Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
  • H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
  • H01L31/042—PV modules or arrays of single PV cells
  • H01L31/05—Electrical interconnection means between PV cells inside the PV module, e.g. series connection of PV cells
  • H01L31/0504—Electrical interconnection means between PV cells inside the PV module, e.g. series connection of PV cells specially adapted for series or parallel connection of solar cells in a module
  • H01L31/0512—Electrical interconnection means between PV cells inside the PV module, e.g. series connection of PV cells specially adapted for series or parallel connection of solar cells in a module made of a particular material or composition of materials
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
  • H01L31/0248—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies
  • H01L31/036—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes
  • H01L31/0392—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes including thin films deposited on metallic or insulating substrates ; characterised by specific substrate materials or substrate features or by the presence of intermediate layers, e.g. barrier layers, on the substrate
  • H01L31/03921—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes including thin films deposited on metallic or insulating substrates ; characterised by specific substrate materials or substrate features or by the presence of intermediate layers, e.g. barrier layers, on the substrate including only elements of Group IV of the Periodic Table
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
  • H01L31/02—Details
  • H01L31/0224—Electrodes
  • H01L31/022408—Electrodes for devices characterised by at least one potential jump barrier or surface barrier
  • H01L31/022425—Electrodes for devices characterised by at least one potential jump barrier or surface barrier for solar cells
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
  • H01L31/02—Details
  • H01L31/0224—Electrodes
  • H01L31/022408—Electrodes for devices characterised by at least one potential jump barrier or surface barrier
  • H01L31/022425—Electrodes for devices characterised by at least one potential jump barrier or surface barrier for solar cells
  • H01L31/022433—Particular geometry of the grid contacts
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
  • H01L31/02—Details
  • H01L31/0224—Electrodes
  • H01L31/022466—Electrodes made of transparent conductive layers, e.g. TCO, ITO layers
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
  • H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
  • H01L31/042—PV modules or arrays of single PV cells
  • H01L31/0445—PV modules or arrays of single PV cells including thin film solar cells, e.g. single thin film a-Si, CIS or CdTe solar cells
  • H01L31/046—PV modules composed of a plurality of thin film solar cells deposited on the same substrate
  • H01L31/0465—PV modules composed of a plurality of thin film solar cells deposited on the same substrate comprising particular structures for the electrical interconnection of adjacent PV cells in the module
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
  • H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
  • H01L31/042—PV modules or arrays of single PV cells
  • H01L31/0445—PV modules or arrays of single PV cells including thin film solar cells, e.g. single thin film a-Si, CIS or CdTe solar cells
  • H01L31/046—PV modules composed of a plurality of thin film solar cells deposited on the same substrate
  • H01L31/0468—PV modules composed of a plurality of thin film solar cells deposited on the same substrate comprising specific means for obtaining partial light transmission through the module, e.g. partially transparent thin film solar modules for windows
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
  • H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
  • H01L31/06—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices characterised by potential barriers
  • H01L31/075—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices characterised by potential barriers the potential barriers being only of the PIN type, e.g. amorphous silicon PIN 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
  • 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
  • Y02E10/548—Amorphous silicon PV cells

Definitions

• TITLE Semi-transparent thin-film photovoltaic device with optimized metal / native oxide / metal electrical contact
• the present invention relates to a semi-transparent photovoltaic device in thin layers optimizing the resumption of metal / native oxide / metal contact by dimensioning the contact surface of the second deposited metal.
• a photovoltaic device designates any type of photovoltaic cells or modules.
• Photovoltaic modules are composed of a plurality of photovoltaic cells all connected together according to a series, parallel, parallel series or parallel series architecture.
• a thin-film photovoltaic device refers to photovoltaic devices made up of a stack of thin layers with a thickness of less than 20 ⁇ m (excluding substrate).
• This thin layer of native oxide a few nanometers thick is most often electrically insulating. This is particularly the case for aluminum and copper oxides.
• the stack consisting of the metal electrode A, its oxide and the conductor B does not have an improved conductivity as expected by the posterior thickening of the metal electrode because the electrical contact resistance between the two metals is very important, due to the presence between the two metals of the native oxide.
• the same phenomenon is observed when one seeks to put in series or in parallel a posteriori several photovoltaic cells in order to control the voltage and current levels at the output of the photovoltaic modules.
• Semi-transparent thin-film photovoltaic devices (based on amorphous silicon for example) are composed of:
• Photovoltaic zones can be of any shape.
• the critical dimension of said shape is the smallest of the sizes which characterize it. It is for example a side for a square, the width for a rectangle, the height for a triangle.
• the critical dimension CD corresponds to the width of said strip.
• metal / metal type contact resumptions are necessary in order to connect the electrically active zones to the collection and connect the unit cells together (in series and / or parallel) in order to obtain a photovoltaic module.
• the problem of resumption of metal / metal contact is reinforced in the case of semi-transparent photovoltaic devices, because contact resumption is carried out on surfaces whose widest sides do not exceed a few tens of micrometers, thus generating surfaces contact recovery of a few hundred square micrometers.
• the metal electrode is aluminum, its native oxide (alumina) can have a thickness of 3 nm to 6 nm.
• alumina aluminum
• the combination of this material with a contact surface of just a few hundred square micrometers gives precarious electrical contact, which results in a degradation of the electrical efficiency of the device.
• a first solution consists in removing the layer of alumina which has formed on its surface before the deposition of the second metal allowing the resumption of contact. It is possible, for example, to use plasma etching, and to deposit the second metal immediately afterwards without having broken the vacuum conditions between the etching step and that of the metallic deposition. This step requires deposition equipment having a plasma module in the deposition chamber or in an annex chamber. This configuration may not be available in production equipment, in which case the investment to upgrade them may be substantial.
• the present invention seeks to solve the problem of optimizing the recovery of metal / metal contact by considering the case of the use of aluminum and the presence of its native oxide within semi-transparent photovoltaic devices.
• the object of the invention is to propose a semi-transparent photovoltaic device in thin layers, the metal / metal oxide / metal contact recovery surface has been optimized in order to increase the electrical performance of said photovoltaic device.
• the invention applies to a semi-transparent photovoltaic device with thin layers comprising at least:
• a front electrode made of an electrically conductive and transparent material, disposed on the transparent substrate; o an absorber composed of one or more thin photo-active layer (s);
• a rear electrode consisting of a stack of at least:
• CDT areas of transparency of critical dimension denoted CDT separating at least two active photovoltaic areas
• the skilled person would use a Ra ratio of the order of 0.02%.
• the electrical optimization of contact resumption is not achieved.
• the invention provides that a ratio Ra of between 0.2% and 2% must be used, i.e. 0.2% ⁇ Ra ⁇ 2%.
• the subject of the invention is therefore a semi-transparent photovoltaic device with thin layers comprising at least:
• a front electrode made of an electrically conductive and transparent material, disposed on the transparent substrate; o an absorber composed of one or more thin photo-active layer (s);
• a rear electrode consisting of a stack of at least: o a metallic conductive layer;
• a metallic contact recovery layer having a contact surface S with the rear electrode
• the ratio Ra is between 1.2% and 1.6%, i.e. 1.6% ⁇ Ra ⁇ 1.8%.
• the metallic conductive layer is made of aluminum and its native oxide is therefore alumina.
• the metallic contact recovery layer is made of aluminum.
• the contact surface of the metallic contact recovery layer can be of any shape. It can also be composed of several patterns of any shape, all electrically linked together.
• the active photovoltaic zones are strips of length L5 and of critical dimension CD5.
• the contact surface S between the metallic contact recovery layer and the rear electrode is of rectangular shape whose width, ie the critical dimension CD is less than the critical dimension CD5 of the photovoltaic zones.
• FIG IA is a sectional view of a photovoltaic stack in thin layers.
• FIG IB is a top view of the photovoltaic stack of [Fig IA] in which several thin layers have been etched in places to form transparency zones and active photovoltaic zones.
• FIG IC is a top view of the photovoltaic device of [Fig IB] to which have been added the metallic contact recovery zones according to the invention.
• FIG 1D is a sectional view along the direction X of [Fig IC].
• FIG 1E is a sectional view from [Fig 1D] to which the insulation layer has been added.
• FIG 1F is a sectional view from [Fig 1E] to which the metallic contact recovery layers have been added.
• FIG 2A is a diagram of a part of semi-transparent photovoltaic cell according to the invention.
• FIG 2B represents the evolution of the total electrical resistance R of photovoltaic devices with the same intrinsic characteristics as a function of the length L of the rectangular contact surface.
• FIG 3A and FIG 3B are diagrams of photovoltaic cells similar to [Fig 2A] and corresponding to other embodiments of the invention.
• FIG 3C illustrates an embodiment of a photovoltaic cell not in accordance with the invention.
• FIG IA is a sectional view of a photovoltaic stack known from the state of the art.
• the stack is made up:
• a front electrode (2) formed of a transparent conductive oxide, for example zinc oxide doped with aluminum (ZnO: AI); - an absorber (3) composed of several layers based on amorphous silicon (a_Si) forming a pin junction;
• the first step of this process consists in making the transparency zones (6T) and in electrically isolating the collection buses (7 +, 7-) by isolation zones (6i).
• the transparency and insulation zones (6T and 6i) are produced by successive etchings of the thin layers forming the rear electrode, the absorber and the front electrode.
• FIG IB is a top view of semi-transparent photovoltaic cells whose transparency zones (6T) have the form of horizontal bands parallel to each other and separating in pairs the active photovoltaic zones (5) opaque of critical size CDs (corresponding here to their width) and of length L 5 .
• the surface S 5 of the photovoltaic strip is therefore equal to the product of the critical dimension CD 5 by the length L 5 .
• the vertical opaque bands are the collection buses (7 + and 7) electrically isolated from the active photovoltaic zones (5).
• the collection buses (7 + respectively 7) have a critical dimension denoted CD + ' respectively CD-.
• the transparency zones (6T) electrically isolate the active photovoltaic strips (5), each of said strips forming unitary photovoltaic cells.
• the transparency zones (6T) have a critical dimension denoted CDT.
• Step 1 Within the active photovoltaic zones (5) are engraved contact recovery zones of the VIA type (8). An active photovoltaic zone (4A) near the collection bus (7) is left without VIA. It is precisely within this zone that contact is made between the rear electrode (4) and the metal layer (14), the dimensioning of which is the subject of the invention.
• FIG 1D is a sectional view of [Fig IC] in direction X where the contact recovery areas of VIA type (8) and the active photovoltaic area (4A) appear near the collection bus (7 ) left without VIA.
• Step 2 An electrical insulation layer (9) is introduced to electrically isolate the front electrode (2) from the rear electrode (4).
• FIG 1E is a sectional view from [Fig 1D] to which the insulation layer (9) has been added.
• This electrical insulation layer is for example a transparent, permanent and photosensitive resin.
• Rear contact resumption zones (4B) are left vacant within the active photovoltaic zones (4A) available for contact resumption of the rear electrode in order to effect contact resumption on the metal (4).
• Step 3 A metallic contact recovery layer is then deposited and etched. It is then split into two distinct zones (18 and 14) as shown in [Fig 1F]. It can be engraved for example, thanks to a new photolithography step, to connect the front electrode (2) to the collection bus (7 + ) and the rear electrode (4) to the collection bus (7), and this in order to make the semi-transparent photovoltaic module functional.
• the invention aims to improve the resumption of contact between the rear electrode (4) and the collection bus (7) by optimizing the contact area S between the rear electrode (4) and the metallic contact resumption layer ( 14).
• the total surface of said devices is 2.5 cm by 2.5 cm, or 6.26 cm 2 with an area ratio of the transparency zones of 50%.
• These devices include:
• a front electrode (2) consisting of zinc oxide doped with aluminum (ZnO: AI);
• An absorber (3) essentially composed of amorphous silicon (a_Si);
• the theoretical total electrical resistance was calculated from a modeling of the resistances of the different materials that make up said devices, known to those skilled in the art. Also, the interface resistances, including the metal / native oxide / metal contact resistance, are not taken into account in this calculation.
• the theoretical total electrical resistance RTH is estimated at 120 W.
• Current-voltage (IV) measurements made it possible to determine the actual values of the total electrical resistances of each device.
• Curve 9 TM in [Fig 2B] represents the evolution of the theoretical total electrical resistance RTH as a function of length L. Curve 9 TM is actually a horizontal line which means that the contact resistance does not depend on the length L and is negligible compared to the resistance of the different materials that make up the device, in accordance with the state of the art.
• Curve 9 of [Fig 2B] represents the evolution of the total electrical resistance R of the devices produced as a function of the length L. Surprisingly, said curve exhibits an exponential type decrease as a function of the length L. For a length of 80 pm, the overall electrical resistance is 2500 W, or about 20 times greater than the theoretical total electrical resistance estimated at 120 W for these devices. The greater the length L, the lower the total electrical resistance R. The shape of the curve tends towards a horizontal asymptote around 150 W. The difference of 30 W with the theoretical value can be explained by errors of the estimation of resistivities and thicknesses of materials, and / or not taking into account interface resistances.
• the contact surface can take any shape.
• patterns different from those represented in [Fig 2A] can be chosen to solve problems of definition of patterns for lithography or engraving for example.
• An example is presented in [Fig 3A].
• the contact surface is then formed by small rectangles of the same size as the VIAs, electrically connected to each other.
• all the continuous shapes can be suitable to meet the criteria of the invention, even a heart-shaped pattern as proposed in [Fig 3B].
• the optimization of the contact surface is only carried out if all of the different parts of said surface are in electrical contact.
• the surface S is composed of the surfaces Si + S 2 .
• this arrangement therefore does not allow optimization according to the invention.

Landscapes

• Engineering & Computer Science (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Physics & Mathematics (AREA)
• Condensed Matter Physics & Semiconductors (AREA)
• Electromagnetism (AREA)
• General Physics & Mathematics (AREA)
• Computer Hardware Design (AREA)
• Power Engineering (AREA)
• Sustainable Development (AREA)
• Life Sciences & Earth Sciences (AREA)
• Sustainable Energy (AREA)
• Chemical & Material Sciences (AREA)
• Crystallography & Structural Chemistry (AREA)
• Photovoltaic Devices (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=65685405

Family Applications (1)

Country Status (4)

Families Citing this family (1)

Family Cites Families (4)

• 2018
  • 2018-10-26 FR FR1801136A patent/FR3087940B1/fr active Active
• 2019
  • 2019-10-25 WO PCT/IB2019/059164 patent/WO2020084582A1/fr unknown
  • 2019-10-25 EP EP19795358.1A patent/EP3871271A1/de active Pending
• 2021
  • 2021-04-23 US US17/238,891 patent/US20210242359A1/en not_active Abandoned

Also Published As

Similar Documents

Legal Events