Solar cell and manufacturing method therefor

Abstract

The present invention provides a solar cell comprising: a substrate; a first passivation layer provided on one surface of the substrate; a first conductive semiconductor layer provided on one surface of the first passivation layer; a first transparent conductive layer provided on one surface of the first conductive semiconductor layer; and a first electrode provided on one surface of the first transparent conductive layer, wherein the first conductive semiconductor layer comprises: a first semiconductor layer including a nanocrystalline or microcrystalline semiconductor layer; a second semiconductor layer provided on the first semiconductor layer and including a nanocrystalline or microcrystalline oxide semiconductor layer; and a third semiconductor layer provided on the second semiconductor layer and including a nanocrystalline or microcrystalline semiconductor layer.

Description

Solar cell and method of manufacturing the same

[0001] The present invention relates to a solar cell.

[0002] A solar cell is a device that converts light energy into electrical energy by utilizing the properties of semiconductors.

[0003] A solar cell has a PN junction structure formed by joining a P (positive) type semiconductor and an N (negative) type semiconductor. When sunlight is incident on a solar cell of this structure, holes and electrons are generated within the semiconductors due to the energy of the incident sunlight. At this time, the holes (+) move toward the P-type semiconductor and the electrons (-) move toward the N-type semiconductor due to the electric field generated in the PN junction, thereby generating an electric potential and enabling the production of electricity.

[0004] Such solar cells can generally be classified into substrate-type solar cells and thin-film-type solar cells.

[0005] The above-mentioned substrate-type solar cell is manufactured by using a semiconductor material, such as silicon, as a substrate, and the above-mentioned thin-film-type solar cell is manufactured by forming a semiconductor in the form of a thin film on a substrate such as glass.

[0006] The above substrate-type solar cell has the advantage of having slightly superior efficiency compared to the above thin-film-type solar cell, and the above thin-film-type solar cell has the advantage of reduced manufacturing costs compared to the above substrate-type solar cell.

[0007] However, in conventional cases, there are still limitations to improving the efficiency of solar cells.

[0008] The present invention is designed to overcome the limitations of the aforementioned solar cell, and aims to provide a solar cell and a method for manufacturing the same to improve the efficiency of the solar cell by improving the light reception characteristics of the solar cell.

[0009] To achieve the above objective, the present invention provides a method for forming a solar cell comprising a first conductive semiconductor layer on a substrate, wherein the step of forming the first conductive semiconductor layer comprises: forming a first semiconductor layer on the substrate; forming a second semiconductor layer on the first semiconductor layer; and forming a third semiconductor layer on the second semiconductor layer, wherein the second semiconductor layer comprises carbon elements and oxygen elements, and the second semiconductor layer has a higher content of carbon elements and oxygen elements than the first semiconductor layer and the third semiconductor layer.

[0010] The present invention also provides a solar cell comprising: a substrate; a first passivation layer provided on one surface of the substrate; a first conductive semiconductor layer provided on one surface of the first passivation layer; a first transparent conductive layer provided on one surface of the first conductive semiconductor layer; and a first electrode provided on one surface of the first transparent conductive layer, wherein the first conductive semiconductor layer comprises a first semiconductor layer including a nanocrystalline or microcrystalline semiconductor layer, a second semiconductor layer provided on the first semiconductor layer including a nanocrystalline or microcrystalline oxide semiconductor layer, and a third semiconductor layer provided on the second semiconductor layer including a nanocrystalline or microcrystalline semiconductor layer.

[0011] The present invention also comprises: a process of forming a first passivation layer on one surface of a substrate; a process of forming a first conductive semiconductor layer on one surface of the first passivation layer; and a process of forming a first transparent conductive layer on one surface of the first conductive semiconductor layer. The present invention provides a method for manufacturing a solar cell comprising a process of forming a first electrode on one surface of the first transparent conductive layer, wherein the process of forming the first conductive semiconductor layer comprises: a process of forming a first semiconductor layer including a nanocrystalline or microcrystalline N-type or P-type semiconductor layer through a thin film deposition process using a silicon-containing gas, a hydrogen-containing gas, and a dopant-containing gas; a process of forming a second semiconductor layer including a nanocrystalline or microcrystalline N-type or P-type oxide semiconductor layer on the first semiconductor layer through a thin film deposition process using a silicon-containing gas, a hydrogen-containing gas, a dopant-containing gas, and an oxygen-containing gas; and a process of forming a third semiconductor layer including a nanocrystalline or microcrystalline N-type or P-type semiconductor layer on the second semiconductor layer through a thin film deposition process using a silicon-containing gas, a hydrogen-containing gas, and a dopant-containing gas.

[0012] According to the present invention based on the above configuration, the following effects are achieved.

[0013] According to one embodiment of the present invention, a first conductive semiconductor layer located on the front surface of a substrate, which is the surface where sunlight is incident, comprises a first semiconductor layer, a second semiconductor layer, and a third semiconductor layer, wherein the amount of light absorbed by sunlight can be increased by the second semiconductor layer being composed of an oxide semiconductor layer having excellent light-receiving characteristics, and furthermore, the mobility of carriers at the interface between the first conductive semiconductor layer and the first transparent conductive layer above it can be improved by the third semiconductor layer being composed of a semiconductor layer containing a high concentration dopant having excellent electrical conductivity.

[0014] According to another embodiment of the present invention, a second conductive semiconductor layer located on the rear surface of a substrate opposite to the surface on which sunlight is incident comprises a first semiconductor layer, a second semiconductor layer, and a third semiconductor layer, wherein the amount of light absorbed by reflected sunlight can be increased by the second semiconductor layer being composed of an oxide semiconductor layer having excellent light-receiving characteristics, and furthermore, the mobility of carriers at the interface between the second conductive semiconductor layer and the second transparent conductive layer below it can be improved by the third semiconductor layer being composed of a semiconductor layer containing a high concentration dopant having excellent electrical conductivity.

[0015] FIG. 1 is a schematic cross-sectional view of a solar cell according to one embodiment of the present invention.

[0016] FIG. 2 is a schematic cross-sectional view of a solar cell according to another embodiment of the present invention.

[0017] FIG. 3 is a schematic cross-sectional view of a solar cell according to another embodiment of the present invention.

[0018] FIG. 4 is a schematic cross-sectional view of a solar cell according to another embodiment of the present invention.

[0019] FIGS. 5a to 5g are schematic cross-sectional views of a manufacturing process of a solar cell according to one embodiment of the present invention, which relate to the manufacturing process of a solar cell according to FIG. 1 described above.

[0020] FIGS. 6a to 6d are graphs according to various embodiments of the present invention showing the supply process of a dopant-containing gas and the supply process of an oxygen-containing gas introduced in the processes of FIGS. 5a to 5c.

[0021] FIGS. 7a to 7g are schematic cross-sectional views of a manufacturing process of a solar cell according to another embodiment of the present invention, which relates to the manufacturing process of a solar cell according to FIG. 2 described above.

[0022] Figure 8 is a graph showing the supply process of the dopant-containing gas and the supply process of the oxygen-containing gas introduced in the processes of Figures 7a to 7c.

[0023] FIG. 9 is a schematic side cross-sectional view of a substrate processing apparatus for forming a semiconductor layer according to the present invention.

[0024] FIG. 10 is a schematic side cross-sectional view of the third electrode and the fourth electrode in a substrate processing apparatus for forming a semiconductor layer according to the present invention.

[0025] FIG. 11 is a schematic side cross-sectional view of the third electrode and the fourth electrode in a substrate processing apparatus for forming a semiconductor layer according to the present invention.

[0026] FIG. 12 is a conceptual side view illustrating a modified embodiment regarding the positions of the first injection part and the second injection part in a substrate processing apparatus for forming a semiconductor layer according to the present invention.

[0027] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims.

[0028] Shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining embodiments of the present invention are exemplary, and therefore the present invention is not limited to the depicted details. Throughout the specification, the same reference numerals refer to the same components. Furthermore, in describing the present invention, if it is determined that a detailed description of related prior art could unnecessarily obscure the essence of the present invention, such detailed description is omitted. Where terms such as "includes," "has," or "is made up" are used in this specification, other parts may be added unless "only" is used. Where a component is expressed in the singular, it includes cases where it is included in the plural unless specifically stated otherwise.

[0029] In interpreting the components, they are interpreted to include a margin of error even in the absence of a separate explicit statement.

[0030] In the case of describing a positional relationship, for example, when the positional relationship between two parts is described using expressions such as 'on,' 'upper,' 'lower,' or 'next to,' one or more other parts may be located between the two parts unless 'immediately' or 'directly' is used.

[0031] In the case of an explanation of a temporal relationship, for example, when the temporal sequence is explained using 'after', 'following', 'next', 'before', etc., it may include cases where the sequence is not continuous unless 'immediately' or 'directly' is used.

[0032] Although terms such as "first," "second," etc. are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another. Accordingly, the first component mentioned below may be the second component within the technical scope of the present invention.

[0033] The features of each of the various embodiments of the present invention may be combined or combined with one another, either partially or wholly, and may technically enable various interlocking and operation. Each embodiment may be implemented independently of one another or may be implemented together in an associated relationship.

[0034] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

[0035] FIG. 1 is a schematic cross-sectional view of a solar cell according to one embodiment of the present invention.

[0036] As can be seen in FIG. 1, a solar cell according to one embodiment of the present invention comprises a substrate (100), a first passivation layer (210), a second passivation layer (220), a first conductive semiconductor layer (310), a second conductive semiconductor layer (320), a first transparent conductive layer (410), a second transparent conductive layer (420), a first electrode (510), and a second electrode (520).

[0037] The substrate (100) may be made of a semiconductor wafer, for example, a silicon wafer, and specifically, may be made of an N-type silicon wafer or a P-type silicon wafer. Such a substrate (100) is made of the same polarity as either the first conductivity type semiconductor layer (310) or the second conductivity type semiconductor layer (320).

[0038] Although not illustrated, an uneven structure may be formed on at least one of the upper or lower surfaces of the substrate (100). When an uneven structure is formed on the upper and lower surfaces of the substrate (100), an uneven structure may also be formed on the surfaces of the first passivation layer (210), the second passivation layer (220), the first conductive semiconductor layer (310), the second conductive semiconductor layer (320), the first transparent conductive layer (410), and the second transparent conductive layer (420).

[0039] The first passivation layer (210) is formed in the form of a thin film on one side, for example, the upper surface, of the substrate (100) made of the semiconductor wafer.

[0040] The first passivation layer (210) is formed through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD), and may be composed of an intrinsic semiconductor layer, for example, an intrinsic amorphous silicon layer. However, depending on the case, the first passivation layer (210) may be composed of a semiconductor layer doped with a small amount of dopant, for example, a semiconductor layer doped with a small amount of dopant having the same polarity as the first conductive semiconductor layer (310), for example, an amorphous silicon layer doped with a small amount of dopant.

[0041] The second passivation layer (220) is formed in the form of a thin film on the other side, for example, the lower side, of the substrate (100) made of the semiconductor wafer.

[0042] The second passivation layer (220) is formed through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD), and may be composed of an intrinsic semiconductor layer, for example, an intrinsic amorphous silicon layer. However, depending on the case, the second passivation layer (220) may be composed of a semiconductor layer doped with a small amount of dopant, for example, a semiconductor layer doped with a small amount of dopant having the same polarity as the second conductive semiconductor layer (320), for example, an amorphous silicon layer doped with a small amount of dopant.

[0043] The first conductive semiconductor layer (310) is formed in the form of a thin film on one side of the first passivation layer (210), for example, on the upper surface.

[0044] The first conductivity semiconductor layer (310) may have the same polarity as the substrate (100). For example, if the substrate (100) is made of an N-type silicon wafer, the first conductivity semiconductor layer (310) may be made of an N-type semiconductor layer, and if the substrate (100) is made of a P-type silicon wafer, the first conductivity semiconductor layer (310) may be made of a P-type semiconductor layer. For example, the first conductivity semiconductor layer (310) may be made of P-type amorphous silicon doped with a group 3 element such as boron (B), and may be made of N-type amorphous silicon doped with a group 5 element such as phosphorus (P).

[0045] The first conductive semiconductor layer (310) located on the front surface of the substrate (100), which is the surface where sunlight is incident, comprises a first semiconductor layer (311), a second semiconductor layer (312), and a third semiconductor layer (313).

[0046] The first semiconductor layer (311) is formed in the form of a thin film on one side of the first passivation layer (210), for example, on the upper surface.

[0047] The first semiconductor layer (311) is a seed layer. The first semiconductor layer (311) is a layer with a higher degree of crystallinity than the second semiconductor layer (312) and the third semiconductor layer (313). The first semiconductor layer (311) may be composed of a nanocrystalline (nc) or microcrystalline (uc) semiconductor layer. For example, the first semiconductor layer (311) may be composed of nanocrystalline (nc) or microcrystalline (uc) N-type or P-type Si:H.

[0048] When the first semiconductor layer (311) comprises nanocrystalline (nc) or microcrystalline (uc) N-type Si:H, the first semiconductor layer (311) can be formed through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) using a silicon-containing gas such as SiH4, a hydrogen-containing gas such as H2, and an N-type dopant-containing gas such as PH3.

[0049] When the first semiconductor layer (311) comprises nanocrystalline (nc) or microcrystalline (uc) P-type Si:H, the first semiconductor layer (311) can be formed through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) using a silicon-containing gas such as SiH4, a hydrogen-containing gas such as H2, and a P-type dopant-containing gas such as B2H6.

[0050] The second semiconductor layer (312) is formed in the form of a thin film on one side of the first semiconductor layer (311), for example, on the upper surface.

[0051] The second semiconductor layer (312) is an oxide layer. The second semiconductor layer (312) is a layer with higher light reception characteristics than the first semiconductor layer (311) and the third semiconductor layer (313). The second semiconductor layer (312) may be composed of a nanocrystalline (nc) or microcrystalline (uc) oxide semiconductor layer. For example, the second semiconductor layer (312) may be composed of a nanocrystalline (nc) or microcrystalline (uc) N-type or P-type SiO:H.

[0052] When the second semiconductor layer (312) comprises nanocrystalline (nc) or microcrystalline (uc) N-type SiO:H, the second semiconductor layer (312) can be formed through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) using a silicon-containing gas such as SiH4, a hydrogen-containing gas such as H2, an N-type dopant-containing gas such as PH3, and an oxygen-containing gas such as CO2.

[0053] When the second semiconductor layer (312) comprises nanocrystalline (nc) or microcrystalline (uc) P-type Si:H, the second semiconductor layer (312) can be formed through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) using a silicon-containing gas such as SiH4, a hydrogen-containing gas such as H2, a P-type dopant-containing gas such as B2H6, and an oxygen-containing gas such as CO2.

[0054] The SiO:H included in the second semiconductor layer (312) has a larger band gap than the Si:H included in the first semiconductor layer (311) and the third semiconductor layer (313), so the amount of light absorption can be increased.

[0055] Although O2 may be used as the oxygen-containing gas to obtain SiO:H contained in the second semiconductor layer (312), in this case, the high reactivity may increase the oxygen content in the obtained SiO:H, potentially forming an insulating layer rather than a semiconductor layer. Therefore, CO2 may be preferable to O2 as the oxygen-containing gas to obtain SiO:H contained in the second semiconductor layer (312).

[0056] The concentration of the dopant included in the second semiconductor layer (312) is higher than the concentration of the dopant included in the first semiconductor layer (311).

[0057] The third semiconductor layer (313) is formed in the form of a thin film on one side of the second semiconductor layer (312), for example, on the upper surface.

[0058] The third semiconductor layer (313) is a layer in contact with the first transparent conductive layer (410). The third semiconductor layer (313) is a layer with higher electrical conductivity than the first semiconductor layer (311) and the second semiconductor layer (312).

[0059] The third semiconductor layer (313) may be composed of a nanocrystalline (nc) or microcrystalline (uc) semiconductor layer. For example, the third semiconductor layer (313) may be composed of a nanocrystalline (nc) or microcrystalline (uc) N-type or P-type Si:H.

[0060] When the third semiconductor layer (313) comprises nanocrystalline (nc) or microcrystalline (uc) N-type Si:H, the third semiconductor layer (313) can be formed through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) using a silicon-containing gas such as SiH4, a hydrogen-containing gas such as H2, and an N-type dopant-containing gas such as PH3.

[0061] When the third semiconductor layer (313) comprises nanocrystalline (nc) or microcrystalline (uc) P-type Si:H, the third semiconductor layer (313) can be formed through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) using a silicon-containing gas such as SiH4, a hydrogen-containing gas such as H2, and a P-type dopant-containing gas such as B2H6.

[0062] The concentration of N-type or P-type dopants included in the third semiconductor layer (313) is higher than the concentration of N-type or P-type dopants included in the first semiconductor layer (311) and the concentration of N-type or P-type dopants included in the second semiconductor layer (312).

[0063] The first semiconductor layer (311), the second semiconductor layer (312), and the third semiconductor layer (313) all include a dopant of the same polarity, for example, they may all include the same dopant.

[0064] The second conductive semiconductor layer (320) is formed in the form of a thin film on the other side, for example, the lower side, of the second passivation layer (220).

[0065] The second conductivity semiconductor layer (320) may have a different polarity from the substrate (100) and the first conductivity semiconductor layer (310). For example, if the substrate (100) is made of an N-type silicon wafer, the second conductivity semiconductor layer (320) may be made of a P-type semiconductor layer, and if the substrate (100) is made of a P-type silicon wafer, the second conductivity semiconductor layer (320) may be made of an N-type semiconductor layer. For example, the second conductivity semiconductor layer (320) may be made of P-type amorphous silicon doped with a group 3 element such as boron (B), and may be made of N-type amorphous silicon doped with a group 5 element such as phosphorus (P).

[0066] The second conductive semiconductor layer (320), which is located on the other side of the substrate (100) opposite to the side where sunlight is incident, can be formed as a single layer, unlike the first conductive semiconductor layer (310).

[0067] The second conductivity type semiconductor layer (320) may be composed of a nanocrystalline (nc) or microcrystalline (uc) semiconductor layer. For example, the second conductivity type semiconductor layer (320) may be composed of nanocrystalline (nc) or microcrystalline (uc) P-type or N-type Si:H.

[0068] When the second conductivity semiconductor layer (320) comprises nanocrystalline (nc) or microcrystalline (uc) P-type Si:H, the second conductivity semiconductor layer (320) can be formed through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) using a silicon-containing gas such as SiH4, a hydrogen-containing gas such as H2, and a P-type dopant-containing gas such as B2H6.

[0069] When the second conductivity semiconductor layer (320) comprises nanocrystalline (nc) or microcrystalline (uc) N-type Si:H, the second conductivity semiconductor layer (320) can be formed through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) using a silicon-containing gas such as SiH4, a hydrogen-containing gas such as H2, and an N-type dopant-containing gas such as PH3.

[0070] The first transparent conductive layer (410) is formed in the form of a thin film on one side, for example, the upper surface, of the first conductive semiconductor layer (310). The first transparent conductive layer (410) can collect carriers, for example, holes, generated in the substrate (100) and move the collected carriers to the first electrode (510).

[0071] The first transparent conductive layer (410) may be formed through a thin film deposition process such as chemical vapor deposition (CVD) or atomic layer deposition (ALD), or may be formed through a sputtering process.

[0072] The first transparent conductive layer (410) may be made of a transparent conductive material such as ITO (Indium Tin Oxide), ZnOH, ZnO:B, ZnO:Al, SnO2, SnO2:F, etc., and ITO may be selected from among them.

[0073] The second transparent conductive layer (420) is formed in the form of a thin film on the other side, for example, the bottom side, of the second conductive semiconductor layer (320). The second transparent conductive layer (420) collects carriers, for example, electrons, generated from the substrate (100) and moves the collected carriers to the second electrode (520).

[0074] The second transparent conductive layer (420) may be formed through a thin film deposition process such as chemical vapor deposition (CVD) or atomic layer deposition (ALD), or may be formed through a sputtering process.

[0075] The above second transparent conductive layer (420) may be made of a transparent conductive material such as ITO (Indium Tin Oxide), ZnOH, ZnO:B, ZnO:Al, SnO2, SnO2:F, etc., and ITO may be selected among them.

[0076] The first electrode (510) is formed on one side, for example, the upper surface, of the first transparent conductive layer (410) to form the front electrode of the solar cell. The first electrode (510) is patterned in a predetermined shape so that sunlight can be transmitted into the solar cell. The first electrode (510) can be formed by various pattern forming processes known in the art, such as screen printing.

[0077] The first electrode (510) may be made of any one metal selected from the group consisting of Ag, Cu, Al, Mo, and W. The first electrode (510) may be formed as a single-layer structure or a multi-layer structure of two or more layers.

[0078] The second electrode (520) is formed on the other side, for example, the bottom side, of the second transparent conductive layer (420). Since the second electrode (520) is formed on the back side of the solar cell, it may be formed over the entire bottom side of the second transparent conductive layer (420), but it may be formed in a pattern so that reflected sunlight can be incident through the back side of the solar cell. The second electrode (520) can be formed by various pattern forming processes known in the art, such as screen printing.

[0079] The second electrode (520) may be made of any one metal selected from the group consisting of Ag, Cu, Al, Mo, and W. The second electrode (520) may be formed as a single-layer structure or a multi-layer structure of two or more layers.

[0080] In this way, according to one embodiment of the present invention, the first conductive semiconductor layer (310) located on the front surface of the substrate (100), which is the surface where sunlight is incident, comprises a first semiconductor layer (311), a second semiconductor layer (312), and a third semiconductor layer (313), and the amount of light absorbed by sunlight can be increased by the second semiconductor layer (312) being composed of an oxide semiconductor layer with excellent light-receiving characteristics.

[0081] In addition, the third semiconductor layer (313) is formed as a semiconductor layer containing a high concentration dopant with excellent electrical conductivity, thereby improving the mobility of carriers at the interface between the first conductive semiconductor layer (310) and the first transparent conductive layer (410).

[0082] FIG. 2 is a schematic cross-sectional view of a solar cell according to another embodiment of the present invention, which is identical to the solar cell according to FIG. 1 described above, except that the configuration of the second semiconductor layer (312) of the first conductivity type semiconductor layer (310) has been changed. Accordingly, the same reference numerals have been assigned to identical configurations, and only different configurations will be described below.

[0083] As can be seen in FIG. 2, the first conductive semiconductor layer (310) comprises a first semiconductor layer (311), a second semiconductor layer (312), and a third semiconductor layer (313), wherein the second semiconductor layer (312) comprises a first sublayer (312a), a second sublayer (312b), and a third sublayer (312c).

[0084] The first sublayer (312a) is formed in the form of a thin film on one side of the first semiconductor layer (311), for example, on the upper surface, the second sublayer (312b) is formed in the form of a thin film on one side of the first sublayer (312a), for example, on the upper surface, and the third sublayer (312c) is formed in the form of a thin film on one side of the second sublayer (312b), for example, on the upper surface.

[0085] The first sublayer (312a), the second sublayer (312b), and the third sublayer (312c) are composed of oxide layers. The first sublayer (312a), the second sublayer (312b), and the third sublayer (312c) may each be composed of a nanocrystalline (nc) or microcrystalline (uc) oxide semiconductor layer, and may, for example, be composed of a nanocrystalline (nc) or microcrystalline (uc) N-type or P-type SiO:H.

[0086] When the first sublayer (312a), the second sublayer (312b), and the third sublayer (312c) each contain nanocrystalline (nc) or microcrystalline (uc) N-type SiO:H, the first sublayer (312a), the second sublayer (312b), and the third sublayer (312c) can each be formed through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) using a silicon-containing gas such as SiH4, a hydrogen-containing gas such as H2, an N-type dopant-containing gas such as PH3, and an oxygen-containing gas such as CO2.

[0087] When the first sublayer (312a), the second sublayer (312b), and the third sublayer (312c) each contain nanocrystalline (nc) or microcrystalline (uc) P-type Si:H, the first sublayer (312a), the second sublayer (312b), and the third sublayer (312c) can each be formed through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) using a silicon-containing gas such as SiH4, a hydrogen-containing gas such as H2, a P-type dopant-containing gas such as B2H6, and an oxygen-containing gas such as CO2.

[0088] At this time, the supply amount of silicon-containing gas such as SiH4, the supply amount of hydrogen-containing gas such as H2, the supply amount of N-type dopant-containing gas such as PH3, and the supply amount of P-type dopant-containing gas such as B2H6 may be the same between the first sublayer (312a), the second sublayer (312b), and the third sublayer (312c).

[0089] However, the supply amount of oxygen-containing gas, such as CO2, may differ between the first sublayer (312a), the second sublayer (312b), and the third sublayer (312c). For example, the supply amount of oxygen-containing gas when forming the second sublayer (312b) may be greater than the supply amount of oxygen-containing gas when forming the first sublayer (312a) and the supply amount of oxygen-containing gas when forming the third sublayer (312c).

[0090] For example, the supply amount of silicon-containing gas to the supply amount of oxygen-containing gas during the process of forming the first sublayer (312a) and the third sublayer (312c) may be in the range of 1:0.4 to 1:0.5, and the supply amount of silicon-containing gas to the supply amount of oxygen-containing gas during the process of forming the second sublayer (312b) may be in the range of 1:0.9 to 1:1.1.

[0091] Accordingly, the oxygen content of the second sublayer (312b) may be greater than the oxygen content of the first sublayer (312a) and the oxygen content of the third sublayer (312c). Therefore, the light reception characteristics of the second sublayer (312b) may be higher than the light reception characteristics of the first sublayer (312a) and the third sublayer (312c). Additionally, the electrical conductivity of the second sublayer (312b) may be lower than the electrical conductivity of the first sublayer (312a) and the electrical conductivity of the third sublayer (312c).

[0092] FIG. 3 is a schematic cross-sectional view of a solar cell according to another embodiment of the present invention, which is identical to the solar cell according to FIG. 1 described above except that the configuration of the second conductivity type semiconductor layer (320) has been changed. Accordingly, the same reference numerals have been assigned to identical configurations, and only different configurations will be described below.

[0093] As can be seen in FIG. 3, the second conductive semiconductor layer (320) located on the other side of the substrate (100) opposite to the side where sunlight is incident is formed by including a first semiconductor layer (321), a second semiconductor layer (322), and a third semiconductor layer (323).

[0094] The first semiconductor layer (321) is formed in the form of a thin film on the other side, for example, the lower side, of the second passivation layer (220).

[0095] The first semiconductor layer (321) is a seed layer. The first semiconductor layer (321) is a layer with a higher degree of crystallinity than the second semiconductor layer (322) and the third semiconductor layer (323). The first semiconductor layer (321) may be composed of a nanocrystalline (nc) or microcrystalline (uc) semiconductor layer. For example, the first semiconductor layer (321) may be composed of nanocrystalline (nc) or microcrystalline (uc) N-type or P-type Si:H.

[0096] When the first semiconductor layer (321) comprises nanocrystalline (nc) or microcrystalline (uc) N-type Si:H, the first semiconductor layer (321) can be formed through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) using a silicon-containing gas such as SiH4, a hydrogen-containing gas such as H2, and an N-type dopant-containing gas such as PH3.

[0097] When the first semiconductor layer (321) comprises nanocrystalline (nc) or microcrystalline (uc) P-type Si:H, the first semiconductor layer (321) can be formed through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) using a silicon-containing gas such as SiH4, a hydrogen-containing gas such as H2, and a P-type dopant-containing gas such as B2H6.

[0098] The second semiconductor layer (322) is formed in the form of a thin film on the other side, for example, the lower side, of the first semiconductor layer (321).

[0099] The second semiconductor layer (322) is an oxide layer. The second semiconductor layer (322) is a layer with higher light reception characteristics than the first semiconductor layer (321) and the third semiconductor layer (323). The second semiconductor layer (322) may be composed of a nanocrystalline (nc) or microcrystalline (uc) oxide semiconductor layer. For example, the second semiconductor layer (322) may be composed of a nanocrystalline (nc) or microcrystalline (uc) N-type or P-type SiO:H.

[0100] When the second semiconductor layer (322) comprises nanocrystalline (nc) or microcrystalline (uc) N-type SiO:H, the second semiconductor layer (322) can be formed through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) using a silicon-containing gas such as SiH4, a hydrogen-containing gas such as H2, an N-type dopant-containing gas such as PH3, and an oxygen-containing gas such as CO2.

[0101] When the second semiconductor layer (322) comprises nanocrystalline (nc) or microcrystalline (uc) P-type Si:H, the second semiconductor layer (322) can be formed through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) using a silicon-containing gas such as SiH4, a hydrogen-containing gas such as H2, a P-type dopant-containing gas such as B2H6, and an oxygen-containing gas such as CO2.

[0102] The SiO:H included in the second semiconductor layer (322) has a larger band gap than the Si:H included in the first semiconductor layer (321) and the third semiconductor layer (323), so the amount of light absorption can be increased.

[0103] Although O2 may be used as the oxygen-containing gas to obtain the SiO:H contained in the second semiconductor layer (322), in this case, the high reactivity may increase the oxygen content in the obtained SiO:H, potentially forming an insulating layer rather than a semiconductor layer. Therefore, CO2 may be preferable to O2 as the oxygen-containing gas to obtain the SiO:H contained in the second semiconductor layer (322).

[0104] The concentration of the dopant included in the second semiconductor layer (322) is higher than the concentration of the dopant included in the first semiconductor layer (321).

[0105] The third semiconductor layer (323) is formed in the form of a thin film on the other side, for example, the lower side, of the second semiconductor layer (322).

[0106] The third semiconductor layer (323) is a layer in contact with the second transparent conductive layer (420). The third semiconductor layer (323) is a layer with higher electrical conductivity than the first semiconductor layer (321) and the second semiconductor layer (322).

[0107] The third semiconductor layer (323) may be composed of a nanocrystalline (nc) or microcrystalline (uc) semiconductor layer. For example, the third semiconductor layer (323) may be composed of a nanocrystalline (nc) or microcrystalline (uc) N-type or P-type Si:H.

[0108] When the third semiconductor layer (323) comprises nanocrystalline (nc) or microcrystalline (uc) N-type Si:H, the third semiconductor layer (323) can be formed through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) using a silicon-containing gas such as SiH4, a hydrogen-containing gas such as H2, and an N-type dopant-containing gas such as PH3.

[0109] When the third semiconductor layer (323) comprises nanocrystalline (nc) or microcrystalline (uc) P-type Si:H, the third semiconductor layer (323) can be formed through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) using a silicon-containing gas such as SiH4, a hydrogen-containing gas such as H2, and a P-type dopant-containing gas such as B2H6.

[0110] The concentration of N-type or P-type dopants included in the third semiconductor layer (323) is higher than the concentration of N-type or P-type dopants included in the first semiconductor layer (321) and the concentration of N-type or P-type dopants included in the second semiconductor layer (322).

[0111] The first semiconductor layer (321), the second semiconductor layer (322), and the third semiconductor layer (323) all include a dopant of the same polarity, for example, they may all include the same dopant.

[0112] In this way, according to another embodiment of the present invention, the second conductive semiconductor layer (320) located on the rear surface of the substrate (100) opposite to the surface on which sunlight is incident comprises a first semiconductor layer (321), a second semiconductor layer (322), and a third semiconductor layer (323), and the amount of light absorbed by the reflected sunlight can be increased by the second semiconductor layer (322) being composed of an oxide semiconductor layer with excellent light-receiving characteristics.

[0113] In addition, the third semiconductor layer (323) is formed as a semiconductor layer containing a high concentration dopant with excellent electrical conductivity, thereby improving the mobility of carriers at the interface between the second conductive semiconductor layer (320) and the second transparent conductive layer (420).

[0114] FIG. 4 is a schematic cross-sectional view of a solar cell according to another embodiment of the present invention, which is identical to the solar cell according to FIG. 3 described above except that the configuration of the second semiconductor layer (312) of the first conductivity type semiconductor layer (310) and the second semiconductor layer (322) of the second conductivity type semiconductor layer (320) have been changed. Accordingly, the same reference numerals have been assigned to identical configurations, and only different configurations will be described below.

[0115] As can be seen in FIG. 4, the second semiconductor layer (312) of the first conductive semiconductor layer (310) is formed by including a first sublayer (312a), a second sublayer (312b), and a third sublayer (312c).

[0116] The first sublayer (312a) is formed in the form of a thin film on one side of the first semiconductor layer (311), for example, on the upper surface, the second sublayer (312b) is formed in the form of a thin film on one side of the first sublayer (312a), for example, on the upper surface, and the third sublayer (312c) is formed in the form of a thin film on one side of the second sublayer (312b), for example, on the upper surface.

[0117] The first sublayer (312a), the second sublayer (312b), and the third sublayer (312c) are composed of oxide layers. The first sublayer (312a), the second sublayer (312b), and the third sublayer (312c) may each be composed of a nanocrystalline (nc) or microcrystalline (uc) oxide semiconductor layer, and may, for example, be composed of a nanocrystalline (nc) or microcrystalline (uc) N-type or P-type SiO:H.

[0118] When the first sublayer (312a), the second sublayer (312b), and the third sublayer (312c) each contain nanocrystalline (nc) or microcrystalline (uc) N-type SiO:H, the first sublayer (312a), the second sublayer (312b), and the third sublayer (312c) can each be formed through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) using a silicon-containing gas such as SiH4, a hydrogen-containing gas such as H2, an N-type dopant-containing gas such as PH3, and an oxygen-containing gas such as CO2.

[0119] When the first sublayer (312a), the second sublayer (312b), and the third sublayer (312c) each contain nanocrystalline (nc) or microcrystalline (uc) P-type Si:H, the first sublayer (312a), the second sublayer (312b), and the third sublayer (312c) can each be formed through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) using a silicon-containing gas such as SiH4, a hydrogen-containing gas such as H2, a P-type dopant-containing gas such as B2H6, and an oxygen-containing gas such as CO2.

[0120] At this time, the supply amount of silicon-containing gas such as SiH4, the supply amount of hydrogen-containing gas such as H2, the supply amount of N-type dopant-containing gas such as PH3, and the supply amount of P-type dopant-containing gas such as B2H6 may be the same between the first sublayer (312a), the second sublayer (312b), and the third sublayer (312c).

[0121] However, the supply amount of oxygen-containing gas, such as CO2, may differ between the first sublayer (312a), the second sublayer (312b), and the third sublayer (312c). For example, the supply amount of oxygen-containing gas when forming the second sublayer (312b) may be greater than the supply amount of oxygen-containing gas when forming the first sublayer (312a) and the supply amount of oxygen-containing gas when forming the third sublayer (312c).

[0122] For example, the supply amount of silicon-containing gas to the supply amount of oxygen-containing gas during the process of forming the first sublayer (312a) and the third sublayer (312c) may be in the range of 1:0.4 to 1:0.5, and the supply amount of silicon-containing gas to the supply amount of oxygen-containing gas during the process of forming the second sublayer (312b) may be in the range of 1:0.9 to 1:1.1.

[0123] Accordingly, the oxygen content of the second sublayer (312b) may be greater than the oxygen content of the first sublayer (312a) and the oxygen content of the third sublayer (312c). Therefore, the light reception characteristics of the second sublayer (312b) may be higher than the light reception characteristics of the first sublayer (312a) and the third sublayer (312c). Additionally, the electrical conductivity of the second sublayer (312b) may be lower than the electrical conductivity of the first sublayer (312a) and the electrical conductivity of the third sublayer (312c).

[0124] Additionally, the second semiconductor layer (322) of the second conductive semiconductor layer (320) comprises a first sublayer (322a), a second sublayer (322b), and a third sublayer (322c).

[0125] The first sublayer (322a) is formed in the form of a thin film on the other side, for example, the bottom side, of the first semiconductor layer (321), the second sublayer (322b) is formed in the form of a thin film on the other side, for example, the bottom side, of the first sublayer (322a), and the third sublayer (322c) is formed in the form of a thin film on the other side, for example, the bottom side, of the second sublayer (322b).

[0126] The first sublayer (322a), the second sublayer (322b), and the third sublayer (322c) are composed of oxide layers. The first sublayer (322a), the second sublayer (322b), and the third sublayer (322c) may each be composed of a nanocrystalline (nc) or microcrystalline (uc) oxide semiconductor layer, and may, for example, be composed of a nanocrystalline (nc) or microcrystalline (uc) N-type or P-type SiO:H.

[0127] When the first sublayer (322a), the second sublayer (322b), and the third sublayer (322c) each contain nanocrystalline (nc) or microcrystalline (uc) N-type SiO:H, the first sublayer (322a), the second sublayer (322b), and the third sublayer (322c) can each be formed through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) using a silicon-containing gas such as SiH4, a hydrogen-containing gas such as H2, an N-type dopant-containing gas such as PH3, and an oxygen-containing gas such as CO2.

[0128] When the first sublayer (322a), the second sublayer (322b), and the third sublayer (322c) each contain nanocrystalline (nc) or microcrystalline (uc) P-type Si:H, the first sublayer (322a), the second sublayer (322b), and the third sublayer (322c) can each be formed through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) using a silicon-containing gas such as SiH4, a hydrogen-containing gas such as H2, a P-type dopant-containing gas such as B2H6, and an oxygen-containing gas such as CO2.

[0129] At this time, the supply amount of silicon-containing gas such as SiH4, the supply amount of hydrogen-containing gas such as H2, the supply amount of N-type dopant-containing gas such as PH3, and the supply amount of P-type dopant-containing gas such as B2H6 may be the same between the first sublayer (322a), the second sublayer (322b), and the third sublayer (322c).

[0130] However, the supply amount of oxygen-containing gas, such as CO2, may differ between the first sublayer (322a), the second sublayer (322b), and the third sublayer (322c). For example, the supply amount of oxygen-containing gas when forming the second sublayer (322b) may be greater than the supply amount of oxygen-containing gas when forming the first sublayer (322a) and the supply amount of oxygen-containing gas when forming the third sublayer (322c).

[0131] For example, the supply amount of silicon-containing gas to the supply amount of oxygen-containing gas during the process of forming the first sublayer (322a) and the third sublayer (322c) may be in the range of 1:0.4 to 1:0.5, and the supply amount of silicon-containing gas to the supply amount of oxygen-containing gas during the process of forming the second sublayer (322b) may be in the range of 1:0.9 to 1:1.1.

[0132] Accordingly, the oxygen content of the second sublayer (322b) may be greater than the oxygen content of the first sublayer (322a) and the oxygen content of the third sublayer (322c). Therefore, the light reception characteristics of the second sublayer (322b) may be higher than the light reception characteristics of the first sublayer (322a) and the third sublayer (322c). Additionally, the electrical conductivity of the second sublayer (322b) may be lower than the electrical conductivity of the first sublayer (322a) and the electrical conductivity of the third sublayer (322c).

[0133] FIGS. 5a to 5g are schematic cross-sectional views of a manufacturing process of a solar cell according to one embodiment of the present invention, which relate to the manufacturing process of a solar cell according to FIG. 1 described above.

[0134] First, as can be seen in FIG. 5a, a first passivation layer (210) is formed on one side of the substrate (100), for example, on the upper surface.

[0135] The first passivation layer (210) is formed through a thin film deposition process such as chemical vapor deposition (CVD) or atomic layer deposition (ALD), and may consist of an intrinsic semiconductor layer, for example, an intrinsic amorphous silicon layer.

[0136] For example, the first passivation layer (210) may be formed as an a-Si layer using a silicon-containing gas such as SiH4 and a hydrogen-containing gas such as H2, but is not necessarily limited thereto.

[0137] Next, as can be seen in FIG. 5b, a first conductive semiconductor layer (310) is formed on one side of the first passivation layer (210), for example, on the upper side, comprising a first semiconductor layer (311), a second semiconductor layer (312), and a third semiconductor layer (313).

[0138] The first semiconductor layer (311) can be formed as a nanocrystalline (nc) or microcrystalline (uc) N-type Si:H through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) using a silicon-containing gas such as SiH4, a hydrogen-containing gas such as H2, and an N-type dopant-containing gas such as PH3.

[0139] Alternatively, the first semiconductor layer (311) may be formed as a nanocrystalline (nc) or microcrystalline (uc) P-type Si:H through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) using a silicon-containing gas such as SiH4, a hydrogen-containing gas such as H2, and a P-type dopant-containing gas such as B2H6.

[0140] When the first semiconductor layer (311) is formed as a nanocrystalline (nc) or microcrystalline (uc) N-type Si:H, the second semiconductor layer (312) can be formed as a nanocrystalline (nc) or microcrystalline (uc) N-type SiO:H through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) using a silicon-containing gas such as SiH4, a hydrogen-containing gas such as H2, an N-type dopant-containing gas such as PH3, and an oxygen-containing gas such as CO2 on one side of the first semiconductor layer (311), for example, the upper side.

[0141] When the first semiconductor layer (311) is formed as nanocrystalline (nc) or microcrystalline (uc) P-type Si:H, the second semiconductor layer (312) can be formed as nanocrystalline (nc) or microcrystalline (uc) P-type Si:H through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) using a silicon-containing gas such as SiH4, a hydrogen-containing gas such as H2, a P-type dopant-containing gas such as B2H6, and an oxygen-containing gas such as CO2.

[0142] When the first semiconductor layer (311) is formed as nanocrystalline (nc) or microcrystalline (uc) N-type Si:H, the third semiconductor layer (313) can be formed as nanocrystalline (nc) or microcrystalline (uc) N-type Si:H through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) using a silicon-containing gas such as SiH4, a hydrogen-containing gas such as H2, and an N-type dopant-containing gas such as PH3 on one side of the second semiconductor layer (312), for example, the upper side.

[0143] When the first semiconductor layer (311) is formed as nanocrystalline (nc) or microcrystalline (uc) P-type Si:H, the third semiconductor layer (313) can be formed as nanocrystalline (nc) or microcrystalline (uc) P-type Si:H through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) using a silicon-containing gas such as SiH4, a hydrogen-containing gas such as H2, and a P-type dopant-containing gas such as B2H6.

[0144] The first semiconductor layer (311), the second semiconductor layer (312), and the third semiconductor layer (313) can all be formed using the same silicon-containing gas, hydrogen-containing gas, and dopant-containing gas.

[0145] The amount of dopant-containing gas supplied when forming the third semiconductor layer (313) is greater than the amount of dopant-containing gas supplied when forming the first semiconductor layer (311) and the amount of dopant-containing gas supplied when forming the second semiconductor layer (312).

[0146] In addition, the amount of dopant-containing gas supplied when forming the second semiconductor layer (312) is greater than the amount of dopant-containing gas supplied when forming the first semiconductor layer (311).

[0147] Next, as can be seen in FIG. 5c, a first transparent conductive layer (410) is formed on one side of the first conductive semiconductor layer (310), for example, on the upper side.

[0148] The first transparent conductive layer (410) can be formed from a transparent conductive material such as ITO (Indium Tin Oxide), ZnOH, ZnO:B, ZnO:Al, SnO2, SnO2:F, etc. through a thin film deposition process such as chemical vapor deposition (CVD) or atomic layer deposition (ALD) or a sputtering process.

[0149] Next, as can be seen in FIG. 5d, a second passivation layer (220) is formed on the other side of the substrate (100), for example, the lower side. The processes of FIG. 5d to FIG. 5f can be performed by flipping the substrate (100) so that the lower side of the substrate (100) faces upward.

[0150] The second passivation layer (220) is formed through a thin film deposition process such as chemical vapor deposition (CVD) or atomic layer deposition (ALD), and may consist of an intrinsic semiconductor layer, for example, an intrinsic amorphous silicon layer.

[0151] For example, the second passivation layer (220) may be formed as an a-Si layer using a silicon-containing gas such as SiH4 and a hydrogen-containing gas such as H2, but is not necessarily limited thereto.

[0152] Next, as can be seen in FIG. 5e, a second conductive semiconductor layer (320) is formed on the other side of the second passivation layer (220), for example, the lower side.

[0153] The above second conductivity type semiconductor layer (320) can be formed as a nanocrystalline (nc) or microcrystalline (uc) P-type Si:H through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) using a silicon-containing gas such as SiH4, a hydrogen-containing gas such as H2, and a P-type dopant-containing gas such as B2H6.

[0154] Alternatively, the second conductivity semiconductor layer (320) can be formed as a nanocrystalline (nc) or microcrystalline (uc) N-type Si:H through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) using a silicon-containing gas such as SiH4, a hydrogen-containing gas such as H2, and an N-type dopant-containing gas such as PH3.

[0155] Next, as can be seen in FIG. 5f, a second transparent conductive layer (420) is formed on the other side, for example, the lower side, of the second conductive semiconductor layer (320).

[0156] The second transparent conductive layer (420) can be formed from a transparent conductive material such as ITO (Indium Tin Oxide), ZnOH, ZnO:B, ZnO:Al, SnO2, SnO2:F, etc. through a thin film deposition process such as chemical vapor deposition (CVD) or atomic layer deposition (ALD) or a sputtering process.

[0157] Next, as can be seen in FIG. 5g, a first electrode (510) is formed on one side of the first transparent conductive layer (410), for example, on the upper surface, and a second electrode (520) is formed on the other side of the second transparent conductive layer (420), for example, on the lower surface.

[0158] The first electrode (510) and the second electrode (520) can be formed as a single layer or a multilayer structure of two or more metals selected from the group consisting of Ag, Cu, Al, Mo, and W using various pattern forming processes known in the art, such as screen printing.

[0159] FIGS. 6a to 6d are graphs according to various embodiments of the present invention showing the supply process of a dopant-containing gas and the supply process of an oxygen-containing gas introduced in the processes of FIGS. 5a to 5c.

[0160] First, as can be seen in FIG. 6a, in the process of FIG. 5a for forming the first passivation layer (210) and the process of FIG. 5c for forming the first transparent conductive layer (410), dopant-containing gas and oxygen-containing gas are not supplied.

[0161] However, in the process of FIG. 5b for forming the first conductive semiconductor layer (310), a dopant-containing gas and an oxygen-containing gas are supplied.

[0162] More specifically, in the process of FIG. 5b, in the process for forming the first semiconductor layer (311) of the first conductive semiconductor layer (310) at first, a dopant-containing gas is supplied in a first amount, but an oxygen-containing gas is not supplied. Then, in the process for forming the second semiconductor layer (312) of the first conductive semiconductor layer (310), a dopant-containing gas is supplied in a second amount, which is greater than the first amount, and an oxygen-containing gas is also supplied. At this time, the amount of oxygen-containing gas supplied may be greater than the amount of dopant-containing gas supplied (the second amount). Then, in the process for forming the third semiconductor layer (313) of the first conductive semiconductor layer (310), a dopant-containing gas is supplied in a third amount, which is greater than the second amount, and an oxygen-containing gas is not supplied. At this time, when forming the third semiconductor layer (313), the amount of dopant-containing gas supplied (the third amount) may be greater than the amount of oxygen-containing gas supplied when forming the second semiconductor layer (312).

[0163] Next, FIGS. 6b to 6d differ from FIG. 6a described above in that oxygen-containing gas is supplied during the formation of the first semiconductor layer (311) and the third semiconductor layer (313) of the first conductive semiconductor layer (310).

[0164] As shown in FIGS. 6b and 6c, oxygen-containing gas can be supplied in pulses during the formation of the first semiconductor layer (311) and the third semiconductor layer (313) of the first conductive semiconductor layer (310). However, the amount of oxygen-containing gas supplied during the formation of the first semiconductor layer (311) and the third semiconductor layer (313) is less than the amount of oxygen-containing gas supplied during the formation of the second semiconductor layer (312).

[0165] When forming the first semiconductor layer (311) and the third semiconductor layer (313), a pulse for supplying oxygen-containing gas can be performed multiple times, preferably two or three times.

[0166] In FIG. 6b and FIG. 6c, when the oxygen-containing gas contains CO2, the first semiconductor layer (311) and the third semiconductor layer (313) may alternately have regions containing carbon and oxygen atoms and regions not containing carbon and oxygen atoms from bottom to top. For example, as in FIG. 6b, the lowest surface and the highest surface of the first semiconductor layer (311) and the third semiconductor layer (313) may be regions not containing carbon and oxygen atoms, and as in FIG. 6c, the lowest surface and the highest surface of the first semiconductor layer (311) and the third semiconductor layer (313) may be regions containing carbon and oxygen atoms. In some cases, one of the lowest surface and the highest surface of the first semiconductor layer (311) and the third semiconductor layer (313) may be a region containing carbon and oxygen atoms, and the other may be a region not containing carbon and oxygen atoms.

[0167] As shown in FIG. 6d, when forming the first semiconductor layer (311) and the third semiconductor layer (313) of the first conductive semiconductor layer (310), oxygen-containing gas is supplied in multiple pulses, wherein the size of the multiple pulses in the case of the first semiconductor layer (311) is gradually increased, and the size of the multiple pulses in the case of the third semiconductor layer (313) is gradually decreased. Accordingly, the region containing the carbon element and oxygen element in the first semiconductor layer (311) can gradually increase from bottom to top, and the region containing the carbon element and oxygen element in the third semiconductor layer (313) can gradually decrease from bottom to top.

[0168] FIGS. 7a to 7g are schematic cross-sectional views of a manufacturing process of a solar cell according to another embodiment of the present invention, which relates to the manufacturing process of a solar cell according to FIG. 2 described above.

[0169] First, as can be seen in FIG. 7a, a first passivation layer (210) is formed on one side of the substrate (100), for example, on the upper surface.

[0170] The process of forming the first passivation layer (210) is the same as that described in FIG. 5a above.

[0171] Next, as can be seen in FIG. 7b, a first conductive semiconductor layer (310) is formed on one side of the first passivation layer (210), for example, on the upper side, comprising a first semiconductor layer (311), a second semiconductor layer (312), and a third semiconductor layer (313).

[0172] The process of forming the first semiconductor layer (311) is the same as that described in FIG. 5b.

[0173] The second semiconductor layer (312) can be formed as a nanocrystalline (nc) or microcrystalline (uc) N-type or P-type SiO:H through a thin film deposition process such as Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) using a silicon-containing gas such as SiH4, a hydrogen-containing gas such as H2, an N-type dopant-containing gas such as PH3, a P-type dopant-containing gas such as B2H6, and an oxygen-containing gas such as CO2 on one side of the first semiconductor layer (311), for example, the upper side.

[0174] At this time, the supply amount of silicon-containing gas such as SiH4, the supply amount of hydrogen-containing gas such as H2, the supply amount of N-type dopant-containing gas such as PH3, and the supply amount of P-type dopant-containing gas such as B2H6 are kept constant, while the supply amount of oxygen-containing gas such as CO2 is changed.

[0175] Specifically, when forming the second semiconductor layer (312), a first sublayer (312a) with a relatively small oxygen content is formed by first supplying a small amount of an oxygen-containing gas such as CO2, and then a second sublayer (312b) with a relatively large oxygen content is formed by supplying a large amount of an oxygen-containing gas such as CO2, and then a third sublayer (312c) with a relatively small oxygen content is formed by supplying a small amount of an oxygen-containing gas such as CO2.

[0176] For example, the supply amount of silicon-containing gas to the supply amount of oxygen-containing gas during the process of forming the first sublayer (312a) and the third sublayer (312c) may be in the range of 1:0.4 to 1:0.5, and the supply amount of silicon-containing gas to the supply amount of oxygen-containing gas during the process of forming the second sublayer (312b) may be in the range of 1:0.9 to 1:1.1.

[0177] The process of forming the third semiconductor layer (313) is the same as that described in FIG. 5b.

[0178] The first semiconductor layer (311), the second semiconductor layer (312), and the third semiconductor layer (313) can all be formed using the same silicon-containing gas, hydrogen-containing gas, and dopant-containing gas.

[0179] The amount of dopant-containing gas supplied when forming the third semiconductor layer (313) is greater than the amount of dopant-containing gas supplied when forming the first semiconductor layer (311) and the amount of dopant-containing gas supplied when forming the second semiconductor layer (312).

[0180] In addition, the amount of dopant-containing gas supplied when forming the second semiconductor layer (312) is greater than the amount of dopant-containing gas supplied when forming the first semiconductor layer (311).

[0181] Next, as can be seen in FIG. 7c, a first transparent conductive layer (410) is formed on one side of the first conductive semiconductor layer (310), for example, on the upper side.

[0182] The process of forming the first transparent conductive layer (410) is the same as that described in FIG. 5c.

[0183] Next, as can be seen in FIG. 7d, a second passivation layer (220) is formed on the other side of the substrate (100), for example, the lower side. The processes of FIG. 7d to FIG. 7f can be performed by flipping the substrate (100) so that the lower side of the substrate (100) faces upward.

[0184] The process of forming the second passivation layer (220) is the same as that described in FIG. 5d above.

[0185] Next, as can be seen in FIG. 7e, a second conductive semiconductor layer (320) is formed on the other side of the second passivation layer (220), for example, the lower side.

[0186] The process of forming the second conductivity type semiconductor layer (320) is the same as that described in FIG. 5e.

[0187] Next, as can be seen in FIG. 7f, a second transparent conductive layer (420) is formed on the other side, for example, the lower side, of the second conductive semiconductor layer (320).

[0188] The process of forming the second transparent conductive layer (420) is the same as that described in FIG. 5f.

[0189] Next, as can be seen in FIG. 7g, a first electrode (510) is formed on one side of the first transparent conductive layer (410), for example, on the upper surface, and a second electrode (520) is formed on the other side of the second transparent conductive layer (420), for example, on the lower surface.

[0190] The formation process of the first electrode (510) and the second electrode (520) is the same as that described in FIG. 5g.

[0191] Figure 8 is a graph showing the supply process of the dopant-containing gas and the supply process of the oxygen-containing gas introduced in the processes of Figures 7a to 7c.

[0192] As can be seen in FIG. 8, in the process of FIG. 7a for forming the first passivation layer (210) and the process of FIG. 7c for forming the first transparent conductive layer (410), dopant-containing gas and oxygen-containing gas are not supplied.

[0193] However, in the process of FIG. 7b for forming the first conductive semiconductor layer (310), a dopant-containing gas and an oxygen-containing gas are supplied.

[0194] More specifically, in the process of FIG. 7b, in the process for forming the first semiconductor layer (311) of the first conductive semiconductor layer (310) at first, a dopant-containing gas is supplied in a first amount, but an oxygen-containing gas is not supplied.

[0195] After that, in the process for forming the second semiconductor layer (312) of the first conductive semiconductor layer (310), a dopant-containing gas is supplied in a second amount greater than the first amount, and an oxygen-containing gas is also supplied. At this time, the amount of oxygen-containing gas supplied is initially supplied in a small amount, then supplied in a large amount, and then supplied in a small amount again. Accordingly, the first sublayer (312a) of the second semiconductor layer (312) is formed by initially supplying a small amount of oxygen-containing gas, then the second sublayer (312b) of the second semiconductor layer (312) is formed by subsequently supplying a large amount of oxygen-containing gas, and then the third sublayer (312c) of the second semiconductor layer (312) is formed by subsequently supplying a small amount of oxygen-containing gas again.

[0196] The amount of oxygen-containing gas supplied initially in small quantities for forming the first sublayer (312a) is smaller than the amount of dopant-containing gas supplied (second amount), but the amount of oxygen-containing gas supplied in large quantities for forming the second sublayer (312b) is larger than the amount of dopant-containing gas supplied (second amount), and the amount of oxygen-containing gas supplied in small quantities for forming the third sublayer (312c) is smaller than the amount of dopant-containing gas supplied (second amount).

[0197] After that, in the process for forming the third semiconductor layer (313) of the first conductive semiconductor layer (310), the dopant-containing gas is supplied in a third amount which is greater than the second amount, and the oxygen-containing gas is not supplied.

[0198] Although not specifically illustrated, the manufacturing process of the second conductivity type semiconductor layer (320) in the aforementioned FIG. 3 may be the same as the manufacturing process of the first conductivity type semiconductor layer (310) in the aforementioned FIG. 5b and FIG. 6, except that a dopant of opposite polarity is used.

[0199] In addition, the manufacturing process of the second conductivity type semiconductor layer (320) in the aforementioned FIG. 4 may be the same as the manufacturing process of the first conductivity type semiconductor layer (310) in FIG. 7b and FIG. 8, except that a dopant of opposite polarity is used.

[0200] Although not specifically illustrated, the process of forming the first semiconductor layer (311) and the process of forming the third semiconductor layer (313) in FIG. 8 can be varied as described in FIG. 6b to FIG. 6d above.

[0201] Hereinafter, a substrate processing apparatus for forming a semiconductor layer according to the present invention will be described with reference to FIGS. 9 to 12.

[0202] Referring to FIGS. 9 and 10, the substrate processing device (1) performs a processing process on a substrate (20). For example, the substrate processing device (1) can perform a deposition process for depositing a thin film on the substrate (20). For example, the substrate processing device (1) can perform a deposition process such as CVD (Chemical Vapor Deposition) or ALD (Atomic Layer Deposition). The substrate processing device (1) includes a mounting base (2), a third electrode (3), a fourth electrode (4), a first injection unit (5), a second injection unit (6), a first injection unit (7), and a second injection unit (8).

[0203] Referring to FIG. 9, the mounting base (2) supports the substrate (20). The substrate (20) may be placed on the mounting base (2). The mounting base (2) may be positioned below the fourth electrode (4). In this case, the substrate (20) may be placed on the upper surface of the mounting base (2). The substrate (20) may be a semiconductor substrate, a wafer, etc. The mounting base (2) may support a plurality of substrates (20).

[0204] The above-mentioned mounting stand (2) may be coupled to a chamber (50). The chamber (50) provides a processing space where the processing process takes place. The above-mentioned mounting stand (2) may be placed inside the chamber (50). The above-mentioned mounting stand (2) may also be rotatably coupled to the chamber (50). In this case, the above-mentioned mounting stand (2) may be connected to a rotating part that provides rotational force. By rotating the above-mentioned mounting stand (2), the rotating part can rotate the substrate (20) supported on the above-mentioned mounting stand (2).

[0205] Referring to FIG. 9, the third electrode (3) is located on the upper side of the mounting base (2). The third electrode (3) may be located on the upper side of the fourth electrode (4). The third electrode (3) may be positioned so as to be spaced upward from the fourth electrode (4) by a predetermined distance. The third electrode (3) may be placed inside the chamber (50). The third electrode (3) may be coupled to the chamber (50) so as to be located on the upper side of the chamber (50). The third electrode (3) may be formed in the shape of a square plate overall, but is not limited thereto and may be formed in other shapes such as a disc shape.

[0206] Referring to FIG. 9, the fourth electrode (4) is positioned between the third electrode (3) and the mounting stand (3). The fourth electrode (4) may be positioned below the third electrode (3) and above the mounting stand (3). The fourth electrode (4) may be positioned so as to be spaced upward from the mounting stand (3) by a predetermined distance. The fourth electrode (4) may be positioned inside the chamber (50). The fourth electrode (4) may be formed in the shape of a square plate, but is not limited thereto and may be formed in other shapes such as a disc shape.

[0207] The fourth electrode (4) and the third electrode (3) can be used to generate plasma. RF (Radio Frequency) power may be applied to either the fourth electrode (4) or the third electrode (3), and the other may be grounded. Accordingly, a discharge may occur due to the electric field between the fourth electrode (4) and the third electrode (3), thereby generating plasma. RF power may be applied to the fourth electrode (4), and the third electrode (3) may be grounded. The fourth electrode (4) may be grounded, and RF power may be applied to the third electrode (3).

[0208] An opening (41) may be formed in the fourth electrode (4). The opening (41) may be formed to penetrate the fourth electrode (4). The opening (41) may be formed to penetrate the upper and lower surfaces of the fourth electrode (4). The opening (41) may be formed in a cylindrical shape overall, but is not limited thereto and may be formed in other shapes such as a rectangular shape.

[0209] When the opening (41) is formed in the fourth electrode (4), a protruding electrode (31) may be coupled to the third electrode (3). The protruding electrode (31) may be coupled to the third electrode (3) so as to protrude toward the seat (2). The protruding electrode (31) may protrude from the lower surface of the third electrode (3). The protruding electrode (31) and the third electrode (3) may be formed integrally. When the third electrode (3) is grounded, the protruding electrode (31) may be grounded through the third electrode (3). When RF power is applied to the third electrode (3), RF power may be applied to the protruding electrode (31) through the third electrode (3).

[0210] A plurality of openings (41) may be formed in the fourth electrode (4). The openings (41) may be positioned at locations spaced apart from each other. In this case, a plurality of protruding electrodes (31) may be coupled to the third electrode (3). The protruding electrodes (31) may be positioned at locations spaced apart from each other. The openings (41) may be positioned at locations corresponding to the protruding electrodes (31). Accordingly, the protruding electrodes (31) may protrude toward the openings (41). The protruding electrodes (31) may protrude to a length that is inserted into the openings (41). Although not illustrated, the protruding electrodes (31) may protrude to a length that is not inserted into the openings (41). In this case, the protruding electrodes (31) may be located above the openings (41).

[0211] Referring to FIGS. 9 and FIGS. 10, the first injection part (5) injects the first gas.

[0212] The first gas may be a gas for performing a processing process on the substrate (20). The first gas may include at least one of the aforementioned silicon-containing gas, hydrogen-containing gas, dopant-containing gas, and oxygen-containing gas.

[0213] The first injection unit (5) can inject the first gas into the first injection unit (7). The first gas injected into the first injection unit (7) can flow along the first injection unit (7) so as to be sprayed toward the entire surface of the substrate (20), and then be sprayed toward the mounting base (2) through the third electrode (3). The entire surface of the substrate (20) may correspond to the entire upper surface of the substrate (20). The upper surface of the substrate (20) is a surface positioned to face the fourth electrode (4). The first injection unit (5) can be coupled to the chamber (50).

[0214] Referring to FIGS. 9 to 11, the second injection part (6) injects a second gas.

[0215] The second gas may be a gas for performing a processing process on the substrate (20). The second gas may include at least one of the aforementioned silicon-containing gas, hydrogen-containing gas, dopant-containing gas, and oxygen-containing gas.

[0216] The second injection unit (6) can inject the second gas into the second injection unit (8). The second gas injected into the second injection unit (8) can flow along the second injection unit (8) so as to be sprayed toward the entire surface of the substrate (20), and then be sprayed toward the mounting stand (2) through the third electrode (3). The second injection unit (6) can be coupled to the chamber (50). The second gas injected by the second injection unit (6) and the first gas injected by the first injection unit (5) can be used to perform a processing process on the substrate (20) by spraying toward the substrate (20) supported on the mounting stand (2). Accordingly, the first gas and the second gas can be sprayed by separating the gas injection units.

[0217] The second injection part (6) and the first injection part (5) may each be positioned on the same side with respect to the third electrode (3). The second injection part (6) and the first injection part (5) may inject the second gas and the first gas into the second injection part (8) and the first injection part (7), respectively.

[0218] Next, as illustrated in FIG. 10, the embodiment may have the second injection part (6) positioned on one side (3a) of the third electrode (3) and the first injection part (5) positioned on one side (3a) of the third electrode (3). That is, the embodiment may have the second injection part (6) and the first injection part (5) positioned on the same side with respect to the third electrode (3).

[0219] The second gas injected by the second injection part (6) into the second injection part (8) flows from one side (3a) to the other side (3c) of the third electrode (3). Accordingly, the second gas is injected from one side (21) to the other side (22) of the substrate (20). In FIG. 10, the dotted arrow indicates the second gas.

[0220] The first gas injected by the first injection unit (5) into the first injection unit (7) flows from one side (3a) to the other side (3c) of the third electrode (3). Accordingly, as it flows from one side (21) to the other side (22) of the substrate (20), it is sprayed toward the substrate (20). In FIG. 10, the solid arrow indicates the first gas.

[0221] Although FIG. 10 describes the second injection part (6) and the first injection part (5) being positioned on one side (3a) of the third electrode (3), it is not limited thereto and may be implemented differently if the second injection part (6) and the first injection part (5) are positioned on the same side with respect to the third electrode (3).

[0222] For example, both the second injection part (6) and the first injection part (5) may be positioned on the other side (3c) of the third electrode (3).

[0223] For example, as shown in FIG. 12, the second injection part (6) and the first injection part (5) may both be arranged to inject the second gas and the first gas through the central part of the third electrode (3) on the upper side (3b) of the third electrode (3).

[0224] Referring to FIGS. 10 and 11, the first injection unit (7) injects the first gas through the third electrode (3). The first injection unit (7) can be connected to the first injection unit (5). The first gas injected by the first injection unit (5) into the first injection unit (7) can flow along the first injection unit (7) and be injected toward the seating stand (2).

[0225] The first injection part (7) above may include a first injection member (71).

[0226] The first injection member (71) is disposed inside the third electrode (3). The first injection member (71) can function as a passage for flowing the first gas injected from the first injection unit (5). The first injection member (71) can be formed to extend along the first axial direction (X-axis direction). Accordingly, the first gas injected into the first injection member (71) can flow along the first injection member (71) in the first axial direction (X-axis direction). The first injection member (71) can be implemented as a pipe, a tube, etc. In this case, the first injection member (71) can be coupled to the third electrode (3) so as to be disposed inside the third electrode (3). The first injection member (71) may be implemented to be positioned inside the third electrode (3) by forming a groove inside the third electrode (3). The first injection part (7) may include a first injection hole (72).

[0227] The first injection hole (72) sprays the first gas toward the seating base (2). The first injection hole (72) may be connected to the first injection member (71). Accordingly, the first gas flowing along the first injection member (71) may be sprayed toward the seating base (2) through the first injection hole (72). The first injection hole (72) may be formed such that one end is connected to the first injection member (71) and the other end penetrates the third electrode (3). If the first injection member (71) is formed parallel to the first axial direction (X-axis direction), the first injection hole (72) may be formed parallel to the vertical direction (Z-axis direction).

[0228] The first injection unit (7) may include a plurality of first injection holes (72). The first injection holes (72) may be arranged spaced apart from each other along the first axial direction (X-axis direction). Accordingly, the first injection holes (72) can inject the first gas into different parts of the substrate (20) supported on the stand (2). Each of the first injection holes (72) may be connected to different parts of the first injection member (71). Accordingly, the first gas may flow along the first injection member (71) in the first axial direction (X-axis direction) and be injected toward the stand (2) through the first injection holes (72).

[0229] As the first injection holes (72) are provided in plurality, the first injection unit (7) can be implemented to spray the first gas entirely toward the substrate (20) with respect to the first axis direction (X-axis direction). In order to spray the first gas entirely toward the substrate (20) with respect to the second axis direction (Y-axis direction) perpendicular to the first axis direction (X-axis direction), the first injection unit (7) may include a plurality of the first injection members (71).

[0230] The first injection members (71) may be positioned at locations spaced apart from each other along the second axis direction (Y-axis direction). The second axis direction (Y-axis direction) and the first axis direction (X-axis direction) are axial directions positioned perpendicular to each other on a single plane. A plurality of first injection holes (72) may be connected to each of the first injection members (71). Accordingly, the first injection members (71) can inject the first gas toward the mounting base (2) through the first injection holes (72). Thus, the substrate processing device (1) according to the present invention can not only inject the first gas toward the substrate (20) in relation to the first axis direction (X-axis direction) but also inject the first gas toward the substrate (20) in relation to the second axis direction (Y-axis direction). Accordingly, the substrate processing device (1) according to the present invention is implemented to spray the first gas toward the entire surface of the substrate (20) placed on the mounting stand (2). The first spray holes (72) may be formed to penetrate the protruding electrode (31). In this case, the first gas may flow toward the mounting stand (2) through the opening (41) after being sprayed toward the opening through the first spray holes (72).

[0231] Referring to FIGS. 10 and 11, the second injection unit (8) injects the second gas through the third electrode (3). The second injection unit (8) may be connected to the second injection unit (6). The second gas injected by the second injection unit (6) into the second injection unit (8) may flow along the second injection unit (8) and be injected toward the seating stand (2).

[0232] The second injection part (8) above may include a second injection member (81).

[0233] The second injection member (81) is disposed inside the third electrode (3). The second injection member (81) can function as a passage for flowing the second gas injected from the second injection part (6). The second injection member (81) can be formed to extend along the first axial direction (X-axis direction). Accordingly, the second gas injected into the second injection member (81) can flow along the second injection member (81) in the first axial direction (X-axis direction). The second injection member (81) can be implemented as a pipe, a tube, etc. In this case, the second injection member (81) can be coupled to the third electrode (3) so as to be disposed inside the third electrode (3). The second injection member (81) may be implemented to be placed inside the third electrode (3) by forming a groove inside the third electrode (3). In this case, if the substrate processing device (1) needs to control the temperature of the second gas flowing along the second injection member (81), it can directly control the temperature of the second gas by controlling the temperature of the third electrode (3). Accordingly, the substrate processing device (1) can improve the ease and accuracy of the operation of controlling the temperature of the second gas.

[0234] The second injection part (8) above may include a second injection hole (82).

[0235] The second injection hole (82) sprays the second gas toward the seating base (2). The second injection hole (82) may be connected to the second injection member (81). Accordingly, the second gas flowing along the second injection member (81) may be sprayed toward the seating base (2) through the second injection hole (82). The second injection hole (82) may be formed such that one end is connected to the second injection member (81) and the other end penetrates the third electrode (3). If the second injection member (81) is formed parallel to the first axial direction (X-axis direction), the second injection hole (82) may be formed parallel to the vertical direction (Z-axis direction).

[0236] The second injection unit (8) may include a plurality of the second injection holes (82). The second injection holes (82) may be arranged spaced apart from each other along the first axial direction (X-axis direction). Accordingly, the second injection holes (82) can inject the second gas into different parts of the substrate (20) supported on the stand (2). Each of the second injection holes (82) may be connected to different parts of the second injection member (81). Accordingly, the second gas may flow along the second injection member (81) in the first axial direction (X-axis direction) and be injected toward the stand (2) through the second injection holes (82). As shown in FIG. 7, the second injection holes (82) and the first injection holes (72) may be arranged alternately in multiple numbers based on the first axial direction (X-axis direction).

[0237] As the second injection holes (82) are provided in plurality, the second injection unit (8) can be implemented to spray the second gas entirely toward the substrate (20) with respect to the first axis direction (X-axis direction). In order to spray the second gas entirely toward the substrate (20) with respect to the second axis direction (Y-axis direction) perpendicular to the first axis direction (X-axis direction), the second injection unit (8) may include a plurality of the second injection members (81).

[0238] The second injection members (81) may be positioned at locations spaced apart from each other along the second axis direction (Y-axis direction). A plurality of second injection holes (82) may be connected to each of the second injection members (81). Accordingly, the second injection members (81) can inject the second gas toward the mounting stand (2) through the second injection holes (82). Thus, the substrate processing device (1) according to the present invention can not only inject the second gas entirely toward the substrate (20) based on the first axis direction (X-axis direction), but also inject the second gas entirely toward the substrate (20) based on the second axis direction (Y-axis direction). Accordingly, the substrate processing device (1) according to the present invention is implemented to inject the second gas toward the entire surface of the substrate (20) mounted on the mounting stand (2). The second injection holes (82) may be positioned above the fourth electrode (4). In this case, the second gas may be injected between the third electrode (3) and the fourth electrode (4) through the second injection holes (82), and then flow toward the mounting base (2) through the opening (41).

[0239] Although embodiments of the present invention have been described in more detail with reference to the attached drawings, the present invention is not necessarily limited to these embodiments and may be modified in various ways within the scope of the technical spirit of the present invention. Accordingly, the embodiments disclosed in the present invention are intended to explain, not limit, the technical spirit of the present invention, and the scope of the technical spirit of the present invention is not limited by these embodiments. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. The scope of protection of the present invention shall be interpreted by the claims, and all technical spirits within an equivalent scope shall be interpreted as being included within the scope of rights of the present invention.

Claims

1. A method for forming a solar cell comprising a first conductivity type semiconductor layer on a substrate, wherein The step of forming the first conductivity type semiconductor layer is, A step of forming a first semiconductor layer on the above substrate; A step of forming a second semiconductor layer on the first semiconductor layer; and The method includes the step of forming a third semiconductor layer on the second semiconductor layer, The second semiconductor layer above includes carbon elements and oxygen elements, and A method for forming a solar cell in which the second semiconductor layer has a higher content of carbon and oxygen elements than the first semiconductor layer and the third semiconductor layer.

2. In Paragraph 1, A method for forming a solar cell in which the first semiconductor layer and the third semiconductor layer alternately repeat regions containing carbon and oxygen atoms and regions not containing carbon and oxygen atoms.

3. In Paragraph 2, A method for forming a solar cell in which the region containing the carbon element and oxygen element in the first semiconductor layer gradually increases from bottom to top.

4. In Paragraph 2, A method for forming a solar cell in which the region containing the carbon element and oxygen element in the third semiconductor layer gradually decreases from bottom to top.

5. In Paragraph 1, A method for forming a solar cell in which the first conductivity type semiconductor layer is an N-type or P-type semiconductor layer.

6. In claim 1, the step of forming the second semiconductor layer is, Step of forming a first sublayer; A step of forming a second sublayer on the first sublayer; and The method includes the step of forming a third sublayer on the second sublayer, and A method for forming a solar cell in which the second sublayer has a higher content of carbon and oxygen elements than the first sublayer and the third sublayer.

7. Substrate; A first passivation layer provided on one surface of the above substrate; A first conductive semiconductor layer provided on one surface of the first passivation layer; A first transparent conductive layer provided on one surface of the first conductive semiconductor layer; and It comprises a first electrode provided on one surface of the first transparent conductive layer, and A solar cell characterized by comprising: a first conductive semiconductor layer comprising a first semiconductor layer including a nanocrystalline or microcrystalline semiconductor layer; a second semiconductor layer provided on the first semiconductor layer and comprising a nanocrystalline or microcrystalline oxide semiconductor layer; and a third semiconductor layer provided on the second semiconductor layer and comprising a nanocrystalline or microcrystalline semiconductor layer.

8. In Paragraph 7, The above first passivation layer is composed of an intrinsic semiconductor layer, and A solar cell characterized in that the first semiconductor layer, the second semiconductor layer, and the third semiconductor layer of the first conductivity type semiconductor layer are composed of the same P-type or N-type semiconductor layer.

9. In Paragraph 8, The concentration of the dopant included in the third semiconductor layer of the first conductivity type semiconductor layer is higher than the concentration of the dopant included in the first semiconductor layer of the first conductivity type semiconductor layer and the concentration of the dopant included in the second semiconductor layer of the first conductivity type semiconductor layer, and A solar cell characterized in that the concentration of a dopant included in the second semiconductor layer of the first conductivity type semiconductor layer is higher than the concentration of a dopant included in the first semiconductor layer of the first conductivity type semiconductor layer.

10. In Paragraph 7, A solar cell characterized in that the first semiconductor layer of the first conductivity type semiconductor layer has a higher degree of crystallinity than the second semiconductor layer and the third semiconductor layer of the first conductivity type semiconductor layer.

11. In Paragraph 7, A solar cell characterized in that the second semiconductor layer of the first conductivity type semiconductor layer has a larger band gap than the first semiconductor layer and the third semiconductor layer of the first conductivity type semiconductor layer, and thus has a larger amount of light absorption.

12. In Paragraph 7, A solar cell characterized in that the third semiconductor layer of the first conductivity type semiconductor layer has a greater electrical conductivity than the first semiconductor layer and the second semiconductor layer of the first conductivity type semiconductor layer.

13. In Paragraph 7, The second semiconductor layer of the first conductivity type semiconductor layer comprises a first sublayer, a second sublayer provided on the first sublayer, and a third sublayer provided on the second sublayer, and A solar cell characterized in that the oxygen content of the second sublayer is greater than the oxygen content of the first sublayer and the oxygen content of the third sublayer.

14. In Paragraph 13, The light reception characteristics of the second sublayer are higher than the light reception characteristics of the first sublayer and the light reception characteristics of the third sublayer, and A solar cell characterized in that the electrical conductivity of the second sublayer is lower than the electrical conductivity of the first sublayer and the electrical conductivity of the third sublayer.

15. A process of forming a first passivation layer on one side of a substrate; A process of forming a first conductive semiconductor layer on one surface of the first passivation layer; A process of forming a first transparent conductive layer on one surface of the first conductive semiconductor layer; and The method comprises a process of forming a first electrode on one surface of the first transparent conductive layer, and The process of forming the first conductivity type semiconductor layer above is, A process for forming a first semiconductor layer including a nanocrystalline or microcrystalline N-type or P-type semiconductor layer through a thin film deposition process using a silicon-containing gas, a hydrogen-containing gas, and a dopant-containing gas, A process for forming a second semiconductor layer comprising a nanocrystalline or microcrystalline N-type or P-type oxide semiconductor layer on the first semiconductor layer above through a thin film deposition process using a silicon-containing gas, a hydrogen-containing gas, a dopant-containing gas, and an oxygen-containing gas, and A method for manufacturing a solar cell, characterized by comprising a process of forming a third semiconductor layer including a nanocrystalline or microcrystalline N-type or P-type semiconductor layer on the second semiconductor layer through a thin film deposition process using a silicon-containing gas, a hydrogen-containing gas, and a dopant-containing gas.

16. In Paragraph 15, The amount of dopant-containing gas supplied when forming the third semiconductor layer of the first conductive semiconductor layer is greater than the amount of dopant-containing gas supplied when forming the first semiconductor layer of the first conductive semiconductor layer and the amount of dopant-containing gas supplied when forming the second semiconductor layer of the first conductive semiconductor layer. A method for manufacturing a solar cell characterized in that the amount of dopant-containing gas supplied when forming the second semiconductor layer of the first conductive semiconductor layer is greater than the amount of dopant-containing gas supplied when forming the first semiconductor layer of the first conductive semiconductor layer.

17. In Paragraph 16, A method for manufacturing a solar cell characterized in that the amount of oxygen-containing gas supplied when forming the second semiconductor layer of the first conductivity type semiconductor layer is greater than the amount of dopant-containing gas supplied when forming the first semiconductor layer of the first conductivity type semiconductor layer, and less than the amount of dopant-containing gas supplied when forming the third semiconductor layer of the first conductivity type semiconductor layer.

18. In Paragraph 15, The process of forming a second semiconductor layer of the first conductivity type semiconductor layer comprises a process of forming a first sublayer, a process of forming a second sublayer on the first sublayer, and a process of forming a third sublayer on the second sublayer. A method for manufacturing a solar cell characterized in that the amount of oxygen-containing gas supplied during the process of forming the second sublayer is greater than the amount of oxygen-containing gas supplied during the process of forming the first sublayer and the amount of oxygen-containing gas supplied during the process of forming the third sublayer.

19. In Paragraph 18, The supply amount of silicon-containing gas and the supply amount of oxygen-containing gas during the process of forming the first sublayer and the process of forming the third sublayer are in the range of 1:0.4 to 1:0.5, and A method for manufacturing a solar cell characterized in that the supply amount of silicon-containing gas and the supply amount of oxygen-containing gas during the process of forming the second sublayer are in the range of 1:0.9 to 1:1.

1.

20. In Paragraph 15, A method for forming a solar cell in which the first semiconductor layer and the third semiconductor layer alternately repeat regions containing carbon and oxygen atoms and regions not containing carbon and oxygen atoms.

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