CN202210522U - 基于p型硅片的背接触异质结太阳电池结构 - Google Patents

基于p型硅片的背接触异质结太阳电池结构 Download PDF

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CN202210522U
CN202210522U CN2011201939979U CN201120193997U CN202210522U CN 202210522 U CN202210522 U CN 202210522U CN 2011201939979 U CN2011201939979 U CN 2011201939979U CN 201120193997 U CN201120193997 U CN 201120193997U CN 202210522 U CN202210522 U CN 202210522U
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张黎明
李玉花
刘鹏
姜言森
杨青天
高岩
徐振华
张春艳
王兆光
程亮
任现坤
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Linuo Solar Power Co Ltd
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    • HELECTRICITY
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    • H01L31/00Semiconductor 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
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    • H01L31/022441Electrode arrangements specially adapted for back-contact solar cells
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00Semiconductor 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
    • H01L31/04Semiconductor 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
    • H01L31/06Semiconductor 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
    • H01L31/072Semiconductor 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
    • H01L31/0745Semiconductor 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 comprising a AIVBIV heterojunction, e.g. Si/Ge, SiGe/Si or Si/SiC solar cells
    • H01L31/0747Semiconductor 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 comprising a AIVBIV heterojunction, e.g. Si/Ge, SiGe/Si or Si/SiC solar cells comprising a heterojunction of crystalline and amorphous materials, e.g. heterojunction with intrinsic thin layer or HIT® solar cells; solar cells
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    • Y02E10/547Monocrystalline silicon PV cells

Abstract

本实用新型涉及一种太阳电池,具体涉及一种基于P型硅片的背接触异质结太阳电池结构。从背面特征分为N型区域和P型区域,N型区域形成P+a-si/i-a-si/P-c-si/P+c-si/i-a-si/N-a-si异质结结构,P型区域形成P+a-si/i-a-si/P-c-si/P+c-si异质结结构,具有更好的光谱响应特性,太阳光在电池内传播光程更长,电池较常规晶硅太阳能电池厚度大大减薄;电极全部印刷在电池背面,避免了常规太阳能电池正面电极遮光的问题,提高了太阳能电池短路电流,进而大大提高太阳电池的转化效率;低温烧结工艺大大简化生产工艺、降低生产成本,适用于产业化生产。

Description

基于P型硅片的背接触异质结太阳电池结构
技术领域
本实用新型涉及一种太阳电池结构,具体涉及一种基于P型硅片的背接触异质结太阳电池结构。 
背景技术
二十一世纪,能源危机和环境污染已经成为亟待解决的全球问题。开发绿色能源成为解决危机的主要方法。其中太阳电池因其洁净、安全、可再生成为世界各国竞相发展的目标。目前太阳电池主要发展方向是降低成本、增加效率。 
新型非晶硅和晶硅构成的异质结太阳电池具有结构简单、工艺简易、它将晶体硅具有高载流子迁移率优点与低温化学气相沉积非晶硅工艺优势相结合,成为太阳能行业的热点发展方向。如日本三sanyo集团开发的以N型晶体硅为衬底的HIT电池实验室装换效率已经突破22%,产业化电池片转化效率达到19%。 
上述HIT结构的太阳电池存在以下问题:第一非晶硅薄膜的缺陷较多,增加了薄膜体内的载流子复合缺陷密度,影响光生电流的收集及传输;第二正面的栅线设计是电池受光面积减少,从而降低短路电流,影响太阳电池最终的转化效率。 
发明内容
本实用新型的目的就是针对上述存在的缺陷而提供一种基于P型硅片的背接触异质结太阳电池结构,具有更好的光谱响应特性,太阳光在电池内传播光程更长,电池较常规晶硅太阳能电池厚度大大减薄;电极全部印刷在电池背面,即避免了常规太阳能电池正面电极遮光的问题,提高了太阳能电池短路电流,进而大大提高太阳电池的转化效率;低温烧结工艺大大简化生产工艺、降低生产成本,适用于产业化生产。 
本实用新型采用的技术方案为,一种基于P型硅片的背接触异质结太阳电池结构,从背面特征分为N型区域和P型区域,P型区域包括由上到下依次叠层结合的受光面减反射膜、P+ a-Si P+非晶硅薄膜、i-a-Si本征非晶硅薄膜、P-C-Si P型晶体硅、P+ c-Si P+晶硅层、透明导电薄膜TCO和背电极,形成P+ a-si/ i- a-si/P-c-si/P+c-si异质结结构,N型区域包括由上到下依次叠层结合的受光面减反射膜、P+ a-Si P+非晶硅薄膜、i-a-Si本征非晶硅薄膜、P-C-Si P型晶体硅、P+ c-Si P+晶硅层、i-a-Si本征非晶硅薄膜、N-a-Si非晶硅薄膜、透明导电薄膜TCO和背电极,形成P+ a-si/ i- a-si/P-c-si/P+c-si/i-a-si/N-a-si异质结结构。 
所述的受光面减反射膜为SiO2、Si3N4、Ta2O5或TiO2,减反射膜厚度为70~90nm,折射率为1.5~2.5。 
采用化学气相沉积工艺在P型晶体硅上面和N型区域的N+晶硅层下面制作本征非晶硅薄膜,厚度为1~50nm。 
所述的P型晶体硅为单晶硅、太阳能级或金属级多晶硅、带状硅,其厚度为120~220um,掺杂浓度为1×1015~5×1017/cm3。 
所述的P+型晶体硅层,其厚度为0.1~0.5um,浓硼掺杂浓度为1×1018~5×1020/cm3。 
在N型区域中,采用化学气相沉积工艺在本征非晶硅薄膜下面沉积一层P-a-Si非晶硅薄膜,厚度为1~50nm。 
透明导电薄膜TCO为氧化物透明导电材料体系,为In2O3、SnO2、ZnO、In2O3:Sn(ITO)、In2O3:Mo(IMO)、SnO2:Sb(ATO)、SnO2:F(FTO)、ZnO:Al(ZnO)、ZnO·SnO2、ZnO·In2O3、CdSb2O6、MgIn2O4、In4Sn3O12、Zn2In2O5、CdIn2O4、Cd2SnO4、Zn2SnO4、GaInO3中的一种,其厚度为50nm~900nm。 
所述的背电极为Al、Ag、Au、Ni 、Cu/Ni、Al/Ni或Ti/Pd/Ag电极,其厚度为50nm~600um。 
本实用新型的基于P型硅片的背接触异质结太阳电池结构具有以下有益效果:一是是低温制作工艺,降低生产成本;三是背接触电极降低接触电阻,有效降低电池受光面的遮光率,从而提高太阳电池的短路电流,大大提高太阳能电池的转化效率。四是温度系数低,适合高温环境使用。 
本实用新型的基于P型硅片的背接触异质结太阳电池结构,从背面特征分为N型区域和P型区域,P型区域包括由上到下依次叠层结合的受光面减反射膜、P+ a-Si P+非晶硅薄膜、i-a-Si本征非晶硅薄膜、P-C-Si P型晶体硅、P+ c-Si P+晶硅层、透明导电薄膜TCO和背电极,形成P+ a-si/ i- a-si/P-c-si/P+c-si异质结结构,N型区域包括由上到下依次叠层结合的受光面减反射膜、P+ a-Si P+非晶硅薄膜、i-a-Si本征非晶硅薄膜、P-C-Si P型晶体硅、P+ c-Si P+晶硅层、i-a-Si本征非晶硅薄膜、N-a-Si非晶硅薄膜、透明导电薄膜TCO和背电极,形成P+ a-si/ i- a-si/P-c-si/P+c-si/i-a-si/N-a-si异质结结构。该结构的具体作用如下: 
背接触电极主要起到收集电流作用。
所述的透明导电薄膜TCO具有较高的透光性和电导率,主要起到收集电流的作用,另外还将透过电池体内的太阳光反射回去,增加太阳电池光吸收的作用。 
采用化学气相沉积工艺在P型晶体硅上面和N型区域的N+晶硅层下面制作本征非晶硅薄膜,厚度为1~50nm。主要起到减少界面缺陷态,增加表面钝化效应。 
所述的N-a-Si非晶硅薄膜采用化学气相沉积工艺在本征非晶硅薄膜上再沉积一层,厚度为1~50nm。N-a-si非晶硅薄膜沉积在i-a-si本征非晶硅薄膜层上与P型晶硅电池形成核心结构HIT异质结。 
所述的P+型晶体硅层,其厚度为0.1~0.5um,浓硼掺杂浓度为1×1018~5×1020/cm3。其作用是形成高低结,提升开路电压,同时起到背面钝化的作用。 
所述的减反射膜为SiO2、Si3N4、Ta2O5、TiO2中的一种,减反射膜厚度为70~90nm,折射率为1.5~2.5。其作用主要是增加光吸收,减低太阳光在电池表面的反射损失,另外,减反射膜还具有表面钝化的作用。 
采用以上技术方案制作的P型硅片的背接触式HIT太阳电池,制备方法简单,能够迅速产业化。另外其背接触的结构在太阳电池的受光面无栅线覆盖,不仅增加了太阳电池的受光面积,还在在组件生产中可简化了焊接工序外观要求,节约生产时间,降低组件生产成本。 
附图说明
图1所示为本实用新型电池结构示意图; 
图2所示为本实用新型实施例1中背面电极的示意图;
图3所示为本实用新型实施例1工艺流程示意图.
图中,1、受光面减反射膜,2、P+ a-Si非晶硅薄膜,3、本征非晶硅薄膜,4、P型晶体硅,5、P+晶硅层,6、N-a-Si非晶硅薄膜,7、透明导电薄膜TCO,8、背电极;a.  P型硅片检测、清洗及表面织构化;b.    在下表面扩散一层P+型重掺杂层;c. 在上下表面沉积一层本征非晶硅薄层;d. 在上表面沉积一层P+型非晶硅薄层;e.   在下表面沉积一层n型非晶硅薄膜;f.    在上表面PECVD制备氮化硅减反射膜;g.   使用腐蚀浆料腐蚀至露出P型硅基体;h.  在下表面溅射一层TCO导电层,用激光将P区和n区分开;i.    丝网印刷电极,低温烧结。
具体实施方式:
下面结合附图和实例来说明本实用新型的技术方案,但是本实用新型并不局限于此。
实施例1 
P型晶体硅4选用P型单晶硅片,采用半导体清洗工艺对P型晶体硅4表面预清洗和表面织构。所用P型晶体硅4厚度在200um, 电阻率为0.5~3Ω.cm,用1~5%的氢氟酸去除硅片表面的二氧化硅层,在浓度小于3%的NaOH和IPA(异丙醇)的混合液中80℃左右制备金字塔形状绒面。增加对太阳光的吸收,增加PN结面积,提高短路电流。再用酸清洗工艺将之后的P型晶体硅4清洗干净-甩干。将制绒后P型晶体硅4放入扩散炉中用硼烷在850℃左右进行单面重扩散,在P型晶体硅4下表面形成一层P+晶硅层5,经等离子刻蚀后,用HF溶液清洗,去离子水清洗后甩干;
用等离子体增强化学气相沉积(PECVD)工艺,在250℃扩散后晶硅的上下表面分别沉积一层本征非晶硅薄膜3,厚度约5nm,有钝化作用。在晶硅的上表面沉积高浓度P+ a-Si非晶硅薄膜2,厚度为5~10nm;在背表面沉积一层N-a-si非晶硅薄层6,厚度为5~10nm;在400℃下,用PECVD在硅片正表面生长氮化硅受光面减反射膜1,厚度为85nm,折射率为2.05;其作用减少电池表面的反射损失,镀膜后的太阳电池光反射损失可以减少到4%以内;同时对电池进行有效地表面钝化和体钝化,减少复合中心,提高少子寿命,增加光电流。在硅片背面印刷上腐蚀性浆料,腐蚀掉印刷区域的N-a-si 非晶硅薄层6和本征非晶硅薄膜3,露出P+晶硅层5表面,未腐蚀区域的HIT结构被保存下来。最后用去离子水超声清洗干净后,烘干。通过磁控溅射工艺在硅片的背面沉积一层厚度为30~100nm的透明导电层薄膜TCO 7。再用激光将P型区域与N型区域分割。在背表面的N型区域和P型区域分别丝网印刷导电浆料经低温烧结制成背电极8。电池背面图形2 所示。N型区域上采用的电极印刷材料为银浆;P型区域上采用的电极印刷材料为银浆、银铝浆,或者是类似常规太阳能电池背面银铝浆结构的一种。
本实施例制备的基于N型多晶硅片的背接触异质结太阳电池的电性能输出参数:在标准测量条件下:测量温度25oC,光强1000W/m2,AM1.5 光谱测试,短路电流密度40mA/cm2;开路电压681mV,填充因子79%;光电转换效率21.1 %。 

Claims (8)

1.一种基于P型硅片的背接触异质结太阳电池结构,从背面特征分为N型区域和P型区域,其特征在于:P型区域包括由上到下依次叠层结合的受光面减反射膜、P+ a-Si P+非晶硅薄膜、i-a-Si本征非晶硅薄膜、P-C-Si P型晶体硅、P+ c-Si P+晶硅层、透明导电薄膜TCO和背电极,形成P+ a-si/ i- a-si/P-c-si/P+c-si异质结结构,N型区域包括由上到下依次叠层结合的受光面减反射膜、P+ a-Si P+非晶硅薄膜、i-a-Si本征非晶硅薄膜、P-C-Si P型晶体硅、P+ c-Si P+晶硅层、i-a-Si本征非晶硅薄膜、N-a-Si非晶硅薄膜、透明导电薄膜TCO和背电极,形成P+ a-si/ i- a-si/P-c-si/P+c-si/i-a-si/N-a-si异质结结构。
2.根据权利要求1所述的基于P型硅片的背接触异质结太阳电池结构,其特征在于:所述的受光面减反射膜为SiO2、Si3N4、Ta2O5或TiO2,减反射膜厚度为70~90nm,折射率为1.5~2.5。
3.根据权利要求1所述的基于P型硅片的背接触异质结太阳电池结构,其特征在于:所述的i-a-Si本征非晶硅薄膜,厚度为1~50nm。
4.根据权利要求1所述的基于P型硅片的背接触异质结太阳电池结构,其特征在于:所述的P型晶体硅为单晶硅、太阳能级或金属级多晶硅、带状硅,其厚度为120~220um,掺杂浓度为1×1015~5×1017/cm3。
5.根据权利要求1所述的基于P型硅片的背接触异质结太阳电池结构,其特征在于:所述的P+型晶体硅层,其厚度为0.1~0.5um。
6.根据权利要求1所述的基于P型硅片的背接触异质结太阳电池结构,其特征在于:在N型区域中, P-a-Si非晶硅薄膜厚度为1~50nm。
7.根据权利要求1所述的基于P型硅片的背接触异质结太阳电池结构,其特征在于:透明导电薄膜TCO为氧化物透明导电材料体系,为In2O3、SnO2、ZnO、In2O3:Sn(ITO)、In2O3:Mo(IMO)、SnO2:Sb(ATO)、SnO2:F(FTO)、ZnO:Al(ZnO)、ZnOSnO2、ZnOIn2O3、CdSb2O6、MgIn2O4、In4Sn3O12、Zn2In2O5、CdIn2O4、Cd2SnO4、Zn2SnO4、GaInO3中的一种,其厚度为50nm~900nm。
8.根据权利要求1所述的基于P型硅片的背接触异质结太阳电池结构,其特征在于:所述的背电极为Al、Ag、Au、Ni 、Cu/Ni、Al/Ni或Ti/Pd/Ag电极,其厚度为50nm~600um。
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102214720A (zh) * 2011-06-10 2011-10-12 山东力诺太阳能电力股份有限公司 基于p型硅片的背接触异质结太阳电池
CN110676343A (zh) * 2018-06-15 2020-01-10 君泰创新(北京)科技有限公司 一种背接触太阳能电池及其制备方法
EP4239690A3 (en) * 2022-10-28 2024-04-24 Trina Solar Co., Ltd Solar cell and preparation method thereof

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102214720A (zh) * 2011-06-10 2011-10-12 山东力诺太阳能电力股份有限公司 基于p型硅片的背接触异质结太阳电池
CN110676343A (zh) * 2018-06-15 2020-01-10 君泰创新(北京)科技有限公司 一种背接触太阳能电池及其制备方法
EP4239690A3 (en) * 2022-10-28 2024-04-24 Trina Solar Co., Ltd Solar cell and preparation method thereof

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