Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B82—NANOTECHNOLOGY
  • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
  • B82Y10/00—Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B82—NANOTECHNOLOGY
  • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
  • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K30/00—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation
  • H10K30/30—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation comprising bulk heterojunctions, e.g. interpenetrating networks of donor and acceptor material domains
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K30/00—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation
  • H10K30/354—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation comprising a metal-insulator-semiconductor [m-i-s] structure
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K30/00—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation
  • H10K30/80—Constructional details
  • H10K30/81—Electrodes
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K30/00—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation
  • H10K30/50—Photovoltaic [PV] devices
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K85/00—Organic materials used in the body or electrodes of devices covered by this subclass
  • H10K85/10—Organic polymers or oligomers
  • H10K85/111—Organic polymers or oligomers comprising aromatic, heteroaromatic, or aryl chains, e.g. polyaniline, polyphenylene or polyphenylene vinylene
  • H10K85/114—Poly-phenylenevinylene; Derivatives thereof
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K85/00—Organic materials used in the body or electrodes of devices covered by this subclass
  • H10K85/20—Carbon compounds, e.g. carbon nanotubes or fullerenes
  • H10K85/211—Fullerenes, e.g. C60
• • 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
  • Y02E10/549—Organic PV 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
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S977/00—Nanotechnology
  • Y10S977/902—Specified use of nanostructure
  • Y10S977/932—Specified use of nanostructure for electronic or optoelectronic application
  • Y10S977/949—Radiation emitter using nanostructure
  • Y10S977/95—Electromagnetic energy

Definitions

• the invention relates to a photovoltaic cell with a photoactive layer of two molecular components, namely an electron donor and an electron acceptor, in particular a conjugated polymer component and a fullerene component, and with two metallic electrodes provided on both sides of the photoactive layer.
• conjugated plastics Plastics with extensive ⁇ -electron systems, in which single and double bonds alternate, are referred to as conjugated plastics. These conjugated plastics have comparable energy bands in terms of electron energy to semiconductors, so that they can also be converted from the non-conductive to the metallic conductive state by doping. Examples of such conjugated plastics are polyphenylenes, polyvinylphenylenes (PPV), polythiophenes or polyanilines.
• PV polyvinylphenylenes
• polythiophenes polyanilines.
• the efficiency of the energy conversion of photovoltaic polymer cells from a conjugated polymer is typically between 10 "3 and 10 " 2 %. To improve this efficiency, heterogeneous layers of two conjugated polymer components have already been proposed (US Pat. No.
• the invention is therefore based on the object to design a photovoltaic cell of the type described so that a further increase in the efficiency of energy conversion is possible.
• the invention solves this problem in that an electrically insulating transition layer with a thickness of at most 5 nm is provided at least between an electrode and the photoactive layer.
• the invention is based on the fact that in the transition region between the photoactive layer and the electrode there is a considerable resistance to charge carrier transfer, which is probably due to reactions between the metallic electrode and the organic photoactive layer. If these direct influences can therefore be prevented, an improvement in charge transfer must be expected under otherwise constant conditions, which leads to an increase in efficiency.
• electrically insulating transition layer By providing an electrically insulating transition layer, these immediate reactions between the photoactive layer and the electrode can now be largely eliminated, but the thickness of the electrically insulating transition layer must be limited to a maximum of 5 nm, so that the high electrical resistance of this transition layer does not facilitate the transfer of the charge carriers between Photoactive layer and electrode prevented.
• the barrier that otherwise occurs between the electrode and the photoactive layer can surprisingly be largely removed without additionally complicating the charge carrier transfer.
• this electrically insulating transition layer the efficiency of photovoltaic cells could be increased by up to 20 to 25% compared to cells of the same structure without this transition layer.
• an optimization of the electrically insulating transition layer is necessary. Such optimization can be done by reducing the thickness of the transition layer to at most 2 nm.
• the desired effect can also be influenced by the chemical layer structure.
• transition layers made of a salt in particular of an alkali halide, have proven successful, and particularly good properties have also been found with regard to processing with a transition layer made of a lithium fluoride, which is evaporated in vacuo onto the photoactive layer or the electrode in the desired layer thickness can be.
• Fig. 1 shows a photovoltaic cell according to the invention in a schematic section
• Fig. 2 shows the current-voltage characteristic of a conventional and a photovoltaic cell according to the invention.
• the photovoltaic cell according to FIG. 1 consists of a translucent glass substrate 1, on which an electrode layer 2 made of an indium / tin oxide (ITO) is applied.
• This electrode layer 2 generally has a comparatively rough surface structure, so that it is covered with a smoothing layer 3 made of a polymer which is electrically conductive by doping, usually PEDOT.
• the photoactive layer 4 comprising two components is applied to this smoothing layer 3 with a layer thickness of, for example, 100 nm to a few ⁇ m, depending on the application method.
• the photoactive layer 4 consists of a conjugated polymer, preferably a PPV derivative, as an electron donor and a fullerene, in particular functionalized fullerene PCBM, as an electron acceptor.
• polymer here means both high polymers and oligomers.
• the two components are mixed with a solvent and as a solution on the smoothing layer 3 z. B. applied by spin coating or dripping. Squeegee or printing processes can also be used to coat larger areas with such a photoactive layer 4.
• a fining agent such as chlorobenzene is preferably used as the solvent in order to ensure a fine structure of the heterogeneous layer 4 then has an average grain size smaller than 500 nm.
• the number of contact points between the electron donor and the electron acceptor can thus be increased considerably, which results in improved charge separation and an increase in efficiency to approximately 2.6% under simulated AM 1.5 conditions.
• a thin transition layer 6 is applied to the photoactive layer 4 with a layer thickness of, for example, 0.6 nm, which must have an electrically insulating effect.
• This transition layer in the exemplary embodiment of an alkali metal halide, namely a lithium fluoride, which is vapor-deposited in a vacuum of 2 x 10 "6 torr at a rate of 0.2 nm / min, wherein, however, due to the low layer thickness no continuous closed cover of the photoactive Layer 4 can be expected.
• the electron-collecting electrode When using ITO as a hole-collecting electrode, aluminum is used as the electron-collecting electrode, which is vapor-deposited onto the electrically insulating transition layer 6. Since the interposition of an electrically insulating transition layer 6 between the photoactive layer 4 and the electrode 5 largely prevents the reactions which interfere with the charge transfer between the photoactive layer 4 and the electrode 5 in the immediate border area between the electrode 5 and the active photo layer 4, Because the electrode 5 does not directly adjoin the photoactive layer 4 in large areas, the charge carrier transfer from the photoactive layer 4 to the electrode 5 is improved, provided that the transition layer 6 does not itself form an additional barrier between the photoactive layer 4 and the Electrode 5 builds up, which can be ensured by limiting the layer thickness of the transition layer 6.
• the electrical insulating properties of the transition layer 6 obviously prevent the effects that inhibit the transfer of charge carriers from becoming effective, particularly in the transition region from the photoactive layer 4 to the transition layer 6.
• the current density I is plotted against the voltage U at an excitation energy of 80 mW / cm 2 under simulated AM 1.5 conditions of two photovoltaic cells, which differ only in the presence of a transition layer 6 according to the invention .
• the invention is of course not limited to the illustrated embodiment, which shows the electrically insulating transition layer 6 between the electron-collecting electrode 5 and the photoactive layer 4.
• the electrically insulating transition layer 6 could also be provided between the hole-collecting electrode 2 and the organic layer adjoining it, in the exemplary embodiment the smoothing layer 3.
• the electrically insulating transition layer 6 could only be provided in the area of the electrode 2. Since the effect of the electrically insulating transition layer 6 is not limited to conjugated polymers as electron donors and fullerenes as electron acceptors, the effect according to the invention can also be observed in all photovoltaic cells with a molecular two-component layer composed of an electron donor and an electron acceptor.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Chemical & Material Sciences (AREA)
• Nanotechnology (AREA)
• Electromagnetism (AREA)
• Crystallography & Structural Chemistry (AREA)
• Mathematical Physics (AREA)
• Theoretical Computer Science (AREA)
• Composite Materials (AREA)
• Condensed Matter Physics & Semiconductors (AREA)
• General Physics & Mathematics (AREA)
• Materials Engineering (AREA)
• Photovoltaic Devices (AREA)
• Hybrid Cells (AREA)
• Electroluminescent Light Sources (AREA)

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• 2000
  • 2000-04-27 AT AT0073400A patent/AT411306B/de not_active IP Right Cessation
• 2001
  • 2001-04-27 EP EP01925188A patent/EP1284027A1/de not_active Ceased
  • 2001-04-27 US US10/258,708 patent/US6933436B2/en not_active Expired - Lifetime
  • 2001-04-27 WO PCT/AT2001/000129 patent/WO2001084645A1/de not_active Ceased
  • 2001-04-27 CN CN01808606A patent/CN1426607A/zh active Pending
  • 2001-04-27 AU AU2001252014A patent/AU2001252014A1/en not_active Abandoned
  • 2001-04-27 JP JP2001581357A patent/JP5517386B2/ja not_active Expired - Lifetime
• 2013
  • 2013-04-22 JP JP2013089574A patent/JP2013157633A/ja not_active Withdrawn

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