich) e (iv) iso-propanol (Aldrich) in sequence. In particular, the substrate was placed in a beaker containing the solvent, placed in an ultrasound bath, maintained at 40° C., for a treatment of 10 minutes. After treatments (iii) and (iv), the substrate was dried in a stream of compressed nitrogen.

[0084] The glass/FTO was then further cleaned by treating in an ozone device (UV Ozone Cleaning System EXPO3—Astel), immediately before proceeding to the next step.

[0085] The thus-treated substrate was ready for deposition of the electron transporter layer (Electron Transport Material—ETO). To this end, a layer of compacted titanium dioxide (TiO.sub.2) was deposited by means of reactive sputtering in a direct current (DC), using titanium dioxide (TiO.sub.2) as the target, in the presence of argon (Ar) (20 sccm) and of oxygen (O.sub.2) (4 sccm) on the substrate. The thickness of the layer of titanium dioxide (TiO.sub.2) was equal to 115 nm.

[0086] On top of the layer of titanium dioxide (TiO.sub.2) obtained, a layer of mesoporous titanium dioxide (TiO.sub.2) was deposited by working as follows. To this end, a solution of a mesoporous titanium dioxide (TiO.sub.2) paste (Dyesol 18NRT—Aldrich) (2 g) in ethanol (Aldrich) (6 g) and terpineol (2 g) (Aldrich) was prepared: said solution was deposited by means of spin coating, working at a rotation speed of 2000 rpm (acceleration equal to 1000 rpm/s), for 45 seconds. The thickness of the layer of mesoporous titanium dioxide (TiO.sub.2) was equal to 600 nm. At the end of deposition, all this was subjected to annealing at 500° C. for 2 hours and then again subjected to cleaning by treating in an ozone device (UV Ozone Cleaning System EXPO3—Astel), immediately before proceeding to the next step.

[0087] On top of the layer of mesoporous titanium dioxide (TiO.sub.2) thus obtained, the layer of perovskite, i.e. the layer of methyl ammonium lead iodide (CH.sub.3NH.sub.3PbI.sub.3) was deposited by working as follows: i) the lead iodide (PbI.sub.2) (purity 99%—Aldrich) was dissolved in N,N-dimethyl formamide (purity 99.8%—Aldrich) by working with stirring, at a temperature of 75° C., for 30 minutes, obtaining a solution at a concentration of lead iodide (PbI.sub.2) equal to 462 mg/ml, said solution was deposited on said mesoporous layer of titanium dioxide (TiO.sub.2) by means of spin coating, working at a rotation speed of 6000 rpm (acceleration equal to 1000 rpm/s), for 90 seconds and all this was dried at 100° C., for 15 minutes; ii) after cooling at ambient temperature, all this was subjected to dip coating, for 5 minutes, in a solution of methyl ammonium iodide (MAI) (CH.sub.3NH.sub.3I) (purity 98%—Aldrich) in isopropanol (Aldrich) (concentration MAI equal to 10 mg/ml); iii) spin coating of a solution of methyl ammonium iodide (MAI) (CH.sub.3NH.sub.3I) (purity 98%—Aldrich) in isopropanol (Aldrich) (concentration MAI equal to 5 mg/ml), working at a rotation speed of 6000 rpm (acceleration equal to 1000 rpm/s), for 30 seconds (solar cells in what follows indicated as Type A). Regarding the solar cells hereinafter indicated as Type B, the solution of methyl ammonium iodide (MAI) (CH.sub.3NH.sub.3I) (purity 98%—Aldrich) used in step ii) and in step iii) were obtained using said methyl ammonium iodide (MAI) (CH.sub.3NH.sub.3I) after crystallization from heptane before dissolution in isopropanol (concentration of MAI equal to 10 mg/ml). At the end of deposition, all this was subjected to desiccation at 100° C. for 30 minutes and then cooled to ambient temperature (25° C.). The thickness of the layer of perovskite was equal to 300 nm.

[0088] On top of the layer of perovskite obtained, a layer based on a hole transport material (HTM) was deposited. To this end, 72.3 mg spiro-MeOTAD [2,2′,7,7′-tetrakis(N,N-di-4-methoxyphenylamine)-9,9′-spirobifluorene] (Aldrich) was dissolved in 1 ml chlorobenzene (purity 99.8%—Aldrich) and then 28.8 μl of 4-tert-butylpyridine (purity 96%—Aldrich) and 17.5 μl of a stock solution at a concentration equal to 520 mg/ml of lithio-bis(trifluoromethylsulfonyl)imide (purity 98%—Alfa Aesar) in acetonitrile (purity 99.8%—Aldrich): the solution thus obtained was deposited, by means of spin coating, working at a rotation speed of 2000 rpm (acceleration equal to 500 rpm/s), for 45 seconds. The thickness of the layer based on hole transport material (HTM) was equal to 150 nm.

[0089] On top of said layer based on a hole transport material (HTM) the back contact (cathode) of gold (Au), having a thickness equal to 100 nm, was deposited by evaporation in a vacuum, suitably masking the area of the device in such a way as to obtain an active area equal to 1.28 cm.sup.2.

[0090] Deposition of the cathode was performed in a standard vacuum evaporation chamber containing the substrate and an evaporation container equipped with a heating resistor containing 10 shots of gold (Au) (diameter 1 mm-3 mm) (Aldrich). The evaporation process was conducted in a vacuum, at a pressure of approximately 1×10.sup.−6 bar. The gold (Au), after evaporation, was condensed in the non-masked parts of the device.

[0091] The thicknesses were measured by scanning electron microscopy using a Jeol 7600f scanning electron microscope (SEM) fitted with a field emission electron beam, working with acceleration voltage ranging from 1 kV to 5 kV, and utilising the signal originating from secondary electrons.

Example 5

Preparation of the Solar Device

[0092] On one side of plate 1 (LSC1), obtained as described in Example 1, a perovskite-based solar cell of Type A (PSC—Type A), obtained as described in Example 4, was placed.

[0093] To this end a support was produced with a 3D printer, that was capable of maintaining the Type A perovskite-based solar cell (PSC—Type A) close and aligned along the short side of said plate 1 (LSC1), obtaining the solar device (PSC device—Type A).

[0094] Then, at the end of electrical characterisation of the solar device (PSC—Type A), the perovskite-based solar cell (PSC—Type A) was substituted with the Type B perovskite-based solar cell (PSC—Type B) obtained as described in Example 4, obtaining the solar device (PSC device—Type B).

[0095] For purposes of comparison, at the end of electrical characterisation of the solar device (PSC—Type B), the Type B perovskite-based solar cell (PSC—Type B) was substituted with a silicon solar cell (Si cell) KXOB22-12×1 from IXYS, of dimension 22×6 mm and surface area equal to 1.22 cm.sup.2, obtaining the solar device (Si Cell Device).

[0096] The electrical characterisation of the above-mentioned solar devices, i.e. (PSC Device—Type A), (PSC Device—Type B) and (Si Cell Device), was carried out at ambient temperature (25° C.). The current-voltage (I-V) curves were acquired with a Keithley® 2601A sourcemeter connected to a personal computer to collect the data. The photocurrent was measured by exposing the device to the light of an ABET SUN® 2000-4 solar simulator, positioned at a distance of 10 mm from said plate 1 (LSC 1), capable of providing an irradiation of AM 1.5G, using an illumination spot equal to 100 mm×100 mm: in Table 1, the characteristic parameters are given as mean values.

[0097] Table 1 also shows the expected electrical power density (□.sub.expected) of the solar devices mentioned above, calculated according to the following equation:

(□.sub.expected)=(□Si)×EC.sub.PSC

wherein: [0098] (□Si) is the electrical power density (mWcm.sup.−2) of the solar device comprising the silicon solar cell (Si Cell) and the luminescent solar concentrator (LSC) (Si Cell Device); [0099] EC.sub.PSC is the photoelectric conversion efficiency of the solar device comprising the perovskite-based solar cell and the luminescent solar concentrator (LSC) (i.e. PSC Device—Type A and PSC Device—Type B).

[0100] For the purpose of the present description and of the claims which follow, said photoelectric conversion efficiency (EC.sub.PSC), is defined as the ratio between the number of electrons produced in the external circuit within the semiconductor material of the device and the number of photons incident on the perovskite-based solar cell through the luminescent solar concentrator (LSC) and was calculated according to the following equation:

(EC.sub.PSC)=Jsc.sub.(PSC)×6.24×10.sup.15/DFF

wherein: [0101] Jsc.sub.(PSC) [short-circuit photocurrent density] measured in (mA/cm.sup.2) of the solar device comprising the perovskite-based solar cell and the luminescent solar concentrator (LSC) (i.e. PSC Device—Type A and PSC Device—Type B); [0102] DFF is the photon flow density calculated as stated above. For the purpose of the aforementioned calculation, the external quantum efficiency [EQE (%)] of the silicon solar cell (Si Cell) KXOB22-12×1 from IXYS was used, which as can be seen in FIG. 3, in which the external quantum efficiency [EQE (%)] is shown on the ordinate and the wavelength [□ (nm)] on the abscissa, has a constant value equal to 95% (datum provided by IXYS), within the emission wavelength range (550 nnm-600 nm), of the photoluminescent compounds present in the various luminescent solar concentrators (LSCs), i.e. in plate 1 (LSC1), or in plate 2 (LSC2), or in plate 3 (LSC3): this allows the solar device comprising the silicon solar cell (Si Cell) and the luminescent solar concentrator (LSC) (Si cell Device) to be used for the photon count, i.e. for the photon flow density, which indicates how many photons per second per square centimetre are transported by the above-mentioned luminescent solar concentrators (LSC).

[0103] The photon flow density (DFF) was therefore calculated according to the following equation:

(DFF)=Jsc×6.24×10.sup.15/EQE.sub.Si

wherein: [0104] Jsc [short-circuit photocurrent density] measured in (mA/cm.sup.2) of the solar device comprising the silicon solar cell (Si Cell) and the luminescent solar concentrator (LSC) (Si Cell Device); [0105] EQE.sub.Si is the external quantum efficiency (%) of the silicon solar cell (Si Cell) KXOB22-12×1 from IXYS, which value, as stated above, is equal to 95% (see FIG. 3).

Example 6

Preparation of the Solar Device

[0106] On one side of plate 2 (LSC2), obtained as described in Example 2, a perovskite-based solar cell of Type A (PSC—Type A), obtained as described in Example 4, was placed.

[0107] To this end a support was produced with a 3D printer, that was capable of maintaining the Type A perovskite-based solar cell (PSC—Type A) close and aligned along the short side of said plate 2 (LSC2), obtaining the solar device (PSC device—Type A).

[0108] Then, at the end of electrical characterisation of the solar device (PSC—Type A), the perovskite-based solar cell (PSC—Type A) was substituted with the Type B perovskite-based solar cell (PSC—Type B) obtained as described in Example 4, obtaining the solar device (PSC device—Type B).

[0109] For purposes of comparison, at the end of electrical characterisation of the solar device (PSC—Type B), the Type B perovskite-based solar cell (PSC—Type B) was substituted with the silicon cell (Si cell) mentioned above, obtaining the solar device (Si Cell Device).

[0110] The electrical characterisation of the solar devices obtained was carried out as described above: in Table 1, the characteristic parameters are given as mean values.

Example 7

Preparation of the Solar Device

[0111] On one side of plate 3 (LSC3) obtained as described in Example 3, a perovskite-based solar cell of Type A (PSC—Type A), obtained as described in Example 4, was placed.

[0112] To this end a support was produced with a 3D printer, that was capable of maintaining the Type A perovskite-based solar cell (PSC—Type A) close and aligned along the short side of said plate 3 (LSC3), obtaining the solar device (PSC device—Type A).

[0113] Then, at the end of electrical characterisation of the solar device (PSC—Type A), the Type A perovskite-based solar cell (PSC—Type A) was substituted with the Type B perovskite-based solar cell (PSC—Type B) obtained as described in Example 4, obtaining the solar device (PSC device Type B).

[0114] For purposes of comparison, at the end of electrical characterisation of the solar device (PSC—Type B), the Type B perovskite-based solar cell (PSC—Type B) was substituted with the silicon cell (Si cell) mentioned above, obtaining the solar device (Si Cell Device).

[0115] The electrical characterisation of the solar devices obtained was carried out as described above: in Table 1, the characteristic parameters are given as mean values.

Example 8

Preparation of the Solar Device

[0116] On one side of plate 3 (LSC3) obtained as described in Example 3, a perovskite-based solar cell of Type A (PSC—Type A), obtained as described in Example 4, was placed using the optical gel Norland Index Matching Liquid 150 (product No. 9006 Norland).

[0117] To this end a support was produced with a 3D printer, that was capable of maintaining the Type A perovskite-based solar cell (PSC—Type A) close and aligned along the short side of said plate 3 (LSC3), obtaining the solar device (PSC device—Type A).

[0118] For purposes of comparison, at the end of electrical characterisation of the solar device (PSC—Type A), the Type A perovskite-based solar cell (PSC—Type A) was substituted with the silicon cell (Si cell) mentioned above, obtaining the solar device (Si Cell Device).

[0119] The electrical characterisation of the solar devices obtained was carried out as described above: in Table 1, the characteristic parameters are given as mean values.

TABLE-US-00001 TABLE 1 Si Cell Device EX- DFF.sup.(2) PSC Device-Type A PSC Device-Type B AM- Jsc.sup.(1) (10.sup.15s.sup.−1 .sup.└(3) Jsc.sup.(1) .sup.└.sub.expected.sup.(5) .sup.└(3) .sup.└/ Jsc.sup.(1) .sup.└.sub.expected.sup.(5) .sup.└(3) .sup.└/ PLE (mAcm.sup.−2) cm.sup.−2) (mWcm.sup.−2) (mAcm.sup.−2) ECPsc.sup.(4) (mWcm.sup.−2) (mWcm.sup.−2) .sup.└.sub.expected (mAcm.sup.−2) EC.sub.PSC.sup.(4) (mWcm.sup.−2) (mWcm.sup.−2) .sup.└.sub.expected 5  8.7  57.4 3.4  5.0 0.54 1.8 2.8 1.6 6.2 0.67 2.3 2.9 1.3 6 10.3  67.8 4.1  5.4 0.50 2.0 3.1 1.6 6.1 0.56 2.3 3.2 1.4 7 10.8  71.2 5.0  6.2 0.54 2.7 3.6 1.3 6.7 0.59 2.9 3.7 1.3 8 23.1 151.7 9.9 12.8 0.53 5.2 6.5 1.3 — — — — — .sup.(1)short-circuit photocurrent density; .sup.(2)photon flow density; .sup.(3)electrical power density; .sup.(4)photoelectric conversion efficiency; .sup.(5)electrical power density expected.

[0120] From the data given in Table 1 it can be seen that the photovoltaic device (or solar device) object of the present invention exhibits a ratio between the electrical power density (└) generated and the electrical power density expected (└.sub.expected) defined as stated above, greater than 1 and, consequently, a higher generated electrical power density (└) with respect to that expected.