EP4046205A1 - Transparent passivated contacts for si solar cells - Google Patents

Transparent passivated contacts for si solar cells

Info

Publication number
EP4046205A1
EP4046205A1 EP20792762.5A EP20792762A EP4046205A1 EP 4046205 A1 EP4046205 A1 EP 4046205A1 EP 20792762 A EP20792762 A EP 20792762A EP 4046205 A1 EP4046205 A1 EP 4046205A1
Authority
EP
European Patent Office
Prior art keywords
layer
solar cell
doped
cell according
layers
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.)
Pending
Application number
EP20792762.5A
Other languages
German (de)
French (fr)
Inventor
Paul Alejandro PROCEL MOYA
Guangtao YANG
Luana MAZZARELLA
Olindo ISABELLA
Miroslav Zeman
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.)
Technische Universiteit Delft
Original Assignee
Technische Universiteit Delft
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 Technische Universiteit Delft filed Critical Technische Universiteit Delft
Publication of EP4046205A1 publication Critical patent/EP4046205A1/en
Pending legal-status Critical Current

Links

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
    • H01L31/02—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
    • H01L31/06—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
    • H01L31/072—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 PN heterojunction type
    • 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

Definitions

  • the present invention is in the field of a process for making solar cells, or photovoltaic (PV) cell, with transparent con tacts based on a contact stack of three layers, and solar cells with transparent contacts, typically front and/or rear contacted solar cells.
  • Said solar cells comprise at least one hetero junc tion and optionally two hetero junctions.
  • a solar cell, or photovoltaic (PV) cell is an electrical de vice that converts energy of light, typically sun light (hence “solar”), directly into electricity by the so-called photovol taic effect.
  • the solar cell may be considered a photoelectric cell, having electrical characteristics, such as current, volt age, resistance, and fill factor, which vary when exposed to light and which vary from type of cell to type.
  • Solar cells are described as being photovoltaic irrespective of whether the source is sunlight or an artificial light. They may also be used as photo detector.
  • a solar cell When a solar cell absorbs light it may generate either elec tron-hole pairs or excitons.
  • charge carriers of opposite types are separated.
  • the separated charge carriers are "extracted" to an external cir cuit, typically providing a DC-current.
  • a DC- current may be transformed into an AC-current, e.g. by using a transformer .
  • solar cells are grouped into an array of elements.
  • Various elements may form a panel, and various panels may form a system.
  • Wafer based c-Si solar cells contribute to more than 90% of the total PV market. According to recent predictions, this trend will remain for the upcoming years towards 2020 and many years beyond. Due to their simplified process, conventional c-Si solar cells dominate a large part of the market. As alternative to the industry to improve the power to cost ratio, the silicon heterojunction approach has become increasingly attractive for PV industry, even though the relatively complicated process to deploy the proper front layers, such as a thermal conductive ox ide (TCO) and an inherent low thermal budget of the cells limiting usage of existing production lines and thus result in a negligible market share so far.
  • TCO thermal conductive ox ide
  • a heterojunction is the inter face that occurs between two layers or regions of dissimilar crystalline semiconductors.
  • a homojunction relates to a semiconductor interface formed by typically two layers of similar semiconductor material, wherein these semicon ductor materials have equal band gaps and typically have a dif ferent doping (either in concentration, in type, or both).
  • a common example is a homojunction at the interface between an n- type layer and a p-type layer, which is referred to as a p-n junction.
  • advanced techniques are used to precisely control a deposition thickness of layers involved and to create a lattice-matched abrupt interface.
  • Three types of heterojunctions can be distinguished, a straddling gap, a stag gered gap, and a broken gap.
  • a disadvantage of solar cells is that the conversion per se is not very efficient, typically, for Si-solar cells, limited to some 20%. Theoretically a single p-n junction crystalline sili con device has a maximum power efficiency of 33.7%. An infinite number of layers may reach a maximum power efficiency of 86%.
  • the highest ratio achieved for a solar cell per se at present is about 44%.
  • the record is about 25.6%.
  • the front contacts may be moved to a rear or back side, eliminating shaded areas.
  • thin silicon films were applied to the wafer.
  • Solar cells also suffer from various imperfections, such as recombination losses, reflectance losses, heating during use, thermodynamic losses, shadow, internal resistance, such as shunt and series resistance, leakage, etc.
  • a qualification of performance of a solar cell is the fill factor (FF).
  • the fill factor may be de fined as a ratio of an actual maximum obtainable power to the product of the open circuit voltage and short circuit current.
  • a typical advanced commercial solar cell has a fill fac tor > 0.75, whereas less advanced cells have a fill factor be tween 0.4 and 0.7.
  • Cells with a high fill factor typically have a low equivalent series resistance and a high equivalent shunt resistance; in other words less internal losses occur. Efficiency is nevertheless improving gradually, so every rela tively small improvement is welcomed and of significant im portance.
  • a design of contacts may be complex or complex to manufacture, and manufacture thereof may involve surplus of ma terial.
  • solar cells with full area passivating contacts for both po larizations are now attracting industry interest.
  • the solar cells featuring passivating contacts are designed to de couple the carrier collection via deposited layers that can in Jerusalem absorber bulk carrier separation by themselves (SHJ case) or with the support of doping region (poly-Si alloys).
  • doped deposited layers perform as charge collecting layer. If the layer is not conductive enough, the structure de mands the use of TCO to support the lateral transport of the charge.
  • Doped layers unfortunately limit the amount of generated carriers by increasing parasitic absorption losses.
  • the use of different materials and interfaces make the fabrica tion process more complex and sensitive to variability.
  • US 2015/122329 A1 recites a photovoltaic device including a single junction solar cell provided by an absorption layer of a type IV semiconductor mate rial having a first conductivity, and an emitter layer of a type III-V semiconductor material having a second conductivity, wherein the type III-V semiconductor material has a thickness that is no greater than 50 nm.
  • WO 2018/108403 A2 recites a solar cell comprising a heterojunction photoelectric device comprising, a front electrode layer, a back electrode layer comprising a metallic contact layer, a light-absorbing silicon layer ar ranged between said front electrode and said back electrode lay ers and a doped silicon-based layer arranged between said light absorbing silicon layer and said back electrode layer, charac terized in that said heterojunction photoelectric device further comprises a wide band gap material layer having an electronic band gap greater than 1.4eV, said wide band gap material layer being applied on a surface of the light- absorbing silicon layer between said light-absorbing silicon layer and said doped sili con-based layer.
  • the present heterojunction layer or stack of layers is compatible with thermal annealing and firing processes at T above 600 °C.
  • the present invention relates to an increased efficiency het- ero junction solar cell and various aspects thereof and a sim plified process for manufacturing the solar cell which overcomes one or more of the above disadvantages, without jeopardizing functionality and advantages.
  • the present invention relates in a first aspect to a front and/or rear contacted solar cell according to claim 1, and in a second aspect to a process for making such a solar cell accord ing to claim 25.
  • ref erence can be made to WO2019/066648 Al, which publication and its contents are incorporated by reference.
  • the present stack combines a high conductivity and high transparency for carrier selective contacts. It combines highly doped regions with donors or acceptors, typically close to a silicon bulk interface, a thin passivation layer, and a transparent conductive oxide (TCO) layer, with a contact, typically a metal contact.
  • TCO transparent conductive oxide
  • the transpar ent conductive oxide layer (21) has a thickness of > 25 nm, preferably > 40 nm, such as 50-100 nm, a carrier concentration of >5*10 19 /cm 3 , preferably >8*10 19 /cm 3 , more preferably >l*10 2 °/cm 3 , such as >2*10 20 /cm 3 , and preferably ⁇ l*10 21 /cm 3 .
  • the contact stack has three layers 21,22,23, the stack comprising a transparent conductive oxide layer 21 in contact with a chemical dielectric passivation layer 22, the chemical dielectric pas sivation layer in contact with a field passivation layer and/or field passivation region 23.
  • a cost-effective TCO is enough to support charge collection.
  • the present invention provides a simplified fabrication process wherein solar cell precursors can be fin ished within a couple of steps, and which is a low cost and high throughput process, using compatible industrial standard metallization steps, solar cells featuring a high V oc (>710 mV) due to the full passivated contacts, solar cells featur ing a high J sc (> 39 mA/cm 2 ) & V oc ( >710 mV)due to the high transparency of the passivating contacts, solar cells featur ing a relatively high fill factor (FF) (>79%) due to improved transport inside a bulk, such as c-Si, and wherein the design is applicable to both a front/rear contacted conventional so lar cell architecture, a bifacial solar cell architecture and for both n-type and p-type bulk material.
  • FF fill factor
  • the present invention relates in a first aspect to front and/or rear contacted solar cell according to claim 1, and in a second aspect to a process for making such a solar cell according to claim 26.
  • the field passivation layer or region may have a ⁇ 400 meV activation energy, such as ⁇ 300 meV, and is preferably a continuous layer (apart from possible contacts).
  • the field passivation material may be selected from a doped sub-re gion, such as by adding an acceptor or donor, such as by implan tation, and diffusion, from a supra-region, such as layers, which may be in-situ or ex-situ doped, wherein layers are pro vided by Epitaxial growth, Poly-Si alloys deposition, PECVD, and LT PECVD.
  • a dopant concentration of the field passivation layer may be >5*10 19 /cm 3 , preferably >8*10 19 /cm 3 , more preferably >l*10 2 °/cm 3 , such as >2*10 20 /cm 3
  • a junction depth may be ⁇ 200 pm, preferably 10-100 pm
  • a thickness may be ⁇ 500 nm, preferably 50- 200 nm, and combinations thereof.
  • the chemical passivation layer may comprise a wide band gap mate rial.
  • the chemical passivation layer material may be a-SiH, wherein a-SiH may comprise N, C, or 0, SiO x , Si x N y , A10 x , HfO x .
  • the chemical passivation layer may have a thickness of 0.1-20 nm, such as 0.2-10 nm, and combinations thereof, and is preferably a continuous layer (apart from possible contacts).
  • the bulk substrate material may be selected from Micro-crystalline Silicon, Multi-crystalline Silicon, Czochralski Silicon, Float ing zone Silicon, Epitaxial Silicon, Ribbon Silicon, Liquid phase Silicon.
  • the bulk substrate may be selected from n-type, p-type, intrinsic, and combinations thereof.
  • the solar cell may be an IBC solar cell, and wherein the solar cell may comprise an n-doped field passivation region and a p-doped field passivation region at one side of the solar cell.
  • the solar cell may be a front- and rear-contacted solar cell, and may comprise a stack of three layers at the front and at the rear.
  • the solar cell may be a bifacial solar cell, and wherein at the front the field passivation region may comprise n-type dopants and wherein at the back the field passivation region may com prise p-type dopants.
  • the transparent conductive oxide may selected from zinc oxide, in dium oxide, tin oxide, cadmium oxide, gallium oxide, doped ox ides, such as doped with F, and combinations thereof.
  • At least one contact may comprise a stack of layers, which stack comprises a first layer of > 10 nm thickness, such as an n- doped or p-doped poly SiOx layer, a second layer of 100 nm-5000 nm thickness, such as a n-doped or p-doped crystalline Si layer , wherein the first and layer are both p-doped or are both n- doped, and in between said layers a dielectric barrier layer (15) of thickness of 0 ⁇ tdiei ⁇ 2.5 nm, wherein said layers cover one and another, wherein the ratio of doping of first layer /second layer at the dielectric barrier layer is > 2, preferably > 5, more preferably > 10, even more preferably > 10 2 .
  • the contact stack 18b,18f may be a carrier selective passivating contact .
  • the contact 18b,18f may be transparent.
  • the present solar cell may com prise a single sided or double sided textured substrate 10.
  • the present solar cell may com prise a 5*10 14 -0.5*10 19 dopants/cm 3 n- or p-type doped crystalline Si layer , wherein a doping concentration is preferably spa tially constant, wherein n-type dopants may be selected from P, As, Bi, Sb and Li, and wherein p-type dopants may be selected from B, Ga, and In.
  • the present solar cell may com prise a dielectric passivation layer or dielectric passivation stack on the cell.
  • the present solar cell may com prise a 10 14 —10 17 dopants/cm 3 n- or p-type doped substrate 10.
  • the present solar cell may com prise at least one of a metal layer on a back side 18b, metal contacts on a front side 18f and/or on a back side 18b, and a transparent conductive layer.
  • the present solar cell may com prise at least one dielectric barrier layer each independently of thickness of 0.1 nm-1.4 nm, wherein the dielectric barrier layer independently may comprise at least one material selected from SiCb, HfCt, and W 2 O 5 .
  • the material of the transparent conductive layer may be selected from ITO, IOH, ZnO or doped ZnO, and IWO.
  • a thickness of the transparent conductive layer may be ⁇ 100 nm, such as 10-40 nm.
  • the refractive index of the transparent conductive layer may be ⁇ 2.2.
  • the layer such as the n-doped or p-doped poly SiOx layer
  • the layer such as the n-doped or p-doped crystalline Si layer
  • the dielectric barrier layer may be each independently in full contact with one and another over an area of >50% of a surface of the largest of two contacting sur faces.
  • the present solar cell may com prise at least one textured surface , wherein the textured sur face may have an aspect ratio height:depth of a textured struc ture of 2-10.
  • the present solar cell may have n-doped or p-doped poly SiOx layer independently of 10 nm- 5000 nm thickness, and may comprise 1*10 19 -5*10 22 n- or p-type dopants/cm 3 , wherein a doping profile is preferably substantially constant over the thickness of the layer , wherein n-type do pants may be selected from P, As, Bi, Sb and Li, and wherein p-type dopants may be selected from B, Ga, and In.
  • the present solar cell may comprise at least one dielectric layer each independently of thickness of 10 nm-2000 nm, wherein the dielectric layer inde pendently may comprise at least one material selected from SiN x , AIOc, SiO x , a n-type or p-type doped or un-doped transparent con ductive oxide.
  • the metal of the metal layers 18b and metal contacts 18f inde pendent may comprise at least one of Cu, Al, W, Ti, Ni, and Ag, wherein a thickness of said metal 18b,18f may be 200-5000 nm.
  • the n- doped or p-doped poly SiOx layer may be provided by PECVD, or LPCVD, wherein dopants may be constantly provided during deposi tion.
  • metal contacts and/or metal layers 18b,18f may be provided by metal deposition and lift off of non-contact areas, screen printing, and electrical plating.
  • dopants in the poly SiOx layer may be activated.
  • Figures 1-5 show a schematic representation of examples of the present solar cell.
  • Figures 1-5 show the present a contact stack of three layers 21,22,23 encircled.
  • Figure 1 shows a contact stack with Si based bulk 10, a field passivation region 23, a chemical passivation layer 22, a TCO 21, and a metal contact 18b or 18f.
  • Figure 2 shows a front and rear contacted, monofacial, solar cell with bulk silicon 10, with two stacks with a field pas sivation region 23, a chemical passivation layer 22, a TCO 21, and a metal contact 18b or 18f, at either side.
  • Figure 3 shows an IBC monofacial solar cell with bulk silicon 10, with two stacks (left and right) with a field passivation region 23, a chemical passivation layer 22, a TCO 21, and a metal contact 18b, at either side, wherein the right field pas sivation region 23p is positively charged and wherein the left field passivation region 23n is negatively charged. Further an antireflective coating layer 19 is provided.
  • Figure 4 shows an IBC bifacial solar cell with bulk silicon 10, with two stacks (left and right) with a field passivation region 23, a chemical passivation layer 22, a TCO 21, and a metal contact 18b, at either side, wherein the right field pas sivation region 23p is positively charged and wherein the left field passivation region 23n is negatively charged. Further an antireflective coating layer 19 is provided.
  • Figure 5 shows a front and rear contacted, bifacial, solar cell with bulk silicon 10, with two stacks with a field pas sivation region 23, a chemical passivation layer 22, a TCO 21, and a metal contact 18b or 18f, at either side, wherein the top field passivation region 23p is positively charged and wherein the bottom field passivation region 23n is negatively charged.
  • results of the present solar cells are found to be good. For instance, an excellent surface passivation is achieved.
  • the V oc and fill factor FF of the cells are found to be sensitive to the transparent conductive oxide application process.
  • the p-type solar cell Jo of 23 fA/cm 2 and implied V 0c as high as 700 mV is obtained.
  • the calculated solar cell pre sents an efficiency of 24%, a FF up to 83.5%, and J Sc up to 41 mA/cm 2 with a double side textured surface.

Landscapes

  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Electromagnetism (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Photovoltaic Devices (AREA)

Abstract

The present invention is in the field of a process for making solar cells, or photovoltaic (PV) cell, with transparent contacts based on a contact stack of three layers, and solar cells with transparent contacts, typically front and/or rear contacted solar cells. Said solar cells comprise at least one hetero junction and optionally two hetero junctions.

Description

Transparent passivated contacts for Si solar cells
FIELD OF THE INVENTION
The present invention is in the field of a process for making solar cells, or photovoltaic (PV) cell, with transparent con tacts based on a contact stack of three layers, and solar cells with transparent contacts, typically front and/or rear contacted solar cells. Said solar cells comprise at least one hetero junc tion and optionally two hetero junctions.
BACKGROUND OF THE INVENTION
A solar cell, or photovoltaic (PV) cell, is an electrical de vice that converts energy of light, typically sun light (hence "solar"), directly into electricity by the so-called photovol taic effect. The solar cell may be considered a photoelectric cell, having electrical characteristics, such as current, volt age, resistance, and fill factor, which vary when exposed to light and which vary from type of cell to type.
Solar cells are described as being photovoltaic irrespective of whether the source is sunlight or an artificial light. They may also be used as photo detector.
When a solar cell absorbs light it may generate either elec tron-hole pairs or excitons. In order to obtain an electrical current charge carriers of opposite types are separated. The separated charge carriers are "extracted" to an external cir cuit, typically providing a DC-current. For practical use a DC- current may be transformed into an AC-current, e.g. by using a transformer .
Typically solar cells are grouped into an array of elements. Various elements may form a panel, and various panels may form a system.
Wafer based c-Si solar cells contribute to more than 90% of the total PV market. According to recent predictions, this trend will remain for the upcoming years towards 2020 and many years beyond. Due to their simplified process, conventional c-Si solar cells dominate a large part of the market. As alternative to the industry to improve the power to cost ratio, the silicon heterojunction approach has become increasingly attractive for PV industry, even though the relatively complicated process to deploy the proper front layers, such as a thermal conductive ox ide (TCO) and an inherent low thermal budget of the cells limiting usage of existing production lines and thus result in a negligible market share so far. A heterojunction is the inter face that occurs between two layers or regions of dissimilar crystalline semiconductors. These semiconducting materials have unequal band gaps as opposed to a homojunction. A homojunction relates to a semiconductor interface formed by typically two layers of similar semiconductor material, wherein these semicon ductor materials have equal band gaps and typically have a dif ferent doping (either in concentration, in type, or both). A common example is a homojunction at the interface between an n- type layer and a p-type layer, which is referred to as a p-n junction. In heterojunctions advanced techniques are used to precisely control a deposition thickness of layers involved and to create a lattice-matched abrupt interface. Three types of heterojunctions can be distinguished, a straddling gap, a stag gered gap, and a broken gap.
A disadvantage of solar cells is that the conversion per se is not very efficient, typically, for Si-solar cells, limited to some 20%. Theoretically a single p-n junction crystalline sili con device has a maximum power efficiency of 33.7%. An infinite number of layers may reach a maximum power efficiency of 86%.
The highest ratio achieved for a solar cell per se at present is about 44%. For commercial silicon solar cells the record is about 25.6%. In view of efficiency the front contacts may be moved to a rear or back side, eliminating shaded areas. In addi tion thin silicon films were applied to the wafer. Solar cells also suffer from various imperfections, such as recombination losses, reflectance losses, heating during use, thermodynamic losses, shadow, internal resistance, such as shunt and series resistance, leakage, etc. A qualification of performance of a solar cell is the fill factor (FF). The fill factor may be de fined as a ratio of an actual maximum obtainable power to the product of the open circuit voltage and short circuit current.
It is considered to be a key parameter in evaluating perfor mance. A typical advanced commercial solar cell has a fill fac tor > 0.75, whereas less advanced cells have a fill factor be tween 0.4 and 0.7. Cells with a high fill factor typically have a low equivalent series resistance and a high equivalent shunt resistance; in other words less internal losses occur. Efficiency is nevertheless improving gradually, so every rela tively small improvement is welcomed and of significant im portance.
Typically a design of contacts may be complex or complex to manufacture, and manufacture thereof may involve surplus of ma terial.
Solar cells with full area passivating contacts for both po larizations are now attracting industry interest. Commonly, the solar cells featuring passivating contacts are designed to de couple the carrier collection via deposited layers that can in duce absorber bulk carrier separation by themselves (SHJ case) or with the support of doping region (poly-Si alloys). In both cases, doped deposited layers perform as charge collecting layer. If the layer is not conductive enough, the structure de mands the use of TCO to support the lateral transport of the charge. Doped layers unfortunately limit the amount of generated carriers by increasing parasitic absorption losses. Moreover, the use of different materials and interfaces make the fabrica tion process more complex and sensitive to variability.
Some documents may be referred to. US 2015/122329 A1 recites a photovoltaic device including a single junction solar cell provided by an absorption layer of a type IV semiconductor mate rial having a first conductivity, and an emitter layer of a type III-V semiconductor material having a second conductivity, wherein the type III-V semiconductor material has a thickness that is no greater than 50 nm. WO 2018/108403 A2 recites a solar cell comprising a heterojunction photoelectric device compris ing, a front electrode layer, a back electrode layer comprising a metallic contact layer, a light-absorbing silicon layer ar ranged between said front electrode and said back electrode lay ers and a doped silicon-based layer arranged between said light absorbing silicon layer and said back electrode layer, charac terized in that said heterojunction photoelectric device further comprises a wide band gap material layer having an electronic band gap greater than 1.4eV, said wide band gap material layer being applied on a surface of the light- absorbing silicon layer between said light-absorbing silicon layer and said doped sili con-based layer. The present heterojunction layer or stack of layers is compatible with thermal annealing and firing processes at T above 600 °C.
The present invention relates to an increased efficiency het- ero junction solar cell and various aspects thereof and a sim plified process for manufacturing the solar cell which overcomes one or more of the above disadvantages, without jeopardizing functionality and advantages.
SUMMARY OF THE INVENTION
The present invention relates in a first aspect to a front and/or rear contacted solar cell according to claim 1, and in a second aspect to a process for making such a solar cell accord ing to claim 25. For some aspects of the present invention ref erence can be made to WO2019/066648 Al, which publication and its contents are incorporated by reference. The present stack combines a high conductivity and high transparency for carrier selective contacts. It combines highly doped regions with donors or acceptors, typically close to a silicon bulk interface, a thin passivation layer, and a transparent conductive oxide (TCO) layer, with a contact, typically a metal contact. The transpar ent conductive oxide layer (21) has a thickness of > 25 nm, preferably > 40 nm, such as 50-100 nm, a carrier concentration of >5*1019/cm3, preferably >8*1019/cm3, more preferably >l*102°/cm3, such as >2*1020/cm3, and preferably <l*1021/cm3. The contact stack has three layers 21,22,23, the stack comprising a transparent conductive oxide layer 21 in contact with a chemical dielectric passivation layer 22, the chemical dielectric pas sivation layer in contact with a field passivation layer and/or field passivation region 23.
In the present invention, to simplify the process of solar cell fabrication, a novel and yet simple approach is disclosed for high transparent passivating contacts. Such an approach uses only TCO layer on top of a passivating layer capping a silicon absorber bulk with p+ and n+ regions at the interface. Main ad vantages of invention are:
(1) A simplified fabrication process: (i) solar cell precursors featuring highly doped regions (field passivation region) on standard processes, (ii) low cost, high throughput, and indus trial standard metallization steps are applicable to the present solar cell process.
(2) Solar cells featuring high Voc are obtained, due to the full passivated contacts.
(3) Solar cells are obtained featuring high Jsc & Voc due to the high transparency of the passivating contacts.
(4) Solar cells are obtained featuring a relatively high fill factor (FF) due to the direct carrier collection supported on high conductivity of TCO.
(5) The materials and approach for increasing the cell FF (ad vantage (4)) are feasible for both front/rear contacted prior art solar cell architecture and also bifacial solar cell archi tecture.
(6) FF and Voc are found to be almost insensitive to metalliza tion, as TCO layers are found to perform as efficient carrier collection, through only one interface.
(7) For bi-facial solar cells no efficiency degradation is expe rienced (advantage (6)), thus exhibiting a high bi-faciality factor, such as above 95%.
(8) A cost-effective TCO is enough to support charge collection.
(9) for IBC solar cells, the process flow is simplified.
In summary the present invention provides a simplified fabrication process wherein solar cell precursors can be fin ished within a couple of steps, and which is a low cost and high throughput process, using compatible industrial standard metallization steps, solar cells featuring a high Voc (>710 mV) due to the full passivated contacts, solar cells featur ing a high Jsc (> 39 mA/cm2) & Voc (>710 mV)due to the high transparency of the passivating contacts, solar cells featur ing a relatively high fill factor (FF) (>79%) due to improved transport inside a bulk, such as c-Si, and wherein the design is applicable to both a front/rear contacted conventional so lar cell architecture, a bifacial solar cell architecture and for both n-type and p-type bulk material.
Thereby the present invention provides a solution to one or more of the above mentioned problems.
Advantages of the present description are detailed throughout the description. References to the figures are not limiting, and are only intended to guide the person skilled in the art through details of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates in a first aspect to front and/or rear contacted solar cell according to claim 1, and in a second aspect to a process for making such a solar cell according to claim 26.
In an exemplary embodiment of the present solar cell the field passivation layer or region may have a <400 meV activation energy, such as <300 meV, and is preferably a continuous layer (apart from possible contacts).
In an exemplary embodiment of the present solar cell the field passivation material may be selected from a doped sub-re gion, such as by adding an acceptor or donor, such as by implan tation, and diffusion, from a supra-region, such as layers, which may be in-situ or ex-situ doped, wherein layers are pro vided by Epitaxial growth, Poly-Si alloys deposition, PECVD, and LT PECVD.
In an exemplary embodiment of the present solar cell in a sub-region a dopant concentration of the field passivation layer may be >5*1019/cm3, preferably >8*1019/cm3, more preferably >l*102°/cm3, such as >2*1020/cm3, a junction depth may be <200 pm, preferably 10-100 pm, a thickness may be <500 nm, preferably 50- 200 nm, and combinations thereof.
In an exemplary embodiment of the present solar cell the chemical passivation layer may comprise a wide band gap mate rial.
In an exemplary embodiment of the present solar cell the chemical passivation layer material may be a-SiH, wherein a-SiH may comprise N, C, or 0, SiOx, SixNy, A10x, HfOx.
In an exemplary embodiment of the present solar cell the chemical passivation layer may have a thickness of 0.1-20 nm, such as 0.2-10 nm, and combinations thereof, and is preferably a continuous layer (apart from possible contacts).
In an exemplary embodiment of the present solar cell the bulk substrate material may be selected from Micro-crystalline Silicon, Multi-crystalline Silicon, Czochralski Silicon, Float ing zone Silicon, Epitaxial Silicon, Ribbon Silicon, Liquid phase Silicon.
In an exemplary embodiment of the present solar cell the bulk substrate may be selected from n-type, p-type, intrinsic, and combinations thereof.
In an exemplary embodiment of the present solar cell the solar cell may be an IBC solar cell, and wherein the solar cell may comprise an n-doped field passivation region and a p-doped field passivation region at one side of the solar cell.
In an exemplary embodiment of the present solar cell the solar cell may be a front- and rear-contacted solar cell, and may comprise a stack of three layers at the front and at the rear.
In an exemplary embodiment of the present solar cell the solar cell may be a bifacial solar cell, and wherein at the front the field passivation region may comprise n-type dopants and wherein at the back the field passivation region may com prise p-type dopants.
In an exemplary embodiment of the present solar cell the transparent conductive oxide may selected from zinc oxide, in dium oxide, tin oxide, cadmium oxide, gallium oxide, doped ox ides, such as doped with F, and combinations thereof.
In an exemplary embodiment of the present solar cell at least one contact may comprise a stack of layers, which stack comprises a first layer of > 10 nm thickness, such as an n- doped or p-doped poly SiOx layer, a second layer of 100 nm-5000 nm thickness, such as a n-doped or p-doped crystalline Si layer , wherein the first and layer are both p-doped or are both n- doped, and in between said layers a dielectric barrier layer (15) of thickness of 0 < tdiei<2.5 nm, wherein said layers cover one and another, wherein the ratio of doping of first layer /second layer at the dielectric barrier layer is > 2, preferably > 5, more preferably > 10, even more preferably > 102.
In an exemplary embodiment of the present solar cell the contact stack 18b,18f may be a carrier selective passivating contact .
In an exemplary embodiment of the present solar cell the contact 18b,18f may be transparent.
In an exemplary embodiment the present solar cell may com prise a single sided or double sided textured substrate 10.
In an exemplary embodiment the present solar cell may com prise a 5*1014-0.5*1019 dopants/cm3 n- or p-type doped crystalline Si layer , wherein a doping concentration is preferably spa tially constant, wherein n-type dopants may be selected from P, As, Bi, Sb and Li, and wherein p-type dopants may be selected from B, Ga, and In.
In an exemplary embodiment the present solar cell may com prise a dielectric passivation layer or dielectric passivation stack on the cell.
In an exemplary embodiment the present solar cell may com prise a 1014—1017 dopants/cm3 n- or p-type doped substrate 10.
In an exemplary embodiment the present solar cell may com prise at least one of a metal layer on a back side 18b, metal contacts on a front side 18f and/or on a back side 18b, and a transparent conductive layer.
In an exemplary embodiment the present solar cell may com prise at least one dielectric barrier layer each independently of thickness of 0.1 nm-1.4 nm, wherein the dielectric barrier layer independently may comprise at least one material selected from SiCb, HfCt, and W2O5.
In an exemplary embodiment of the present solar cell the material of the transparent conductive layer may be selected from ITO, IOH, ZnO or doped ZnO, and IWO.
In an exemplary embodiment of the present solar cell a thickness of the transparent conductive layer may be <100 nm, such as 10-40 nm.
In an exemplary embodiment of the present solar cell the refractive index of the transparent conductive layer may be <2.2.
In an exemplary embodiment of the present solar cell in the stack of layers, the layer , such as the n-doped or p-doped poly SiOx layer, the layer , such as the n-doped or p-doped crystalline Si layer, and the dielectric barrier layer may be each independently in full contact with one and another over an area of >50% of a surface of the largest of two contacting sur faces.
In an exemplary embodiment the present solar cell may com prise at least one textured surface , wherein the textured sur face may have an aspect ratio height:depth of a textured struc ture of 2-10.
In an exemplary embodiment the present solar cell may have n-doped or p-doped poly SiOx layer independently of 10 nm- 5000 nm thickness, and may comprise 1*1019-5*1022 n- or p-type dopants/cm3, wherein a doping profile is preferably substantially constant over the thickness of the layer , wherein n-type do pants may be selected from P, As, Bi, Sb and Li, and wherein p-type dopants may be selected from B, Ga, and In.
In an exemplary embodiment the present solar cell may comprise at least one dielectric layer each independently of thickness of 10 nm-2000 nm, wherein the dielectric layer inde pendently may comprise at least one material selected from SiNx, AIOc, SiOx, a n-type or p-type doped or un-doped transparent con ductive oxide.
In an exemplary embodiment of the present solar cell the metal of the metal layers 18b and metal contacts 18f inde pendently may comprise at least one of Cu, Al, W, Ti, Ni, and Ag, wherein a thickness of said metal 18b,18f may be 200-5000 nm.
In an exemplary embodiment of the present method the n- doped or p-doped poly SiOx layer may be provided by PECVD, or LPCVD, wherein dopants may be constantly provided during deposi tion.
In an exemplary embodiment of the present method metal contacts and/or metal layers 18b,18f may be provided by metal deposition and lift off of non-contact areas, screen printing, and electrical plating.
In an exemplary embodiment of the present method dopants in the poly SiOx layer may be activated.
The invention is further detailed by the accompanying fig ures and examples, which are exemplary and explanatory of na ture and are not limiting the scope of the invention. To the person skilled in the art it may be clear that many variants, being obvious or not, may be conceivable falling within the scope of protection, defined by the present claims.
SUMMARY OF FIGURES
Figures 1-5 show a schematic representation of examples of the present solar cell.
DETAILED DESCRIPTION OF FIGURES
100 solar cell
10 substrate, e.g. doped Si
18b back side metal contacts or back side metal layer 18f front side metal contacts or front side metal layer 20 textured surface
21 transparent conductive oxide layer
22 chemical dielectric passivation layer
23 field passivation layer and/or field passivation region
The figures are further detailed in the description of the experiments below.
Figures 1-5 show the present a contact stack of three layers 21,22,23 encircled.
Figure 1 shows a contact stack with Si based bulk 10, a field passivation region 23, a chemical passivation layer 22, a TCO 21, and a metal contact 18b or 18f.
Figure 2 shows a front and rear contacted, monofacial, solar cell with bulk silicon 10, with two stacks with a field pas sivation region 23, a chemical passivation layer 22, a TCO 21, and a metal contact 18b or 18f, at either side.
Figure 3 shows an IBC monofacial solar cell with bulk silicon 10, with two stacks (left and right) with a field passivation region 23, a chemical passivation layer 22, a TCO 21, and a metal contact 18b, at either side, wherein the right field pas sivation region 23p is positively charged and wherein the left field passivation region 23n is negatively charged. Further an antireflective coating layer 19 is provided.
Figure 4 shows an IBC bifacial solar cell with bulk silicon 10, with two stacks (left and right) with a field passivation region 23, a chemical passivation layer 22, a TCO 21, and a metal contact 18b, at either side, wherein the right field pas sivation region 23p is positively charged and wherein the left field passivation region 23n is negatively charged. Further an antireflective coating layer 19 is provided.
Figure 5 shows a front and rear contacted, bifacial, solar cell with bulk silicon 10, with two stacks with a field pas sivation region 23, a chemical passivation layer 22, a TCO 21, and a metal contact 18b or 18f, at either side, wherein the top field passivation region 23p is positively charged and wherein the bottom field passivation region 23n is negatively charged.
EXAMPLES/EXPERIMENTS
Results of the present solar cells are found to be good. For instance, an excellent surface passivation is achieved. The Voc and fill factor FF of the cells are found to be sensitive to the transparent conductive oxide application process. For the n-type solar cell Jo of 3 fA/cm2 and implied a V0c as high as 740 mV, the p-type solar cell Jo of 23 fA/cm2 and implied V0c as high as 700 mV, is obtained. The calculated solar cell pre sents an efficiency of 24%, a FF up to 83.5%, and JSc up to 41 mA/cm2 with a double side textured surface. The invention although described in detailed explanatory context may be best understood in conjunction with the accom panying figures.
It should be appreciated that for commercial application it may be preferable to use one or more variations of the present system, which would similar be to the ones disclosed in the pre sent application and are within the spirit of the invention.

Claims

1. Front and/or rear contacted solar cell (100) comprising at least one hetero junction, a bulk substrate (10), a contact stack of three layers (21,22,23), the stack com prising a transparent conductive oxide layer (21) in contact with a chemical dielectric passivation layer (22), the chemical dielectric passivation layer in contact with a field passivation layer and/or region (23), wherein the transparent conductive oxide layer (21) is at an outside of the solar cell, wherein the field passivation layer/region (22) comprises n-type or p-type dopants, wherein the transparent conductive oxide layer (21) has a thickness of > 25 nm, a carrier concentration of >5*1019/cm3, and is preferably not-textured, and on the transparent conductive oxide layer (21) at least one front and/or back contact (18b,18f), preferably a metal contact.
2. Solar cell according to claim 1, wherein the field pas sivation layer or region has a <400 meV activation energy, and is preferably a continuous layer.
3. Solar cell according to any of claims 1-2, wherein the field passivation material is selected from a doped sub-region, such as by adding an acceptor or donor, such as by implantation, and diffusion, from a supra-region, such as layers, which may be in- situ or ex-situ doped, wherein layers are provided by Epitaxial growth, Poly-Si alloys deposition, PECVD, and LT PECVD, and/or wherein in a sub-region a dopant concentration is >5*1019/cm3, a junction depth is < 200 pm, a thickness is < 500 nm, and combi nations thereof.
4. Solar cell according to any of claims 1-3, wherein the chemi cal passivation layer comprises a wide band gap material, and/or wherein the chemical passivation layer material is a-SiH, wherein a-SiH may comprise N, C, or 0, SiOx, SixNy, A10x, HfOx, and/or wherein the chemical passivation layer has a thickness of 0.1-20 nm, and combinations thereof, and is preferably a contin uous layer.
5. Solar cell according to any of claims 1-4, wherein the bulk substrate material is selected from Micro-crystalline Silicon, Multi-crystalline Silicon, Czochralski Silicon, Floating zone Silicon, Epitaxial Silicon, Ribbon Silicon, and Liquid phase Silicon, and/or wherein the bulk substrate is selected from n- type, p-type, intrinsic, and combinations thereof.
6. Solar cell according to any of claims 1-5, wherein the solar cell is an IBC solar cell, and wherein the solar cell comprises an n-doped field passivation region and a p-doped field pas sivation region at one side of the solar cell.
7. Solar cell according to any of claims 1-5, wherein the solar cell is a front- and rear-contacted solar cell, and comprises a stack of three layers at the front and at the rear.
8. Solar cell according to claim 7, wherein the solar cell is a bifacial solar cell, and wherein at the front the field pas sivation region comprises n-type dopants and wherein at the back the field passivation region comprises p-type dopants.
9. Solar cell according to any of claims 1-8, wherein the trans parent conductive oxide is selected from zinc oxide, indium ox ide, tin oxide, cadmium oxide, gallium oxide, doped oxides, such as doped with F, and combinations thereof.
10. Solar cell according to any of claims 1-9, wherein at least one contact comprises a stack of layers, which stack comprises a first layer of > 10 nm thickness, such as an n-doped or p-doped poly SiOx layer , a second layer of 100 nm-5000 nm thickness, such as a n-doped or p-doped crystalline Si layer, wherein the first layer and second layer are both p-doped or are both n- doped, and in between said layers a dielectric barrier layer of thickness of 0 < tdiei<2.5 nm, wherein said layers cover one and another, wherein the ratio of doping of first layer /second layer at the dielectric barrier layer is > 2, preferably > 5, more preferably > 10, even more preferably > 102.
11. Solar cell according to any of claims 1-10, wherein the con tact stack (18b,18f) is a carrier selective passivating contact.
12. Solar cell according to any of claims 1-11, wherein the con tact (18b,18f) is transparent.
13. Solar cell according to any of claims 1-12, comprising a single sided or double sided textured substrate (10).
14. Solar cell according to any of claims 1-13, comprising a 5*1014-0.5*1019 dopants/cm3 n- or p-type doped crystalline Si layer, wherein a doping concentration is preferably spatially constant, wherein n-type dopants are selected from P, As, Bi, Sb and Li, and wherein p-type dopants are selected from B, Ga, and In.
15. Solar cell according to any of claims 1-14, comprising a di electric passivation layer or dielectric passivation stack on the cell.
16. Solar cell according to any of claims 1-15, comprising a 1014—1017 dopants/cm3 n- or p-type doped substrate (10).
17. Solar cell according to any of claims 1-16, comprising at least one of a metal layer on a back side (18b), metal contacts on a front side (18f) and/or on a back side (18b), and a trans parent conductive layer (19).
18. Solar cell according to any of claims 1-17, comprising at least one dielectric barrier layer each independently of thick ness of 0.1 nm-1.4 nm, wherein the dielectric barrier layer independently comprises at least one material selected from S1O2, HfCh, and W2O5.
19. Solar cell according to any of claims 1-18, wherein the ma terial of the transparent conductive layer is selected from ITO, IOH, ZnO or doped ZnO, IFO, and IWO, and/or wherein a thickness of the transparent conductive layer is <100 nm, and/or wherein the refractive index is <2.2.
20. Solar cell according to any of claims 1-19, wherein in the stack of layers, the first layer , such as the n-doped or p- doped poly SiOx layer, the n-doped or p-doped second layer , such as the n-doped or p-doped crystalline Si layer, and the di electric barrier layer are each independently in full contact with one and another over an area of >50% of a surface of the largest of two contacting surfaces.
21. Solar cell according to any of claims 1-20, comprising at least one textured surface , wherein the textured surface has an aspect ratio (height:depth of a textured structure) of 2-10.
22. Solar cell according to any of claims 1-21, having n-doped or p-doped poly SiOx layer independently of 10 nm- 5000 nm thickness, and comprising 1*1019-5*1022 n- or p-type dopants/cm3, wherein a dop ing profile is preferably substantially constant over the thick ness of the layer , wherein n-type dopants are selected from P, As, Bi, Sb and Li, wherein p-type dopants are selected from B, Ga, and In.
23. Solar cell according to any of claims 1-21, comprising at least one dielectric layer each independently of thickness of 10 nm-2000 nm, wherein the dielectric layer independently comprises at least one material selected from SiNx, A10x, SiOx, a n-type or p-type doped or un-doped transparent conductive oxide.
24. Solar cell according to any of claims 1-23, wherein the metal of the metal layers (18b) and metal contacts (18f) inde pendently comprises at least one of Cu, Al, W, Ti, Ni, and Ag, wherein a thickness of said metal (18b,18f) is 200-5000 nm.
25. Method of producing a solar cell according to any of claims 1-24 comprising at least one of providing a silicon substrate (10), texturing a rear and/or front substrate surface (10), doping a front side , doping a rear side , annealing said doped sides at a temperature of less than 1000 °C during a sufficient period of time, providing a 0<tdiei<2.5 nm thick dielectric layer on the doped front side and/or doped rear side, providing n-doped or p-doped poly SiOx layer of > 10 nm thick ness on the dielectric layer , wherein the ratio of doping of poly SiOx:crystalline Si at the dielectric barrier layer is > 2, providing at least one dielectric layer on the poly SiOx layer r and providing a metal layer (18b) and/or metal contacts (18f) at a rear and front side being in electrical contact with the n- doped or p-doped poly SiOx layer , respectively.
26. Method according to claim 25, wherein the n-doped or p-doped poly SiOx layer is provided by PECVD, or LPCVD, wherein dopants are constantly provided during deposition.
27. Method according to claims 25 or 26, wherein metal contacts and/or metal layers (18b,18f) are provided by metal deposition and lift off of non-contact areas, screen printing, and electri cal plating.
28. Method according to any of claims 25-27, wherein dopants in the poly SiOx layer are activated.
EP20792762.5A 2019-10-16 2020-10-06 Transparent passivated contacts for si solar cells Pending EP4046205A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
NL2024024A NL2024024B1 (en) 2019-10-16 2019-10-16 Transparent passivated contacts for Si solar cells
PCT/NL2020/050617 WO2021075956A1 (en) 2019-10-16 2020-10-06 Transparent passivated contacts for si solar cells

Publications (1)

Publication Number Publication Date
EP4046205A1 true EP4046205A1 (en) 2022-08-24

Family

ID=68582310

Family Applications (1)

Application Number Title Priority Date Filing Date
EP20792762.5A Pending EP4046205A1 (en) 2019-10-16 2020-10-06 Transparent passivated contacts for si solar cells

Country Status (3)

Country Link
EP (1) EP4046205A1 (en)
NL (1) NL2024024B1 (en)
WO (1) WO2021075956A1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115188837B (en) * 2022-06-27 2023-08-04 隆基绿能科技股份有限公司 Back contact solar cell, preparation method and cell assembly

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20150122329A1 (en) * 2011-11-07 2015-05-07 International Business Machines Corporation Silicon heterojunction photovoltaic device with non-crystalline wide band gap emitter
EP3552244B1 (en) * 2016-12-12 2021-01-06 Ecole Polytechnique Federale de Lausanne (EPFL) Silicon heterojunction solar cells and methods of manufacture
NL2019634B1 (en) 2017-09-27 2019-04-03 Univ Delft Tech Solar cells with transparent contacts based on poly-silicon-oxide

Also Published As

Publication number Publication date
NL2024024B1 (en) 2021-06-17
WO2021075956A1 (en) 2021-04-22

Similar Documents

Publication Publication Date Title
KR101139443B1 (en) Hetero-junction solar cell and fabrication method thereof
KR101626248B1 (en) Silicon solar cell and method of manufacturing the same
US20110139249A1 (en) High Power Efficiency Polycrystalline CdTe Thin Film Semiconductor Photovoltaic Cell Structures for Use in Solar Electricity Generation
US20090314337A1 (en) Photovoltaic devices
US20100243042A1 (en) High-efficiency photovoltaic cells
KR100850641B1 (en) Fabrication method of high-efficiency crystalline silicon solar cells
KR101918737B1 (en) Solar cell
KR20120084104A (en) Solar cell
US20130104985A1 (en) Photovoltaic device with mangenese and tellurium interlayer
KR101886818B1 (en) Method for manufacturing of heterojunction silicon solar cell
KR100990864B1 (en) Solar cell and method for manufacturing the same
KR20160029501A (en) Solar cell
EP3688819B1 (en) Solar cells with transparent contacts based on poly-silicon-oxide
WO2021075956A1 (en) Transparent passivated contacts for si solar cells
KR20180101679A (en) Back contact silicon solar cell and method for manufacturing the same
AU2011204838A1 (en) Photovoltaic device
KR101770267B1 (en) Thin film solar cell module
EP0248953A1 (en) Tandem photovoltaic devices
KR101898996B1 (en) Silicon Solar Cell having Carrier Selective Contact
KR20110003787A (en) Solar cell and method for manufacturing the same
KR101098813B1 (en) Solar cell
KR101130193B1 (en) Solar cell
Mil'Shtein et al. Design and fabrication steps of silicon heterostructured piin solar cell with corrugated surface
CN104037242A (en) Photovoltaic element and method for manufacturing same
KR101640815B1 (en) Thin film solar cell and method for fabricaitng the same

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: UNKNOWN

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

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

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

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

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20220407

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 RS SE SI SK SM TR

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)
P01 Opt-out of the competence of the unified patent court (upc) registered

Effective date: 20230525

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

Free format text: STATUS: EXAMINATION IS IN PROGRESS

17Q First examination report despatched

Effective date: 20240503