WO2022012180A1 - Interdigitated back contact heterojunction solar cell based on lpcvd efficient amorphous silicon doping technology - Google Patents

Interdigitated back contact heterojunction solar cell based on lpcvd efficient amorphous silicon doping technology Download PDF

Info

Publication number
WO2022012180A1
WO2022012180A1 PCT/CN2021/096254 CN2021096254W WO2022012180A1 WO 2022012180 A1 WO2022012180 A1 WO 2022012180A1 CN 2021096254 W CN2021096254 W CN 2021096254W WO 2022012180 A1 WO2022012180 A1 WO 2022012180A1
Authority
WO
WIPO (PCT)
Prior art keywords
amorphous silicon
doped amorphous
lpcvd
solar cell
silicon substrate
Prior art date
Application number
PCT/CN2021/096254
Other languages
French (fr)
Chinese (zh)
Inventor
欧文凯
Original Assignee
普乐新能源科技(徐州)有限公司
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 普乐新能源科技(徐州)有限公司 filed Critical 普乐新能源科技(徐州)有限公司
Publication of WO2022012180A1 publication Critical patent/WO2022012180A1/en

Links

Images

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
    • H01L31/06—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 at least one potential-jump barrier or surface barrier
    • 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 at least one potential-jump barrier or surface barrier the potential barriers being only of the PN heterojunction type
    • 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
    • H01L31/0216—Coatings
    • H01L31/02161—Coatings for devices characterised by at least one potential jump barrier or surface barrier
    • H01L31/02167—Coatings 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
    • H01L31/022441—Electrode arrangements specially adapted for back-contact 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
    • H01L31/0248—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
    • H01L31/0352—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 shape or by the shapes, relative sizes or disposition of the semiconductor regions
    • H01L31/035272—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 shape or by the shapes, relative sizes or disposition of the semiconductor regions characterised by at least one potential jump barrier or surface barrier
    • 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 invention relates to the technical field of solar cells, and provides a growth method for a low-cost, high-quality doped amorphous silicon passivation layer. It is especially suitable for the formation of doped amorphous silicon passivation layers in interdigitated back-contact heterojunction solar cells (HBC).
  • HBC interdigitated back-contact heterojunction solar cells
  • the HBC battery has both the high short-circuit current of the IBC battery and the high open voltage of the HJT battery.
  • the laboratory conversion efficiency is as high as 26.63%, and its development potential has been proved.
  • the P and N layers on the back show an orderly and regular staggered arrangement, which greatly reduces the series resistance Rs, and the metal electrodes in contact with the P and N layers can form a good ohmic contact. short-circuit current.
  • the excellent intrinsic passivation layer can achieve high open circuit voltage.
  • the doped amorphous silicon passivation layer is the core step, and the PECVD amorphous silicon coating or ion implantation technology is currently used in the market.
  • the current mainstream technology is the PECVD technology route.
  • Meyer Burger, Ideal Energy, and American Applied Materials are the current major suppliers. Their equipment costs are extremely high, the battery production cost is very high, and the road to mass production is relatively long.
  • the technical problem to be solved by the present invention is to provide an interdigitated back-contact heterojunction solar cell based on LPCVD-based high-efficiency doped amorphous silicon technology in view of the problems existing in the background technology.
  • An interdigitated back-contact heterojunction solar cell based on LPCVD high-efficiency doped amorphous silicon technology comprising a crystalline silicon substrate, and a front surface of the crystalline silicon substrate includes at least one passivation layer;
  • the back surface of the silicon substrate includes a tunnel oxide layer, an alternately arranged n+-doped amorphous silicon layer/p+-doped amorphous silicon layer, a laser grooved region, a passivation layer and a metal electrode from the inside to the outside.
  • the crystalline silicon substrate is any one of an N-type single crystal silicon substrate or a P-type single crystal silicon substrate.
  • the front surface of the crystalline silicon substrate is a textured surface
  • the back surface is either an acid polished surface or an alkali polished surface.
  • the passivation layer provided on the front surface of the crystalline silicon substrate is one or a combination of SiO2, AlOx, SiNx, and SiONx.
  • the tunnel oxide layer on the back surface of the crystalline silicon substrate is prepared by any one of atmospheric pressure thermal oxygen oxidation and LPCVD thermal oxygen oxidation.
  • alternately arranged n+ doped amorphous silicon layers/p+ doped amorphous silicon layers are realized by LPCVD doping technology, wherein B doping is realized by using BCl3 gaseous doping source.
  • n+ doped amorphous silicon layer and the p+ doped amorphous silicon layer are alternately realized by using a mask and a laser grooving technology respectively.
  • the passivation layer on the back surface of the crystalline silicon substrate is one or a combination of SiNx and SiONx.
  • the metal electrode is silver paste.
  • the present invention adopts the battery structure combining the back contact method and the heterojunction method, optimizes the growth method of doped amorphous silicon, improves the passivation ability and contact ability of the solar cell while retaining the characteristics of high short-circuit current of IBC, and at the same time Effectively reduce the manufacturing cost. It has been verified that the mass-produced HBC cell using the structure of the present invention has a conversion efficiency of more than 25% and an open circuit voltage of more than 710mV, which is higher than the 23.5% mass-produced conversion efficiency of the current mainstream heterojunction or TOPCon technology.
  • the HBC cell of the present invention is based on the LPCVD high-efficiency doped amorphous silicon technology.
  • the LPCVD doping technology and the mask slotting technology are used to realize the n+-doped amorphous silicon layer and the p+-doped amorphous silicon layer respectively.
  • Amorphous silicon layer this technology retains the characteristics of the front surface of the interdigitated back contact battery without shielding and high short-circuit current, and at the same time realizes the passivation contact ability on the back side, which greatly improves the open circuit voltage of the battery, and mass-produces HBC batteries The efficiency reaches more than 25%, and the battery open circuit voltage reaches more than 710mV.
  • the n+ doped amorphous silicon layer is prepared by using the LPCVD method in the existing TOPCon technology, and the low temperature p+ doped amorphous layer is realized by using the BCl3 gaseous source at the same time,
  • the doping concentration is easy to control, and more importantly, the manufacturing cost is reduced, and a solution that can be combined with the existing TOPCon mass production technology is provided, which can realize the rapid technical upgrade of the mass production line.
  • FIG. 1 is a cross-sectional view of the HBC cell structure of the present invention.
  • an interdigitated back-contact heterojunction solar cell based on LPCVD high-efficiency doped amorphous silicon technology includes a crystalline silicon substrate 1.
  • the crystalline silicon substrate 1 It is an N-type single crystal silicon substrate or a P-type single crystal silicon substrate.
  • the front surface of the crystalline silicon substrate 1 is a single crystal solar cell, and conventional KOH or NaOH is used to make a textured surface to obtain the required textured reflectivity. It should be less than 11% so that better light absorption and optimal short-circuit current can be obtained.
  • the back surface of the crystalline silicon substrate adopts either an acid polishing surface prepared with 2:1:5 HNO3/HF/H2O or a KOH alkali polishing surface with a concentration of 49%, and the back surface requires a reflectivity greater than 30%. And after 5-10min O3 cleaning to achieve the optimal surface state, reduce the surface recombination that may be caused by pollution, and provide better conditions for the subsequent passivation process.
  • the front surface of the crystalline silicon substrate 1 includes at least one passivation layer 2 ; the back surface of the crystalline silicon substrate 1 includes a tunnel oxide layer 3 and n+ doped amorphous silicon alternately arranged from inside to outside. Layer 4 and p+ doped amorphous silicon layer 5 , laser grooved region 6 , passivation layer 7 and metal electrode 8 .
  • the passivation layer on the front surface of the crystalline silicon substrate 1 is one or a combination of SiO2, Al2O3, Si3N4, and SiON, and the passivation film can choose to use the no-wrap plating technology to reduce the influence of the backside wrapping.
  • the preparation of passivation film can be realized by horizontal PECVD equipment.
  • the tunnel oxide layer on the back surface of the crystalline silicon substrate 1 is prepared by any one of atmospheric pressure thermal oxygen oxidation and LPCVD thermal oxygen oxidation. carrier tunneling effect.
  • the n+ doped amorphous silicon layer and the p+ doped amorphous silicon layer can be realized by LPCVD doping technology, wherein the B doping is realized by using BCl3 gaseous doping source, the n+ doped amorphous silicon layer and the p+ doped amorphous silicon layer are realized.
  • the crystalline silicon layer is alternately realized by mask and laser slotting technology. Specifically, a layer of n+ doped amorphous silicon layer is first formed through mask and laser slotting, and then a layer of n+ doped amorphous silicon layer is formed through mask and laser slotting. p+ doped amorphous silicon layer, ..., and so on.
  • the reaction source used is the reaction of BCl3 gas and SiH4 gas, and the main steps are:
  • Step 1 Open the furnace door of the LPCVD equipment and put the samples of doped amorphous silicon into the carrier, and the equipment is evacuated.
  • Step 2 Under the condition that the vacuum is kept at 200-500mtorr, the temperature is raised to 500-600°C and kept at a constant temperature for several times, so that the silicon wafer can be heated under low pressure and stabilized, and the surface of the silicon wafer can be kept clean under vacuum.
  • Step 3 The BCl3 gas of 10-200 sccm and the SiH4 gas of 300-700 sccm are introduced into the reaction source, and the amorphous silicon is continuously grown for 60-180 minutes.
  • Step 4 Purge the special gas pipeline with N2, and at the same time lower the temperature to below 500 °C, and pass N2 to back pressure the furnace tube to normal pressure.
  • Step 5 The sample production of the furnace door is completed.
  • the passivation layer on the back surface of the crystalline silicon substrate adopts one or a combination of Si3N4 and SiON. Different from the front surface, there is no need to use an Al2O3 passivation film here, because the Al2O3 film has a There are negative charges on the back of the N-type cell to form an inversion, which is not conducive to the transport of carriers.
  • the metal electrode is silver paste.
  • the HBC battery prepared by the invention retains the features of the interdigitated back-contact battery with no shielding on the front surface and high short-circuit current, and at the same time realizes the passivation contact ability on the back side, which greatly improves the open-circuit voltage of the battery.
  • the electrical properties of the prepared HBC cells were tested by standard solar cell testing methods.
  • the mass-produced HBC cells had an efficiency of over 25% and an open circuit voltage of over 710 mV.

Abstract

Provided is an interdigitated back contact heterojunction solar cell based on LPCVD efficient amorphous silicon doping technology. The solar cell comprises a crystalline silicon substrate. The front surface of the crystalline silicon substrate comprises at least one kind of passivation layer, and the back surface of the crystalline silicon substrate respectively comprises, from inside to outside, a tunneling oxide layer, alternately arranged n+ doped amorphous silicon layers/p+ doped amorphous silicon layers, a laser grooving area, a passivation layer and a metal electrode. In the present invention, by using a cell structure combining a back contact manner and a heterojunction manner, the growth manner of doped amorphous silicon is optimized, the passivation capability and the contact capability of the solar cell are improved while the characteristic of an IBC high short-circuit current is retained, and manufacturing costs are also effectively reduced. It is verified that the efficiency of HBC cells which are mass produced and use the structure of the present invention reaches a conversion efficiency of 25% or above, an open-circuit voltage reaches 710 mV or above, and the efficiency is higher than the mass production conversion efficiency of 23.5% of present mainstream heterojunction or TOPCon technology.

Description

一种基于LPCVD的高效掺杂非晶硅技术的交叉指式背接触异质结太阳电池An Interdigitated Back Contact Heterojunction Solar Cell Based on High Efficiency Doped Amorphous Silicon Technology Based on LPCVD 技术领域technical field
本发明涉及太阳能电池技术领域，提供一种用于低成本、高质量的掺杂非晶硅钝化层的生长方法。尤其适用于在交叉指式背接触异质结太阳电池(HBC)中作为掺杂非晶硅钝化层的形成。The invention relates to the technical field of solar cells, and provides a growth method for a low-cost, high-quality doped amorphous silicon passivation layer. It is especially suitable for the formation of doped amorphous silicon passivation layers in interdigitated back-contact heterojunction solar cells (HBC).
背景技术Background technique
近年来，能源危机与环境压力促进了太阳电池研究和产业的迅速发展。目前，晶体硅太阳电池是技术最成熟、应用最广泛的太阳电池，在光伏市场中的比例超过90％，并且在未来相当长的时间内都将占据主导地位。在高速发展的光伏产业中，光电转换效率的提高和电池制造成本的降低已经成为整个光伏行业的根本，随着光伏电池技术的不断进步，越来越多的高效太阳电池进入人们的视野。In recent years, the energy crisis and environmental pressure have promoted the rapid development of solar cell research and industry. At present, crystalline silicon solar cells are the most mature and widely used solar cells, accounting for more than 90% of the photovoltaic market, and will occupy a dominant position for a long time in the future. In the rapidly developing photovoltaic industry, the improvement of photoelectric conversion efficiency and the reduction of cell manufacturing costs have become the fundamentals of the entire photovoltaic industry. With the continuous advancement of photovoltaic cell technology, more and more efficient solar cells have entered people's field of vision.
HBC电池同时具备了IBC电池的高短路电流以及HJT电池的高开压，实验室转换效率高达26.63％，其发展潜力已得证明。The HBC battery has both the high short-circuit current of the IBC battery and the high open voltage of the HJT battery. The laboratory conversion efficiency is as high as 26.63%, and its development potential has been proved.
HBC电池结构前表面无金属电极，背部P、N层呈现有序规则的交错排列，大大降低了串联电阻Rs，且与P、N层接触相间的金属电极能够形成很好的欧姆接触，增大了短路电流。另外，优异的本征钝化层能够获取高的开路电压。There is no metal electrode on the front surface of the HBC battery structure, and the P and N layers on the back show an orderly and regular staggered arrangement, which greatly reduces the series resistance Rs, and the metal electrodes in contact with the P and N layers can form a good ohmic contact. short-circuit current. In addition, the excellent intrinsic passivation layer can achieve high open circuit voltage.
目前报道的HBC电池中，其掺杂非晶硅钝化层为核心步骤，目前市场选用的是PECVD非晶硅镀膜或者离子注入技术。当前的主流技术为PECVD技术路线，梅耶博格、理想能源、美国应材为当前主要供应商，其设备成本极为高昂，电池生产成本很高，量产化之路较为漫长。需要一种HBC电池结构能够结合目前现有量产化技术，实现高效技术的快速推广应用。In the currently reported HBC cells, the doped amorphous silicon passivation layer is the core step, and the PECVD amorphous silicon coating or ion implantation technology is currently used in the market. The current mainstream technology is the PECVD technology route. Meyer Burger, Ideal Energy, and American Applied Materials are the current major suppliers. Their equipment costs are extremely high, the battery production cost is very high, and the road to mass production is relatively long. There is a need for an HBC battery structure that can be combined with the current mass production technology to achieve rapid popularization and application of high-efficiency technology.
发明内容SUMMARY OF THE INVENTION
本发明所要解决的技术问题是，针对背景技术中存在的问题，提供一种基于LPCVD的高效掺杂非晶硅技术的交叉指式背接触异质结太阳电池。The technical problem to be solved by the present invention is to provide an interdigitated back-contact heterojunction solar cell based on LPCVD-based high-efficiency doped amorphous silicon technology in view of the problems existing in the background technology.
本发明解决上述技术问题所采用的技术方案是：The technical scheme adopted by the present invention to solve the above-mentioned technical problems is:
一种基于LPCVD的高效掺杂非晶硅技术的交叉指式背接触异质结太阳电池，包括晶硅衬底，所述晶硅衬底的前表面包括至少一种钝化层；所述晶硅衬底的背 表面从内到外分别包括隧穿氧化层、交替排列的n+掺杂非晶硅层/p+掺杂非晶硅层、激光开槽区、钝化层和金属电极。An interdigitated back-contact heterojunction solar cell based on LPCVD high-efficiency doped amorphous silicon technology, comprising a crystalline silicon substrate, and a front surface of the crystalline silicon substrate includes at least one passivation layer; The back surface of the silicon substrate includes a tunnel oxide layer, an alternately arranged n+-doped amorphous silicon layer/p+-doped amorphous silicon layer, a laser grooved region, a passivation layer and a metal electrode from the inside to the outside.
进一步地，所述晶硅衬底为N型单晶硅衬底或P型单晶硅衬底中的任意一种。Further, the crystalline silicon substrate is any one of an N-type single crystal silicon substrate or a P-type single crystal silicon substrate.
进一步地，所述晶硅衬底的前表面为制绒面，背表面为酸抛光面或碱抛光面中的任意一种。Further, the front surface of the crystalline silicon substrate is a textured surface, and the back surface is either an acid polished surface or an alkali polished surface.
进一步地，所述晶硅衬底的前表面设置的钝化层为SiO2、AlOx、SiNx、SiONx中的一种或几种组合。Further, the passivation layer provided on the front surface of the crystalline silicon substrate is one or a combination of SiO2, AlOx, SiNx, and SiONx.
进一步地，所述晶硅衬底的背表面的隧穿氧化层通过常压热氧氧化、LPCVD热氧氧化中的任意一种方式制得。Further, the tunnel oxide layer on the back surface of the crystalline silicon substrate is prepared by any one of atmospheric pressure thermal oxygen oxidation and LPCVD thermal oxygen oxidation.
进一步地，所述交替排列的n+掺杂非晶硅层/p+掺杂非晶硅层，采用LPCVD掺杂技术实现，其中B掺杂利用BCl3气态掺杂源实现。Further, the alternately arranged n+ doped amorphous silicon layers/p+ doped amorphous silicon layers are realized by LPCVD doping technology, wherein B doping is realized by using BCl3 gaseous doping source.
进一步地，n+掺杂非晶硅层和p+掺杂非晶硅层交替采用掩膜和激光开槽技术分别实现。Further, the n+ doped amorphous silicon layer and the p+ doped amorphous silicon layer are alternately realized by using a mask and a laser grooving technology respectively.
进一步地，所述晶硅衬底背表面钝化层为SiNx和SiONx其中一种或两种组合。Further, the passivation layer on the back surface of the crystalline silicon substrate is one or a combination of SiNx and SiONx.
进一步地，所述金属电极为银浆。Further, the metal electrode is silver paste.
本发明的有益效果是：The beneficial effects of the present invention are:
(1)本发明采用背接触方式和异质结方式结合的电池结构，优化了掺杂非晶硅生长方式，在保留IBC高短路电流的特点下，提高太阳电池钝化能力和接触能力，同时有效地降低了制造成本。经验证，采用本发明的结构的量产化HBC电池效率达到25％以上的转换效率，开路电压达到710mV以上，高于目前主流异质结或TOPCon技术23.5％的量产转换效率。(1) The present invention adopts the battery structure combining the back contact method and the heterojunction method, optimizes the growth method of doped amorphous silicon, improves the passivation ability and contact ability of the solar cell while retaining the characteristics of high short-circuit current of IBC, and at the same time Effectively reduce the manufacturing cost. It has been verified that the mass-produced HBC cell using the structure of the present invention has a conversion efficiency of more than 25% and an open circuit voltage of more than 710mV, which is higher than the 23.5% mass-produced conversion efficiency of the current mainstream heterojunction or TOPCon technology.
(2)本发明的HBC电池基于LPCVD的高效掺杂非晶硅技术，与现有技术相比，利用LPCVD掺杂技术和掩膜开槽技术分别实现n+掺杂非晶硅层和p+掺杂非晶硅层，该技术保留了交叉指式背接触电池的前表面无遮挡、高短路电流的特点，同时在背面实现了钝化接触能力，大幅提升了电池的开路电压，量产化HBC电池效率达到25％以上，电池开路电压达到710mV以上。(2) The HBC cell of the present invention is based on the LPCVD high-efficiency doped amorphous silicon technology. Compared with the prior art, the LPCVD doping technology and the mask slotting technology are used to realize the n+-doped amorphous silicon layer and the p+-doped amorphous silicon layer respectively. Amorphous silicon layer, this technology retains the characteristics of the front surface of the interdigitated back contact battery without shielding and high short-circuit current, and at the same time realizes the passivation contact ability on the back side, which greatly improves the open circuit voltage of the battery, and mass-produces HBC batteries The efficiency reaches more than 25%, and the battery open circuit voltage reaches more than 710mV.
(3)本发明尤其在掺杂非晶硅层工艺制备中，利用现有TOPCon技术中的 LPCVD方法制备n+掺杂非晶硅层，同时利用BCl3气态源实现了低温p+掺杂非晶层，且掺杂浓度容易控制，更关键降低了制造成本，提供了一种可以结合现有TOPCon量产技术的方案，可以实现量产线的快速技术升级。(3) In the present invention, especially in the preparation of the doped amorphous silicon layer, the n+ doped amorphous silicon layer is prepared by using the LPCVD method in the existing TOPCon technology, and the low temperature p+ doped amorphous layer is realized by using the BCl3 gaseous source at the same time, In addition, the doping concentration is easy to control, and more importantly, the manufacturing cost is reduced, and a solution that can be combined with the existing TOPCon mass production technology is provided, which can realize the rapid technical upgrade of the mass production line.
附图说明Description of drawings
图1是本发明的HBC电池结构的截面图。FIG. 1 is a cross-sectional view of the HBC cell structure of the present invention.
图中标号：晶硅衬底1，钝化层2，隧穿氧化层3，n+掺杂非晶硅层4，p+掺杂非晶硅层5，激光开槽区6，钝化层7，金属电极8。Labels in the figure: crystalline silicon substrate 1, passivation layer 2, tunnel oxide layer 3, n+ doped amorphous silicon layer 4, p+ doped amorphous silicon layer 5, laser grooved region 6, passivation layer 7, Metal electrode 8.
具体实施方式detailed description
以下结合附图对本发明的技术方案做进一步详细说明，应当指出的是，具体实施方式只是对本发明的详细说明，不应视为对本发明的限定。The technical solutions of the present invention will be described in further detail below with reference to the accompanying drawings. It should be noted that the specific embodiments are only detailed descriptions of the present invention and should not be regarded as limitations of the present invention.
如图1所示，一种基于LPCVD的高效掺杂非晶硅技术的交叉指式背接触异质结太阳电池，包括晶硅衬底1，在本实施例中，所述晶硅衬底1为N型单晶硅衬底或P型单晶硅衬底，所述晶硅衬底1的前表面为单晶太阳电池采用常规KOH或NaOH制绒绒面，制得所需绒面反射率要小于11％，以便可以得到更好的光吸收和最优短路电流。所述晶硅衬底的背表面采用2：1：5的HNO3/HF/H2O制备的酸抛光面或49％浓度的KOH碱抛光面中的任意一种，背表面要求反射率大于30％，并经过5-10min的O3清洗以达到最优表面状态，降低污染可能带来的表面复合，为后道钝化工序提供较优条件。As shown in FIG. 1, an interdigitated back-contact heterojunction solar cell based on LPCVD high-efficiency doped amorphous silicon technology includes a crystalline silicon substrate 1. In this embodiment, the crystalline silicon substrate 1 It is an N-type single crystal silicon substrate or a P-type single crystal silicon substrate. The front surface of the crystalline silicon substrate 1 is a single crystal solar cell, and conventional KOH or NaOH is used to make a textured surface to obtain the required textured reflectivity. It should be less than 11% so that better light absorption and optimal short-circuit current can be obtained. The back surface of the crystalline silicon substrate adopts either an acid polishing surface prepared with 2:1:5 HNO3/HF/H2O or a KOH alkali polishing surface with a concentration of 49%, and the back surface requires a reflectivity greater than 30%. And after 5-10min O3 cleaning to achieve the optimal surface state, reduce the surface recombination that may be caused by pollution, and provide better conditions for the subsequent passivation process.
所述晶硅衬底1的前表面包括至少一种钝化层2；所述晶硅衬底1的背表面从内到外分别包括隧穿氧化层3、交替排列的n+掺杂非晶硅层4和p+掺杂非晶硅层5、激光开槽区6、钝化层7和金属电极8。The front surface of the crystalline silicon substrate 1 includes at least one passivation layer 2 ; the back surface of the crystalline silicon substrate 1 includes a tunnel oxide layer 3 and n+ doped amorphous silicon alternately arranged from inside to outside. Layer 4 and p+ doped amorphous silicon layer 5 , laser grooved region 6 , passivation layer 7 and metal electrode 8 .
所述晶硅衬底1的前表面钝化层为SiO2、Al2O3、Si3N4、SiON中的一种或几种组合，钝化膜可以选择利用无绕镀技术来减少背面绕镀影响。钝化膜的制备可以利用水平PECVD设备实现。The passivation layer on the front surface of the crystalline silicon substrate 1 is one or a combination of SiO2, Al2O3, Si3N4, and SiON, and the passivation film can choose to use the no-wrap plating technology to reduce the influence of the backside wrapping. The preparation of passivation film can be realized by horizontal PECVD equipment.
所述晶硅衬底1的背表面的隧穿氧化层通过常压热氧氧化、LPCVD热氧氧化中的任意一种方式制得，氧化层的厚度在1-3nm之间可获得较好的载流子隧穿效应。The tunnel oxide layer on the back surface of the crystalline silicon substrate 1 is prepared by any one of atmospheric pressure thermal oxygen oxidation and LPCVD thermal oxygen oxidation. carrier tunneling effect.
所述n+掺杂非晶硅层和p+掺杂非晶硅层，可以利用LPCVD掺杂技术实现，其中B掺杂利用BCl3气态掺杂源实现，n+掺杂非晶硅层和p+掺杂非晶硅层交替利用掩膜和激光开槽技术分别实现，具体来说，先通过掩膜和激光开槽形成一层n+掺杂非晶硅层，然后再通过掩膜和激光开槽形成一层p+掺杂非晶硅层，……，以此类推。The n+ doped amorphous silicon layer and the p+ doped amorphous silicon layer can be realized by LPCVD doping technology, wherein the B doping is realized by using BCl3 gaseous doping source, the n+ doped amorphous silicon layer and the p+ doped amorphous silicon layer are realized. The crystalline silicon layer is alternately realized by mask and laser slotting technology. Specifically, a layer of n+ doped amorphous silicon layer is first formed through mask and laser slotting, and then a layer of n+ doped amorphous silicon layer is formed through mask and laser slotting. p+ doped amorphous silicon layer, ..., and so on.
具体来说，在采用LPCVD掺杂技术的过程中，其采用的反应源为BCl3气体与SiH4气体反应，其主要步骤为：Specifically, in the process of adopting LPCVD doping technology, the reaction source used is the reaction of BCl3 gas and SiH4 gas, and the main steps are:
步骤1：LPCVD设备开炉门将制作掺杂非晶硅的样品放入载具，设备抽真空。Step 1: Open the furnace door of the LPCVD equipment and put the samples of doped amorphous silicon into the carrier, and the equipment is evacuated.
步骤2：在真空保持在200-500mtorr情况下，同时升温至500～600℃并恒温若干时间，使硅片在低压状况进行升温并达到稳定，真空下可保证硅片的表面清洁。Step 2: Under the condition that the vacuum is kept at 200-500mtorr, the temperature is raised to 500-600°C and kept at a constant temperature for several times, so that the silicon wafer can be heated under low pressure and stabilized, and the surface of the silicon wafer can be kept clean under vacuum.
步骤3：通入反应源10-200sccm的BCl3气体与300-700sccm的SiH4气体，持续生长非晶硅60-180min。Step 3: The BCl3 gas of 10-200 sccm and the SiH4 gas of 300-700 sccm are introduced into the reaction source, and the amorphous silicon is continuously grown for 60-180 minutes.
步骤4：通N2吹扫特气管道，同时降温至500℃以下，通N2使炉管回压至常压。Step 4: Purge the special gas pipeline with N2, and at the same time lower the temperature to below 500 ℃, and pass N2 to back pressure the furnace tube to normal pressure.
步骤5：开炉门样品制作完成。Step 5: The sample production of the furnace door is completed.
本发明实施例中，所述晶硅衬底的背表面的钝化层采用Si3N4和SiON其中一种或两种组合，区别于前表面，此处不需要使用Al2O3钝化薄膜，因为Al2O3薄膜带有负电荷在N型电池背面回形成反型不利于载流子的传输。In the embodiment of the present invention, the passivation layer on the back surface of the crystalline silicon substrate adopts one or a combination of Si3N4 and SiON. Different from the front surface, there is no need to use an Al2O3 passivation film here, because the Al2O3 film has a There are negative charges on the back of the N-type cell to form an inversion, which is not conducive to the transport of carriers.
本发明实施例中，所述金属电极为银浆。In the embodiment of the present invention, the metal electrode is silver paste.
利用本发明制备的HBC电池保留了交叉指式背接触电池的前表面无遮挡、高短路电流的特点，同时在背面实现了钝化接触能力，大幅提升了电池的开路电压。利用标准太阳能电池测试方法对制备的HBC电池进行电性能测试，量产化HBC电池效率达到25％以上，电池开路电压达到710mV以上。The HBC battery prepared by the invention retains the features of the interdigitated back-contact battery with no shielding on the front surface and high short-circuit current, and at the same time realizes the passivation contact ability on the back side, which greatly improves the open-circuit voltage of the battery. The electrical properties of the prepared HBC cells were tested by standard solar cell testing methods. The mass-produced HBC cells had an efficiency of over 25% and an open circuit voltage of over 710 mV.
显然，所描述的实施例仅仅是本发明的一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都应当属于本发明保护的范围。Obviously, the described embodiments are only some, but not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Claims (9)

  1. 一种基于LPCVD的高效掺杂非晶硅技术的交叉指式背接触异质结太阳电池，其特征在于，包括晶硅衬底，所述晶硅衬底的前表面包括至少一种钝化层；所述晶硅衬底的背表面从内到外分别包括隧穿氧化层、交替排列的n+掺杂非晶硅层/p+掺杂非晶硅层、激光开槽区、钝化层和金属电极。An interdigitated back-contact heterojunction solar cell based on LPCVD high-efficiency doped amorphous silicon technology, characterized in that it includes a crystalline silicon substrate, and the front surface of the crystalline silicon substrate includes at least one passivation layer ; The back surface of the crystalline silicon substrate includes a tunnel oxide layer, an alternately arranged n+-doped amorphous silicon layer/p+-doped amorphous silicon layer, a laser grooved region, a passivation layer and a metal layer from the inside to the outside. electrode.
  2. 根据权利要求1所述的一种基于LPCVD的高效掺杂非晶硅技术的交叉指式背接触异质结太阳电池，其特征在于，所述晶硅衬底为N型单晶硅衬底或P型单晶硅衬底中的任意一种。The LPCVD-based high-efficiency doped amorphous silicon technology interdigitated back-contact heterojunction solar cell according to claim 1, wherein the crystalline silicon substrate is an N-type single crystal silicon substrate or Any of the P-type single crystal silicon substrates.
  3. 根据权利要求1所述的一种基于LPCVD的高效掺杂非晶硅技术的交叉指式背接触异质结太阳电池，其特征在于，所述晶硅衬底的前表面为制绒面，背表面为酸抛光面或碱抛光面中的任意一种。The interdigitated back-contact heterojunction solar cell based on LPCVD-based high-efficiency doped amorphous silicon technology according to claim 1, wherein the front surface of the crystalline silicon substrate is a textured surface, and the back surface is a textured surface. The surface is either an acid polished surface or an alkali polished surface.
  4. 根据权利要求1所述的一种基于LPCVD的高效掺杂非晶硅技术的交叉指式背接触异质结太阳电池，其特征在于，所述晶硅衬底的前表面设置的钝化层为SiO2、AlOx、SiNx、SiONx中的一种或几种组合。The interdigitated back-contact heterojunction solar cell based on LPCVD-based high-efficiency doped amorphous silicon technology according to claim 1, wherein the passivation layer provided on the front surface of the crystalline silicon substrate is One or a combination of SiO2, AlOx, SiNx, SiONx.
  5. 根据权利要求1所述的一种基于LPCVD的高效掺杂非晶硅技术的交叉指式背接触异质结太阳电池，其特征在于，所述晶硅衬底的背表面的隧穿氧化层通过常压热氧氧化、LPCVD热氧氧化中的任意一种方式制得。The interdigitated back-contact heterojunction solar cell based on LPCVD-based high-efficiency doped amorphous silicon technology according to claim 1, wherein the tunnel oxide layer on the back surface of the crystalline silicon substrate passes through the It is prepared by any one of atmospheric pressure thermal oxygen oxidation and LPCVD thermal oxygen oxidation.
  6. 根据权利要求1所述的一种基于LPCVD的高效掺杂非晶硅技术的交叉指式背接触异质结太阳电池，其特征在于，所述交替排列的n+掺杂非晶硅层/p+掺杂非晶硅层，采用LPCVD掺杂技术实现，其中B掺杂利用BCl3气态掺杂源实现。The interdigitated back-contact heterojunction solar cell based on LPCVD-based high-efficiency doped amorphous silicon technology according to claim 1, wherein the alternately arranged n+ doped amorphous silicon layers/p+ doped amorphous silicon layers The hetero-amorphous silicon layer is realized by LPCVD doping technology, wherein B doping is realized by using BCl3 gaseous doping source.
  7. 根据权利要求1所述的一种基于LPCVD的高效掺杂非晶硅技术的交叉指式背接触异质结太阳电池，其特征在于，n+掺杂非晶硅层和p+掺杂非晶硅层交替采用掩膜和激光开槽技术分别实现。The interdigitated back-contact heterojunction solar cell based on LPCVD-based high-efficiency doped amorphous silicon technology according to claim 1, characterized in that the n+ doped amorphous silicon layer and the p+ doped amorphous silicon layer Alternately, masking and laser grooving techniques are used.
  8. 根据权利要求1所述的一种基于LPCVD的高效掺杂非晶硅技术的交叉指式背接触异质结太阳电池，其特征在于，所述晶硅衬底背表面钝化层为SiNx和SiONx其中一种或两种组合。The interdigitated back-contact heterojunction solar cell based on LPCVD-based high-efficiency doped amorphous silicon technology according to claim 1, wherein the passivation layer on the back surface of the crystalline silicon substrate is SiNx and SiONx One or a combination of both.
  9. 根据权利要求1所述的一种基于LPCVD的高效掺杂非晶硅技术的交叉指式背接触异质结太阳电池，其特征在于，所述金属电极为银浆。The interdigitated back-contact heterojunction solar cell based on LPCVD-based high-efficiency doped amorphous silicon technology according to claim 1, wherein the metal electrode is silver paste.
PCT/CN2021/096254 2020-07-14 2021-05-27 Interdigitated back contact heterojunction solar cell based on lpcvd efficient amorphous silicon doping technology WO2022012180A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202010673017.9A CN111816727A (en) 2020-07-14 2020-07-14 Interdigital back contact heterojunction solar cell based on LPCVD (low pressure chemical vapor deposition) high-efficiency amorphous silicon doping technology
CN202010673017.9 2020-07-14

Publications (1)

Publication Number Publication Date
WO2022012180A1 true WO2022012180A1 (en) 2022-01-20

Family

ID=72843364

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2021/096254 WO2022012180A1 (en) 2020-07-14 2021-05-27 Interdigitated back contact heterojunction solar cell based on lpcvd efficient amorphous silicon doping technology

Country Status (2)

Country Link
CN (1) CN111816727A (en)
WO (1) WO2022012180A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114937717A (en) * 2022-05-30 2022-08-23 江苏日托光伏科技股份有限公司 Preparation method of perovskite-HBC laminated double-sided battery
CN115101621A (en) * 2022-05-24 2022-09-23 中南大学 P-topcon battery and preparation method thereof

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111816727A (en) * 2020-07-14 2020-10-23 普乐新能源科技(徐州)有限公司 Interdigital back contact heterojunction solar cell based on LPCVD (low pressure chemical vapor deposition) high-efficiency amorphous silicon doping technology
CN112736163B (en) * 2021-02-10 2022-07-29 普乐（合肥）光技术有限公司 Preparation method of polycrystalline silicon thin film passivation back electrode interdigital solar cell
CN113604791B (en) * 2021-06-16 2023-10-10 拉普拉斯新能源科技股份有限公司 Based on BCl 3 Gas LPCVD boron doped amorphous silicon horizontal coating method and application
CN113284961B (en) * 2021-07-22 2021-09-28 浙江爱旭太阳能科技有限公司 Solar cell and passivation contact structure thereof, cell module and photovoltaic system
CN114038920B (en) * 2021-09-17 2024-01-26 普乐新能源科技(泰兴)有限公司 Ultra-efficient interdigital back contact heterojunction solar cell
CN115207137B (en) * 2022-09-16 2023-02-17 金阳(泉州)新能源科技有限公司 Combined passivation back contact battery and preparation method thereof

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100108130A1 (en) * 2008-10-31 2010-05-06 Crystal Solar, Inc. Thin Interdigitated backside contact solar cell and manufacturing process thereof
CN102623517A (en) * 2012-04-11 2012-08-01 中国科学院苏州纳米技术与纳米仿生研究所 Back contact type crystalline silicon solar cell and production method thereof
CN108963005A (en) * 2018-07-05 2018-12-07 深圳市拉普拉斯能源技术有限公司 A kind of full rear heteroj connection solar cell of compound structure for new residence and preparation method
CN110047949A (en) * 2019-04-04 2019-07-23 国家电投集团西安太阳能电力有限公司 A kind of hetero-junctions back contact solar cell and preparation method thereof
CN210403753U (en) * 2019-07-15 2020-04-24 国家电投集团西安太阳能电力有限公司 Interdigital back contact solar cell structure
CN111816727A (en) * 2020-07-14 2020-10-23 普乐新能源科技(徐州)有限公司 Interdigital back contact heterojunction solar cell based on LPCVD (low pressure chemical vapor deposition) high-efficiency amorphous silicon doping technology

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9705017B2 (en) * 2013-09-27 2017-07-11 Danmarks Tekniske Universitet Nanostructured silicon based solar cells and methods to produce nanostructured silicon based solar cells
US9401450B2 (en) * 2013-12-09 2016-07-26 Sunpower Corporation Solar cell emitter region fabrication using ion implantation
US10079319B2 (en) * 2015-12-16 2018-09-18 Sunpower Corporation Solar cell fabrication using laser patterning of ion-implanted etch-resistant layers and the resulting solar cells
CN106876501A (en) * 2017-03-10 2017-06-20 泰州乐叶光伏科技有限公司 One kind passivation contact all back-contact electrodes solar battery structure and preparation method thereof
CN206595264U (en) * 2017-03-10 2017-10-27 泰州隆基乐叶光伏科技有限公司 One kind passivation contact all back-contact electrodes solar battery structure
CN108336154A (en) * 2018-02-02 2018-07-27 中国科学院微电子研究所 Crystal silicon solar energy battery and preparation method thereof
CN110634961A (en) * 2018-05-31 2019-12-31 福建金石能源有限公司 Double-sided passivation back contact heterojunction solar cell and manufacturing method thereof

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100108130A1 (en) * 2008-10-31 2010-05-06 Crystal Solar, Inc. Thin Interdigitated backside contact solar cell and manufacturing process thereof
CN102623517A (en) * 2012-04-11 2012-08-01 中国科学院苏州纳米技术与纳米仿生研究所 Back contact type crystalline silicon solar cell and production method thereof
CN108963005A (en) * 2018-07-05 2018-12-07 深圳市拉普拉斯能源技术有限公司 A kind of full rear heteroj connection solar cell of compound structure for new residence and preparation method
CN110047949A (en) * 2019-04-04 2019-07-23 国家电投集团西安太阳能电力有限公司 A kind of hetero-junctions back contact solar cell and preparation method thereof
CN210403753U (en) * 2019-07-15 2020-04-24 国家电投集团西安太阳能电力有限公司 Interdigital back contact solar cell structure
CN111816727A (en) * 2020-07-14 2020-10-23 普乐新能源科技(徐州)有限公司 Interdigital back contact heterojunction solar cell based on LPCVD (low pressure chemical vapor deposition) high-efficiency amorphous silicon doping technology

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115101621A (en) * 2022-05-24 2022-09-23 中南大学 P-topcon battery and preparation method thereof
CN115101621B (en) * 2022-05-24 2023-12-12 中南大学 P-topcon battery and preparation method thereof
CN114937717A (en) * 2022-05-30 2022-08-23 江苏日托光伏科技股份有限公司 Preparation method of perovskite-HBC laminated double-sided battery
CN114937717B (en) * 2022-05-30 2023-09-01 江苏日托光伏科技股份有限公司 perovskite-HBC laminated double-sided battery preparation method

Also Published As

Publication number Publication date
CN111816727A (en) 2020-10-23

Similar Documents

Publication Publication Date Title
WO2022012180A1 (en) Interdigitated back contact heterojunction solar cell based on lpcvd efficient amorphous silicon doping technology
WO2023178918A1 (en) Low-cost contact-passivation all-back electrode solar cell and preparation method therefor
CN109494261A (en) Silica-based solar cell and preparation method, photovoltaic module
TWI463682B (en) Heterojunction solar cell having intrinsic amorphous silicon film
CN102110734B (en) Nanocrystalline silicon/crystalline silicon heterojunction photovoltaic cell
CN101976710A (en) Method for preparing crystalline silicon hetero-junction solar cell based on hydrogenated microcrystalline silicon film
CN102403369A (en) Passivation dielectric film for solar cell
CN111477720A (en) Passivated contact N-type back junction solar cell and preparation method thereof
CN111416013A (en) Heterojunction solar cell with hydrogenated amorphous silicon oxynitride film as passivation layer
WO2024066207A1 (en) New solar cell and fabrication method therefor
CN106876595B (en) A kind of silicon heterogenous solar battery of N-type and preparation method thereof
CN108461554A (en) Full back-contact heterojunction solar battery and preparation method thereof
WO2024060933A1 (en) Solar cell and manufacturing method therefor
CN111416014B (en) Passivated contact back junction silicon heterojunction solar cell and preparation method thereof
CN115176345A (en) Solar cell laminated passivation structure and preparation method thereof
JPH05299677A (en) Solar battery and its manufacture
CN218918901U (en) Heterojunction solar cell
CN114038924A (en) Back contact heterojunction solar cell based on RIE plasma etching texturing
CN114725239B (en) Preparation method of heterojunction battery
CN116130558A (en) Preparation method of novel all-back electrode passivation contact battery and product thereof
CN115425115A (en) TOPCon battery and manufacturing method thereof
CN215118914U (en) Solar cell and passivation contact structure thereof, cell module and photovoltaic system
CN113506842A (en) Preparation method of heterojunction solar cell
CN103107236B (en) Heterojunction solar battery and preparation method thereof
CN112768549A (en) HJT battery with high photoelectric conversion efficiency and preparation method thereof

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21841347

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 21841347

Country of ref document: EP

Kind code of ref document: A1