阅读说明：本技术 异质结太阳能电池片、叠瓦组件及制造方法 (Heterojunction solar cell, laminated tile assembly and manufacturing method ) 是由 薛建锋 王月斌 余义 苏世杰 王秀鹏 石刚 李岩 于 2020-06-10 设计创作，主要内容包括：本发明提供了一种异质结太阳能电池片、叠瓦组件和制造异质结太阳能电池片的方法。异质结太阳能电池片包括衬底层、本征非晶硅薄膜层、掺杂层、透光导电层以及电极。位于衬底层顶侧和底侧的本征非晶硅薄膜层均包括四层结构,这四层结构彼此不同。根据本发明,衬底层的顶侧和底侧的本征非晶硅薄膜层结构均包括四层结构,这四层结构彼此的成分均不相同,组合在一起能够较大程度地发挥出本征非晶硅薄膜层的优势,并能够提升太阳能电池片整体的电性能或效率。(The invention provides a heterojunction solar cell, a laminated assembly and a method for manufacturing the heterojunction solar cell. The heterojunction solar cell comprises a substrate layer, an intrinsic amorphous silicon thin film layer, a doping layer, a light-transmitting conducting layer and an electrode. The intrinsic amorphous silicon thin film layers on the top and bottom sides of the substrate layer each include four layer structures, which are different from each other. According to the invention, the intrinsic amorphous silicon thin film layer structures on the top side and the bottom side of the substrate layer respectively comprise four-layer structures, the four-layer structures have different components, the combination of the four-layer structures can exert the advantages of the intrinsic amorphous silicon thin film layer to a greater extent, and the integral electrical property or efficiency of the solar cell can be improved.)

1. A heterojunction solar cell comprising a substrate sheet, electrodes disposed on a top surface and a bottom surface of the substrate sheet, wherein the substrate sheet comprises:

a monocrystalline silicon substrate layer;

the two groups of intrinsic amorphous silicon thin film layers comprise a first group of intrinsic amorphous silicon thin film layers arranged on the top side of the monocrystalline silicon substrate layer and a second group of intrinsic amorphous silicon thin film layers arranged on the bottom side of the monocrystalline silicon substrate layer, and the first group of intrinsic amorphous silicon thin film layers and the second group of intrinsic amorphous silicon thin film layers respectively comprise the following four-layer structures which are sequentially arranged in the direction from the monocrystalline silicon substrate layer to the electrode:

the first intrinsic amorphous silicon thin film layer is of an integral layered structure of carbon-same-family doped silicon;

the second intrinsic amorphous silicon thin film layer is of an integral layered structure formed by depositing a silicon source atmosphere;

the third intrinsic amorphous silicon thin film layer is of an integral layered structure formed by deposition of mixed gas of at least one of hydrogen-containing atmosphere and deuterium-containing atmosphere and silicon source atmosphere;

the fourth intrinsic amorphous silicon thin film layer is of an integral layered structure formed by deposition of mixed gas of at least one of hydrogen-containing atmosphere and deuterium-containing atmosphere, silicon source atmosphere and carbon source atmosphere;

the N-type doping layer is positioned on the top side of the first group of intrinsic amorphous silicon thin film layers;

the P-type doping layer is positioned at the bottom side of the second group of intrinsic amorphous silicon thin film layers;

and the light-transmitting conductive layers are respectively arranged on the top side of the N-type doped layer and the bottom side of the P-type doped layer, and the electrodes are arranged on the surface of the light-transmitting conductive layers.

2. The heterojunction solar cell of claim 1, wherein the first intrinsic amorphous silicon thin film layer is an integral layered structure deposited from a mixture of silane doped with at least one of alkane, alkene, and alkyne.

3. The heterojunction solar cell of claim 1, wherein the third intrinsic amorphous silicon thin film layer is an integral layered structure deposited from a mixed gas having a ratio of the amounts of hydrogen and silane gases in the range of 3 to 15.

4. The heterojunction solar cell of claim 1, wherein the fourth intrinsic amorphous silicon thin film layer is an integral layered structure deposited from a mixed gas having a ratio of the amount of alkane to hydrogen in the range of 1/20-3/5.

5. The heterojunction solar cell of claim 1, wherein the N-type doped layer and the P-type doped layer each comprise a first doped layer in contact with the fourth intrinsic amorphous silicon thin film layer and a second doped layer in contact with the transparent conductive layer, the first doped layer is an amorphous silicon integral layered structure, the second doped layer is a microcrystalline silicon integral layered structure, and the doping concentration of the second doped layer is greater than the doping concentration of the first doped layer.

6. The heterojunction solar cell sheet of claim 5,

the first doped layer of the N-type doped layer is of an integral layered structure formed by deposition of mixed gas of silane and phosphine and at least one of hydrogen-containing atmosphere and deuterium-containing atmosphere;

the second layer doped layer of the N-type doped layer is an integral layered structure formed by deposition of mixed gas of silane, phosphane and carbon dioxide and at least one of hydrogen-containing atmosphere and deuterium-containing atmosphere.

7. The heterojunction solar cell sheet of claim 5,

the first layer of doped layer of the P-type doped layer is of an integral layered structure formed by deposition of mixed gas of silane and trimethylboron and at least one of hydrogen-containing atmosphere and deuterium-containing atmosphere;

the second layer doped layer of the P-type doped layer is of an integral layered structure formed by deposition of a mixed gas of silane, borane and carbon dioxide and at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere.

8. The heterojunction solar cell of claim 5 or 6, wherein the first of the N-doped layers is doped with phosphorus in an amount of 14ppm to 17 ppm.

9. The heterojunction solar cell of claim 5 or 6, wherein the crystallinity of the second of the N-doped layers is 40% -65% and the doping amount of phosphorus in the second of the N-doped layers is 18ppm-22 ppm.

10. The heterojunction solar cell of claim 5 or 7, wherein the doping amount of boron in the first one of the P-type doped layers is 14ppm to 17 ppm.

11. The heterojunction solar cell of claim 5 or 7, wherein the crystallinity of the second doped layer of the P-type doped layer is 40% -65%, and the doping amount of boron of the second doped layer of the P-type doped layer is 18ppm-22 ppm.

12. The heterojunction solar cell of claim 1, wherein the substrate layer is an N-type single crystal silicon substrate layer.

13. A stack of tiles, characterized in that the stack of tiles is formed by connecting the heterojunction solar cells of any of claims 1 to 12 in a stacked manner.

14. A heterojunction solar cell comprising a substrate sheet, electrodes disposed on top and bottom surfaces of the substrate sheet, the substrate sheet comprising:

the two groups of intrinsic amorphous silicon thin film layers comprise a first group of intrinsic amorphous silicon thin film layers arranged on the top side of the monocrystalline silicon substrate layer and a second group of intrinsic amorphous silicon thin film layers arranged on the bottom side of the monocrystalline silicon substrate layer, and the first group of intrinsic amorphous silicon thin film layers and the second group of intrinsic amorphous silicon thin film layers respectively comprise four-layer structures;

the N-type doping layer is positioned on the top side of the first group of intrinsic amorphous silicon thin film layers;

the P-type doping layer is positioned at the bottom side of the second group of intrinsic amorphous silicon thin film layers;

a light-transmissive conductive layer disposed on a top side of the N-type doped layer and a bottom side of the P-type doped layer, respectively, the electrodes being disposed on a surface of the light-transmissive conductive layer,

and the N-type doping layer and the P-type doping layer respectively comprise a first doping layer in contact with the intrinsic amorphous silicon thin film layer and a second doping layer in contact with the light-transmitting conductive layer, the first doping layer is of an amorphous silicon integral layered structure, the second doping layer is of a microcrystalline silicon integral layered structure, and the doping concentration of the second doping layer is greater than that of the first doping layer.

15. The heterojunction solar cell of claim 14,

the first doped layer of the N-type doped layer is of an integral layered structure formed by deposition of mixed gas of silane and phosphine and at least one of hydrogen-containing atmosphere and deuterium-containing atmosphere;

the second layer doped layer of the N-type doped layer is an integral layered structure formed by deposition of mixed gas of silane, phosphane and carbon dioxide and at least one of hydrogen-containing atmosphere and deuterium-containing atmosphere.

16. The heterojunction solar cell of claim 14,

the first layer of doped layer of the P-type doped layer is of an integral layered structure formed by deposition of mixed gas of silane and trimethylboron and at least one of hydrogen-containing atmosphere and deuterium-containing atmosphere;

the second layer doped layer of the P-type doped layer is of an integral layered structure formed by deposition of a mixed gas of silane, borane and carbon dioxide and at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere.

17. The heterojunction solar cell of claim 14 or 15, wherein the first of the N-doped layers is doped with phosphorus in an amount of 14ppm to 17 ppm.

18. The heterojunction solar cell of claim 14 or 15, wherein the crystallinity of the second of the N-doped layers is 40% -65% and the doping amount of phosphorus in the second of the N-doped layers is 18ppm-22 ppm.

19. The heterojunction solar cell of claim 14 or 16, wherein the doping amount of boron in the first one of the P-type doped layers is 14ppm to 17 ppm.

20. The heterojunction solar cell of claim 14 or 16, wherein the crystallinity of the second of the P-doped layers is 40% -65% and the doping amount of boron in the second of the P-doped layers is 18ppm-22 ppm.

21. A stack of tiles, characterized in that the stack of tiles is formed by connecting the heterojunction solar cells of any of claims 14 to 20 in a stacked manner.

22. A method for manufacturing a heterojunction solar cell, comprising a step of manufacturing a heterojunction solar cell monolith and a step of splitting the heterojunction solar cell monolith, wherein the step of manufacturing the heterojunction solar cell monolith further comprises the steps of:

setting a monocrystalline silicon substrate layer;

arranging a first group of intrinsic amorphous silicon thin film layers on the top side of the monocrystalline silicon substrate layer, and arranging a second group of intrinsic amorphous silicon thin film layers on the bottom side of the monocrystalline silicon substrate layer;

arranging an N-type doping layer on the top side of the first group of intrinsic amorphous silicon thin film layers, and arranging a P-type doping layer on the bottom side of the second group of intrinsic amorphous silicon thin film layers;

arranging light-transmitting conducting layers on the top side of the N-type doped layer and the bottom side of the P-type doped layer;

electrodes are applied to the exposed surfaces of the light-transmissive electrically conductive layer,

the steps of arranging the first group of intrinsic amorphous silicon thin film layers and the second group of intrinsic amorphous silicon thin film layers respectively comprise the following steps:

depositing a first intrinsic amorphous silicon thin film layer on the top surface or the bottom surface of the monocrystalline silicon substrate layer by using a mixed gas of carbon and family-doped silicon;

depositing a second intrinsic amorphous silicon thin film layer on the exposed surface of the first intrinsic amorphous silicon thin film layer by using a silicon source atmosphere;

forming a third intrinsic amorphous silicon thin film layer on the exposed surface of the second intrinsic amorphous silicon thin film layer by deposition using a mixed gas of a silicon source atmosphere and at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere;

and depositing the exposed surface of the third intrinsic amorphous silicon thin film layer by using the mixed gas of at least one of hydrogen-containing atmosphere and deuterium-containing atmosphere, silicon source atmosphere and carbon source atmosphere to form a fourth intrinsic amorphous silicon thin film layer.

23. The method of claim 22, wherein the step of providing the first intrinsic amorphous silicon thin film layer comprises: the first intrinsic amorphous silicon thin film layer is formed using mixed gas deposition of silane doped at least one of alkane, alkene, alkyne.

24. The method of claim 22, wherein the step of providing a third intrinsic amorphous silicon thin film layer comprises: and forming a third intrinsic amorphous silicon thin film layer by deposition using a mixed gas having a ratio of the amounts of hydrogen gas and silane gas in the range of 3-15.

25. The method of claim 22, wherein the step of providing the fourth intrinsic amorphous silicon thin film layer comprises: the fourth intrinsic amorphous silicon thin film layer is formed by deposition using a mixed gas having a ratio of the amount of alkane to the amount of hydrogen ranging from 1/20 to 3/5.

26. The method of claim 22, wherein the step of providing an N-doped layer and the step of providing a P-doped layer each comprise the steps of:

generating a first doping layer made of amorphous silicon materials on the fourth intrinsic amorphous silicon thin film layer by using mixed gas with first doping concentration;

a second doped layer of microcrystalline silicon material is formed on the first doped layer using a gas mixture having a second doping concentration greater than the first doping concentration.

27. The method of claim 26, wherein the step of providing an N-doped layer comprises the steps of:

forming a first doped layer by deposition using a mixed gas of silane and phosphine and at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere;

the second layer doping layer is formed by deposition using a mixed gas of silane, phosphane, and carbon dioxide, and at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere.

28. The method of claim 27, wherein the step of providing a P-doped layer comprises the steps of:

forming a first doped layer by deposition using a mixed gas of silane and trimethylboron mixed with at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere;

the second layer doped layer is formed by deposition using a mixed gas of silane, borane, and carbon dioxide in a mixture with at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere.

29. The method of claim 27, wherein the step of fabricating the first one of the N-doped layers comprises: the proportions of the components in the mixed gas are controlled so that the doping amount of phosphorus of the first doped layer of the N-type doped layer is 14ppm-17 ppm.

30. The method of claim 27, wherein the step of fabricating the second N-doped layer comprises: the proportion of each component in the mixed gas is controlled so that the crystallinity of the second doping layer of the N-type doping layer is 40-65% and the doping amount of phosphorus is 18-22 ppm.

31. The method of claim 28, wherein the step of fabricating the first doped layer of the P-doped layer comprises: the proportion of each component in the mixed gas is controlled so that the doping amount of boron of the first layer doping layer of the formed P-type doping layer is 14ppm-17 ppm.

32. The method of claim 28, wherein the step of fabricating the second doped layer of the P-doped layer comprises: the proportion of each component in the mixed gas is controlled so that the crystallinity of the second doping layer of the formed P-type doping layer is 40-65% and the doping amount of boron is 18-22 ppm.

33. The method of claim 22, wherein the monocrystalline silicon substrate layer is provided as an N-type monocrystalline silicon substrate layer.

34. A method for manufacturing a heterojunction solar cell, comprising a step of manufacturing a heterojunction solar cell monolith and a step of splitting the heterojunction solar cell monolith, wherein the step of manufacturing the heterojunction solar cell monolith further comprises the steps of:

setting a monocrystalline silicon substrate layer;

arranging a first group of intrinsic amorphous silicon thin film layers on the top side of the monocrystalline silicon substrate layer, arranging a second group of intrinsic amorphous silicon thin film layers on the bottom side of the monocrystalline silicon substrate layer, wherein the first group of intrinsic amorphous silicon thin film layers and the second group of intrinsic amorphous silicon thin film layers respectively comprise four-layer structures;

arranging an N-type doping layer on the top side of the first group of intrinsic amorphous silicon thin film layers, and arranging a P-type doping layer on the bottom side of the second group of intrinsic amorphous silicon thin film layers;

arranging light-transmitting conducting layers on the top side of the N-type doped layer and the bottom side of the P-type doped layer;

electrodes are applied to the exposed surfaces of the light-transmissive electrically conductive layer,

the step of arranging the N-type doping layer and the step of arranging the P-type doping layer both comprise the following steps of:

generating a first doping layer made of amorphous silicon materials on the fourth intrinsic amorphous silicon thin film layer by using mixed gas with first doping concentration;

a second doped layer of microcrystalline silicon material is formed on the first doped layer using a gas mixture having a second doping concentration greater than the first doping concentration.

35. The method of claim 34, wherein the step of providing an N-doped layer comprises the steps of:

forming a first doped layer by deposition using a mixed gas of silane and phosphine and at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere;

the second layer doping layer is formed by deposition using a mixed gas of silane, phosphane, and carbon dioxide, and at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere.

36. The method of claim 34, wherein the step of providing a P-doped layer comprises the steps of:

forming a first doped layer by deposition using a mixed gas of silane and trimethylboron mixed with at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere;

the second layer doped layer is formed by deposition using a mixed gas of silane, borane, and carbon dioxide in a mixture with at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere.

37. The method of claim 35, wherein the step of fabricating the first one of the N-doped layers comprises: the proportions of the components in the mixed gas are controlled so that the doping amount of phosphorus of the first doped layer of the N-type doped layer is 14ppm-17 ppm.

38. The method of claim 35, wherein the step of fabricating the second N-doped layer comprises: the proportion of each component in the mixed gas is controlled so that the crystallinity of the second doping layer of the N-type doping layer is 40-65% and the doping amount of phosphorus is 18-22 ppm.

39. The method of claim 36, wherein the step of fabricating the first doped layer of the P-doped layer comprises: the proportion of each component in the mixed gas is controlled so that the doping amount of boron of the first layer doping layer of the formed P-type doping layer is 14ppm-17 ppm.

40. The method of claim 36, wherein the step of fabricating the second doped layer of the P-doped layer comprises: the proportion of each component in the mixed gas is controlled so that the crystallinity of the second doping layer of the formed P-type doping layer is 40-65% and the doping amount of boron is 18-22 ppm.

Technical Field

The invention relates to the field of energy, in particular to a heterojunction solar cell, a laminated tile assembly and a manufacturing method of the heterojunction solar cell.

Background

With the increasing consumption of conventional fossil energy such as global coal, oil, natural gas and the like, the ecological environment is continuously deteriorated, and particularly, the sustainable development of the human society is seriously threatened due to the increasingly severe global climate change caused by the emission of greenhouse gases. Various countries in the world make respective energy development strategies to deal with the limitation of conventional fossil energy resources and the environmental problems caused by development and utilization. Solar energy has become one of the most important renewable energy sources by virtue of the characteristics of reliability, safety, universality, long service life, environmental protection and resource sufficiency, and is expected to become a main pillar of global power supply in the future.

In a new energy revolution process, the photovoltaic industry in China has grown into a strategic emerging industry with international competitive advantages. However, the development of the photovoltaic industry still faces many problems and challenges, and the conversion efficiency and reliability are the biggest technical obstacles restricting the development of the photovoltaic industry, while the cost control and the scale-up are economically restricted.

At present, the heterojunction solar cell has a series of advantages of high conversion efficiency, short manufacturing process flow, thin silicon wafer, low temperature coefficient, no light attenuation, double-sided power generation, high double-sided efficiency and the like, and is praised as the next generation ultra-high efficiency solar cell technology with the best industrialization potential.

The top side and the bottom side of the conventional heterojunction solar cell comprise a multi-layer structure, and the layers are relatively independent, and the layers are not matched with each other, i.e., the simple combination of the layers does not fully exert their advantages. Moreover, for any single layer, the performances of different aspects of the single layer are generally mutually restricted, for example, the single layer cannot achieve better conductivity and light transmittance; if the function of a single layer is maximized, the electrical performance or efficiency of the whole cell may be affected, i.e., the function of the single layer and the efficiency of the whole solar cell cannot be considered.

There is thus a need to provide a heterojunction solar cell, a stack of tiles and a method of manufacturing a heterojunction solar cell that at least partially solve the above-mentioned problems.

Disclosure of Invention

The invention aims to provide a heterojunction solar cell, a laminated tile assembly and a manufacturing method of the heterojunction solar cell.

Specifically, in the four-layer structure, the components of the first intrinsic amorphous silicon thin film layer enable the amorphous silicon thin film layer not to become long-range order and not to grow into epitaxial silicon, and the light absorption performance of the first intrinsic amorphous silicon thin film layer is poor, so that the short-circuit current of the battery piece can be improved; the second intrinsic amorphous silicon thin film layer can improve the passivation effect and ensure the open-circuit voltage of the solar cell; the third intrinsic amorphous silicon thin film layer can provide hydrogen passivation and has smaller thickness, so that the contact resistance of the film layer is reduced, the filling factor is improved, the light absorption of the film layer is reduced, and the short-circuit current is improved; the fourth intrinsic amorphous silicon thin film layer can be compact so as to effectively prevent doped atoms from diffusing, and the layer structure can also have high transmittance so as to improve short-circuit current.

In addition, in the invention, the doping layers on the top side and the bottom side of the intrinsic amorphous silicon thin film layer can have two-layer structures, namely the amorphous silicon layer with low doping concentration and the microcrystalline silicon layer with high doping concentration, so that the outward diffusion of impurity atoms of the amorphous silicon layer is relatively less, the microcrystalline silicon layer can be in good contact with the light-transmitting conducting layer to reduce contact resistance and improve filling factors, and the transmittance of the microcrystalline silicon layer is high, so that the absorption of the film layer to light can be reduced, and the short-circuit current can be improved.

According to a first aspect of the present invention, there is provided a heterojunction solar cell comprising a substrate sheet, electrodes disposed on a top surface and a bottom surface of the substrate sheet, the substrate sheet comprising:

a monocrystalline silicon substrate layer;

the two groups of intrinsic amorphous silicon thin film layers comprise a first group of intrinsic amorphous silicon thin film layers arranged on the top side of the monocrystalline silicon substrate layer and a second group of intrinsic amorphous silicon thin film layers arranged on the bottom side of the monocrystalline silicon substrate layer, and the first group of intrinsic amorphous silicon thin film layers and the second group of intrinsic amorphous silicon thin film layers respectively comprise the following four-layer structures which are sequentially arranged in the direction from the monocrystalline silicon substrate layer to the electrode:

the first intrinsic amorphous silicon film layer is made of carbon

An integral layered structure of group-doped silicon;

a second intrinsic amorphous silicon thin film layer made of silicon

The whole laminated structure is formed by deposition of source atmosphere;

the third intrinsic amorphous silicon thin film layer is composed of

At least one of hydrogen atmosphere and deuterium-containing atmosphere and silicon source atmosphere

Forming an integral laminated structure;

a fourth intrinsic amorphous silicon thin film layer consisting of

Mixed gas of at least one of hydrogen atmosphere and deuterium-containing atmosphere, silicon source atmosphere and carbon source atmosphere

Bulk deposition to form an integral layered structure;

the N-type doping layer is positioned on the top side of the first group of intrinsic amorphous silicon thin film layers;

the P-type doping layer is positioned at the bottom side of the second group of intrinsic amorphous silicon thin film layers;

and the light-transmitting conductive layers are respectively arranged on the top side of the N-type doped layer and the bottom side of the P-type doped layer, and the electrodes are arranged on the surface of the light-transmitting conductive layers.

In one embodiment, the first intrinsic amorphous silicon thin film layer is an integral layered structure deposited by silane doping with a mixed gas of at least one of alkane, alkene, and alkyne.

In one embodiment, the third intrinsic amorphous silicon thin film layer is an overall layered structure deposited from a mixed gas in which the ratio of the amounts of hydrogen gas and silane gas is in the range of 3 to 15.

In one embodiment, the fourth intrinsic amorphous silicon thin film layer is an overall layered structure deposited from a mixed gas in which the ratio of the amount of alkane to the amount of hydrogen is in the range of 1/20-3/5.

In one embodiment, each of the N-type doped layer and the P-type doped layer includes a first doped layer in contact with the fourth intrinsic amorphous silicon thin film layer and a second doped layer in contact with the light-transmitting conductive layer, the first doped layer has an amorphous silicon integral layered structure, the second doped layer has a microcrystalline silicon integral layered structure, and the doping concentration of the second doped layer is greater than that of the first doped layer.

In one embodiment, the first doped layer of the N-type doped layer is an integral layered structure deposited by a mixed gas of silane and phosphine and at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere;

the second layer doped layer of the N-type doped layer is an integral layered structure formed by deposition of mixed gas of silane, phosphane and carbon dioxide and at least one of hydrogen-containing atmosphere and deuterium-containing atmosphere.

In one embodiment, the first doped layer of the P-type doped layer is a whole layer structure deposited by a mixed gas of silane and trimethylboron and at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere;

the second layer doped layer of the P-type doped layer is of an integral layered structure formed by deposition of a mixed gas of silane, borane and carbon dioxide and at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere.

In one embodiment, the first of the N-doped layers has a doping level of phosphorus in the range of 14ppm to 17 ppm.

In one embodiment, the crystallinity of the second one of the N-type doped layers is 40% to 65% and the doping amount of phosphorus of the second one of the N-type doped layers is 18ppm to 22 ppm.

In one embodiment, the first one of the P-type doped layers has a boron doping level of 14ppm to 17 ppm.

In one embodiment, the crystallinity of the second one of the P-type doped layers is 40% -65%, and the doping amount of boron of the second one of the P-type doped layers is 18ppm-22 ppm.

In one embodiment, the substrate layer is an N-type single crystal silicon substrate layer.

According to a second aspect of the present invention, a laminated assembly is provided, wherein the laminated assembly is formed by connecting the heterojunction solar cells according to any one of the above aspects in a laminated manner.

According to a third aspect of the present invention, there is provided a heterojunction solar cell comprising a substrate sheet, electrodes disposed on a top surface and a bottom surface of the substrate sheet, the substrate sheet comprising:

the two groups of intrinsic amorphous silicon thin film layers comprise a first group of intrinsic amorphous silicon thin film layers arranged on the top side of the monocrystalline silicon substrate layer and a second group of intrinsic amorphous silicon thin film layers arranged on the bottom side of the monocrystalline silicon substrate layer, and the first group of intrinsic amorphous silicon thin film layers and the second group of intrinsic amorphous silicon thin film layers respectively comprise four-layer structures;

the N-type doping layer is positioned on the top side of the first group of intrinsic amorphous silicon thin film layers;

the P-type doping layer is positioned at the bottom side of the second group of intrinsic amorphous silicon thin film layers;

a light-transmissive conductive layer disposed on a top side of the N-type doped layer and a bottom side of the P-type doped layer, respectively, the electrodes being disposed on a surface of the light-transmissive conductive layer,

and the N-type doping layer and the P-type doping layer respectively comprise a first doping layer in contact with the intrinsic amorphous silicon thin film layer and a second doping layer in contact with the light-transmitting conductive layer, the first doping layer is of an amorphous silicon integral layered structure, the second doping layer is of a microcrystalline silicon integral layered structure, and the doping concentration of the second doping layer is greater than that of the first doping layer.

In one embodiment, the first doped layer of the N-type doped layer is an integral layered structure deposited by a mixed gas of silane and phosphine and at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere;

the second layer doped layer of the N-type doped layer is an integral layered structure formed by deposition of mixed gas of silane, phosphane and carbon dioxide and at least one of hydrogen-containing atmosphere and deuterium-containing atmosphere.

In one embodiment, the first doped layer of the P-type doped layer is a whole layer structure deposited by a mixed gas of silane and trimethylboron and at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere;

the second layer doped layer of the P-type doped layer is of an integral layered structure formed by deposition of a mixed gas of silane, borane and carbon dioxide and at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere.

In one embodiment, the first of the N-doped layers has a doping level of phosphorus in the range of 14ppm to 17 ppm.

In one embodiment, the crystallinity of the second one of the N-type doped layers is 40% to 65% and the doping amount of phosphorus of the second one of the N-type doped layers is 18ppm to 22 ppm.

In one embodiment, the first one of the P-type doped layers has a boron doping level of 14ppm to 17 ppm.

In one embodiment, the crystallinity of the second one of the P-type doped layers is 40% -65%, and the doping amount of boron of the second one of the P-type doped layers is 18ppm-22 ppm.

According to a fourth aspect of the present invention, a laminated assembly is provided, wherein the laminated assembly is formed by connecting the heterojunction solar cells according to any one of the above aspects in a laminated manner.

According to a fifth aspect of the present invention, there is provided a method for manufacturing a heterojunction solar cell, the method comprising a step of manufacturing a heterojunction solar cell slice monolith and a step of breaking the heterojunction solar cell slice monolith, wherein the step of manufacturing the heterojunction solar cell slice monolith further comprises the steps of:

setting a monocrystalline silicon substrate layer;

arranging a first group of intrinsic amorphous silicon thin film layers on the top side of the monocrystalline silicon substrate layer, and arranging a second group of intrinsic amorphous silicon thin film layers on the bottom side of the monocrystalline silicon substrate layer;

arranging an N-type doping layer on the top side of the first group of intrinsic amorphous silicon thin film layers, and arranging a P-type doping layer on the bottom side of the second group of intrinsic amorphous silicon thin film layers;

arranging light-transmitting conducting layers on the top side of the N-type doped layer and the bottom side of the P-type doped layer;

electrodes are applied to the exposed surfaces of the light-transmissive electrically conductive layer,

the steps of arranging the first group of intrinsic amorphous silicon thin film layers and the second group of intrinsic amorphous silicon thin film layers respectively comprise the following steps:

depositing a first intrinsic amorphous silicon thin film layer on the top surface or the bottom surface of the monocrystalline silicon substrate layer by using a mixed gas of carbon and family-doped silicon;

depositing a second intrinsic amorphous silicon thin film layer on the exposed surface of the first intrinsic amorphous silicon thin film layer by using a silicon source atmosphere;

forming a third intrinsic amorphous silicon thin film layer on the exposed surface of the second intrinsic amorphous silicon thin film layer by deposition using a mixed gas of a silicon source atmosphere and at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere;

and depositing the exposed surface of the third intrinsic amorphous silicon thin film layer by using the mixed gas of at least one of hydrogen-containing atmosphere and deuterium-containing atmosphere, silicon source atmosphere and carbon source atmosphere to form a fourth intrinsic amorphous silicon thin film layer.

In one embodiment, the step of disposing the first intrinsic amorphous silicon thin film layer includes: the first intrinsic amorphous silicon thin film layer is formed using mixed gas deposition of silane doped at least one of alkane, alkene, alkyne.

In one embodiment, the step of providing the third intrinsic amorphous silicon thin film layer includes: and forming a third intrinsic amorphous silicon thin film layer by deposition using a mixed gas having a ratio of the amounts of hydrogen gas and silane gas in the range of 3-15.

In one embodiment, the step of disposing the fourth intrinsic amorphous silicon thin film layer includes: the fourth intrinsic amorphous silicon thin film layer is formed by deposition using a mixed gas having a ratio of the amount of alkane to the amount of hydrogen ranging from 1/20 to 3/5.

In one embodiment, the step of disposing the N-type doped layer and the step of disposing the P-type doped layer each include the steps of:

generating a first doping layer made of amorphous silicon materials on the fourth intrinsic amorphous silicon thin film layer by using mixed gas with first doping concentration;

a second doped layer of microcrystalline silicon material is formed on the first doped layer using a gas mixture having a second doping concentration greater than the first doping concentration.

In one embodiment, the step of providing an N-type doped layer comprises the steps of:

forming a first doped layer by deposition using a mixed gas of silane and phosphine and at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere;

the second layer doping layer is formed by deposition using a mixed gas of silane, phosphane, and carbon dioxide, and at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere.

In one embodiment, the step of disposing the P-type doped layer includes the steps of:

forming a first doped layer by deposition using a mixed gas of silane and trimethylboron mixed with at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere;

the second layer doped layer is formed by deposition using a mixed gas of silane, borane, and carbon dioxide in a mixture with at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere.

In one embodiment, the step of fabricating the first one of the N-doped layers comprises: the proportions of the components in the mixed gas are controlled so that the doping amount of phosphorus of the first doped layer of the N-type doped layer is 14ppm-17 ppm.

In one embodiment, the step of fabricating the second one of the N-doped layers comprises: the proportion of each component in the mixed gas is controlled so that the crystallinity of the second doping layer of the N-type doping layer is 40-65% and the doping amount of phosphorus is 18-22 ppm.

In one embodiment, the step of fabricating the first one of the P-type doped layers comprises: the proportion of each component in the mixed gas is controlled so that the doping amount of boron of the first layer doping layer of the formed P-type doping layer is 14ppm-17 ppm.

In one embodiment, the step of fabricating the second one of the P-type doped layers comprises: the proportion of each component in the mixed gas is controlled so that the crystallinity of the second doping layer of the formed P-type doping layer is 40-65% and the doping amount of boron is 18-22 ppm.

In one embodiment, the monocrystalline silicon substrate layer is provided as an N-type monocrystalline silicon substrate layer.

According to a sixth aspect of the present invention, there is provided a method for manufacturing a heterojunction solar cell, the method comprising a step of manufacturing a heterojunction solar cell monolith and a step of breaking the heterojunction solar cell monolith, wherein the step of manufacturing the heterojunction solar cell monolith further comprises the steps of:

setting a monocrystalline silicon substrate layer;

arranging a first group of intrinsic amorphous silicon thin film layers on the top side of the monocrystalline silicon substrate layer, arranging a second group of intrinsic amorphous silicon thin film layers on the bottom side of the monocrystalline silicon substrate layer, wherein the first group of intrinsic amorphous silicon thin film layers and the second group of intrinsic amorphous silicon thin film layers respectively comprise four-layer structures;

arranging an N-type doping layer on the top side of the first group of intrinsic amorphous silicon thin film layers, and arranging a P-type doping layer on the bottom side of the second group of intrinsic amorphous silicon thin film layers;

arranging light-transmitting conducting layers on the top side of the N-type doped layer and the bottom side of the P-type doped layer;

electrodes are applied to the exposed surfaces of the light-transmissive electrically conductive layer,

the step of arranging the N-type doping layer and the step of arranging the P-type doping layer both comprise the following steps of:

generating a first doping layer made of amorphous silicon materials on the fourth intrinsic amorphous silicon thin film layer by using mixed gas with first doping concentration;

a second doped layer of microcrystalline silicon material is formed on the first doped layer using a gas mixture having a second doping concentration greater than the first doping concentration.

In one embodiment, the step of providing an N-type doped layer comprises the steps of:

forming a first doped layer by deposition using a mixed gas of silane and phosphine and at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere;

the second layer doping layer is formed by deposition using a mixed gas of silane, phosphane, and carbon dioxide, and at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere.

In one embodiment, the step of disposing the P-type doped layer includes the steps of:

forming a first doped layer by deposition using a mixed gas of silane and trimethylboron mixed with at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere;

the second layer doped layer is formed by deposition using a mixed gas of silane, borane, and carbon dioxide in a mixture with at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere.

In one embodiment, the step of fabricating the first one of the N-doped layers comprises: the proportions of the components in the mixed gas are controlled so that the doping amount of phosphorus of the first doped layer of the N-type doped layer is 14ppm-17 ppm.

In one embodiment, the step of fabricating the second one of the N-doped layers comprises: the proportion of each component in the mixed gas is controlled so that the crystallinity of the second doping layer of the N-type doping layer is 40-65% and the doping amount of phosphorus is 18-22 ppm.

In one embodiment, the step of fabricating the first one of the P-type doped layers comprises: the proportion of each component in the mixed gas is controlled so that the doping amount of boron of the first layer doping layer of the formed P-type doping layer is 14ppm-17 ppm.

In one embodiment, the step of fabricating the second one of the P-type doped layers comprises: the proportion of each component in the mixed gas is controlled so that the crystallinity of the second doping layer of the formed P-type doping layer is 40-65% and the doping amount of boron is 18-22 ppm.

According to the heterojunction solar cell, the intrinsic amorphous silicon thin film layer structures on the top side and the bottom side of the substrate layer comprise four-layer structures, the four-layer structures are different in composition, the advantages of the intrinsic amorphous silicon thin film layer can be exerted to a greater extent when the four-layer structures are combined together, and the overall electrical property or efficiency of the solar cell can be improved.

Specifically, in the four-layer structure, the components of the first intrinsic amorphous silicon thin film layer enable the amorphous silicon thin film layer not to become long-range order and not to grow into epitaxial silicon, and the light absorption performance of the first intrinsic amorphous silicon thin film layer is poor, so that the short-circuit current of the battery piece can be improved; the second intrinsic amorphous silicon thin film layer can improve the passivation effect and ensure the open-circuit voltage of the solar cell; the third intrinsic amorphous silicon thin film layer can provide hydrogen passivation and has smaller thickness, so that the contact resistance of the film layer is reduced, the filling factor is improved, the light absorption of the film layer is reduced, and the short-circuit current is improved; the fourth intrinsic amorphous silicon thin film layer can be compact so as to effectively prevent doped atoms from diffusing, and the layer structure can also have high transmittance so as to improve short-circuit current.

In addition, in the invention, the doping layers on the top side and the bottom side of the intrinsic amorphous silicon thin film layer can have two-layer structures, namely the amorphous silicon layer with low doping concentration and the microcrystalline silicon layer with high doping concentration, so that the outward diffusion of impurity atoms of the amorphous silicon layer is relatively less, the microcrystalline silicon layer can be in good contact with the light-transmitting conducting layer to reduce contact resistance and improve filling factors, and the transmittance of the microcrystalline silicon layer is high, so that the absorption of the film layer to light can be reduced, and the short-circuit current can be improved.

Drawings

For a better understanding of the above and other objects, features, advantages and functions of the present invention, reference should be made to the preferred embodiments illustrated in the accompanying drawings. Like reference numerals in the drawings refer to like parts. It will be appreciated by persons skilled in the art that the drawings are intended to illustrate preferred embodiments of the invention without any limiting effect on the scope of the invention, and that the various components in the drawings are not drawn to scale.

Fig. 1 is a schematic view of a heterojunction solar cell according to a preferred embodiment of the invention;

fig. 2 is a schematic view of a heterojunction solar cell according to another preferred embodiment of the invention.

Detailed Description

Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings. What has been described herein is merely a preferred embodiment in accordance with the present invention and other ways of practicing the invention will occur to those skilled in the art and are within the scope of the invention.

The invention provides a heterojunction solar cell, a laminated tile assembly and a method for manufacturing the heterojunction solar cell. Fig. 1 and 2 show schematic views of heterojunction solar cells according to two preferred embodiments of the invention.

First embodiment

Referring to fig. 1, in a first embodiment, a heterojunction solar cell sheet comprises a substrate sheet having a top surface printed with a positive electrode and a bottom surface printed with a back electrode, the positive and back electrodes preferably being made of silver. The base piece comprises a plurality of battery piece layers which are stacked in the direction perpendicular to the base piece, and the battery piece layers comprise a monocrystalline silicon substrate layer, a first group of intrinsic amorphous silicon thin film layers, a second layer of intrinsic amorphous silicon thin film layers, a doping layer and a light-transmitting conducting layer. The monocrystalline silicon substrate layer may be, for example, an N-type monocrystalline silicon substrate layer.

The first group of intrinsic amorphous silicon thin film layers are arranged on the top side of the monocrystalline silicon substrate layer, the second group of intrinsic amorphous silicon thin film layers are arranged on the bottom side of the monocrystalline silicon substrate layer, and the first group of intrinsic amorphous silicon thin film layers and the second group of intrinsic amorphous silicon thin film layers respectively comprise a first intrinsic amorphous silicon thin film layer, a second intrinsic amorphous silicon thin film layer, a third intrinsic amorphous silicon thin film layer and a fourth intrinsic amorphous silicon thin film layer which are sequentially arranged in the direction from the monocrystalline silicon substrate layer to the electrodes.

The first intrinsic amorphous silicon thin film layer is of a carbon-same-family doped silicon integral layered structure; the second intrinsic amorphous silicon thin film layer is of an integral layered structure formed by depositing a silicon source atmosphere; the third intrinsic amorphous silicon thin film layer is of an integral layered structure formed by deposition of mixed gas of at least one of hydrogen-containing atmosphere and deuterium-containing atmosphere and silicon source atmosphere; the fourth intrinsic amorphous silicon thin film layer is of an integral layer structure formed by deposition of mixed gas of at least one of hydrogen-containing atmosphere and deuterium-containing atmosphere, silicon source atmosphere and carbon source atmosphere.

Preferably, the first intrinsic amorphous silicon thin film layer is an integral layered structure deposited by a mixed gas of silane doped with at least one of alkane, alkene and alkyne; the third intrinsic amorphous silicon thin film layer is of an integral layered structure formed by deposition of mixed gas with the ratio of the amounts of hydrogen gas and silane gas being in the range of 3-15; the fourth intrinsic amorphous silicon thin film layer is an integral layered structure deposited by mixed gas with the ratio of the amount of alkane to the amount of hydrogen being in the range of 1/20-3/5.

The four intrinsic amorphous silicon thin film layers have different structures, so that the advantages of the intrinsic amorphous silicon thin film layers can be exerted to a greater extent by combining the four intrinsic amorphous silicon thin film layers, and the overall electrical property or efficiency of the solar cell can be improved.

Specifically, the components of the first intrinsic amorphous silicon thin film layer enable the amorphous silicon thin film layer not to become long-range order and not to grow into epitaxial silicon, and the light absorption performance of the first intrinsic amorphous silicon thin film layer is poor, so that the short-circuit current of the battery piece can be improved; the second intrinsic amorphous silicon thin film layer can improve the passivation effect and ensure the open-circuit voltage of the solar cell; the third intrinsic amorphous silicon thin film layer can provide hydrogen passivation and has smaller thickness, so that the contact resistance of the film layer is reduced, the filling factor is improved, the light absorption of the film layer is reduced, and the short-circuit current is improved; the fourth intrinsic amorphous silicon thin film layer can be compact so as to effectively prevent doped atoms from diffusing, and the layer structure can also have high transmittance so as to improve short-circuit current.

Continuing with fig. 1, the doped layer on the top side of the first set of intrinsic amorphous silicon thin film layers is a phosphorus-doped N-type doped layer, and the doped layer on the bottom side of the second set of intrinsic amorphous silicon thin film layers is a boron-doped P-type doped layer. The N-type doped layer and the P-type doped layer can be of a single-layer structure or at least of a two-layer structure.

The embodiment also provides a laminated assembly, wherein the laminated assembly is formed by arranging a plurality of heterojunction solar cells in the heterojunction solar cell shown in fig. 1 in a laminated manner.

The present embodiment also provides a method of fabricating the heterojunction solar cell as shown in fig. 1. The method comprises a step of manufacturing a heterojunction solar cell piece and a step of splitting the heterojunction solar cell piece. The step of manufacturing the heterojunction solar cell slice integral piece comprises the following steps: setting a monocrystalline silicon substrate layer; arranging a first group of intrinsic amorphous silicon thin film layers on the top side of the monocrystalline silicon substrate layer, and arranging a second group of intrinsic amorphous silicon thin film layers on the bottom side of the monocrystalline silicon substrate layer; arranging an N-type doping layer on the top side of the first group of intrinsic amorphous silicon thin film layers, and arranging a P-type doping layer on the bottom side of the second group of intrinsic amorphous silicon thin film layers; arranging light-transmitting conducting layers on the top side of the N-type doped layer and the bottom side of the P-type doped layer; an electrode is applied to the exposed surface of the light-transmissive electrically conductive layer.

The steps of arranging the first group of intrinsic amorphous silicon thin film layers and the second group of intrinsic amorphous silicon thin film layers respectively comprise the following steps: depositing a first intrinsic amorphous silicon thin film layer on the top surface or the bottom surface of the monocrystalline silicon substrate layer by using a mixed gas of carbon and family-doped silicon; depositing a second intrinsic amorphous silicon thin film layer on the exposed surface of the first intrinsic amorphous silicon thin film layer by using a silicon source atmosphere; forming a third intrinsic amorphous silicon thin film layer on the exposed surface of the second intrinsic amorphous silicon thin film layer by deposition using a mixed gas of a silicon source atmosphere and at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere; and depositing the exposed surface of the third intrinsic amorphous silicon thin film layer by using the mixed gas of at least one of hydrogen-containing atmosphere and deuterium-containing atmosphere, silicon source atmosphere and carbon source atmosphere to form a fourth intrinsic amorphous silicon thin film layer.

Preferably, the step of disposing the first intrinsic amorphous silicon thin film layer includes: the first intrinsic amorphous silicon thin film layer is formed using mixed gas deposition of silane doped at least one of alkane, alkene, alkyne. The step of disposing the third intrinsic amorphous silicon thin film layer includes: and forming a third intrinsic amorphous silicon thin film layer by deposition using a mixed gas having a ratio of the amounts of hydrogen gas and silane gas in the range of 3-15. The step of disposing the fourth intrinsic amorphous silicon thin film layer includes: the fourth intrinsic amorphous silicon thin film layer is formed by deposition using a mixed gas having a ratio of the amount of alkane to the amount of hydrogen ranging from 1/20 to 3/5.

In addition, the step of arranging the N-type doping layer and the step of arranging the P-type doping layer both comprise the following steps: generating a first doping layer made of amorphous silicon materials on the fourth intrinsic amorphous silicon thin film layer by using mixed gas with first doping concentration; a second doped layer of microcrystalline silicon material is formed on the first doped layer using a gas mixture having a second doping concentration greater than the first doping concentration.

Preferably, the step of providing the N-type doped layer includes the steps of: forming a first doped layer by deposition using a mixed gas of silane and phosphine and at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere; the second layer doping layer is formed by deposition using a mixed gas of silane, phosphane, and carbon dioxide, and at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere.

More preferably, the step of fabricating the first doped layer of the N-doped layer comprises: the proportions of the components in the mixed gas are controlled so that the doping amount of phosphorus of the first doped layer of the N-type doped layer is 14ppm-17 ppm. The step of fabricating the second doped layer of the N-doped layer comprises: the proportion of each component in the mixed gas is controlled so that the crystallinity of the second doping layer of the N-type doping layer is 40-65% and the doping amount of phosphorus is 18-22 ppm.

Also preferably, the step of disposing the P-type doped layer includes the steps of: forming a first doped layer by deposition using a mixed gas of silane and trimethylboron mixed with at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere; the second layer doped layer is formed by deposition using a mixed gas of silane, borane, and carbon dioxide in a mixture with at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere.

More preferably, the step of fabricating the first doped layer of the P-doped layer comprises: the proportion of each component in the mixed gas is controlled so that the doping amount of boron of the first layer doping layer of the formed P-type doping layer is 14ppm-17 ppm. The step of fabricating the second doped layer of the P-doped layer comprises: the proportion of each component in the mixed gas is controlled so that the crystallinity of the second doping layer of the formed P-type doping layer is 40-65% and the doping amount of boron is 18-22 ppm.

Second embodiment

Fig. 2 shows a heterojunction solar cell according to a second preferred embodiment of the invention. The heterojunction solar cell sheet in this embodiment comprises a substrate sheet having a top surface printed with a positive electrode and a bottom surface printed with a back electrode, the positive and back electrodes preferably being made of silver. The base piece comprises a plurality of battery piece layers which are stacked in the direction perpendicular to the base piece, and the battery piece layers comprise a monocrystalline silicon substrate layer, a first group of intrinsic amorphous silicon thin film layers, a second layer of intrinsic amorphous silicon thin film layers, a doping layer and a light-transmitting conducting layer.

The first group of intrinsic amorphous silicon thin film layers and the second group of intrinsic amorphous silicon thin film layers each include a four-layer structure, and the four-layer structure may be as described in the above embodiment, or may be another structure different from the above embodiment.

In the embodiment shown in fig. 2, each of the N-type doped layer and the P-type doped layer includes a two-layer structure, i.e., a first doped layer in contact with the fourth intrinsic amorphous silicon thin film layer and a second doped layer in contact with the transparent conductive layer, wherein the first doped layer is an amorphous silicon layer with a low doping concentration, and the second doped layer is a microcrystalline silicon layer with a high doping concentration.

Specifically, the first doping layer of the N-type doping layer is an integral layered structure formed by deposition of a mixed gas of silane and phosphine and at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere; the second layer doped layer of the N-type doped layer is an integral layered structure formed by deposition of mixed gas of silane, phosphane and carbon dioxide and at least one of hydrogen-containing atmosphere and deuterium-containing atmosphere.

Preferably, the doping amount of the phosphorus of the first layer of the N-type doping layer is 14ppm to 17ppm, the crystallinity of the second layer of the N-type doping layer is 40% to 65%, and the doping amount of the phosphorus of the second layer of the N-type doping layer is 18ppm to 22 ppm.

The first layer of doped layer of the P-type doped layer is of an integral layered structure formed by deposition of mixed gas of silane and trimethylboron and at least one of hydrogen-containing atmosphere and deuterium-containing atmosphere; the second layer doped layer of the P-type doped layer is of an integral layered structure formed by deposition of a mixed gas of silane, borane and carbon dioxide and at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere.

Preferably, the doping amount of boron of the first layer of the P-type doping layer is 14ppm-17ppm, the crystallinity of the second layer of the P-type doping layer is 40% -65%, and the doping amount of boron of the second layer of the P-type doping layer is 18ppm-22 ppm.

The doping layers on the top side and the bottom side of the intrinsic amorphous silicon thin film layer are respectively provided with two layers of structures, namely an amorphous silicon layer with low doping concentration and a microcrystalline silicon layer with high doping concentration, so that impurity atoms diffused outwards by the amorphous silicon layer are relatively few, the microcrystalline silicon layer can be in good contact with the light-transmitting conducting layer to reduce contact resistance and improve filling factors, and the microcrystalline silicon layer has high transmittance and can reduce the absorption of the film layer to light, so that short-circuit current is improved.

The present embodiment also provides a stack assembly, which may be formed by arranging the heterojunction solar cells shown in fig. 2 in a stack manner.

The present embodiment also provides a method of fabricating the heterojunction solar cell as shown in fig. 2. The method comprises a step of manufacturing a heterojunction solar cell slice integral piece and a step of splitting the heterojunction solar cell slice integral piece, wherein the step of manufacturing the heterojunction solar cell slice integral piece comprises the following steps: setting a monocrystalline silicon substrate layer; arranging a first group of intrinsic amorphous silicon thin film layers on the top side of the monocrystalline silicon substrate layer, arranging a second group of intrinsic amorphous silicon thin film layers on the bottom side of the monocrystalline silicon substrate layer, wherein the first group of intrinsic amorphous silicon thin film layers and the second group of intrinsic amorphous silicon thin film layers respectively comprise four-layer structures; arranging an N-type doping layer on the top side of the first group of intrinsic amorphous silicon thin film layers, and arranging a P-type doping layer on the bottom side of the second group of intrinsic amorphous silicon thin film layers; arranging light-transmitting conducting layers on the top side of the N-type doped layer and the bottom side of the P-type doped layer; an electrode is applied to the exposed surface of the light-transmissive electrically conductive layer.

The step of arranging the N-type doping layer and the step of arranging the P-type doping layer both comprise the following steps of: generating a first doping layer made of amorphous silicon materials on the fourth intrinsic amorphous silicon thin film layer by using mixed gas with first doping concentration; a second doped layer of microcrystalline silicon material is formed on the first doped layer using a gas mixture having a second doping concentration greater than the first doping concentration.

Preferably, the step of providing the N-type doped layer includes the steps of: forming a first doped layer by deposition using a mixed gas of silane and phosphine and at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere; the second layer doping layer is formed by deposition using a mixed gas of silane, phosphane, and carbon dioxide, and at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere.

More preferably, the step of fabricating the first doped layer of the N-doped layer comprises: the proportions of the components in the mixed gas are controlled so that the doping amount of phosphorus of the first doped layer of the N-type doped layer is 14ppm-17 ppm. The step of fabricating the second doped layer of the N-doped layer comprises: the proportion of each component in the mixed gas is controlled so that the crystallinity of the second doping layer of the N-type doping layer is 40-65% and the doping amount of phosphorus is 18-22 ppm.

Also preferably, the step of disposing the P-type doped layer includes the steps of: forming a first doped layer by deposition using a mixed gas of silane and trimethylboron mixed with at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere; the second layer doped layer is formed by deposition using a mixed gas of silane, borane, and carbon dioxide in a mixture with at least one of a hydrogen-containing atmosphere and a deuterium-containing atmosphere.

More preferably, the step of fabricating the first doped layer of the P-doped layer comprises: the proportion of each component in the mixed gas is controlled so that the doping amount of boron of the first layer doping layer of the formed P-type doping layer is 14ppm-17 ppm. The step of fabricating the second doped layer of the P-doped layer comprises: the proportion of each component in the mixed gas is controlled so that the crystallinity of the second doping layer of the formed P-type doping layer is 40-65% and the doping amount of boron is 18-22 ppm.

In the heterojunction solar cell, the intrinsic amorphous silicon thin film layer structures on the top side and the bottom side of the substrate layer respectively comprise four layers, the four layers have different components, the intrinsic amorphous silicon thin film layers are combined together, the advantages of the intrinsic amorphous silicon thin film layers can be exerted to a greater extent, and the integral electrical property or efficiency of the solar cell can be improved.

Specifically, in the four-layer structure, the components of the first intrinsic amorphous silicon thin film layer enable the amorphous silicon thin film layer not to become long-range order and not to grow into epitaxial silicon, and the light absorption performance of the first intrinsic amorphous silicon thin film layer is poor, so that the short-circuit current of the battery piece can be improved; the second intrinsic amorphous silicon thin film layer can improve the passivation effect and ensure the open-circuit voltage of the solar cell; the third intrinsic amorphous silicon thin film layer can provide hydrogen passivation and has smaller thickness, so that the contact resistance of the film layer is reduced, the filling factor is improved, the light absorption of the film layer is reduced, and the short-circuit current is improved; the fourth intrinsic amorphous silicon thin film layer can be compact so as to effectively prevent doped atoms from diffusing, and the layer structure can also have high transmittance so as to improve short-circuit current.

In addition, in the invention, the doping layers on the top side and the bottom side of the intrinsic amorphous silicon thin film layer can have two-layer structures, namely the amorphous silicon layer with low doping concentration and the microcrystalline silicon layer with high doping concentration, so that the outward diffusion of impurity atoms of the amorphous silicon layer is relatively less, the microcrystalline silicon layer can be in good contact with the light-transmitting conducting layer to reduce contact resistance and improve filling factors, and the transmittance of the microcrystalline silicon layer is high, so that the absorption of the film layer to light can be reduced, and the short-circuit current can be improved.

The foregoing description of various embodiments of the invention is provided for the purpose of illustration to one of ordinary skill in the relevant art. It is not intended that the invention be limited to a single disclosed embodiment. As above, many alternatives and modifications of the present invention will be apparent to those of ordinary skill in the art in light of the above teachings. Thus, while some alternative embodiments are specifically described, other embodiments will be apparent to, or relatively easily developed by, those of ordinary skill in the art. The present invention is intended to embrace all such alternatives, modifications and variances of the present invention described herein, as well as other embodiments that fall within the spirit and scope of the present invention as described above.