NL2027662B1

NL2027662B1 - Photovoltaic glass pane and method of producing a photovoltaic glass pane

Info

Publication number: NL2027662B1
Application number: NL2027662A
Authority: NL
Inventors: Makris Theodoros; Giannopoulos Panagiotis; Katsagounos Ioannis; Stathatos Ilias; Kanopoulos Nikolaos; Tselepidis Georgios
Original assignee: Brite Hellas Ae
Priority date: 2020-09-28
Filing date: 2021-02-26
Publication date: 2022-05-30
Also published as: CN112382684A

Abstract

Photovoltaic glass pane, comprising a glass panel, one or more photovoltaic cells arranged on or in the glass panel, each of the one or more photovoltaic cells having a light receiving surface to be exposed to light from a light source and being comprised of a semiconducting material having a spectral response to the light, and a spectral conversion layer arranged between the light receiving surface and the light source and conﬁgured to convert photons from the light source of a ﬁrst energy into photons of a second energy, wherein the spectral response to the photons of the second energy is higher than the spectral response to the photons of the ﬁrst energy.

Description

PHOTOVOLTAIC GLASS PANE AND

METHOD OF PRODUCING A PHOTOVOLTAIC GLASS PANE The present invention relates to a photovoltaic glass pane. Furthermore, the present S$ invention relates to a method of producing a photovoltaic glass pane.

BACKGROUND INFORMATION Solar panels are well-known-for capturing solar energy and converting the energy into electrical power. At present, solar panels can convert the visible light portion (400 nm — 700 nm) of the incident light into electrical power and have a conversion efficiency of 15% - 20%. Solar modules composed of crystalline or amorphous silicon are wide spread for electricity generation exhibiting enhanced performance and stability over the vears. Typically, a series of silicon wafers are soldered together with electrical flat wires to form a solar panel which are encapsulated on the back side by thermoplastic polymer material such as EVA, PVB ctc. The bus wires that exit the IS module are electrically connected to a junction box at the back side of the solar panel. The solar cells are laminated to encapsulate laver/layers to be protected from environmental changes, humidity and corrosion. In principle. a solar module is accomplished by a front glass made light receiving side, the solar cells with interconnection wires which are in close contact with glass pane and the back non-light receiving side with the encapsulant layer and junction box{es).

Although the efficiency of the crystalline silicon based solar modules is high among many technologies, even more efficient solar modules are highly desired in combination with possible transparency for specific applications which is almost negligible in current photovoltaic modules. Silicon crystalline panels with special dves have been proposed for improved performance of the solar cells, but this configuration absorbs specific wavelengths in the visible which may not be desired in several applications.

SUMMARY The present invention relates to the use of nano-coatings that absorb UV part of solar radiation and emit light in the visible region as co-sensitizers to solar cells is an mspired structure for enhanced performance of the PV module. In the case that the solar cells partially cover the glass and a part of the glass is free of solar cells could give transparency to the solar panel. The combination of UV absorbing and visible emitting nano-coatings with transparent solar modules could give extra light for solar cells and also enhanced PAR radiation.

The present invention further relates to solar modules and mm particular, backcoatings and related matenals for solar modules. Specifically, it relates to semi-transparent crystalline silicon solar modules and their modification with new nano-coatings for spectral shift from UV region to the Visible region of solar light for solar cell enhanced performance and PAR (Photosynthetically Active Radiation) increment. The nano-coating is based on a single layer or monolayer film that is composed primanly of an organic/inorganic compound. The nano-coating may contain one or two S$ optional films deposited by inkjet printed method or any other deposition method on the backside of glass hosts the solar cells and 1n contact with them. There can be other variation, modification and alternatives to the structure aiming the best performance of the solar module.

Specifically. the present invention provides according to a first aspect thereof a photovoltaic glass pane, comprising a glass panel, one or more photovoltaic cells arranged on or in the glass panel, zach of the one or more photovoltaic cells having a light receiving surface to be exposed to light from a light source and being comprised of a semiconducting material having a spectral response to the light, and a spectral conversion layer arranged between the hight receiving surface and the light source and configured fo convert photons from the hight source of a first energy into photons of a second energy, wherein the spectral response to the photons of the second IS energy is higher than the spectral response to the photons of the first energy.

In a preferred embodiment of the photovoltaic glass pane, the spectral conversion layer is a luminescent down-shifting layer configured to convert the photons of the first encrgy into the photons of the second cnergy, wherein the first energy is higher than the second energy.

In a preferred embodiment, the photons of the first energy are photons having wavelengths in the UV part of the light spectrum and wherein the photons of the second energy are photons having wavelengths in the visible part of the light spectrum.

In a preferred embodiment, the luminescent down-shitting layer is made of a material comprising a compound of one or more rare earth elements.

In a preferred embodiment, the one or more rare earth elements comprise Europium or Samarium, and wherein the photons of the second energy are red light photons.

In a preferred embodiment, the one or more rare earth elements comprise Terbium, and wherein the photons of the second energy are green light photons.

In a preferred embodiment, the luminescent down-shifting layer is made of a material comprising organic molecules or polymeric matenals based on aromatic compounds, and wherein the photons of the second energy are blue light photons.

In a preferred embodiment, the spectral conversion layer is arranged on top of the light receiving surface of each of the one or more photovoltaic cells and/or a surface of the glass panel between the Light receiving surface and the light source.

In a preferred embodiment, the spectral conversion layer is arranged between the light receiving surface and the glass panel.

In a preferred embodiment, the spectral conversion laver is arranged on top of a light receiving surface of the glass panel that faces the hight source.

In a preferred embodiment, the spectral conversion laver is arranged across the whole surface of the glass panel.

In a preferred embodiment, the spectral conversion layer is a nano-coating.

Preferably, the one or more photovoltaic cells cover only a portion of the surface area of the glass pane, so that another portion of the glass pane is transparent to the light from the light source, at least the visible thereof.

According to a second aspect, the present invention provides a method of manufacturing a photovoltaic glass pane, comprising providing a glass panel, arranging one or more photovoltaic cells on or in the glass panel, each of the one or more photovoltaic cells having a light receiving surface to be exposed to light from a light source and being comprised of a semiconducting material having a spectral response to the light, and arranging a spectral conversion layer between IS the hight receiving surface and the light source which is configured to convert photons from the hight source of a first energy into photons of a second energy, wherein the spectral response to the photons of the second energy is higher than the spectral response to the photons of the first energy.

In a preferred embodiment of the method. the spectral conversion layer is a nano-coating and wherein the step of amanging the spectral conversion layer between the light receiving surface and the light source comprises printing the nano-coating on the light receiving surface and/or a surface of the glass panel between the light receiving surface and the light source.

In a preferred erobodiment, the nano-coating 1s printed such that it is arranged between the Light receiving surface and the glass panel.

In a preferred embodiment, the nano-coating 1s printed on top of a hight receiving surface of the glass panel that faces the hight source.

In a preferred embodiment, the nano-coating is printed across the whole surface of the glass panel.

In a preferred embodiment, the step of printing the nano-coating comprises inkjet printing the nano-coating.

In a preferred embodiment, the spectral conversion layer is a luminescent down-shifting layer configured to convert the photons of the first energy into the photons of the second energy, wherein the first energy is higher than the second energy.

In a preferred embodiment, the photons of the first energy are photons having wavelengths in the UV part of the lieht spectrum and wherein the photons of the second energy are photons baving wavelengths in the visible part of the light spectrum.

In a preferred embodiment, the luminescent down-shifting layer is made of a material comprising a compound of one or more rare earth elements.

In a preferred embodiment, the one or more rare earth elements comprise Eoropiom or Samarnim, and wherein the photons of the second energy are red light photons.

In a preferred embodiment, the one or more rare carth clements comprise Terbium, and wherein the photons of the second energy are green light photons.

In a preferred embodiment, the luminescent down-shifting layer is made of a material comprising organic molecules or polymeric materials based on aromatic compounds, and wherein the photons of the second energy are blue ight photons.

The present mvention allows for UV to visible light spectrom shift using nanc-coatings applied with inkjet printing or any other related printing technique on the backside of the glass that holds the solar cells m a solar module and in contact with them. The present invention enables increasing the efficiency of all commercialized and also emerging photovoltaic (PV) technologies IS by giving them the ability to effectively harvest more wavelengths of light available in the solar spectrum and the production of transparent solar glass utilizing this increased efficiency. Specifically, for better solar light utilization spectral converters are used to absorb solar photons that cannot be effectively captured and convert them to wavelengths more suitable for conversion, by overcoming the non-absorption and thermalization losses in the above crystalline silicon PV technology which has been a bottleneck limiting their efficiency. For example, in single-junction crystalling silicon {c-Si} PY cells, the Shocklev—Queisser limit shows that the conversion efficiency 1s placed at around 30%. The photo generation of charge camers only occurs if the device absorbs solar photons with energies equal or larger to that of the bandgap encrgy (Eg). All photons of energy less than Ec falling on the PV cell are transmitted through the device and are finally lost. Forthermore, the absorption of photons greater than Eg is also efficient, since the excess energy gained is lost as heat through non-radiative recombination of the photo-excited charge carriers. Intrinsic spectral losses thus represent a major efficiency fall in PV cells. For that reason, the overall performance of single-Junction crystalline silicon {c-S1) PV cells is increased by the present invention which extends the solar light utilization.

Preferably, the method according to the present allows for the production of solar glass panels utilizing spectral converters to absorb solar photons that cannot be effectively captured and convert them to wavelengths more suitable for conversion to electricity.

Preferably, the method according to the present allows for the production of solar glass panels 353 can be m different sizes and shapes depending on the needs of each application.

Preferably, the method according to the present allows for the production of solar glass panels with different levels of transparency and power output using a different number of embedded solar cells depending on the needs of cach application.

Preferably, the method according to the present allows for the production of solar glass panels 5 with a single junction box or two junction boxes {positive and negative} for installation flexibility depending on the needs of each application.

Preferably, the method according to the present allows for the application of nano-coatings as spectral converters on the existing solar panels to the mterior side of the glass and In contact with solar cells.

iQ

BRIEF DESCRIPTION OF THE DRAWINGS By reference to the appended drawings, which illustrate exemplary embodiments of the present invention according to aspects thereof, the detailed description provided below explains in detail various features, advantages and aspects of this invention. As such, features of this invention IS can be more clearly understood from the following detailed description considered in conjunction with the following drawings. Each exeraplary aspect or embodiment illustrated in the drawings is not intended to be to scale, to be comprehensive of all aspects, or to be limiting of the invention’s scope, for the invention may admit to other equally effective embodiments and aspects. As such, the drawings are included to provide a further understanding and are incorporated in and constitute a part of this specification, wherein: - Figure 1A shows a top view of a schematic representation a solar/photovoltaic glass pane comprising multiple solar cells connected In series; he - Figure 1B shows a side view of a cross section of the schematic representation of Figure - IA according to the dashed line as shown in Figure 1A; - Figure 2 shows photoluminescence processes employed in spectral converter and a simplified energy level diagram for a down-shiffing (DS) compound: - Figure 3A and 3B show a c-Si BV panel without (fig. 3A) and with (fig. 3B) a down- shifting luminescent compound nano-coating, respectively: - Figures 4A, 4C and 4D show absorption and emission spectra of nano-coatmgs based on red (fig. 4A), green (fig. 4B) and blue (fig. 4D) emitting compounds, respectively; - Figure 4B shows the relative spectral response of c-Si PV; - Figure 5 shows the transmittance of the uncovered part of solar panel with solar cells in the presence of luminescent downshifting material:

- Figures 6A and 6B show pictures of glass panels covered with DS red light emitting nano- coating while excited by solar light; and - Figures 6C and 6D show pictures of glass panels covered with DS red hight emitting nano- < coating while excited by UV light from UV lamps.

DETAILED DESCRIPTION Before any embodiments of the present disclosure ars explained in detail, it is to be understood that the disclosure ts not limited in its application to the details of the construction and the arrangement of components set to the following description. Any numerical range recited hereafter is intended to include and to specifically disclose the end points specified and also integers and fractions within that range.

The present invention relates to mkjet printed solar spectral converters on solar glasses of different size, transparency level and power output. The present invention will be described mn reference to the drawings in which exemplary embodiments of the invention are shown. In Figure 1A, a top view of a schematic representation of a semitransparent solar glass 10 with inkjet printed solar spectral converters in the form of a spectral conversion layer 12 1s presented. In particular, the PV glass 10 is made according to existing solar cell technology with an additional layer of spectral converters 12 made with inkjet printable materials succeeding higher efficiency in the visible region of the light. The solar glass 10 comprises 12 dividual solar cells 13 in series interconnected depending on the size of the glass 11, the target transparency and power output. The distance between the individual cells 13 can be also varied depending on the desired visual effect. The transmittance of the solar glasses can be varied in terms of the number of solar cells used and is inversely proportional to the final power output.

For better solar light utilization, spectral converters are used to absorb solar photons that cannot be effectively captured and convert them to wavelengths more suitable for conversion, by overcoming the non-absorption and thermalization losses in the above crystalline silicon PV technology. Since (c-Si) PV have relatively strong absorption in the middle wavelength region in comparison to UV-blue shortwave length region of visible irradiation, lominescence down-shifting {DS}, which converts the higher energy photons that cannot be sufficiently utilized into lower energy photons that can be well used for photocurrent generation, is an interesting route to improve the UV-blue response (Figure 2). Using a Juminescent down-shifting layer facing the light receiving side of the mmdividual solar cells 13 of solar/photovoltaic glass pane 10 which is only partially covered by the cells, allows for increasing the efficiency of the solar cells 13, while at the same time increasing the amount of photosvnthetically active radiation (PAR) emitted from the surface of the glass pane 10 that faces away from the hight source.

To illustrate this concept, Figure 3A shows a solar glass pane 10 with crystalline silicon PV cells 13 without a down-shifting luminescent compound nano-coating, while Figure 3B shows a solar glass pane 10 with crystalline silicon PV cells 13 with a down-shifting luminescent compound nano-coating layer 12 applied across the whole surface of the glass 11 and in front of tbe solar cells 13 as seen in the direction of the incoming light. The down-shifing luminescent compound nano-coating laver 12 converts UV light into one of visible red, green or blue light, which is indicated by the shading in Figure 3B.

The application of these DS compounds could be by dispersing or inkjet-printing luminescent species, such as rare carth element luminophores, in a completely transparent (in the visible range of light) matrix and applying them in a first embodiment in front of the (¢-81) PV themselves or in a second embodiment to the glass that keeps the PVs in the panel. DS integration does not need any adjustment in device architecture or output electrical circuit for given {c-Si} PV. The DS integration for {c-Si} PV preferably satisfies the essential requirement that the luminescent species have high photoluminescence quantum yield but kittie absorption overlap in the response IS region of PV materials.

In the following, three examples of materials are presented that are used as light concentrators in the visible by selective absorption in the UV region. In particular, as a fust embodiment, two rare carth based compounds with selective emission in the visible (in red for Europium and in green for Terbium based compounds) are used to cover the glass pane that hosts the silicon photovoltaie cells in the inner side of the glass and in contact with the solar cells, The low spectral response of silicon PV in the UV region {sce Figure 4B) in relation to the absorption spectra of both compounds in UV avoids any shading effect to the solar cell while there is promotion to the visible hight utilization by the strong emission of these compounds. A third example is presented, in the case that selective emission in the blue region of the visible spectrum is desirable. In this embodiment small organic molecules or polymeric materials based on aromatic compounds are used.

Usually the materials cover this application as light concentrators have to exhibit high transmittance and suitable refractive index (n=1.4-2.4} to prevent scattering and absorption, especially in the spectral region where the (c-Si} PV have strong response. All the aforementioned materials have high transmittance in the visible (see Figures 4A, 4C and 4D} and refractive index within the as described range. Although, the glass is covered by the DS material the space in the middle where solar cells do not exist into the panel is completely transparent in the visible region of light as it can be seen in Figure 5.

The rare earth element luminophores as DS materials could be from a variety of europium 353 complexes for red light emission such as Europium or Samarium with thenoyl trifluoroacetone ligands, Europium or Samarium with phenanthroline ligands. Europtum or Samarium with 2-(5.6- diphenyl-1,2 4-triazin-3-v1} pyndme Hgands, europium with 2-(1H-1.2 4-Triazol-3-vl} pyridine ligands or a combination of them. For green light emission a series of Terbium complexes can be used. As examples, Terbium with acetyl acetone ligands or Terbium with phenanthroline ligands or combination of them can be used. A series of other rarer carths such as Erbium, Prascodymium and Yttrium could alternatively be used in the form of complexes of previous ligands. For blue light cmission a series of small organic molecules or polymeric materials, mclading but not limited to anthracene, carbazolc. quinoline, methoxyquinoline, benzoihlguinoline, quinine, quinidine, acridine, fluorene and more complex organic compounds or polymeric materials based on the IO above structures.

The application of these compounds on glass or alternatively on the silicon PVs before installation to the panel can be made by inkjet printing of special inks with high coverage and uniformity besides high consumption of the materials taking the advantage of the inkjet printing technology. In a c-S1 PV panel special designed for greenhouse applications, the part of the glass 1S that faces the solar cells is covered with luminescent compound so that after UV illumination (part of solar light} strongly emits red hight efficiently captured bv the solar cells. The UV light which is not productive and in some cases is detrimental to the long time operation of the solar cells is efficiently absorbed by the same luminescent compound. Figure 3B shows that the area among the solar cells is also covered by the luminescent compound as the specific emission in the red region of solar light could be efficiently used to the photosynthesis of the plants when these panels are installed to the shell of a greenhouse.

A typical example of nano-coating formation for red light shifting using inkjet printing method is the following: The ink is used for printing process may contain but not exclusively 10 ml of isopropanol and 0.02-0.04 grams of Europium Chlonde or Europium Nitrate or any other Europnan salt, Besides 0.056-0.112 grams of thenoyi trifluoroacetone or any other diketonate could be present.

0.015-0.030 grams of Phenatbroline, or other ligands such as 2-{5.6-diphenyi-1,2,4-triazin-3-v1) pyridine or 2-(1H-1,2,4-Tnazol-3-v1) pyridine or other pyridine ligands could also be used. Instead, or in addition to the pyridine ligands, an asalogous amount of amine such as methylamine, propylamine, 2,2,2-Trifluorocthylamine, Oleylamme, or other primary amine could be used. A combination of the above-mentioned materials could also be used. The solution pH must be adjusted to muldly acidic, or mildly basic by the addition of an appropriate amount of AcOH IM or NaOH IM. In order to covalently link the complex to the glass matrix one or more functionalized Silicon-based materials, such as Tetraethyl orthosdicate, 3-Cyanopropyltrietboxysilane, (3- Aminopropyl}trethoxysilanc. 3-(TricthoxysilyDpropyl isocvanate, or other can also be used In this case, the Silicon-based material/Europmm salt molecular ratio is varied between 3/1 and 19/1, Fmaliy, a polymer matrix is used to host the luminescent material with a polymer/matenal weight ratio varied between 0.5/1 and 50/1. The polymeric host could be poly(methyl methacrylate) (PMMA). polviviny! difluoride) (PVDF), poly{vmylpolypyrrolidone) (PVP), polystyrene (PS), polyvinyl-butyral (FVB) or copolymers of the above.

A typical example of nano-coatmg formation for green light shifting using inkjet printing method 1s the following: The ink is used for printing process may contain but not exclusively 10 mi of isopropanol and 0.02-0.04 grams of Terbium Chloride or Terbium Nitrate or any other Terbium salt. Besides

0.056-0.112 grams of acetyl acetone or any other diketonate could be present. 0.015-0.030 grams of Phenathroline, or other ligands such as 2-{5,6-diphenyl-1,2,4-+triazin-3-yl} pyridine or 2-{1H- 1,2. 4-Triazol-3-v1} pyridme or other pyndine ligands could also be used. Instead, or in addition to the pyridine ligands, an analogous amount of amine such as methylamine, propylamine, 2.2.2- Trifluoroethviamine, Oleylamme, or another primary amine could be used, A combination of the 1S above-mentioned materials could also be used. The solution pH must be adjusted to mildly acidic, or mildly basic by the addition of an appropriate amount of AcOH 1M or NaOH IM. In order to covalently link the complex to the glass matrix one or more functionalized Silicon-based materials, such as Tetracthy! orthosilicate, 3-Cyanopropyltnetboxvsilane, (3-Aminopropvliiricthoxysilane, 3- (Trethoxysilybpropyl isocyanate, or other can also be used. In this case, the Silicon-based matenial/Terbrum salt molecular rato is varied between 3/1 and 10/1. Finally, a polymer matrix 15 used to host the lummescent material with a polymer/material weight ratio varied between 0.5/1 and 50/1. The polymeric host could be polvimethyl methacrylate) (PMMA). polv(vinyl difluoride) (PVDF), poly(vinvipolvpyrrolidone) (PVP), polystyrene (PS). polvvinvl-butyvral (PVB) or copolymers of the above.

A typical example of nano-coating formation for blue light shifting using inkjet printing method 1s the following: The mk is used for punting process may contain but not exclusively 10 ml of Dimethylformamide and 0.02-0.10 grams of anthracene, carbazole, quinoline, methoxyquinoline, benzofhlquinoling, quinine, gumdme, acridine, fluorene or different organic compounds or polymeric materials based on the above structures. The solution pH must be adjusted to mildly acidic, or mildly basic by the addition of an appropriate amount of AcOH IM or NaOH IM In order to covalently link the compound to the glass matrix one or more functionalized Silicon-based materials, such as Tetracthyl orthosilicate, 3-Uyanopropyltniethoxysidane, (3- Aminopropyltriethoxysilanc. 3-{Triethoxysilvlipropyl isocyanate, or other can also be used. In 353 this case, the Silicon-based material/organic compound molecular ratio is varied between 3/1 and

10/1. Finally. a polymer matrix is used to host the luminescent material with a polymer/material weight ratio varied between 0.5/1 and 50/1. The polvmeric host could be polv(methyl methacrylate) (PMMA) poly{vmyl difluoride) (PVDF), pols(vinylpolspyrrohdone) (PVP), polystyrene (PS). polvvinyl-butyral (PVB) or copolvimers of the above. If a luminescent polymeric material, based on the previously described structures is used, no other polymer matrix is used.

The inkjet printing station may include a drop-on-demand (DOD) piezoelectric mkiet nozzle head with 16 or more nozzles, depending on the printer, spaced at about 254 microns with typical drop sizes of between | and 10 picoliters. The print head preferably is mounted onto a computer-controlled thrce-axis system capable of movement accuracy of Sum, For printing of europium ink, as an example, the substrate temperature (Top) set at 25°C, while the temperature of the cartridge (Tag) may be set at about 30°C. The Cartridge Print Height (hear), which is the gap between the nozzle and the printed surfaces, may be about 0.6 mm or more during printing depending on the material. The cjection of the droplets may be performed using 16 to 128 nozzles by applying a firing voltage of 15 to 18 volts for an impulse having an overall pulse IS duration lasting at about 15 ps, at a jetting frequency of about 10 kHz. Optimal film uniformity may be achieved by printing at dot-to-dot spacing of 5-10 pm, known as drop spacing. Exemplary parameters followed for other inkjet printed materials appear in Table 1. Analogous parameters are followed for the inks that are used for green or blue light shifting.

Table 1: Exemplary printing parameters for Europiom based ink.

Width of waveform (us): 15.296 Maximun Jetting Frequency (kHz): 10 Firing voltage (V): 16 Meniscus Vacuum {inches H;0): 3 Cartridge Temperature (°C): 30 Cartridge Height (mm): 0.600 Substrate Temperature (°C): 25 The emission of proposed rare earth complexes and organic molecules as nano-coatings on glass is very strong in the visible region of light by absorbing UV light. A typical example for red emitting Hght can be seen in FIG .6. Either by absorbing natural solar light (Figures 6A and 6B) or UV light (Figures 6C and 6D} the emitting light is very strong. The nano-coatings may exist in the whole arca of the solar panel on the inner side of the glass either in contact with solar cells or not.

I The increase to the solar cell performance by the presence of nano-coating can be varied from 2- 10% and the PAR from 1-3% depending on the kind of the nano-coating. The foregoing description discloses exemplary embodiments of the invention. While the invention herein disclosed has been described by means of specific embodiments and applications thereof, numerous modifications and vanations could be made there to by those skilled in the art without departing from the scope of the invention set forth in the claims. Modifications of the above disclosed apparatus and methods that fall within the scope of the invention will be readily apparent to those of ordinary skill in the art. Accordingly, other embodiments may fall within the spint and scope of the invention, as defined by the following claims.

In the description above, mamerous specific details are set forth in order to provide a more thorough understanding of embodiments of the invention. It will be apparent, however, to an artisan of ordmary skill that the invention may be practiced without incorporating all aspects of the specific details described herein. In other instances, specifie details well known to those of ordinary skill in the art have not been described 1n detail so as not to obscure the invention.

IS Although examples of the mvention are set forth herein, the claims, and the full scope of any equivalents, define the metes and bounds of the invention.

Claims

CONCLUSIONS

1. Photovoltaic glass plate, consisting of: a glass panel; one or more photovoltaic cells disposed on or in the glass panel, each of the one or more photovoltaic cells having a light-receiving surface exposed to light from a light source and comprising a semiconductor material having a spectral response to the light; and a spectral conversion layer disposed between the light-receiving surface and the light source and adapted to convert photons of the light source of a first energy into photons of a second energy, wherein the spectral response to the photons of the second energy is higher than the spectral response to the photons of the first energy.

The photovoltaic glass sheet of claim 1, wherein the spectral conversion layer is a laminescent downshifting layer adapted to convert the photons of the first energy into the photons of the second energy, the first energy being higher than the second energy .

The photovoltaic glass sheet of claim 2, wherein the photons of the first energy are photons with wavelengths in the UV part of the light spectrum and wherein the photons of the second energy are photons with wavelengths in the visible part of the light spectrum.

A photovoltaic glass sheet according to claim 2 or 3, wherein the huminescent downward shifting layer is made of a material comprising a composition of one or more rare earth elements.

The photovoltaic glass sheet of claim 4, wherein the one or more rare earth elements comprise Europium or Samarium, and wherein the photons of the second energy are red light photons.

The photovoltaic glass sheet of claim 4, wherein the one or more rare earth elements comprise Terbium, and wherein the photons of the second energy are green light photons.

The photovoltaic glass sheet according to claim 2 or 3, wherein the luminescent downward shifting layer is made of a material comprising organic molecules or polymeric materials based on aromatic compounds, and wherein the photons of the second energy are blue light photons.

A photovoltaic glass sheet according to any one of the preceding claims, wherein the spectral conversion layer is disposed on top of the light-receiving surface of each of the one or more photovoltaic cells and/or a surface of the glass panel between the light-receiving surface and the light source.

The photovoltaic glass sheet of claim 8, wherein the spectral conversion layer is disposed between the light-receiving surface and the glass panel.

The photovoltaic glass sheet according to claim 8 or 9, wherein the spectral conversion layer is provided on top of a light-receiving surface of the glass panel facing the light source.

The photovoltaic glass sheet according to any one of claims 8 to 10, wherein the spectral conversion layer is applied over the entire surface of the glass panel.

A photovoltaic glass sheet according to any one of the preceding claims, wherein the spectral conversion layer is a nano-coating.

A method of manufacturing a photovoltaic glass sheet, comprising; providing a glass panel; disposing one or more photovoltaic cells on or in the glass panel, each of the one or more photovoltaic cells having a light-receiving surface exposed to light from a light source and comprising a semiconductor material having a spectral response to the light; and interposing between the light-receiving surface and the light source a spectral conversion layer adapted to convert photons of the light source of a first energy into photons of a second energy, wherein the spectral response to the photons of the second energy is higher than the spectral response to the photons of the first energy.

The method of claim 13, wherein the spectral conversion layer is a nano-coating and wherein the step of applying the spectral conversion layer between the light-receiving surface and the light source is printing the nano-coating on the light-receiving surface and/or a surface of the glass panel between the light receiving surface and the light source.

The method of claim 14, wherein the nano-coating is printed such that it is interposed between the light-receiving surface and the glass panel.

The method of claim 14 or 15, wherein the nano-coating is printed on top of a light-receiving surface of the glass panel that faces the light source.

A method according to any one of claims 14 to 16, wherein the nano-coating is printed over the entire surface of the glass panel.

The method of any one of claims 14 to 17, wherein the step of printing the nano-coating comprises inkjet printing the nano-coating.

A method according to any one of claims 13 to 18, wherein the spectral conversion layer is a luminescent downshifting layer adapted to convert the photons of the first energy to the photons of the second energy, the first energy higher than the second energy.

The method of claim 19, wherein the photons of the first energy are photons of wavelengths in the UV portion of the light spectrum and wherein the photons of the second energy are photons of wavelengths in the visible portion of the light spectrum.

The method of claim 19 or 20, wherein the luminescent downshifting layer is made of a material comprising a composite of one or more rare earth elements.

The method of claim 21, wherein the one or more rare earth elements comprise Europium or Samarium, and wherein the photons of the second energy are red light photons.

The method of claim 21, wherein the one or more rare earth elements comprise Terbium, and wherein the photons of the second energy are green light photons.

The method of claim 19 or 20, wherein the luminescent downshifting layer is made of a material comprising organic molecules or polymeric materials based on aromatic compounds, and wherein the photons of the second energy are blue light photons.