EP2457243A1 - A method of manufacturing working electrodes for dye sensitised solar cells - Google Patents

A method of manufacturing working electrodes for dye sensitised solar cells

Info

Publication number
EP2457243A1
EP2457243A1 EP10742425A EP10742425A EP2457243A1 EP 2457243 A1 EP2457243 A1 EP 2457243A1 EP 10742425 A EP10742425 A EP 10742425A EP 10742425 A EP10742425 A EP 10742425A EP 2457243 A1 EP2457243 A1 EP 2457243A1
Authority
EP
European Patent Office
Prior art keywords
layer
conductive layer
providing
transparent
metal oxide
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
EP10742425A
Other languages
German (de)
French (fr)
Inventor
Maarten Wijdekop
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Swansea University
Original Assignee
Tata Steel UK Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tata Steel UK Ltd filed Critical Tata Steel UK Ltd
Priority to EP10742425A priority Critical patent/EP2457243A1/en
Publication of EP2457243A1 publication Critical patent/EP2457243A1/en
Ceased legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G9/00—Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture
    • H01G9/20—Light-sensitive devices
    • H01G9/2068—Panels or arrays of photoelectrochemical cells, e.g. photovoltaic modules based on photoelectrochemical cells
    • H01G9/2081—Serial interconnection of cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G9/00—Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture
    • H01G9/20—Light-sensitive devices
    • H01G9/2022—Light-sensitive devices characterized by he counter electrode
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G9/00—Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture
    • H01G9/20—Light-sensitive devices
    • H01G9/2027—Light-sensitive devices comprising an oxide semiconductor electrode
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G9/00—Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture
    • H01G9/20—Light-sensitive devices
    • H01G9/2095—Light-sensitive devices comprising a flexible sustrate
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K71/00—Manufacture or treatment specially adapted for the organic devices covered by this subclass
    • H10K71/60—Forming conductive regions or layers, e.g. electrodes
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K71/00—Manufacture or treatment specially adapted for the organic devices covered by this subclass
    • H10K71/621—Providing a shape to conductive layers, e.g. patterning or selective deposition
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/542—Dye sensitized solar cells
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • This invention relates to working electrodes and to a method of manufacturing working electrodes.
  • the invention further relates to a module of series connected dye sensitised solar cells and to a method of manufacturing a module of series connected dye sensitised solar cells.
  • Dye sensitised solar cells as first developed by Dr Michael Gratzel and co- workers comprise a working electrode and a counter electrode, which when sealed encapsulate an electrolyte.
  • the working electrode comprised a conductive layer of fluorine doped tin oxide (SnO 2 :F) deposited onto a glass carrier substrate and a PV absorber layer on the layer of SnO 2 :F, the PV absorber layer being composed of sintered metal oxide nanometer-sized particles such as TiO 2 that are sensitised with a light absorbing dye.
  • the counter electrode comprised a conductive SnO 2 :F coated glass substrate onto which a layer of platinum catalyst was deposited.
  • photons of light enter the cell through the working electrode and strike dye molecules that are chemically linked to the metal oxide semiconductor.
  • Photon absorption by the dye promotes electrons of the dye from their ground state to an excited state, from where they can be injected into the conduction band of the metal oxide semiconductor, while almost simultaneously recombining with electrons that are stripped from the electrolyte.
  • Electrons from the conduction band of the metal oxide semiconductor then diffuse to the conductive layer of the working electrode as a result of an electron concentration gradient. From the conductive layer of the working electrode these electrons pass via an external circuit to the conductive layer of the counter electrode and through the catalytic material to regenerate the electrolyte before the cycle is repeated.
  • the working electrode acts as the 'window' electrode and for that reason the carrier substrate and the conductive layer of the working electrode must be transparent to allow light to reach the photoabsorber layer. Since the metal oxide semiconductor of the working electrode undergoes a high temperature sintering step, the carrier substrate and the conductive layer should also be resistant to the temperatures of said sintering step. This therefore limits the choice of materials that can be used for the working electrode. Despite the low fabrication costs associated with dye sensitised solar cells based on Gratzel's design, sintering the metal oxide on a rigid transparent substrate such as glass limits DSC fabrication to a batch process, which cannot be easily modified into a continuous reel-to-reel production line.
  • DSCs comprising a polymeric substrate and a metal oxide layer having a large surface area and a high concentration of interconnected metal oxide particles.
  • a layer of metal oxide is provided on a metal foil such as titanium, which is then subjected to a high temperature sintering process. Because this is a separate process, i.e. not in the presence of the polymeric substrate, the polymeric substrate is not thermally degraded.
  • the sintered metal oxide coated metal foil is then introduced into a production line where the metal foil acts as the conductive layer of the working electrode.
  • foils such as titanium are prohibitively expensive, difficult to handle and difficult to integrate into a continuous process.
  • the industrialisation of dye sensitised solar cells comprising such foils is restrictive.
  • each dye sensitised solar cell comprising a working electrode, a transparent counter electrode and an electrolyte, wherein the working electrodes are manufactured continuously in a reel-to-reel production line comprising the steps of:
  • i Providing a metal carrier strip substrate having a first side and a second side; u Providing an organic electrically insulating layer on the first side of the metal carrier substrate having a temperature resistance in the range of 200°C to 600°C; in Providing an organic conductive layer on the electrically insulating layer having a temperature resistance in the range of 200°C to 600°C, optionally comprising conductive inorganic additives;
  • the use of a metal substrate in accordance with the invention enables dye sensitised solar cells to be manufactured in a reel-to-reel process due to the inherent flexibility, strength and temperature resistance of the metal carrier substrate.
  • the organic electrically insulating layer is resistant to high temperatures in the range of 200-600°C and resistant against the electrolyte which is capable of oxidising and corroding the metal carrier substrate.
  • the use of an organic material has the benefit that vacuum based processes such as sputtering are not required when depositing the electrically insulating layer onto the metal carrier substrate, which enables the working electrode to be manufactured continuously in a reel-to-reel production line.
  • the organic conductive layer optionally comprising conductive inorganic additives exhibits good adhesion to the electrically insulating layer and can be used as an effective substrate to deposit the metal oxide layer.
  • the conductive layer possesses a sheet resistivity no higher than 100 ohms per square and more preferably no higher than 15 ohms per square so that resistive losses within the organic conductive layer are minimised.
  • the presence of the optional inorganic conductive additives could increase the conductivity of the layer.
  • the conductive layer is resistant to temperatures in the range of 200- 600°C, which are required when sintering the metal oxide.
  • scribing divides the organic conductive layer of the working electrode into separate cells, which enables a high output voltage to be obtained since resistive losses in the organic conductive layer are minimised. Scribing may be performed by mechanical scribing or laser scribing. In accordance with the invention the step of scribing is implemented in a continuous reel-to-reel production line that will reduce processing times and manufacturing costs. The scribed regions do not affect the overall integrity of the organic conductive layer.
  • the metal oxide layer is deposited onto the organic conductive layer in a paste using screen printing, gravure printing or roller coating, the paste comprising the metal oxide, a binder and a solvent.
  • the paste is then subjected to a heat treatment to remove the solvent and the binder from the paste, leaving behind a mesoporous metal oxide layer on top of the conductive substrate.
  • the metal oxide is readily available, cheap, non-toxic, possesses good stability under visible radiation in solution, and has an extremely high surface area suitable for dye adsorption.
  • the metal oxide layer is also porous enough to allow good penetration by the electrolyte ions, which is essential for effective dye regeneration. Finally, the metal oxide layer scatters incident photons effectively to increase its light harvesting efficiency.
  • the metal substrate, organic electrically insulating layer, organic conductive layer and the metal oxide layer are heated to a temperature in the range of 200-600°C to increase the internal surface area of the metal oxide layer, the number of electrical interconnections between metal oxide particles (sintering), and consequently the electrical conductivity of the metal oxide layer.
  • subjecting the above layers to the heat treatment ensures that any residual solvents, which could be detrimental to the long term durability and functionally of the DSC, are removed.
  • the heat treatment can be carried out using a conventional conduction oven or by using near infrared radiation, which will reduce processing times still further. Both heat treatments can be implemented into a continuous reel-to-reel production line.
  • a photosensitive dye is either adsorbed or chemically bonded to the sintered metal oxide layer having an increased internal surface area. Sensitising the metal oxide in this way increases the light harvesting capability of the cell and therefore improves overall cell performance. Dyes in accordance with the invention are able to absorb radiation across a large part of the electromagnetic spectrum i.e. in the infrared and/or the green and blue regions of the electromagnetic spectrum.
  • a method of manufacturing working electrodes which comprises the consecutive steps of providing in a pattern first busbars and first current collectors on the scribed organic conductive layer after the step of sintering the metal oxide layer, drying the first busbars and the first current collectors and sintering the first busbars and the first current collectors.
  • Busbars are defined as the larger conductive tracks around the perimeter of a cell, and current collectors are the smaller tracks that are located between two strips of metal oxide.
  • the consecutive steps of providing the first busbars and first current collectors on the organic conductive layer reduces the sheet resistance of the organic conductive layer. Drying the first busbars and first current collectors removes any solvent that could be detrimental to DSC operation and efficiency, whereas sintering the first busbars and the first current collectors increases the electrical conductivity between the first busbars and the first current collectors and the organic conductive layer, which will reduce resistive losses in the organic conductive layer.
  • the metal oxide will experience a 'second' sinter during the sintering of the first busbars and the first current collectors, which will further increase the concentration of electrical interconnections in the metal oxide and between the metal oxide and the organic conductive layer.
  • the first busbars and the first current collectors may be applied using electroplating, screen printing, gravure printing or flexographic printing, which can be implemented into a continuous reel-to-reel process. If first busbars and first current collectors are required, the metal oxide layer is typically deposited in the form of strips. The first busbars and first current collectors are then provided in a pattern that is complimentary to the metal oxide strips, which are specifically designed to minimise resistive losses in the conductive layer.
  • a method of manufacturing working electrodes which comprises the consecutive steps of providing in a pattern first bars and first current collectors on the organic conductive layer prior to the step of sintering the metal oxide layer, drying the first busbars and the first current collectors and sintering the metal oxide layer, the first busbars and the first current collectors.
  • providing first busbars and first current collectors on the scribed organic conductive layer reduces the resistive losses within the scribed organic conductive layer, which increases the overall conductivity of this layer.
  • the step of drying the first busbars and the first current collectors ensures that no residual solvent remains that could adversely affect the adhesion between the scribed organic conductive layer and the first busbars and the first current collectors.
  • the advantage of sintering the metal oxide layer, the first busbars and the first current collectors together is a reduction in the processing time and a reduction in the costs associated with DSC manufacture, since only one sintering step is required to sinter the metal oxide layer and the first busbars and the first current collectors.
  • the first busbars and the first current collectors may be applied using electroplating, screen printing, gravure printing or flexographic printing, which can be implemented into a continuous reel-to-reel process.
  • a method of manufacturing working electrodes wherein the first busbars and the first current collectors are provided with a first protective layer to protect the first busbars and first current collectors from the electrolyte.
  • a first protective layer may be provided on the first busbars and the first current collectors, which prevents the electrolyte from corroding the first busbars and the first current collectors.
  • the first protective layer may be applied by screen printing or gravure printing, which can be implemented into a continuous reel- to-reel process. Following the step of printing, the first protective layer is subjected to a UV and/or heat treatment to cure the first protective layer. Since the first protective layer is provided after the step of sintering the metal oxide, the first busbars and the first current collectors, the first protective layer may be a low temperature resistant material.
  • the first protective layer is not required if the first busbars and first current collectors are not provided as a consequence of the resistive losses in the organic conductive layer being sufficiently low, i.e. ⁇ 1 Ohms/square, preferably below 0.5 Ohms/square
  • a working electrode for series connected dye sensitised solar cells comprising:
  • a metal carrier substrate having a first side and a second side
  • an organic electrically insulating layer on the first side of the metal carrier substrate having a temperature resistance in the range of 200°C and 600°C; a scribed organic conductive layer on the electrically insulating layer having a temperature resistance in the range of 200°C and 600°C;
  • the flexible metal carrier substrate of the working electrode is protected by the organic electrically insulating layer to prevent corrosion by the electrolyte.
  • the flexible organic electrically insulating layer is also resistant to high temperatures (200-600 0 C) and has good compatibility with the organic conductive layer thereon.
  • the scribed organic conductive layer is flexible, resistant to high temperatures
  • the sintered metal oxide layer on the scribed organic conductive layer has a large internal surface area and a high concentration of interconnected metal oxide particles to maximise the light harvesting capability of the DSC and the conductivity of the metal oxide layer respectively.
  • the metal oxide layer comprises a wide band gap metal oxide such as SnO 2 ZnO or TiO 2.
  • the dye thereon absorbs electromagnetic radiation in the green, blue and/or infrared regions of the electromagnetic spectrum that enables the dye sensitised metal oxide to act as a 'light sponge'.
  • a working electrode comprising in a pattern first busbars and first current collectors on the scribed organic conductive layer.
  • the first busbars and first current collectors reduce the resistive losses within the organic conductive layer as described above. However, if the sheet resistance of the organic conductive layer is sufficiently low then the provision of the first busbars and the first current collectors is not required.
  • a working electrode comprising a first protective layer on the first busbars and the first current collectors.
  • the optional first protective layer protects the first busbars and first current collectors from corrosion by the electrolyte so that the durability of the first busbars and the first current collectors is increased.
  • a method of manufacturing a module of series connected dye sensitised solar cells comprising the steps of:
  • a providing a working electrode according to the second aspect of the invention; a providing a first sealant material on a scribed organic conductive layer of the working electrode, the sealant material being provided in a pattern that surrounds a dye sensitised metal oxide on the organic conductive layer;
  • m providing an interconnect adjacent to every scribe, either on a first busbar or on the organic conductive layer of the working electrode;
  • iv providing an electrolyte on the dye sensitised metal oxide of working electrode; v providing a transparent counter electrode comprising a transparent polymer film and a transparent conductive layer;
  • ii providing an external protective coating on the first side of the counter electrode; vi ⁇ . providing an external connection on an interconnect to connect the module of series connected dye sensitised solar cells to an external circuit.
  • the working electrode provided in the series connected dye sensitised solar cell has the advantages of the working electrode discussed in the second aspect of the invention and the manufacturing method thereof discussed in the first aspect of the invention.
  • the working electrode is further provided with interconnects on the organic conductive layer or optionally on the first busbars, to electrically interconnect two or more dye sensitised solar cells, thus forming a DSC module having a useful output voltage.
  • the interconnects comprise a metal loaded paste that is printed onto the organic conductive layer or the first busbars, the paste is then subjected to a heat treatment to promote adhesion between the metal loaded paste and the organic conductive layer or the first busbars.
  • the first sealant material is resistant to the electrolyte and protects against moisture and air ingress and egress of the electrolyte.
  • the first sealant material may be provided by printing.
  • the electrolyte is preferably in the form of a dispensable gel that is dispensed directly onto the dye sensitised metal oxide, the electrolyte comprising a redox couple, an organic solvent and additives that aid charge transfer.
  • the counter electrode and the working electrode are aligned in a registered fashion that permits series connection of adjacent dye sensitised solar cells.
  • the counter electrode and the first sealant material are sealed using a heat and/or UV curable second sealant material.
  • the first sealant material provides a perimeter seal around the electrolyte, which has been deposited onto the dye sensitised metal oxide layer. Thus, egress of the electrolyte is reduced.
  • the external protective coating which is weather and impact resistant can then be deposited by spraying or doctor blading on the first side of the counter electrode.
  • the external protective coating comprises an organic material such as polyurethanes, acrylates, or halogenated polymers such as polyvinyl fluoride (PVF), polytetrafluoroethylene (PTFE) or ethylene-tetrafluoroethylene (ETFE).
  • PVF polyvinyl fluoride
  • PTFE polytetrafluoroethylene
  • ETFE ethylene-tetrafluoroethylene
  • a method of manufacturing a module of series connected dye sensitised solar cells wherein the step of providing the transparent counter electrode comprises the following steps:
  • iii providing a first transparent barrier coating on the first side of the transparent film, the first transparent barrier coating comprising a transparent inorganic layer and/or a transparent organic layer;
  • the counter electrode is manufactured separately and then combined with a working electrode so that the transparent film and subsequent layers are not subjected to the high temperature step of sintering the metal oxide, which would lead to thermal degradation of the transparent film, hi this arrangement, the counter electrode is the top 'window electrode' and the working electrode is a 'bottom' electrode. Since the counter electrode is transparent, sunlight may pass through the counter electrode and induce a dye excited state. In this reverse design, the working electrode is the 'bottom' electrode and the requirement for layers of the working electrode to be transparent is removed, meaning more suitable less-transparent layers having increased flexibility, conductivity and/or barrier resistance can be applied on the metal substrate instead.
  • the transparent film is flexible, low cost and may be coiled and uncoiled in a continuous reel-to-reel production line if required.
  • the transparent film is a suitable substrate for the large scale manufacture of counter electrodes for series connected dye sensitised solar cells.
  • the transparent conductive layer permits sunlight to reach the dye sensitised metal oxide of the working electrode to initiate the photo- electrochemical process.
  • the transparent conductive layer is also stable in the presence of the corrosive electrolyte and is a suitable substrate for a layer of catalytic material to be deposited thereon.
  • the transparent conductive layer could be a conductive oxide, which may be provided on the second side of the transparent film using low temperature vapour or sputter deposition processes to ensure the transparent film is not thermally degraded.
  • the transparent conductive layer may be a transparent organic material such as a conductive polymer or carbon dispersed in a transparent polymer, which can be deposited by roller coating, spray coating, doctor blading, or printing.
  • the first transparent barrier coating comprises a transparent inorganic layer and/or a transparent organic layer.
  • the transparent inorganic layer may be deposited using vapour or sputter processes so that the transparent film is not thermally degraded.
  • Transparent organic layers may also be applied by vapour or sputter processes or by doctor blading, printing, extrusion and roller coating if the transparent organic layer is polymer-based or solution-based.
  • the first transparent barrier coating comprises transparent inorganic layers alternated with transparent organic layers, which is expected to form an excellent barrier against water and air from the external environment.
  • the transparent inorganic material comprises SiO 2, TiO 2 or Al 2 O 3 and preferably the transparent organic material is a highly cross-linked polymer that will prevent moisture entering the series connected DSC.
  • the catalytic material is provided from solution by roller coating or spraying, which is followed by a chemical treatment and a drying step.
  • This may be implemented into a continuous or semi-continuous production line.
  • the layer of catalytic material may be based on carbon or platinum and promotes the transfer of electrons from the transparent conductive layer to ions in the electrolyte.
  • scribing divides the transparent conductive layer of the counter electrode into separate cells, which enables series connection and minimises resistive losses in the transparent conductive layer so that a useful output voltage may be obtained.
  • optionally providing second busbars and second current collectors may be achieved by screen printing, gravure printing, flexographic printing or electroplating, which can be incorporated into a continuous or a semi-continuous production line.
  • the application of second busbars and second current collectors on the transparent conductive layer of the counter electrode will minimise the resistive losses within the transparent conductive layer.
  • a second protective layer on the second busbars and the second current collectors protects the second busbars and the second current collectors from the corrosive electrolyte.
  • the second protective layer may be applied using screen printing or gravure printing, which can be implemented in a continuous or semi-continuous production line.
  • a method of manufacturing a module of series connected dye sensitised solar cells which comprises the steps of providing a second transparent film on the transparent film of the counter electrode, providing a second barrier coating on the second transparent film, providing an end seal and encapsulating the module of dye sensitised solar cell.
  • the above manufacturing method removes the requirement for providing coatings on both sides of the transparent film, i.e., providing a first barrier coating on a first side and a conductive coating on a second side.
  • a second barrier coating is provided on the second transparent film using a sputter process for example and then the second transparent film comprising the second barrier coating is provided on the transparent film of the counter electrode.
  • a method of manufacturing a module of series connected dye sensitised solar cells wherein a coated or an uncoated end portion of the metal substrate is subjected to a forming operation such that the first side of the metal substrate is in contact with a first side of an end seal, the second side of the end seal contacting the first transparent barrier coating.
  • the dye sensitised solar cell module having the formed metal portion displays enhanced corrosion resistance to the environment since the formed metal portion acts as a perimeter seal for the DSC module, thus moisture is prevented from penetrating the DSC module that would reduce the lifespan of the module.
  • the forming operation may also be implemented into a continuous production line that would reduce processing times and operating costs when manufacturing DSC modules.
  • the end seal acts as an additional barrier to prevent moisture ingress.
  • a module of series connected dye sensitised solar cells comprising:
  • the series connected dye sensitised solar cell module comprises the properties of the working electrode according to the second aspect of the invention and optionally the properties of the counter electrode described in the embodiments hereinabove.
  • the dye sensitised solar cell module When laminated and sealed together to encapsulate an electrolyte, the dye sensitised solar cell module is able to generate a useful output voltage.
  • the purpose of the electrolyte is to provide charge transfer from the counter electrode to dye molecules of the working electrode to regenerate the dye. Failure to regenerate the dye will lead to failure of the series connected dye sensitised solar cell and modules thereof.
  • the first barrier coating on the first side of the transparent film impedes the ingress of moisture whereas the external protective coating prevents UV light from entering the DSC module, which would be detrimental to DSC performance, and also enhances the weather and impact resistance of the DSC module.
  • the external protective coating comprises polyurethanes, acrylates or halogenated polymers such as polyvinyl fluoride (PVF), polytetrafluoroethylene (PTFE) or ETFE.
  • PVF polyvinyl fluoride
  • PTFE polytetrafluoroethylene
  • ETFE halogenated polymers
  • a module of series connected dye sensitised solar cells comprising a second transparent film, a second barrier coating on the second transparent film and an end seal, wherein the second transparent film and the second barrier coating encapsulate the module of dye sensitised solar cells.
  • the encapsulation of the module of dye sensitised solar cells with the second transparent film and the second barrier coating should prevent moisture ingress, which could be detrimental to DSC performance.
  • a module of series connected dye sensitised solar cells according to the fourth aspect of the invention wherein the second barrier coating comprises a stack of alternating inorganic and organic layers, wherein the first stack layer and last stack layer are inorganic layers.
  • the stack consists of five alternating inorganic and organic layers wherein the inorganic layer comprises SiO 2 , TiO 2 or Al 2 O 3 and the transparent organic layer is a material which comprises one or more heteroatoms.
  • the transparent organic layer is a cross-linked material or an epoxy.
  • the barrier film should has a visible light transmission of at least 85% and the barrier performance of the barrier film is ⁇ 5.0E '04 g/m 2 /day at 38°C and 90% relative humidity.
  • a module of series connected dye sensitised solar cells which comprises a transparent laminate barrier, the transparent laminate barrier comprising a first barrier arrangement comprising a transparent film and an inorganic barrier layer thereon, and a second barrier arrangement, comprising a transparent film and an inorganic barrier layer thereon, wherein an adhesive is disposed between the inorganic layer of the first barrier arrangement and the inorganic layer of the second barrier arrangement.
  • the first barrier arrangement and the second barrier arrangement are part of the same uncut barrier arrangement.
  • the first barrier arrangement is provided by applying the inorganic barrier layer on the transparent film.
  • the adhesive is then applied on the inorganic barrier layer and the first barrier arrangement comprising the adhesive is then folded such that a part of the first barrier arrangement is folded onto itself with the adhesive disposed therebetween.
  • the folded part of the first barrier arrangement can be considered as equivalent to the second barrier arrangement hereinabove.
  • the transparent laminate barrier is provided on the transparent film of the counter electrode.
  • the transparent film of the barrier arrangements comprises a polymeric material such as PET, PEN or polycarbonate
  • the inorganic barrier layer of the barrier arrangements comprises SiO 2, TiO 2 or Al 2 O 3.
  • the adhesive comprises an organic polymer.
  • Figure 1 shows a top view of two electrically interconnected dye sensitised solar cells, with cross section (A) relating to the viewing plane of Figure 2 and cross section (B) to that of Figure 3.
  • Figure 2 shows a side view of four electrically interconnected dye sensitised solar cells.
  • Figure 3 shows a transverse view (perpendicular to the side view) of one dye sensitised solar cell, with cross section (C) related to the viewing plane of figure 1.
  • a metal carrier substrate (2) is uncoiled in a first step of a continuous reel-to- reel production line for manufacturing working electrodes (1) for series connected dye sensitised solar cells and modules thereof.
  • the metal carrier substrate is preferably in the form of a strip comprising steel or aluminium.
  • An organic electrically insulating layer (3) is deposited thereon, which is resistant to temperatures associated with subsequent processing steps in the range of 200 to 600°C.
  • the electrically insulating layer comprising polyimides, sol gels, polyethersulphones (PES) and polytetrafluoroethylene (PTFE) can be applied to the metal carrier substrate by roller coating, doctor-blading or printing.
  • the next step in the continuous reel-to-reel process is to deposit the organic conductive layer (4) on the electrically insulating layer (3), which is achieved by roller coating, doctor-blading or printing.
  • the organic conductive layer is also resistant to temperatures in the range of 200 to 600°C and comprises organic conductive materials such as conductive polymers or a dispersion of carbon nanotubes and/or conductive additives in a high temperature resistant polymeric material.
  • the organic conductive layer may also comprise inorganic additives that increase the conductivity of the layer.
  • the organic conducive layer (4) is then scribed by mechanical scribing or laser scribing to form a scribe (5), which divides the organic conductive layer into cells that are electrically separated. Preferably this is performed prior to depositing the metal oxide layer on the organic conductive layer.
  • a paste comprising a metal oxide (6) in addition to a binder and a solvent is then deposited onto the scribed organic conductive layer (4) by screen printing, gravure printing or roller coating.
  • Metal oxides in accordance with the invention comprise SnO 2i ZnO or TiO 2
  • the paste coated substrate is then subjected to a heat treatment in the range of 200 to 600°C using a convection oven or near infrared radiation (NIR).
  • NIR near infrared radiation
  • the purpose of the heat treatment is to first remove the solvent which is a low boiling point solvent such as tcrpeniol, ethanol and/or water, and then the binder such as polyethyelene glycol (PEG) or ethylene cellulose (EC), which increases the surface area of the metal oxide layer once it has been removed.
  • the solvent is a low boiling point solvent such as tcrpeniol, ethanol and/or water
  • the binder such as polyethyelene glycol (PEG) or
  • a photosensitive dye (7) is either adsorbed or chemically bonded to the sintered metal oxide (6) layer having an increased internal surface area, which may be achieved by dipping the sintered metal oxide coated metal carrier substrate into a vessel containing the photosensitive dye.
  • An increase in temperature in the range of 30 to 80°C has been shown to increase the speed of the dying process. However, preferably a temperature of 80°C should not be exceeded since this could degrade the dye.
  • Dyes used in accordance with the invention preferably absorb electromagnetic radiation across a large part of the electromagnetic spectrum i.e. in the infrared and/or the green and blue regions of the electromagnetic spectrum. Suitable dyes comprise ruthenium based dyes and dyes derived from phthalocyanines.
  • first busbars (8) and first current collectors (9) are required, the metal oxide layer (6) is typically deposited in the form of strips on the organic conductive layer ( Figure 1) by screen printing, gravure printing or flexo graphic printing. First busbars and first current collectors comprising silver, aluminium or gold loaded pastes are then deposited by screen printing, gravure printing or fiexographic printing on the organic conductive layer (4), in a pattern that surrounds the strips of the metal oxide layer (If first busbars and first current collectors are not required, then the metal oxide layer is preferably not deposited in the form of strips).
  • the first busbars and first current collectors are then dried and subjected to a heat treatment (sintering) to adhere the first busbars and the first current collectors to the organic conductive layer. Sintering must be carried out prior to sensitising the metal oxide layer with a dye so that dye degradation is avoided.
  • a first protective layer (10) is then provided on the first busbars and first current collectors by screen printing or gravure printing.
  • the first protective layer comprising acrylates, polyurethanes, thermoplastics and epoxies.
  • the first busbars and first current collectors are not coated with a first protective layer if metals such as cobalt, molybdenum or tungsten and metal alloys thereof are deposited on the transparent conductive layer using electroplating.
  • the counter electrode (11) is prepared separately due to the use of a transparent thin film (12) having a first side and a second side, which is not resistant to the temperatures in the range of 200 to 600 0 C that are required for sintering the metal oxide layer (6) of the working electrode (1).
  • the transparent thin film comprises a polymeric material such as PET, PEN or polycarbonate preferably having a thickness in the range of 25 ⁇ m to 200 ⁇ m and more preferably a thickness in the range of 125 ⁇ m to 175 ⁇ m. Since the transparent thin film can be coiled and uncoiled it is a suitable substrate for a continuous or semi-continuous reel-to-reel process.
  • the transparent thin film (12) is uncoiled and introduced into a production line where a transparent conductive layer (13) such as conductive oxides comprising indium tin oxide, fluorine doped tin oxide or zinc oxide are deposited on the second side of the transparent thin film by low temperature vapour or sputter processes, which prevents degradation of the transparent thin film.
  • a transparent conductive layer based on organic materials can be deposited by roller coating, spray coating or printing, providing the conductive layer is transparent.
  • a barrier coating (14) is provided on the first side of the transparent thin film (12), the barrier coating layer comprising a transparent organic layer and an inorganic layer.
  • the transparent inorganic layer typically comprises oxides such as silica or alumina, which are deposited by low temperature vapour or sputter processes.
  • the transparent inorganic layer is alternated with the transparent organic layer that comprises cross-linked polymeric materials.
  • the transparent organic layer may also be deposited by low temperature vapour or sputter processes or by roller coating, spray coating or printing.
  • a layer of catalytic material (15) is subsequently deposited on the transparent conductive layer (13) of the counter electrode (11) using a roller coating process.
  • the layer of catalytic material typically comprises platinum which once deposited from a salt solution is reduced with a reducing agent.
  • organic materials such as carbon nanotubes having good conductivity and transparency could be used.
  • the transparent conductive layer (13) of the counter electrode (11) is then scribed by mechanical scribing or by laser scribing to form a second scribe (16), which divides the transparent conductive layer into cells that are electrically separated.
  • Second busbars (17) and second current collectors (18) comprising silver, aluminium or gold loaded pastes are then provided on the transparent conductive layer to reduce the resistive losses therein, and may be provided by screen printing, gravure printing or flexographic printing.
  • the second busbars and second current collectors are then coated with a second protective layer (19) by screen printing or gravure printing, the first protective layer comprising acrylates, polyurethanes, thermoplastics and/or epoxies.
  • the second busbars and second current collectors are not coated with a second protective layer if metals such as cobalt, molybdenum or tungsten and metal alloys thereof are deposited on the transparent conductive layer using electroplating.
  • the flexible counter electrode (11) is subsequently coiled in preparation for lamination with the working electrode (1) to form a module of series connected dye sensitised solar cells.
  • the working electrode (1) is uncoiled and fed into a continuous reel-to-reel production line wherein a sealant material (not shown) comprising epoxies, hot melts or other adhesive materials is provided by screen printing, gravure printing or flexographic printing.
  • a sealant material (not shown) comprising epoxies, hot melts or other adhesive materials is provided by screen printing, gravure printing or flexographic printing.
  • interconnects (20) comprising silver, aluminium or gold loaded pastes, or conductive tapes, are preferably dispensed adjacent to every scribe on a first busbar (8) or directly on the organic conductive layer (4); the metal loaded pastes are then cured at a temperature of 100 to 180°C to adhere the interconnect to the substrate.
  • An electrolyte (21) comprising a redox couple such as an iodide/tri-iodide redox couple in a suitable organic solvent such as acetonitrile or proprionitrile is subsequently dispensed on the metal oxide layer (6).
  • the counter electrode (11) is then fed into the production line, registered with the working electrode (1) and laminated at a temperature preferably no higher than 100°C since this could desorb or degrade the dye (7) and/or trigger reactions between certain electrolyte (21) components and the dye and/or the sealant material.
  • An external protective coating (22) comprising polyurethanes, acrylates, halogenated polymers such as polyvinyl fluoride (PVF), polytetrafluoroethylene (PTFE) or ETFE is then deposited by spraying or doctor blading on the barrier coating (14) of the counter electrode (11).
  • an external connection (not shown) is provided on an interconnect (20) to connect the module of series connected dye sensitised solar cells to an external circuit which enables energy produced by the module to be utilised.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Hybrid Cells (AREA)
  • Photovoltaic Devices (AREA)

Abstract

A method of manufacturing working electrodes for series connected dye sensitised solar cells in a continuous reel-to-reel production line comprising the steps of: i. Providing a metal carrier strip substrate having a first side and a second side; ii. Providing an organic electrically insulating layer on the first side of the metal carrier substrate having a temperature resistance in the range of 200°C to 600°C; iii. Providing an organic conductive layer on the electrically insulating layer having a temperature resistance in the range of 200°C to 600°C, optionally comprising conductive inorganic additives; iv. Scribing the organic conductive layer at regular intervals to divide the organic conductive layer into cells that are electrically separated; v. Providing a metal oxide layer on the scribed organic conductive layer; vi. Sintering the metal oxide layer; vii. Sensitising the sintered metal oxide layer with a dye.

Description

A METHOD OF MANUFACTURING WORKING ELECTRODES FOR DYE
SENSITISED SOLAR CELLS
This invention relates to working electrodes and to a method of manufacturing working electrodes. The invention further relates to a module of series connected dye sensitised solar cells and to a method of manufacturing a module of series connected dye sensitised solar cells.
Dye sensitised solar cells as first developed by Dr Michael Gratzel and co- workers comprise a working electrode and a counter electrode, which when sealed encapsulate an electrolyte. The working electrode comprised a conductive layer of fluorine doped tin oxide (SnO2:F) deposited onto a glass carrier substrate and a PV absorber layer on the layer of SnO2:F, the PV absorber layer being composed of sintered metal oxide nanometer-sized particles such as TiO2 that are sensitised with a light absorbing dye. The counter electrode comprised a conductive SnO2 :F coated glass substrate onto which a layer of platinum catalyst was deposited.
In operation, photons of light enter the cell through the working electrode and strike dye molecules that are chemically linked to the metal oxide semiconductor. Photon absorption by the dye promotes electrons of the dye from their ground state to an excited state, from where they can be injected into the conduction band of the metal oxide semiconductor, while almost simultaneously recombining with electrons that are stripped from the electrolyte. Electrons from the conduction band of the metal oxide semiconductor then diffuse to the conductive layer of the working electrode as a result of an electron concentration gradient. From the conductive layer of the working electrode these electrons pass via an external circuit to the conductive layer of the counter electrode and through the catalytic material to regenerate the electrolyte before the cycle is repeated.
In the above design the working electrode acts as the 'window' electrode and for that reason the carrier substrate and the conductive layer of the working electrode must be transparent to allow light to reach the photoabsorber layer. Since the metal oxide semiconductor of the working electrode undergoes a high temperature sintering step, the carrier substrate and the conductive layer should also be resistant to the temperatures of said sintering step. This therefore limits the choice of materials that can be used for the working electrode. Despite the low fabrication costs associated with dye sensitised solar cells based on Gratzel's design, sintering the metal oxide on a rigid transparent substrate such as glass limits DSC fabrication to a batch process, which cannot be easily modified into a continuous reel-to-reel production line.
Due to the above constraints, research has since been directed towards reducing process times, reducing costs and manufacturing dye sensitised solar cells on alternative flexible substrates. In this respect polymeric substrates have been used in lieu of glass substrates since higher throughputs can be achieved. However, when using polymeric substrates such as ITO coated poly(ethylene teraphthalate), it is necessary to sinter the metal oxide layer of the working electrode at relatively low temperatures, i.e. approximately 15O0C. Unfortunately, sintering the metal oxide at such low temperatures reduces the overall performance of the dye sensitised solar cell since the metal oxide possesses a reduced surface area and reduced concentration of interconnected metal particles relative to a metal oxide layer that is sintered at higher temperatures.
It is however possible to fabricate DSCs comprising a polymeric substrate and a metal oxide layer having a large surface area and a high concentration of interconnected metal oxide particles. A layer of metal oxide is provided on a metal foil such as titanium, which is then subjected to a high temperature sintering process. Because this is a separate process, i.e. not in the presence of the polymeric substrate, the polymeric substrate is not thermally degraded. The sintered metal oxide coated metal foil is then introduced into a production line where the metal foil acts as the conductive layer of the working electrode. However, the use of foils such as titanium are prohibitively expensive, difficult to handle and difficult to integrate into a continuous process. Thus, the industrialisation of dye sensitised solar cells comprising such foils is restrictive.
Despite DSCs displaying an energy conversion efficiency that is comparable to amorphous silicon solar cells (~10%), the output voltage associated with a single dye sensitised solar cell is not sufficient for industrial application. Therefore, it is necessary to interconnect a number of dye sensitised solar cells in series to generate a useful output voltage.
It is an object of this invention to provide a fast and efficient method of manufacturing working electrodes for a dye sensitised solar cell. It is another object of this invention to provide a cost effective method of manufacturing working electrodes for use in dye sensitised solar cell.
It is another object of this invention to provide a method of manufacturing working electrodes in a reel-to-reel process for use in a dye sensitised solar cell.
It is another object of this invention to provide a method of manufacturing a series of interconnected dye sensitised solar cells having a useful output voltage.
According to a first aspect of the invention there is provided a method of manufacturing working electrodes for series connected dye sensitised solar cells, each dye sensitised solar cell comprising a working electrode, a transparent counter electrode and an electrolyte, wherein the working electrodes are manufactured continuously in a reel-to-reel production line comprising the steps of:
i Providing a metal carrier strip substrate having a first side and a second side; u Providing an organic electrically insulating layer on the first side of the metal carrier substrate having a temperature resistance in the range of 200°C to 600°C; in Providing an organic conductive layer on the electrically insulating layer having a temperature resistance in the range of 200°C to 600°C, optionally comprising conductive inorganic additives;
iv Scribing the organic conductive layer at regular intervals to divide the organic conductive layer into cells that are electrically separated;
v Providing a metal oxide layer on the scribed organic conductive layer;
vi Sintering the metal oxide layer;
vii Sensitising the sintered metal oxide layer with a dye.
Advantageously, the use of a metal substrate in accordance with the invention enables dye sensitised solar cells to be manufactured in a reel-to-reel process due to the inherent flexibility, strength and temperature resistance of the metal carrier substrate.
Advantageously, the organic electrically insulating layer is resistant to high temperatures in the range of 200-600°C and resistant against the electrolyte which is capable of oxidising and corroding the metal carrier substrate. The use of an organic material has the benefit that vacuum based processes such as sputtering are not required when depositing the electrically insulating layer onto the metal carrier substrate, which enables the working electrode to be manufactured continuously in a reel-to-reel production line. Advantageously, the organic conductive layer, optionally comprising conductive inorganic additives exhibits good adhesion to the electrically insulating layer and can be used as an effective substrate to deposit the metal oxide layer. Preferably, the conductive layer possesses a sheet resistivity no higher than 100 ohms per square and more preferably no higher than 15 ohms per square so that resistive losses within the organic conductive layer are minimised. The presence of the optional inorganic conductive additives could increase the conductivity of the layer. It is preferable that the conductive layer is resistant to temperatures in the range of 200- 600°C, which are required when sintering the metal oxide. The deposition of an organic conductive layer enables the working electrode to be manufactured continuously since the organic conductive layer can be provided by printing or by coating, which negates the need for vacuum based processes that lead to a batch manufacturing route. Moreover, the inherent flexibility of the organic conductive layer enables the working electrode to be manufactured in a reel-to-reel process.
Advantageously, scribing divides the organic conductive layer of the working electrode into separate cells, which enables a high output voltage to be obtained since resistive losses in the organic conductive layer are minimised. Scribing may be performed by mechanical scribing or laser scribing. In accordance with the invention the step of scribing is implemented in a continuous reel-to-reel production line that will reduce processing times and manufacturing costs. The scribed regions do not affect the overall integrity of the organic conductive layer.
Advantageously, the metal oxide layer is deposited onto the organic conductive layer in a paste using screen printing, gravure printing or roller coating, the paste comprising the metal oxide, a binder and a solvent. The paste is then subjected to a heat treatment to remove the solvent and the binder from the paste, leaving behind a mesoporous metal oxide layer on top of the conductive substrate. The metal oxide is readily available, cheap, non-toxic, possesses good stability under visible radiation in solution, and has an extremely high surface area suitable for dye adsorption. The metal oxide layer is also porous enough to allow good penetration by the electrolyte ions, which is essential for effective dye regeneration. Finally, the metal oxide layer scatters incident photons effectively to increase its light harvesting efficiency.
Advantageously, once the metal oxide layer has been deposited onto the conductive layer, the metal substrate, organic electrically insulating layer, organic conductive layer and the metal oxide layer are heated to a temperature in the range of 200-600°C to increase the internal surface area of the metal oxide layer, the number of electrical interconnections between metal oxide particles (sintering), and consequently the electrical conductivity of the metal oxide layer. Moreover, subjecting the above layers to the heat treatment ensures that any residual solvents, which could be detrimental to the long term durability and functionally of the DSC, are removed. The heat treatment can be carried out using a conventional conduction oven or by using near infrared radiation, which will reduce processing times still further. Both heat treatments can be implemented into a continuous reel-to-reel production line.
Advantageously a photosensitive dye is either adsorbed or chemically bonded to the sintered metal oxide layer having an increased internal surface area. Sensitising the metal oxide in this way increases the light harvesting capability of the cell and therefore improves overall cell performance. Dyes in accordance with the invention are able to absorb radiation across a large part of the electromagnetic spectrum i.e. in the infrared and/or the green and blue regions of the electromagnetic spectrum.
In another preferred embodiment of the invention there is provided a method of manufacturing working electrodes, which comprises the consecutive steps of providing in a pattern first busbars and first current collectors on the scribed organic conductive layer after the step of sintering the metal oxide layer, drying the first busbars and the first current collectors and sintering the first busbars and the first current collectors. Busbars are defined as the larger conductive tracks around the perimeter of a cell, and current collectors are the smaller tracks that are located between two strips of metal oxide.
Advantageously the consecutive steps of providing the first busbars and first current collectors on the organic conductive layer reduces the sheet resistance of the organic conductive layer. Drying the first busbars and first current collectors removes any solvent that could be detrimental to DSC operation and efficiency, whereas sintering the first busbars and the first current collectors increases the electrical conductivity between the first busbars and the first current collectors and the organic conductive layer, which will reduce resistive losses in the organic conductive layer. In addition, the metal oxide will experience a 'second' sinter during the sintering of the first busbars and the first current collectors, which will further increase the concentration of electrical interconnections in the metal oxide and between the metal oxide and the organic conductive layer. The first busbars and the first current collectors may be applied using electroplating, screen printing, gravure printing or flexographic printing, which can be implemented into a continuous reel-to-reel process. If first busbars and first current collectors are required, the metal oxide layer is typically deposited in the form of strips. The first busbars and first current collectors are then provided in a pattern that is complimentary to the metal oxide strips, which are specifically designed to minimise resistive losses in the conductive layer.
In another preferred embodiment of the invention there is provided a method of manufacturing working electrodes, which comprises the consecutive steps of providing in a pattern first bars and first current collectors on the organic conductive layer prior to the step of sintering the metal oxide layer, drying the first busbars and the first current collectors and sintering the metal oxide layer, the first busbars and the first current collectors.
Advantageously, providing first busbars and first current collectors on the scribed organic conductive layer reduces the resistive losses within the scribed organic conductive layer, which increases the overall conductivity of this layer. The step of drying the first busbars and the first current collectors ensures that no residual solvent remains that could adversely affect the adhesion between the scribed organic conductive layer and the first busbars and the first current collectors. The advantage of sintering the metal oxide layer, the first busbars and the first current collectors together is a reduction in the processing time and a reduction in the costs associated with DSC manufacture, since only one sintering step is required to sinter the metal oxide layer and the first busbars and the first current collectors. The first busbars and the first current collectors may be applied using electroplating, screen printing, gravure printing or flexographic printing, which can be implemented into a continuous reel-to-reel process.
In another preferred embodiment of the invention there is provided a method of manufacturing working electrodes wherein the first busbars and the first current collectors are provided with a first protective layer to protect the first busbars and first current collectors from the electrolyte.
Advantageously, a first protective layer may be provided on the first busbars and the first current collectors, which prevents the electrolyte from corroding the first busbars and the first current collectors. The first protective layer may be applied by screen printing or gravure printing, which can be implemented into a continuous reel- to-reel process. Following the step of printing, the first protective layer is subjected to a UV and/or heat treatment to cure the first protective layer. Since the first protective layer is provided after the step of sintering the metal oxide, the first busbars and the first current collectors, the first protective layer may be a low temperature resistant material. The first protective layer is not required if the first busbars and first current collectors are not provided as a consequence of the resistive losses in the organic conductive layer being sufficiently low, i.e. <1 Ohms/square, preferably below 0.5 Ohms/square
According to a second aspect of the invention there is provided a working electrode for series connected dye sensitised solar cells comprising:
a metal carrier substrate having a first side and a second side;
an organic electrically insulating layer on the first side of the metal carrier substrate having a temperature resistance in the range of 200°C and 600°C; a scribed organic conductive layer on the electrically insulating layer having a temperature resistance in the range of 200°C and 600°C;
a sintered and dye sensitised metal oxide layer on the scribed organic conductive layer.
Advantageously, the flexible metal carrier substrate of the working electrode is protected by the organic electrically insulating layer to prevent corrosion by the electrolyte. The flexible organic electrically insulating layer is also resistant to high temperatures (200-6000C) and has good compatibility with the organic conductive layer thereon. The scribed organic conductive layer is flexible, resistant to high temperatures
(200-6000C) and has a sheet resistance preferably no higher than 100 ohm per square and preferably no higher than 15 ohm per square, which is required to facilitate electron transfer through the scribed organic conductive layer. The sintered metal oxide layer on the scribed organic conductive layer has a large internal surface area and a high concentration of interconnected metal oxide particles to maximise the light harvesting capability of the DSC and the conductivity of the metal oxide layer respectively.
Preferably the metal oxide layer comprises a wide band gap metal oxide such as SnO2 ZnO or TiO2. The dye thereon absorbs electromagnetic radiation in the green, blue and/or infrared regions of the electromagnetic spectrum that enables the dye sensitised metal oxide to act as a 'light sponge'. In another preferred embodiment of the invention there is provided a working electrode comprising in a pattern first busbars and first current collectors on the scribed organic conductive layer.
Advantageously, the first busbars and first current collectors reduce the resistive losses within the organic conductive layer as described above. However, if the sheet resistance of the organic conductive layer is sufficiently low then the provision of the first busbars and the first current collectors is not required.
In another preferred embodiment of the invention there is provided a working electrode comprising a first protective layer on the first busbars and the first current collectors.
Advantageously, the optional first protective layer protects the first busbars and first current collectors from corrosion by the electrolyte so that the durability of the first busbars and the first current collectors is increased.
According to a third aspect of the invention there is provided a method of manufacturing a module of series connected dye sensitised solar cells comprising the steps of:
i providing a working electrode according to the second aspect of the invention; a providing a first sealant material on a scribed organic conductive layer of the working electrode, the sealant material being provided in a pattern that surrounds a dye sensitised metal oxide on the organic conductive layer;
m providing an interconnect adjacent to every scribe, either on a first busbar or on the organic conductive layer of the working electrode;
iv providing an electrolyte on the dye sensitised metal oxide of working electrode; v providing a transparent counter electrode comprising a transparent polymer film and a transparent conductive layer;
vi laminating the transparent counter electrode on the working electrode in a registered fashion and curing of the first sealant material to encapsulate the electrolyte between the working electrode and the counter electrode, wherein the organic conductive layer of the working electrode faces the transparent conductive layer of the counter electrode;
ii providing an external protective coating on the first side of the counter electrode; viϋ. providing an external connection on an interconnect to connect the module of series connected dye sensitised solar cells to an external circuit.
Advantageously, the working electrode provided in the series connected dye sensitised solar cell has the advantages of the working electrode discussed in the second aspect of the invention and the manufacturing method thereof discussed in the first aspect of the invention.
The working electrode is further provided with interconnects on the organic conductive layer or optionally on the first busbars, to electrically interconnect two or more dye sensitised solar cells, thus forming a DSC module having a useful output voltage. The interconnects comprise a metal loaded paste that is printed onto the organic conductive layer or the first busbars, the paste is then subjected to a heat treatment to promote adhesion between the metal loaded paste and the organic conductive layer or the first busbars.
The first sealant material is resistant to the electrolyte and protects against moisture and air ingress and egress of the electrolyte. The first sealant material may be provided by printing.
The electrolyte is preferably in the form of a dispensable gel that is dispensed directly onto the dye sensitised metal oxide, the electrolyte comprising a redox couple, an organic solvent and additives that aid charge transfer.
To laminate the counter electrode and the working electrode together, the counter electrode and the working electrode are aligned in a registered fashion that permits series connection of adjacent dye sensitised solar cells. Once aligned the working electrode, the counter electrode and the first sealant material are sealed using a heat and/or UV curable second sealant material.
The first sealant material provides a perimeter seal around the electrolyte, which has been deposited onto the dye sensitised metal oxide layer. Thus, egress of the electrolyte is reduced.
The external protective coating, which is weather and impact resistant can then be deposited by spraying or doctor blading on the first side of the counter electrode.
The external protective coating comprises an organic material such as polyurethanes, acrylates, or halogenated polymers such as polyvinyl fluoride (PVF), polytetrafluoroethylene (PTFE) or ethylene-tetrafluoroethylene (ETFE). The external connection is provided by leading an insulated wire through a hole made in the working electrode or the counter electrode and then adhering the wire to an interconnect using solder or an adhesive conductive material.
In a preferred embodiment of the invention there is provided a method of manufacturing a module of series connected dye sensitised solar cells, wherein the step of providing the transparent counter electrode comprises the following steps:
i. providing a transparent film having a first side and a second side;
ii. providing a transparent conductive layer on the second side of the transparent film;
iii. providing a first transparent barrier coating on the first side of the transparent film, the first transparent barrier coating comprising a transparent inorganic layer and/or a transparent organic layer;
iv. providing a layer of catalytic material on the transparent conductive layer;
v. scribing the transparent conductive layer and the layer of catalytic material to divide the transparent conductive layer into cells that are electrically separated; vi. optionally providing second busbars and second current collectors on the
scribed layer of catalytic material in a pattern to minimise resistive losses in the transparent conductive layer;
vii. optionally providing a second protective layer on the second busbars and the second current collectors;
Advantageously, the counter electrode is manufactured separately and then combined with a working electrode so that the transparent film and subsequent layers are not subjected to the high temperature step of sintering the metal oxide, which would lead to thermal degradation of the transparent film, hi this arrangement, the counter electrode is the top 'window electrode' and the working electrode is a 'bottom' electrode. Since the counter electrode is transparent, sunlight may pass through the counter electrode and induce a dye excited state. In this reverse design, the working electrode is the 'bottom' electrode and the requirement for layers of the working electrode to be transparent is removed, meaning more suitable less-transparent layers having increased flexibility, conductivity and/or barrier resistance can be applied on the metal substrate instead. The transparent film is flexible, low cost and may be coiled and uncoiled in a continuous reel-to-reel production line if required. Thus, the transparent film is a suitable substrate for the large scale manufacture of counter electrodes for series connected dye sensitised solar cells.
Advantageously the transparent conductive layer permits sunlight to reach the dye sensitised metal oxide of the working electrode to initiate the photo- electrochemical process. The transparent conductive layer is also stable in the presence of the corrosive electrolyte and is a suitable substrate for a layer of catalytic material to be deposited thereon.
The transparent conductive layer could be a conductive oxide, which may be provided on the second side of the transparent film using low temperature vapour or sputter deposition processes to ensure the transparent film is not thermally degraded. Alternatively, the transparent conductive layer may be a transparent organic material such as a conductive polymer or carbon dispersed in a transparent polymer, which can be deposited by roller coating, spray coating, doctor blading, or printing.
Advantageously the first transparent barrier coating comprises a transparent inorganic layer and/or a transparent organic layer. The transparent inorganic layer may be deposited using vapour or sputter processes so that the transparent film is not thermally degraded. Transparent organic layers may also be applied by vapour or sputter processes or by doctor blading, printing, extrusion and roller coating if the transparent organic layer is polymer-based or solution-based. Preferably the first transparent barrier coating comprises transparent inorganic layers alternated with transparent organic layers, which is expected to form an excellent barrier against water and air from the external environment. Preferably the transparent inorganic material comprises SiO2, TiO2 or Al2O3 and preferably the transparent organic material is a highly cross-linked polymer that will prevent moisture entering the series connected DSC.
Advantageously the catalytic material is provided from solution by roller coating or spraying, which is followed by a chemical treatment and a drying step. This may be implemented into a continuous or semi-continuous production line. The layer of catalytic material may be based on carbon or platinum and promotes the transfer of electrons from the transparent conductive layer to ions in the electrolyte.
Advantageously, scribing divides the transparent conductive layer of the counter electrode into separate cells, which enables series connection and minimises resistive losses in the transparent conductive layer so that a useful output voltage may be obtained.
Advantageously, optionally providing second busbars and second current collectors may be achieved by screen printing, gravure printing, flexographic printing or electroplating, which can be incorporated into a continuous or a semi-continuous production line. The application of second busbars and second current collectors on the transparent conductive layer of the counter electrode will minimise the resistive losses within the transparent conductive layer.
Advantageously, optionally providing a second protective layer on the second busbars and the second current collectors protects the second busbars and the second current collectors from the corrosive electrolyte. The second protective layer may be applied using screen printing or gravure printing, which can be implemented in a continuous or semi-continuous production line.
In a preferred embodiment of the invention there is provided a method of manufacturing a module of series connected dye sensitised solar cells, which comprises the steps of providing a second transparent film on the transparent film of the counter electrode, providing a second barrier coating on the second transparent film, providing an end seal and encapsulating the module of dye sensitised solar cell.
Advantageously, the above manufacturing method removes the requirement for providing coatings on both sides of the transparent film, i.e., providing a first barrier coating on a first side and a conductive coating on a second side. Preferably, a second barrier coating is provided on the second transparent film using a sputter process for example and then the second transparent film comprising the second barrier coating is provided on the transparent film of the counter electrode.
In another preferred embodiment of the invention there is provided a method of manufacturing a module of series connected dye sensitised solar cells wherein a coated or an uncoated end portion of the metal substrate is subjected to a forming operation such that the first side of the metal substrate is in contact with a first side of an end seal, the second side of the end seal contacting the first transparent barrier coating.
Advantageously, the dye sensitised solar cell module having the formed metal portion displays enhanced corrosion resistance to the environment since the formed metal portion acts as a perimeter seal for the DSC module, thus moisture is prevented from penetrating the DSC module that would reduce the lifespan of the module. The forming operation may also be implemented into a continuous production line that would reduce processing times and operating costs when manufacturing DSC modules. The end seal acts as an additional barrier to prevent moisture ingress.
According to a fourth aspect of the invention there is provided a module of series connected dye sensitised solar cells comprising:
a working electrode according to the second aspect of the invention;
a counter electrode on the working electrode;
an encapsulated electrolyte between the working electrode, the counter electrode and a first sealant;
- an external protective coating on the first side of the counter electrode;
an external connection.
Advantageously the series connected dye sensitised solar cell module comprises the properties of the working electrode according to the second aspect of the invention and optionally the properties of the counter electrode described in the embodiments hereinabove. When laminated and sealed together to encapsulate an electrolyte, the dye sensitised solar cell module is able to generate a useful output voltage. The purpose of the electrolyte is to provide charge transfer from the counter electrode to dye molecules of the working electrode to regenerate the dye. Failure to regenerate the dye will lead to failure of the series connected dye sensitised solar cell and modules thereof. The first barrier coating on the first side of the transparent film impedes the ingress of moisture whereas the external protective coating prevents UV light from entering the DSC module, which would be detrimental to DSC performance, and also enhances the weather and impact resistance of the DSC module. The external protective coating comprises polyurethanes, acrylates or halogenated polymers such as polyvinyl fluoride (PVF), polytetrafluoroethylene (PTFE) or ETFE. The module is provided with an external connection on an interconnect that allows energy produced by the module to be utilised.
In a preferred embodiment of the invention there is provided a module of series connected dye sensitised solar cells comprising a second transparent film, a second barrier coating on the second transparent film and an end seal, wherein the second transparent film and the second barrier coating encapsulate the module of dye sensitised solar cells. The encapsulation of the module of dye sensitised solar cells with the second transparent film and the second barrier coating should prevent moisture ingress, which could be detrimental to DSC performance.
In a preferred embodiment of the invention there is provided a module of series connected dye sensitised solar cells according to the fourth aspect of the invention wherein the second barrier coating comprises a stack of alternating inorganic and organic layers, wherein the first stack layer and last stack layer are inorganic layers.
Preferably the stack consists of five alternating inorganic and organic layers wherein the inorganic layer comprises SiO2, TiO2 or Al2O3 and the transparent organic layer is a material which comprises one or more heteroatoms. Preferably the transparent organic layer is a cross-linked material or an epoxy. Preferably the barrier film should has a visible light transmission of at least 85% and the barrier performance of the barrier film is < 5.0E'04 g/m2/day at 38°C and 90% relative humidity.
In a preferred embodiment of the invention there is provided a module of series connected dye sensitised solar cells, which comprises a transparent laminate barrier, the transparent laminate barrier comprising a first barrier arrangement comprising a transparent film and an inorganic barrier layer thereon, and a second barrier arrangement, comprising a transparent film and an inorganic barrier layer thereon, wherein an adhesive is disposed between the inorganic layer of the first barrier arrangement and the inorganic layer of the second barrier arrangement.
Preferably the first barrier arrangement and the second barrier arrangement are part of the same uncut barrier arrangement. For instance, the first barrier arrangement is provided by applying the inorganic barrier layer on the transparent film. The adhesive is then applied on the inorganic barrier layer and the first barrier arrangement comprising the adhesive is then folded such that a part of the first barrier arrangement is folded onto itself with the adhesive disposed therebetween. Here, the folded part of the first barrier arrangement can be considered as equivalent to the second barrier arrangement hereinabove.
Preferably the transparent laminate barrier is provided on the transparent film of the counter electrode.
Preferably the transparent film of the barrier arrangements comprises a polymeric material such as PET, PEN or polycarbonate, and the inorganic barrier layer of the barrier arrangements comprises SiO2, TiO2 or Al2O3. Preferably the adhesive comprises an organic polymer.
The invention will now be further explained by the following non-limitative examples wherein:
Figure 1. shows a top view of two electrically interconnected dye sensitised solar cells, with cross section (A) relating to the viewing plane of Figure 2 and cross section (B) to that of Figure 3.
Figure 2. shows a side view of four electrically interconnected dye sensitised solar cells.
Figure 3. shows a transverse view (perpendicular to the side view) of one dye sensitised solar cell, with cross section (C) related to the viewing plane of figure 1.
A metal carrier substrate (2) is uncoiled in a first step of a continuous reel-to- reel production line for manufacturing working electrodes (1) for series connected dye sensitised solar cells and modules thereof. The metal carrier substrate is preferably in the form of a strip comprising steel or aluminium. An organic electrically insulating layer (3) is deposited thereon, which is resistant to temperatures associated with subsequent processing steps in the range of 200 to 600°C. The electrically insulating layer comprising polyimides, sol gels, polyethersulphones (PES) and polytetrafluoroethylene (PTFE) can be applied to the metal carrier substrate by roller coating, doctor-blading or printing.
The next step in the continuous reel-to-reel process is to deposit the organic conductive layer (4) on the electrically insulating layer (3), which is achieved by roller coating, doctor-blading or printing. The organic conductive layer is also resistant to temperatures in the range of 200 to 600°C and comprises organic conductive materials such as conductive polymers or a dispersion of carbon nanotubes and/or conductive additives in a high temperature resistant polymeric material. The organic conductive layer may also comprise inorganic additives that increase the conductivity of the layer.
The organic conducive layer (4) is then scribed by mechanical scribing or laser scribing to form a scribe (5), which divides the organic conductive layer into cells that are electrically separated. Preferably this is performed prior to depositing the metal oxide layer on the organic conductive layer.
A paste comprising a metal oxide (6) in addition to a binder and a solvent is then deposited onto the scribed organic conductive layer (4) by screen printing, gravure printing or roller coating. Metal oxides in accordance with the invention comprise SnO2i ZnO or TiO2 The paste coated substrate is then subjected to a heat treatment in the range of 200 to 600°C using a convection oven or near infrared radiation (NIR). The purpose of the heat treatment is to first remove the solvent which is a low boiling point solvent such as tcrpeniol, ethanol and/or water, and then the binder such as polyethyelene glycol (PEG) or ethylene cellulose (EC), which increases the surface area of the metal oxide layer once it has been removed. At temperatures in the range of 400 to 600°C, sintering of the metal oxide occurs, which increases the number of interconnections between metal oxide particles ("necking") and consequently the electrical conductivity of the metal oxide.
A photosensitive dye (7) is either adsorbed or chemically bonded to the sintered metal oxide (6) layer having an increased internal surface area, which may be achieved by dipping the sintered metal oxide coated metal carrier substrate into a vessel containing the photosensitive dye. An increase in temperature in the range of 30 to 80°C has been shown to increase the speed of the dying process. However, preferably a temperature of 80°C should not be exceeded since this could degrade the dye. Dyes used in accordance with the invention preferably absorb electromagnetic radiation across a large part of the electromagnetic spectrum i.e. in the infrared and/or the green and blue regions of the electromagnetic spectrum. Suitable dyes comprise ruthenium based dyes and dyes derived from phthalocyanines.
If first busbars (8) and first current collectors (9) are required, the metal oxide layer (6) is typically deposited in the form of strips on the organic conductive layer (Figure 1) by screen printing, gravure printing or flexo graphic printing. First busbars and first current collectors comprising silver, aluminium or gold loaded pastes are then deposited by screen printing, gravure printing or fiexographic printing on the organic conductive layer (4), in a pattern that surrounds the strips of the metal oxide layer (If first busbars and first current collectors are not required, then the metal oxide layer is preferably not deposited in the form of strips). The first busbars and first current collectors are then dried and subjected to a heat treatment (sintering) to adhere the first busbars and the first current collectors to the organic conductive layer. Sintering must be carried out prior to sensitising the metal oxide layer with a dye so that dye degradation is avoided. A first protective layer (10) is then provided on the first busbars and first current collectors by screen printing or gravure printing. The first protective layer comprising acrylates, polyurethanes, thermoplastics and epoxies. Preferably, the first busbars and first current collectors are not coated with a first protective layer if metals such as cobalt, molybdenum or tungsten and metal alloys thereof are deposited on the transparent conductive layer using electroplating. Once the working electrodes have been manufactured as above they are subsequently coiled in preparation for lamination with the counter electrode (11).
The counter electrode (11) is prepared separately due to the use of a transparent thin film (12) having a first side and a second side, which is not resistant to the temperatures in the range of 200 to 6000C that are required for sintering the metal oxide layer (6) of the working electrode (1). The transparent thin film comprises a polymeric material such as PET, PEN or polycarbonate preferably having a thickness in the range of 25 μm to 200 μm and more preferably a thickness in the range of 125 μm to 175 μm. Since the transparent thin film can be coiled and uncoiled it is a suitable substrate for a continuous or semi-continuous reel-to-reel process.
The transparent thin film (12) is uncoiled and introduced into a production line where a transparent conductive layer (13) such as conductive oxides comprising indium tin oxide, fluorine doped tin oxide or zinc oxide are deposited on the second side of the transparent thin film by low temperature vapour or sputter processes, which prevents degradation of the transparent thin film. Alternatively a conductive layer based on organic materials can be deposited by roller coating, spray coating or printing, providing the conductive layer is transparent.
Following the deposition of the transparent conductive layer (13), a barrier coating (14) is provided on the first side of the transparent thin film (12), the barrier coating layer comprising a transparent organic layer and an inorganic layer. The transparent inorganic layer typically comprises oxides such as silica or alumina, which are deposited by low temperature vapour or sputter processes. Preferably the transparent inorganic layer is alternated with the transparent organic layer that comprises cross-linked polymeric materials. The transparent organic layer may also be deposited by low temperature vapour or sputter processes or by roller coating, spray coating or printing.
A layer of catalytic material (15) is subsequently deposited on the transparent conductive layer (13) of the counter electrode (11) using a roller coating process. The layer of catalytic material typically comprises platinum which once deposited from a salt solution is reduced with a reducing agent. Alternatively, organic materials such as carbon nanotubes having good conductivity and transparency could be used.
The transparent conductive layer (13) of the counter electrode (11) is then scribed by mechanical scribing or by laser scribing to form a second scribe (16), which divides the transparent conductive layer into cells that are electrically separated. Second busbars (17) and second current collectors (18) comprising silver, aluminium or gold loaded pastes are then provided on the transparent conductive layer to reduce the resistive losses therein, and may be provided by screen printing, gravure printing or flexographic printing. The second busbars and second current collectors are then coated with a second protective layer (19) by screen printing or gravure printing, the first protective layer comprising acrylates, polyurethanes, thermoplastics and/or epoxies. Preferably, the second busbars and second current collectors are not coated with a second protective layer if metals such as cobalt, molybdenum or tungsten and metal alloys thereof are deposited on the transparent conductive layer using electroplating. The flexible counter electrode (11) is subsequently coiled in preparation for lamination with the working electrode (1) to form a module of series connected dye sensitised solar cells.
The working electrode (1) is uncoiled and fed into a continuous reel-to-reel production line wherein a sealant material (not shown) comprising epoxies, hot melts or other adhesive materials is provided by screen printing, gravure printing or flexographic printing. Following the deposition of the sealant material, interconnects (20) comprising silver, aluminium or gold loaded pastes, or conductive tapes, are preferably dispensed adjacent to every scribe on a first busbar (8) or directly on the organic conductive layer (4); the metal loaded pastes are then cured at a temperature of 100 to 180°C to adhere the interconnect to the substrate. An electrolyte (21) comprising a redox couple such as an iodide/tri-iodide redox couple in a suitable organic solvent such as acetonitrile or proprionitrile is subsequently dispensed on the metal oxide layer (6).
The counter electrode (11) is then fed into the production line, registered with the working electrode (1) and laminated at a temperature preferably no higher than 100°C since this could desorb or degrade the dye (7) and/or trigger reactions between certain electrolyte (21) components and the dye and/or the sealant material. An external protective coating (22) comprising polyurethanes, acrylates, halogenated polymers such as polyvinyl fluoride (PVF), polytetrafluoroethylene (PTFE) or ETFE is then deposited by spraying or doctor blading on the barrier coating (14) of the counter electrode (11). Finally, an external connection (not shown) is provided on an interconnect (20) to connect the module of series connected dye sensitised solar cells to an external circuit which enables energy produced by the module to be utilised.

Claims

1. A method of manufacturing working electrodes for series connected dye sensitised solar cells in a continuous reel-to-rccl production line comprising the steps of:
i Providing a metal carrier strip substrate having a first side and a second side;
ii Providing an organic electrically insulating layer on the first side of the metal carrier substrate having a temperature resistance in the range of
2000C to 600°C;
ui Providing an organic conductive layer on the electrically insulating layer having a temperature resistance in the range of 200°C to 600°C, optionally comprising conductive inorganic additives;
lv Scribing the organic conductive layer at regular intervals to divide the organic conductive layer into cells that are electrically separated;
v Providing a metal oxide layer on the scribed organic conductive layer; vi Sintering the metal oxide layer;
vii Sensitising the sintered metal oxide layer with a dye.
2. A method of manufacturing working electrodes according to claim 1 , which comprises the consecutive steps of providing in a pattern first busbars and first current collectors on the scribed organic conductive layer after the step of sintering the metal oxide layer, drying the first busbars and the first current collectors and sintering the first busbars and the first current collectors.
3. A method of manufacturing working electrodes according to claim 1, which comprises the consecutive steps of providing in a pattern first bars and first current collectors on the organic conductive layer prior to the step of sintering the metal oxide layer, drying the first busbars and the first current collectors and sintering the metal oxide layer, the first busbars and the first current collectors.
4. A method of manufacturing working electrodes according to claim 2 or claim 3 wherein the first busbars and the first current collectors are provided with a first protective layer to protect the first busbars and first current collectors from the electrolyte.
5. A working electrode for series connected dye sensitised solar cells produced according to any one of claims 1 to 4 comprising:
a metal carrier substrate having a first side and a second side; an organic electrically insulating layer on the first side of the metal carrier substrate having a temperature resistance in the range of 200°C to 6000C; a scribed organic conductive layer on the electrically insulating layer having a temperature resistance in the range of 200°C and 600°C;
a sintered and dye sensitised metal oxide layer on the scribed organic conductive layer.
6. A working electrode according to claim 5 comprising in a pattern first busbars and first current collectors on the scribed organic conductive layer.
7. A working electrode according to claim 6 comprising a first protective layer on the first busbars and the first current collectors.
8. A method of manufacturing a module of series connected dye sensitised solar cells comprising the steps of:
i providing a working electrode according to claim 5;
H providing a first sealant material on a scribed organic conductive layer of the working electrode, the sealant material being provided in a pattern that surrounds dye sensitised metal oxide on the organic conductive layer; in providing an interconnect adjacent to every scribe, either on a first busbar or on the organic conductive layer of the working electrode; iv providing an electrolyte on the dye sensitised metal oxide of the working electrode ;
v providing a transparent counter electrode comprising a transparent film, and a conductive layer;
vi laminating the transparent counter electrode on the working electrode in a registered fashion and curing of the first sealant material to encapsulate the electrolyte between the working electrode and the counter electrode, wherein the organic conductive layer of the working electrode faces the transparent conductive layer of the counter electrode;
vit providing an external protective coating on the first side of the counter electrode;
viπ providing an external connection on an interconnect to connect the module of series connected dye sensitised solar cells to an external circuit.
9. A method of manufacturing a module of series connected dye sensitised solar cells according to claim 8 wherein the step of providing the transparent counter electrode comprises the following steps:
i providing a transparent film having a first side and a second side;
H providing a transparent conductive layer on the second side of the
transparent film;
in providing a first transparent barrier coating on the first side of the
transparent film, the first transparent barrier coating comprising a transparent inorganic layer and/or a transparent organic layer ;
lv providing a layer of catalytic material on the transparent conductive
layer;
v scribing the transparent conductive layer and the layer of catalytic
material to divide the transparent conductive layer into cells that are electrically separated;
vi optionally providing second busbars and second current collectors on the scribed layer of catalytic material in a pattern to minimise resistive losses in the transparent conductive layer;
vπ optionally providing a second protective layer on the second busbars and the second current collectors.
10. A method of manufacturing a module of series connected dye sensitised solar cells according to claim 8 or claim 9, which comprises the steps of providing a second transparent film on the transparent film of the counter electrode, providing a second barrier coating on the second transparent film, providing an end seal and encapsulating the module of dye sensitised solar cells.
11. A method of manufacturing a module of series connected dye sensitised solar cells according to claim 8 or claim 9 wherein an uncoated end portion of the metal carrier substrate is subjected to a forming operation such that the first side of the metal substrate is in contact with a first side of an end seal, the second side of the end seal contacting the first transparent barrier coating.
12. A module of series connected dye sensitised solar cells produced according to the manufacturing method of any one of claims 8-11, comprising;
- a working electrode according to claim 5;
a counter electrode on the working electrode;
an encapsulated electrolyte between the working electrode, the counter electrode and a first sealant;
an external protective coating on the first side of the counter electrode; - an external connection.
13. A module of series connected dye sensitised solar cells according to claim 12 comprising a second transparent film, a second barrier coating on the second transparent film and an end seal, wherein the second transparent film and the second barrier coating encapsulate the module of dye sensitised solar cells.
14. A module of series connected dye sensitised solar cells according to claim 12 or claim 13 wherein the second barrier coating comprises a stack of alternating inorganic and organic layers.
15. A module of series connected dye sensitised solar cells according to claim 12, which comprises a transparent laminate barrier on the counter electrode, the transparent laminate barrier comprising a first barrier arrangement comprising a transparent film and an inorganic barrier layer thereon, and a second barrier arrangement, which comprises a transparent film and an inorganic barrier layer thereon, wherein an adhesive is disposed between the inorganic layer of the first barrier arrangement and the inorganic layer of the second barrier arrangement.
EP10742425A 2009-07-23 2010-07-23 A method of manufacturing working electrodes for dye sensitised solar cells Ceased EP2457243A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP10742425A EP2457243A1 (en) 2009-07-23 2010-07-23 A method of manufacturing working electrodes for dye sensitised solar cells

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
EP09009582 2009-07-23
EP09013207 2009-10-20
PCT/EP2010/004538 WO2011009631A1 (en) 2009-07-23 2010-07-23 A method of manufacturing working electrodes for dye sensitised solar cells
EP10742425A EP2457243A1 (en) 2009-07-23 2010-07-23 A method of manufacturing working electrodes for dye sensitised solar cells

Publications (1)

Publication Number Publication Date
EP2457243A1 true EP2457243A1 (en) 2012-05-30

Family

ID=42670426

Family Applications (1)

Application Number Title Priority Date Filing Date
EP10742425A Ceased EP2457243A1 (en) 2009-07-23 2010-07-23 A method of manufacturing working electrodes for dye sensitised solar cells

Country Status (2)

Country Link
EP (1) EP2457243A1 (en)
WO (1) WO2011009631A1 (en)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT1403764B1 (en) * 2011-01-31 2013-10-31 Dyepower ELEMENTS OF VERTICAL ELECTRICAL CONNECTION OF PHOTOELECTROCHEMICAL CELLS.
JP5267608B2 (en) * 2011-04-07 2013-08-21 大日本印刷株式会社 Dye-sensitized solar cell module
JP5996995B2 (en) * 2012-10-05 2016-09-21 株式会社フジクラ Dye-sensitized solar cell and dye-sensitized solar cell module
EP2747101A1 (en) * 2012-12-19 2014-06-25 Swansea University An opto-electronic device and method for manufacturing the same
CN104124060A (en) * 2013-04-28 2014-10-29 凯惠科技发展(上海)有限公司 Internal tandem dye-sensitized solar cell, manufacturing method and power source
EP3022748A1 (en) * 2013-07-15 2016-05-25 3GSolar Photovoltaics Ltd. Plastic solar dye cells
GB201315869D0 (en) * 2013-09-05 2013-10-23 Tata Steel Uk Ltd Opto-electronic device module and method for manufacturing the same
GB201504696D0 (en) * 2015-03-19 2015-05-06 Cpi Innovation Services Ltd Back substrate for an opto-electronic device module and a module of opto-electronic devices comprising said back substrate
JP6538018B2 (en) * 2016-10-28 2019-07-03 株式会社昭和 Dye-sensitized solar cell module

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0948004A1 (en) * 1998-03-26 1999-10-06 Akzo Nobel N.V. Method for making a photovoltaic cell containing a dye
US6706963B2 (en) * 2002-01-25 2004-03-16 Konarka Technologies, Inc. Photovoltaic cell interconnection
US7323635B2 (en) * 2001-06-15 2008-01-29 University Of Massachusetts Photovoltaic cell
GB0720553D0 (en) * 2007-10-19 2007-11-28 Isis Innovation Branched materials for photovoltaic devices
JP2009146625A (en) * 2007-12-12 2009-07-02 Sony Corp Dye-sensitized photoelectric conversion element module, manufacturing method thereof, photoelectric conversion element module, and manufacturing method thereof, as well as electronic apparatus

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
ANONYMOUS: "Google Results for Temperature Resistance of Definition", 15 July 2014 (2014-07-15), XP055169343, Retrieved from the Internet <URL:www.google.co.uk> [retrieved on 20150212] *
ANONYMOUS: "Temperature Resistance of Thermoplastics", ELASTOMERS AND THERMOPLASTICS ENGINEERING DESIGN GUIDE, 15 July 2014 (2014-07-15), XP055169342, Retrieved from the Internet <URL:http://www.mnrubber.com/Design_Guide/5-3.html> [retrieved on 20150212] *
See also references of WO2011009631A1 *
SOMBOONSUB B ET AL: "Preparation of the thermally stable conducting polymer PEDOT @? Sulfonated poly(imide)", POLYMER, ELSEVIER SCIENCE PUBLISHERS B.V, GB, vol. 51, no. 6, 11 March 2010 (2010-03-11), pages 1231 - 1236, XP026947918, ISSN: 0032-3861, [retrieved on 20100201], DOI: 10.1016/J.POLYMER.2010.01.048 *

Also Published As

Publication number Publication date
WO2011009631A1 (en) 2011-01-27

Similar Documents

Publication Publication Date Title
EP2457243A1 (en) A method of manufacturing working electrodes for dye sensitised solar cells
AU741400B2 (en) Method for making a photovoltaic cell containing a dye
AU2008258967B2 (en) Dye-sensitized solar cell module and production method thereof
EP2287961B1 (en) Photoelectric conversion element module and method for manufacturing photoelectric conversion element module
US20150302997A1 (en) Flexible electrodes and preparation method thereof, and flexible dye-sensitized solar cells using the same
US11799041B2 (en) Double sided solar cell assembly
AU2008321843B2 (en) Electrode substrate for photoelectric conversion element, method of manufacturing electrode substrate for photoelectric conversion element, and photoelectric conversion element
EP2560231B1 (en) Dye-sensitized solar cell module and method for fabricating same
EP2216850A1 (en) Electrode substrate for photoelectric conversion element
KR20100075552A (en) Dye-sensitized solar cell module
US20160379763A1 (en) Substrate and electrode for solar cells and the corresponding manufacturing process
JP2009193911A (en) Dye-sensitized photoelectric conversion element and its manufacturing method, dye-sensitized photoelectric conversion element module and its manufacturing method, electronic device, and method for manufacturing porous silica film
EP2584645B1 (en) Dye-sensitized solar cell electrode, manufacturing method thereof, and dye-sensitized solar cell
JP5160045B2 (en) Photoelectric conversion element
JP2007227260A (en) Photoelectric converter and photovoltaic generator
JP5095148B2 (en) Working electrode substrate and photoelectric conversion element
EP2690676B1 (en) Manufacturing process for a substrate and an electrode for solar cells
EP2625704B1 (en) Vertical electrical connection of photoelectrochemical cells
WO2013015067A1 (en) Photoelectric-conversion device, electronic instrument and building
WO2018092740A1 (en) Photoelectric conversion element
JP5251149B2 (en) Laminated body for oxide semiconductor electrode, oxide semiconductor electrode, and dye-sensitized solar cell module
Nogueira et al. Substrate and electrode for solar cells and corresponding manufacturing process

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20120223

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK SM TR

DAX Request for extension of the european patent (deleted)
RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: SWANSEA UNIVERSITY

17Q First examination report despatched

Effective date: 20140327

REG Reference to a national code

Ref country code: DE

Ref legal event code: R003

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN REFUSED

18R Application refused

Effective date: 20151120