WO2016132920A1

WO2016132920A1 - Photoelectric conversion element and method for manufacturing photoelectric conversion element

Info

Publication number: WO2016132920A1
Application number: PCT/JP2016/053367
Authority: WO
Inventors: 雄太松本; 親扶岡本; 隆岡村; 奈都子藤原
Original assignee: シャープ株式会社
Priority date: 2015-02-20
Filing date: 2016-02-04
Publication date: 2016-08-25
Also published as: JP2016154169A

Abstract

This photoelectric conversion element is provided with: a semiconductor substrate (1); an amorphous semiconductor film (3) of a first conductivity type, which extends in a first direction (41) on the semiconductor substrate (1); and an amorphous semiconductor film (5) of a second conductivity type, which extends in a second direction (42) on the semiconductor substrate (1). A peripheral portion (5a) of the amorphous semiconductor film (5) of the second conductivity type is positioned on a peripheral portion (3a) of the amorphous semiconductor film (3) of the first conductivity type, and at least one of the edge (3b) of the peripheral portion (3a) of the amorphous semiconductor film (3) of the first conductivity type and the edge (5b) of the peripheral portion (5a) of the amorphous semiconductor film (5) of the second conductivity type is wavy.

Description

Photoelectric conversion element and method for producing photoelectric conversion element

The present invention relates to a photoelectric conversion element and a method for manufacturing the photoelectric conversion element.

In recent years, expectations for solar cells that directly convert solar energy into electrical energy have increased rapidly, especially from the viewpoint of global environmental problems. Of these, the most manufactured and sold solar cells have a structure in which electrodes are formed on the light receiving surface on the side where sunlight enters and the back surface on the opposite side of the light receiving surface, respectively. is there.

However, when an electrode is formed on the light receiving surface, sunlight is reflected and absorbed by the electrode, so that the amount of incident sunlight is reduced by the area of the electrode. Therefore, development of a back junction solar cell in which an electrode is formed only on the back surface is underway (see, for example, Patent Document 1).

FIG. 16 shows a schematic cross-sectional view of the back junction solar cell described in Patent Document 1. The back junction solar cell shown in FIG. 16 has an i-type amorphous semiconductor layer 119, an n-type amorphous semiconductor layer 120, and a protective film 124 on a light-receiving surface of a substrate 111 such as an n-type single crystal silicon substrate. Are sequentially stacked.

In the n-type region 122 corresponding to the n-side electrode 116 on the back surface of the substrate 111, the i-type amorphous semiconductor layer 112, the n-type amorphous semiconductor layer 114, the insulating layer 121, and the n-side electrode are formed on the substrate 111. 116 are sequentially stacked. Further, the n-type amorphous semiconductor layer 114 and the n-side electrode 116 are connected through a hole penetrating the insulating layer 121.

In the p-type region 123 corresponding to the p-side electrode 117 on the back surface of the substrate 111, the i-type amorphous semiconductor layer 113, the p-type amorphous semiconductor layer 115, and the p-side electrode 117 are sequentially stacked on the substrate 111. Has been.

The n-side electrode 116 and the p-side electrode 117 are formed by providing

metal layers

116b and 117b and

organic coatings

116a and 117a in this order on the transparent

conductive layers

116c and 117c, respectively.

FIG. 17 shows a flowchart of the manufacturing method of the back junction solar cell shown in FIG. Hereinafter, with reference to FIG. 17, the manufacturing method of the back junction type solar cell shown by FIG. 16 is demonstrated. First, in step S1a, an i-type amorphous semiconductor layer 119 and an i-type amorphous semiconductor layer 112 are formed on the light-receiving surface and the back surface of the substrate 111 by a CVD method, respectively.

Next, in step S2a, an n-type amorphous semiconductor layer 120 and an n-type amorphous semiconductor layer 120 are formed on the entire surface of the i-type amorphous semiconductor layer 119 on the light-receiving surface side of the substrate 111 and the entire surface of the i-type amorphous semiconductor layer 112 on the back surface side, respectively. A type amorphous semiconductor layer 114 is formed by a CVD method.

Next, in step S3a, the protective film 124 and the insulating layer 121 are formed on the entire surface of the n-type amorphous semiconductor layer 120 on the light-receiving surface side of the substrate 111 and the entire surface of the n-type amorphous semiconductor layer 114 on the back surface side by CVD. To form.

Next, in step S4a, a resist pattern is formed on the insulating layer 121 in order to pattern the n-type region 122 by photolithography. In the resist pattern, a resist film is formed in a region where the n-type region 122 made of a laminate of the i-type amorphous semiconductor layer 112 and the n-type amorphous semiconductor layer 114 is left, and the n-type region 122 is removed. It is formed to have an opening.

Next, in step S5a, the n-type region 122 in the opening of the resist pattern is removed by etching.

Next, in step S6a, the resist film remaining on the n-type region 122 is removed.
Next, in step S7a, an i-type amorphous semiconductor layer 113 is formed by CVD so as to cover the back surface of the substrate 111 where the insulating layer 121 and the n-type region 122 remain.

Next, in step S8a, a p-type amorphous semiconductor layer 115 is formed on the entire surface of the i-type amorphous semiconductor layer 113 by a CVD method.

Next, in step S9a, a resist film is formed on the p-type amorphous semiconductor layer 115. The resist film is formed in a region where the p-type region 123 made of a stacked body of the i-type amorphous semiconductor layer 113 and the p-type amorphous semiconductor layer 115 is left, and an opening is formed in a region where the p-type region 123 is removed. Formed to have.

Next, in step S10a, the p-type region 123 in the opening of the resist film is removed by etching.

Next, in step S11a, the resist film remaining on the p-type region 123 is removed.

Finally, in step S12a, the n-side electrode 116 is formed on the n-type region 122, and the p-side electrode 117 is formed on the p-type region 123, whereby the back junction solar cell shown in FIG. The

JP 2013-2111385 A

However, in Patent Document 1, the manufacturing method of the back junction solar cell requires the use of photolithography, and thus the manufacturing cost is high, and improvement thereof has been demanded. There is also a demand for manufacturing a highly reliable and high-performance element.

The embodiment disclosed herein includes a semiconductor substrate, a first conductive type amorphous semiconductor film extending in the first direction on the semiconductor substrate, and a second conductive type extending in the second direction on the semiconductor substrate. An amorphous semiconductor film, the edge of the second conductive amorphous semiconductor film is located on the edge of the first conductive amorphous semiconductor film, and the first conductive amorphous semiconductor At least one of the edge portion of the film and the edge portion of the second conductive type amorphous semiconductor film is a photoelectric conversion element having undulations.

The embodiment disclosed herein includes a step of patterning a first conductive type amorphous semiconductor film extending in a first direction on a semiconductor substrate, and a second conductive type extending in a second direction on the semiconductor substrate. The step of patterning the amorphous semiconductor film and the step of patterning the second conductive type amorphous semiconductor film include a second conductive type amorphous semiconductor layer on the edge of the patterned first conductive type amorphous semiconductor film. A step of patterning the second conductive amorphous semiconductor film so that the edge of the semiconductor film is located, the edge of the edge of the first conductive amorphous semiconductor film after patterning, and the second after patterning This is a method for manufacturing a photoelectric conversion element in which at least one of the edge portions of the conductive amorphous semiconductor film has undulations.

According to the embodiment disclosed herein, the manufacturing cost can be reduced, and a photoelectric conversion element having high reliability and high characteristics and a method for manufacturing the photoelectric conversion element can be provided.

FIG. 3 is a schematic cross-sectional view of the heterojunction back contact cell of Embodiment 1. (A) is a typical expanded sectional view of the overlap region of the heterojunction type back contact cell of Embodiment 1, and (b) is a schematic when the overlap region shown in (a) is seen from the back side. It is a top view. It is a figure which shows the curve which shows the wave | undulation of the edge part obtained in the projection view when light is irradiated from the direction perpendicular | vertical to a 2nd surface with respect to the 2nd surface of a semiconductor substrate. 6 is a schematic cross-sectional view illustrating a part of the manufacturing process of the example of the method for manufacturing the heterojunction back contact cell of Embodiment 1. FIG. 6 is a schematic cross-sectional view illustrating a part of the manufacturing process of the example of the method for manufacturing the heterojunction back contact cell of Embodiment 1. FIG. 6 is a schematic cross-sectional view illustrating a part of the manufacturing process of the example of the method for manufacturing the heterojunction back contact cell of Embodiment 1. FIG. 6 is a schematic cross-sectional view illustrating a part of the manufacturing process of the example of the method for manufacturing the heterojunction back contact cell of Embodiment 1. FIG. 6 is a schematic cross-sectional view illustrating a part of the manufacturing process of the example of the method for manufacturing the heterojunction back contact cell of Embodiment 1. FIG. 6 is a schematic cross-sectional view illustrating a part of the manufacturing process of the example of the method for manufacturing the heterojunction back contact cell of Embodiment 1. FIG. 6 is a schematic cross-sectional view illustrating a part of the manufacturing process of the example of the method for manufacturing the heterojunction back contact cell of Embodiment 1. FIG. FIG. 10 is a schematic cross-sectional view illustrating a part of the manufacturing process of the example of the method for manufacturing the heterojunction back contact cell according to the second embodiment. FIG. 10 is a schematic cross-sectional view illustrating a part of the manufacturing process of the example of the method for manufacturing the heterojunction back contact cell according to the second embodiment. FIG. 10 is a schematic cross-sectional view illustrating a part of the manufacturing process of the example of the method for manufacturing the heterojunction back contact cell of Embodiment 3. FIG. 10 is a schematic cross-sectional view illustrating a part of the manufacturing process of the example of the method for manufacturing the heterojunction back contact cell of Embodiment 3. FIG. 10 is a schematic cross-sectional view illustrating a part of the manufacturing process of the example of the method for manufacturing the heterojunction back contact cell according to the fourth embodiment. 2 is a schematic cross-sectional view of a back junction solar cell described in Patent Document 1. FIG. It is a flowchart of the manufacturing method of the back junction type solar cell shown by FIG.

Hereinafter, the heterojunction back contact cell and the method of manufacturing the heterojunction back contact cell of Embodiments 1 to 4 will be described as an example of the photoelectric conversion element of the embodiment disclosed herein. In the drawings used to describe the embodiments, the same reference numerals represent the same or corresponding parts.

[Embodiment 1]
<Structure of heterojunction back contact cell>
FIG. 1 is a schematic cross-sectional view of the heterojunction back contact cell of the first embodiment. As shown in FIG. 1, the heterojunction back contact cell of Embodiment 1 includes a first conductivity type semiconductor substrate 1 having a concavo-convex structure on a first surface 1 a serving as a light receiving surface, and a back surface of the semiconductor substrate 1. The first i-type amorphous semiconductor film 2 on the second surface 1b and the second i-type amorphous semiconductor film 2 adjacent to the first i-type amorphous semiconductor film 2 on the second surface 1b of the semiconductor substrate 1 The i-type amorphous semiconductor film 4, the first conductive amorphous semiconductor film 3 on the first i-type amorphous semiconductor film 2, and the second on the second i-type amorphous semiconductor film 4 A conductive amorphous semiconductor film 5, a first electrode 7 on the first conductive amorphous semiconductor film 3, and a second electrode 8 on the second conductive amorphous semiconductor film 5 are provided. A first conductivity type region 51 is formed of a stacked body of the first i-type amorphous semiconductor film 2 and the first conductivity-type amorphous semiconductor film 3, and the second i-type amorphous semiconductor film 4 and the first conductivity-type amorphous semiconductor film 4 A second conductivity type region 52 is constituted by a laminate with the two conductivity type amorphous semiconductor film 5.

In the present embodiment, the first conductivity type semiconductor substrate 1 is an n-type single crystal silicon substrate, and the first i-type amorphous semiconductor film 2 and the second i-type amorphous semiconductor film 4 are i-type, respectively. A case where an amorphous silicon film is used, the first conductive amorphous semiconductor film 3 is an n-type amorphous silicon film, and the second conductive amorphous semiconductor film 5 is a p-type amorphous silicon film will be described. To do.

FIG. 2A shows a schematic enlarged cross-sectional view of the overlapping region of the heterojunction back contact cell of the first embodiment. As shown in FIG. 2A, the second conductive type amorphous semiconductor film 5 is formed on the edge 3 a of the first conductive type amorphous semiconductor film 3 on the first i type amorphous semiconductor film 2. Since the edge 5a is positioned via the second i-type amorphous semiconductor film 4, the first i-type amorphous semiconductor film 2, the first conductive amorphous semiconductor film 3, and the second i An overlapping region is formed in which the type amorphous semiconductor film 4 and the second conductive type amorphous semiconductor film 5 are sequentially overlapped. In the present embodiment, the portion closest to the second electrode 8 at the edge 3a of the first conductive type amorphous semiconductor film 3 is the end 3b of the edge 3a of the first conductive type amorphous semiconductor film 3, A portion of the edge 5 a of the second conductive type amorphous semiconductor film 5 closest to the first electrode 7 is an end 5 b of the edge 5 a of the second conductive type amorphous semiconductor film 5.

FIG. 2 (b) shows a schematic plan view when the overlapping region shown in FIG. 2 (a) is viewed from the back side. As shown in FIG. 2B, in the heterojunction back contact cell of Embodiment 1, the first conductivity type amorphous semiconductor film 3 extends in the first direction 41, and the first conductivity type non-contact. An end 3 b of the edge 3 a of the crystalline semiconductor film 3 extends while undulating in the first direction 41. The second conductive type amorphous semiconductor film 5 extends in the second direction 42, and the end portion 5 b of the edge 5 a of the second conductive type amorphous semiconductor film 5 undulates in the second direction 42. While extending. The first i-type amorphous semiconductor film 2 and the first electrode 7 also extend in the first direction 41, respectively, and the second i-type amorphous semiconductor film 4 and the second electrode 8 also respectively. It extends in the second direction 42. In the present embodiment, the case where the first direction 41 and the second direction 42 are the same direction will be described, but the first direction 41 and the second direction 42 may be different directions.

It is preferable that the undulation curve degree of the edge 3b of the edge 3a of the first conductive type amorphous semiconductor film 3 is 1.03 or more. When the undulation curve degree is 1.03 or more, the passivating property of the second surface 1b of the semiconductor substrate 1 is improved by the overlapping region. Therefore, the reliability of the heterojunction back contact cell of the first embodiment is improved. Can be improved. In this case, the open-circuit voltage (Voc) increases due to the improvement in passivation of the second surface 1b of the semiconductor substrate 1, and therefore the characteristics of the heterojunction back contact cell of the first embodiment tend to be improved. .

It is preferable that the undulation curve degree of the edge 3b of the edge 3a of the first conductive type amorphous semiconductor film 3 is 3.15 or less. When the degree of undulation is 3.15 or less, the end 3b of the edge 3a of the first conductive type amorphous semiconductor film 3 is in contact with the second electrode 8 which is an electrode for reverse conductivity type. Since it becomes difficult, the reliability of the heterojunction back contact cell of Embodiment 1 tends to be improved.

It is preferable that the undulation curve of the edge 5b of the edge 5a of the second conductivity type amorphous semiconductor film 5 is 1.03 or more. When the undulation curve degree is 1.03 or more, the passability of the second surface 1b of the semiconductor substrate 1 can be improved by the overlapping region and Voc can be increased. The characteristics of the type back contact cell tend to be improved.

It is preferable that the undulation curve degree of the edge 5b of the edge 5a of the second conductivity type amorphous semiconductor film 5 is 3.15 or less. When the undulation curve degree is 3.15 or less, the end portion 5b of the edge portion 5a of the second conductive type amorphous semiconductor film 5 is in contact with the first electrode 7 which is an electrode for reverse conductivity type. Since it becomes difficult, the reliability of the heterojunction back contact cell of Embodiment 1 tends to be improved.

In the present embodiment, the “curvature” is obtained in a projection view (FIG. 3) when light is applied to the second surface 1 b of the semiconductor substrate 1 from a direction perpendicular to the second surface 1 b. The length along the curve from the start point S to the end point E in the first direction 41 or the second direction 42 of the curve indicating the undulation of the

end portions

3b and 5b is a straight line from the start point S to the end point E. It is a value divided by the length of the virtual line segment when virtual.

Further, in this embodiment, “i-type” is not only a completely intrinsic state but also a sufficiently low concentration (the n-type impurity concentration is less than 1 × 10 ¹⁵ / cm ³ and the p-type impurity concentration is 1 × (Less than 10 ¹⁵ / cm ³ ) is meant to include n-type or p-type impurities. In the present embodiment, “n-type” means a state where the n-type impurity concentration is 1 × 10 ¹⁵ / cm ³ or more, and “p-type” means that the p-type impurity concentration is 1 × 10 ¹⁵ / cm ³ or more. Means the state. The n-type impurity concentration and the p-type impurity concentration can be measured by, for example, secondary ion mass spectrometry.

In this embodiment, “amorphous silicon” includes not only amorphous silicon in which the dangling bonds of silicon atoms are not terminated with hydrogen, but also dangling bonds of silicon atoms such as hydrogenated amorphous silicon. In which is terminated with hydrogen.

<Method for manufacturing heterojunction back contact cell>
Hereinafter, an example of a method for manufacturing the heterojunction back contact cell of Embodiment 1 will be described with reference to the schematic cross-sectional views of FIGS.

First, as shown in FIG. 4, a semiconductor substrate 1 having a first surface 1 a serving as a light receiving surface is prepared, and a second surface that is a surface opposite to the first surface 1 a of the semiconductor substrate 1. The first i-type amorphous semiconductor film 2 is formed so as to be in contact with the entire surface of 1b, and the first conductivity-type amorphous semiconductor film 3 is formed so as to be in contact with the entire surface of the first i-type amorphous semiconductor film 2. Form. The method for forming the first i-type amorphous semiconductor film 2 and the first conductive amorphous semiconductor film 3 is not particularly limited, and for example, a plasma CVD (Chemical Vapor Deposition) method can be used.

Next, as shown in FIG. 5, an etching resist ink 10 is placed on the first conductive type amorphous semiconductor film 3. Here, the etching resist ink 10 can be placed on the first conductive type amorphous semiconductor film 3 in a strip shape extending in the first direction 41 by, for example, coating or printing. The etching resist ink 10 is installed in a region where the first conductivity type region 51 is left.

Waviness of the edge 3b of the edge 3a of the first conductive type amorphous semiconductor film 3 is formed by bleeding of the etching resist ink 10 at the time of application or printing of the etching resist ink 10. Therefore, by adjusting conditions such as the amount and viscosity of the etching resist ink 10 and adjusting the bleeding of the etching resist ink 10, the undulation of the edge 3 b of the edge 3 a of the first conductive type amorphous semiconductor film 3 is controlled. It becomes possible to adjust.

Next, the etching resist ink 10 is cured to form a cured etching resist ink 10a on the first conductive amorphous semiconductor film 3, as shown in FIG. The etching resist ink 10a can be formed by curing the etching resist ink 10 by a method such as heating or irradiation with ultraviolet light.

Next, as shown in FIG. 7, using the cured etching resist ink 10a as a mask, the first i-type amorphous semiconductor film 2 and the first conductive type amorphous semiconductor film 3 are partially thickened. By etching in the direction, a part of the second surface 1b of the semiconductor substrate 1 is exposed. Thereby, the patterning of the 1st conductivity type area | region 51 can be performed. Thereafter, as shown in FIG. 8, the cured etching resist ink 10a on the first conductivity type region 51 is removed.

Next, as shown in FIG. 9, the second i-type amorphous semiconductor film 4 is formed so as to cover the exposed surface of the semiconductor substrate 1 and the first conductivity type region 51, and then the second i-type is formed. A second conductivity type amorphous semiconductor film 5 is formed so as to be in contact with the amorphous semiconductor film 4. A method for forming the second i-type amorphous semiconductor film 4 and the second conductive type amorphous semiconductor film 5 is not particularly limited, and for example, a plasma CVD method can be used.

Next, as shown in FIG. 10, a part of each of the second i-type amorphous semiconductor film 4 and the second conductivity-type amorphous semiconductor film 5 is etched in the thickness direction to thereby obtain the first conductivity. A part of the type amorphous semiconductor film 3 is exposed. Thereby, the patterning of the 2nd conductivity type area | region 52 can be performed.

Here, the etching in the thickness direction of each of the second i-type amorphous semiconductor film 4 and the second conductive type amorphous semiconductor film 5 is also performed by the method using the etching resist ink 10 described above. It can be carried out. Therefore, the undulation of the end portion 5b of the edge portion 5a of the second conductive type amorphous semiconductor film 5 is formed by bleeding of the etching resist ink 10 at the time of application or printing of the etching resist ink 10. Therefore, by adjusting the conditions such as the amount and viscosity of the etching resist ink 10 and adjusting the bleeding of the etching resist ink 10, the undulation of the end portion 5b of the edge portion 5a of the second conductive type amorphous semiconductor film 5 is controlled. It becomes possible to adjust.

Next, as shown in FIG. 1, the first electrode 7 is formed on the first conductive amorphous semiconductor film 3 and the second electrode 8 is formed on the second conductive amorphous semiconductor film 5. . Although the formation method of the 1st electrode 7 and the 2nd electrode 8 is not specifically limited, For example, a vapor deposition method etc. can be used.

Thus, the heterojunction back contact cell according to the first embodiment having the configuration shown in FIG. 1 is completed.

<Mechanism of problem solving>
Since the heterojunction back contact cell of Embodiment 1 does not need to be manufactured using photolithography as in the conventional Patent Document 1, the manufacturing cost can be significantly reduced. For example, the manufacturing cost per one heterojunction type back contact cell should be 1/10 or less compared to the case where patterning of the first conductivity type region 51 and the second conductivity type region 52 is performed using photolithography. Can do.

In the heterojunction back contact cell of the first embodiment, the end 3b of the edge 3a of the first conductive type amorphous semiconductor film 3 extends while undulating in the first direction 41, and the second The end portion 5 b of the edge portion 5 a of the conductive amorphous semiconductor film 5 extends while undulating in the second direction 42. Therefore, the first conductivity type amorphous on the second surface 1b of the semiconductor substrate 1 is compared with the case where the edge portions of these films are formed to extend linearly using, for example, photolithography. The formation area of the overlapping region between the edge 3a of the crystalline semiconductor film 3 and the edge 5a of the second conductive type amorphous semiconductor film 5 can be increased. Thereby, the passivation property of the second surface 1b of the semiconductor substrate 1 in the overlapping region can be improved, so that the reliability of the heterojunction back contact cell of the first embodiment is improved and the heterogeneity of the first embodiment is improved. The Voc of the junction type back contact cell is increased and the characteristics are improved.

<Modification>
In the above description, the first conductivity type is n-type and the second conductivity type is p-type. However, even when the first conductivity type is p-type and the second conductivity type is n-type. The same effect as described above can be obtained.

Moreover, in the above, when both the edge part 3b of the edge part 3a of the 1st conductivity type amorphous semiconductor film 3 and the edge part 5b of the edge part 5a of the 2nd conductivity type amorphous semiconductor film 5 have a wave | undulation. However, at least one of the end portion 3b of the edge portion 3a of the first conductive type amorphous semiconductor film 3 and the end portion 5b of the edge portion 5a of the second conductive type amorphous semiconductor film 5 has waviness. It only has to be.

[Embodiment 2]
The heterojunction back contact cell of Embodiment 2 is characterized in that the patterning of the first conductivity type region 51 and the patterning of the second conductivity type region 52 are each performed using an etching paste. Hereinafter, an example of a method for manufacturing the heterojunction back contact cell of Embodiment 2 will be described.

First, as shown in FIG. 4, a first i-type amorphous semiconductor film 2 and a first conductive amorphous semiconductor film 3 are formed in this order on the second surface 1 b of the semiconductor substrate 1. Next, as shown in the schematic cross-sectional view of FIG. 11, an etching paste 11 is placed on the first conductive type amorphous semiconductor film 3. Here, the etching paste 11 can be placed on the first conductive type amorphous semiconductor film 3 in a strip shape extending in the first direction 41 by, for example, coating or printing. The etching paste 11 is placed in a region where the first conductivity type region 51 is left.

In the second embodiment, the undulation of the end portion 3b of the edge portion 3a of the first conductive type amorphous semiconductor film 3 is formed by the bleeding of the etching paste 11 when the etching paste 11 is applied or printed. Therefore, the undulation of the edge 3b of the edge 3a of the first conductive type amorphous semiconductor film 3 is adjusted by adjusting the conditions such as the amount and viscosity of the etching paste 11 and adjusting the bleeding of the etching paste 11. It becomes possible.

Next, as shown in the schematic cross-sectional view of FIG. 12, the etching paste 11 is baked by heating the etching paste 11, and the first i-type amorphous semiconductor film 2 and the first conductive amorphous semiconductor Each part of the film 3 is etched in the thickness direction. The etching paste 11 fires through the first i-type amorphous semiconductor film 2 and the first conductive amorphous semiconductor film 3 while etching in the thickness direction during firing, and the fired etching paste 11a becomes the semiconductor. It contacts the second surface 1b of the substrate 1. Thereafter, the baking etching paste 11a is removed, and a part of the second surface 1b of the semiconductor substrate 1 is exposed as shown in FIG. Thereby, the patterning of the 1st conductivity type area | region 51 can be performed.

Next, as shown in FIG. 9, the second i-type amorphous semiconductor film 4 is formed so as to cover the exposed surface of the semiconductor substrate 1 and the first conductivity type region 51, and then the second i-type non-type is formed. A second conductivity type amorphous semiconductor film 5 is formed so as to be in contact with the crystalline semiconductor film 4.

Here, the etching in the thickness direction of a part of each of the second i-type amorphous semiconductor film 4 and the second conductive type amorphous semiconductor film 5 is also performed by the method using the etching paste 11 described above. be able to. Thereby, the undulation of the edge 5b of the edge 5a of the second conductivity type amorphous semiconductor film 5 is formed by bleeding of the etching paste 11 when the etching paste 11 is applied or printed. Therefore, the undulation of the end portion 5b of the edge portion 5a of the second conductive type amorphous semiconductor film 5 is adjusted by adjusting conditions such as the amount and viscosity of the etching paste 11 and adjusting the bleeding of the etching paste 11. It becomes possible.

Thereafter, in the same manner as in the first embodiment, the heterojunction back contact cell of the second embodiment can be manufactured.

Since the description other than the above in the second embodiment is the same as that in the first embodiment, the description thereof will not be repeated.

[Embodiment 3]
The heterojunction back contact cell of Embodiment 3 is characterized in that the patterning of the first conductivity type region 51 and the patterning of the second conductivity type region 52 are each performed using lift-off ink. Hereinafter, an example of a method for manufacturing the heterojunction back contact cell of Embodiment 3 will be described.

First, as shown in FIG. 13, lift-off ink 12 is installed on the second surface 1 b of the semiconductor substrate 1. Here, the lift-off ink 12 can be installed on the second surface 1b of the semiconductor substrate 1 in a strip shape extending in the first direction 41, for example, by coating or printing. The lift-off ink 12 is installed in an area where the first conductivity type area 51 is not formed.

In the third embodiment, the undulation of the end portion 3b of the edge portion 3a of the first conductive type amorphous semiconductor film 3 is formed by bleeding of the lift-off ink 12 when the lift-off ink 12 is applied or printed. Therefore, by adjusting conditions such as the amount and viscosity of the lift-off ink 12 and adjusting the bleeding of the lift-off ink 12, the undulation of the end portion 3b of the edge portion 3a of the first conductive type amorphous semiconductor film 3 is adjusted. It becomes possible.

Next, as shown in the schematic cross-sectional view of FIG. 14, the first i-type amorphous semiconductor film 2 and the first i-type amorphous semiconductor film 2 are formed so as to cover the second surface 1 b of the semiconductor substrate 1 after the lift-off ink 12 is installed. One-conductivity type amorphous semiconductor film 3 is formed in this order. Thereafter, the lift-off ink 12 is removed together with the first i-type amorphous semiconductor film 2 and the first conductive-type amorphous semiconductor film 3 located on the lift-off ink 12, thereby forming a semiconductor substrate as shown in FIG. A part of the first second surface 1b is exposed. Thereby, the patterning of the 1st conductivity type area | region 51 can be performed.

Next, as shown in FIG. 10, the second conductivity type region 52 is patterned. Here, the patterning of the second conductivity type region 52 can also be performed by the method using the lift-off ink 12 described above. As a result, undulation of the end portion 5b of the edge portion 5a of the second conductive type amorphous semiconductor film 5 is formed by bleeding of the lift-off ink 12 at the time of application of the lift-off ink 12 or printing. Therefore, the undulation of the edge 5b of the edge 5a of the second conductive type amorphous semiconductor film 5 is adjusted by adjusting conditions such as the amount and viscosity of the lift-off ink 12 and adjusting the bleeding of the lift-off ink 12. It becomes possible.

Thereafter, in the same manner as in the first embodiment, the heterojunction back contact cell of the third embodiment can be manufactured.

Since the description other than the above in the third embodiment is the same as that in the first embodiment, the description thereof will not be repeated.

[Embodiment 4]
The heterojunction back contact cell of Embodiment 4 is characterized in that the patterning of the first conductivity type region 51 and the patterning of the second conductivity type region 52 are performed by laser ablation, respectively. Hereinafter, an example of the manufacturing method of the heterojunction back contact cell of Embodiment 4 is demonstrated.

First, as shown in FIG. 4, a first i-type amorphous semiconductor film 2 and a first conductive amorphous semiconductor film 3 are formed in this order on the second surface 1 b of the semiconductor substrate 1. Next, as shown in the schematic cross-sectional view of FIG. 15, the first conductive type amorphous semiconductor film 3 is irradiated with a laser beam 13. Here, the laser beam 13 is irradiated while being moved in a strip shape extending in the first direction 41. As a result, the first i-type amorphous semiconductor film 2 and the first conductive type amorphous semiconductor film 3 in the irradiation region of the laser beam 13 are removed in a belt shape extending in the first direction 41 by laser ablation, As shown in FIG. 8, patterning of the first conductivity type region 51 is performed.

In the fourth embodiment, the undulation of the edge 3b of the edge 3a of the first conductive type amorphous semiconductor film 3 is formed depending on the laser ablation condition. Therefore, the undulation of the end 3b of the edge 3a of the first conductive type amorphous semiconductor film 3 can be adjusted by adjusting the conditions of laser ablation such as the shape and size of the irradiation region of the laser beam 13. It becomes possible.

Next, as shown in FIG. 9, the second i-type amorphous semiconductor film 4 is formed so as to cover the exposed surface of the semiconductor substrate 1 and the first conductivity type region 51, and then the second i-type is formed. A second conductivity type amorphous semiconductor film 5 is formed so as to be in contact with the amorphous semiconductor film 4.

Next, as shown in FIG. 10, the second conductivity type region 52 is patterned. Here, the patterning of the second conductivity type region 52 can also be performed by the laser ablation described above. Thereby, the undulation of the end portion 5b of the edge portion 5a of the second conductive type amorphous semiconductor film 5 is formed depending on the shape of the irradiation region of the laser beam 13. Therefore, it is possible to adjust the undulation of the end portion 5 b of the edge portion 5 a of the second conductive type amorphous semiconductor film 5 by adjusting the shape of the irradiation region of the laser beam 13.

Thereafter, in the same manner as in the first embodiment, the heterojunction back contact cell of the fourth embodiment can be manufactured.

Since the description other than the above in the fourth embodiment is the same as that in the first embodiment, the description thereof will not be repeated.

[Appendix]
(1) An embodiment disclosed herein includes a semiconductor substrate, a first conductivity type amorphous semiconductor film extending in a first direction on the semiconductor substrate, and a first extension extending in a second direction on the semiconductor substrate. A second conductivity type amorphous semiconductor film, the edge of the second conductivity type amorphous semiconductor film being located on the edge of the first conductivity type amorphous semiconductor film, At least one of the edge part of the crystalline semiconductor film and the edge part of the second conductive type amorphous semiconductor film is a photoelectric conversion element having undulations. With such a structure, manufacturing cost can be reduced, and a photoelectric conversion element with high reliability and high characteristics can be provided.

(2) The photoelectric conversion element of the embodiment disclosed herein may have a undulation in which the edge of the edge of the first conductive type amorphous semiconductor film extends in the first direction. Also in this case, the manufacturing cost can be reduced, and a photoelectric conversion element having high reliability and high characteristics can be provided.

(3) The photoelectric conversion element of the embodiment disclosed herein may have a undulation in which the edge of the edge of the second conductive amorphous semiconductor film extends in the second direction. Also in this case, the manufacturing cost can be reduced, and a photoelectric conversion element having high reliability and high characteristics can be provided.

(4) In the photoelectric conversion element of the embodiment disclosed here, it is preferable that the degree of undulation is 1.03 or more. In this case, the characteristics of the photoelectric conversion element tend to be further improved.

(5) In the photoelectric conversion element of the embodiment disclosed herein, it is preferable that the degree of undulation is 3.15 or less. In this case, the reliability of the photoelectric conversion element tends to be further improved.

(6) The photoelectric conversion element of the embodiment disclosed herein may further include a first i-type amorphous semiconductor film between the semiconductor substrate and the first conductive amorphous semiconductor film. Also in this case, the manufacturing cost can be reduced, and a photoelectric conversion element having high reliability and high characteristics can be provided.

(7) In the photoelectric conversion element of the embodiment disclosed herein, the first i-type amorphous semiconductor film may be in contact with each of the semiconductor substrate and the first conductivity-type amorphous semiconductor film. Also in this case, the manufacturing cost can be reduced, and a photoelectric conversion element having high reliability and high characteristics can be provided.

(8) The photoelectric conversion element according to the embodiment disclosed herein may further include a second i-type amorphous semiconductor film between the semiconductor substrate and the second conductive amorphous semiconductor film. Also in this case, the manufacturing cost can be reduced, and a photoelectric conversion element having high reliability and high characteristics can be provided.

(9) In the photoelectric conversion element of the embodiment disclosed herein, the second i-type amorphous semiconductor film may be in contact with each of the semiconductor substrate and the second conductivity-type amorphous semiconductor film. Also in this case, the manufacturing cost can be reduced, and a photoelectric conversion element having high reliability and high characteristics can be provided.

(10) The photoelectric conversion element of the embodiment disclosed herein may further include a first electrode on the first conductive type amorphous semiconductor film. Also in this case, the manufacturing cost can be reduced, and a photoelectric conversion element having high reliability and high characteristics can be provided.

(11) The photoelectric conversion element of the embodiment disclosed herein may further include a second electrode on the second conductivity type amorphous semiconductor film. Also in this case, the manufacturing cost can be reduced, and a photoelectric conversion element having high reliability and high characteristics can be provided.

(12) In the embodiment disclosed herein, a step of patterning a first conductivity type amorphous semiconductor film extending in a first direction on a semiconductor substrate, and a step of extending in a second direction on the semiconductor substrate are described. The step of patterning the two-conductivity-type amorphous semiconductor film and the step of patterning the second-conductivity-type amorphous semiconductor film include the second conductivity-type on the edge of the patterned first-conductivity-type amorphous semiconductor film. Including a step of patterning the second conductive type amorphous semiconductor film so that the edge of the amorphous semiconductor film is located, and the edge of the edge of the first conductive type amorphous semiconductor film after patterning and after patterning This is a method for manufacturing a photoelectric conversion element in which at least one of the edge portions of the second conductivity type amorphous semiconductor film has undulations. With such a configuration, manufacturing cost can be reduced, and a highly reliable and high-performance photoelectric conversion element can be manufactured.

(13) In the method for manufacturing a photoelectric conversion element according to the embodiment disclosed herein, the edge of the edge of the first conductive type amorphous semiconductor film may have a undulation extending in the first direction. Good. Also in this case, the manufacturing cost can be reduced, and a highly reliable and high characteristic photoelectric conversion element can be manufactured.

(14) In the method for manufacturing a photoelectric conversion element according to the embodiment disclosed herein, even if the edge of the edge of the second conductive type amorphous semiconductor film has a undulation extending in the second direction. Good. Also in this case, the manufacturing cost can be reduced, and a highly reliable and high characteristic photoelectric conversion element can be manufactured.

(15) In the method of manufacturing a photoelectric conversion element according to the embodiment disclosed herein, it is preferable that the degree of undulation is 1.03 or more. In this case, a photoelectric conversion element with further improved characteristics can be manufactured.

(16) In the method for manufacturing a photoelectric conversion element of the embodiment disclosed herein, it is preferable that the degree of undulation is 3.15 or less. In this case, a photoelectric conversion element with further improved reliability can be manufactured.

(17) In the method for manufacturing a photoelectric conversion element of the embodiment disclosed herein, the step of patterning the first conductive type amorphous semiconductor film is performed from a group consisting of etching resist ink, etching paste, lift-off ink, and laser ablation. A step of patterning the first conductive type amorphous semiconductor film by at least one selected method may be included. Also in this case, the manufacturing cost can be reduced, and a highly reliable and high characteristic photoelectric conversion element can be manufactured.

(18) In the method of manufacturing a photoelectric conversion element according to the embodiment disclosed herein, the step of patterning the first conductive type amorphous semiconductor film includes patterning the first conductive type amorphous semiconductor film with an etching resist ink. And the step of patterning with an etching resist ink includes a step of placing the etching resist ink on a part of the first conductive type amorphous semiconductor film, a step of curing the etching resist ink, and a cured etching resist And a step of etching the first conductive type amorphous semiconductor film using the ink as a mask. Also in this case, the manufacturing cost can be reduced, and a highly reliable and high characteristic photoelectric conversion element can be manufactured.

(19) In the method of manufacturing a photoelectric conversion element according to the embodiment disclosed herein, the step of patterning the first conductive type amorphous semiconductor film is a step of patterning the first conductive type amorphous semiconductor film with an etching paste. And the step of patterning with the etching paste includes the step of placing the etching paste on a part of the first conductive type amorphous semiconductor film, and the step of heating the etching paste to form the first conductive type amorphous semiconductor film. And an etching step. Also in this case, the manufacturing cost can be reduced, and a highly reliable and high characteristic photoelectric conversion element can be manufactured.

(20) In the method of manufacturing a photoelectric conversion element according to the embodiment disclosed herein, the step of patterning the first conductive type amorphous semiconductor film is a step of patterning the first conductive type amorphous semiconductor film with lift-off ink. The step of patterning with lift-off ink includes a step of installing lift-off ink on a semiconductor substrate, a step of forming a first conductivity type amorphous semiconductor film so as to cover the semiconductor substrate on which the lift-off ink is installed, and And removing the lift-off ink together with the first conductive type amorphous semiconductor film located on the lift-off ink. Also in this case, the manufacturing cost can be reduced, and a highly reliable and high characteristic photoelectric conversion element can be manufactured.

(21) In the method of manufacturing a photoelectric conversion element according to the embodiment disclosed herein, the step of patterning the first conductive type amorphous semiconductor film is a step of patterning the first conductive type amorphous semiconductor film by laser ablation. And the step of patterning by laser ablation includes a step of forming a first conductive type amorphous semiconductor film on a semiconductor substrate and a first conductive type by irradiating the first conductive type amorphous semiconductor film with laser light. And removing a part of the type amorphous semiconductor film. Also in this case, the manufacturing cost can be reduced, and a highly reliable and high characteristic photoelectric conversion element can be manufactured.

(22) In the method for manufacturing a photoelectric conversion element according to the embodiment disclosed herein, the step of patterning the second conductive type amorphous semiconductor film is performed from the group consisting of etching resist ink, etching paste, lift-off ink, and laser ablation. A step of patterning the second conductive type amorphous semiconductor film by at least one selected method may be included. Also in this case, the manufacturing cost can be reduced, and a highly reliable and high characteristic photoelectric conversion element can be manufactured.

(23) In the method of manufacturing a photoelectric conversion element according to the embodiment disclosed herein, the step of patterning the second conductive type amorphous semiconductor film includes patterning the second conductive type amorphous semiconductor film with an etching resist ink. And the step of patterning with an etching resist ink includes a step of placing the etching resist ink on a part of the second conductive type amorphous semiconductor film, a step of curing the etching resist ink, and a cured etching resist And etching the second conductive type amorphous semiconductor film using the ink as a mask. Also in this case, the manufacturing cost can be reduced, and a highly reliable and high characteristic photoelectric conversion element can be manufactured.

(24) In the method for manufacturing a photoelectric conversion element according to the embodiment disclosed herein, the step of patterning the second conductive type amorphous semiconductor film is a step of patterning the second conductive type amorphous semiconductor film with an etching paste. And the step of patterning with the etching paste includes a step of placing the etching paste on a part of the second conductive type amorphous semiconductor film, and a step of heating the etching paste to form the second conductive type amorphous semiconductor film. And an etching step. Also in this case, the manufacturing cost can be reduced, and a highly reliable and high characteristic photoelectric conversion element can be manufactured.

(25) In the method of manufacturing a photoelectric conversion element of the embodiment disclosed herein, the step of patterning the second conductive type amorphous semiconductor film is a step of patterning the second conductive type amorphous semiconductor film with lift-off ink. And the step of patterning with lift-off ink includes a step of installing lift-off ink on a semiconductor substrate, a step of forming a second conductivity type amorphous semiconductor film so as to cover the semiconductor substrate on which the lift-off ink is installed, and And removing the lift-off ink together with the second conductive type amorphous semiconductor film located on the lift-off ink. Also in this case, the manufacturing cost can be reduced, and a highly reliable and high characteristic photoelectric conversion element can be manufactured.

(26) In the method of manufacturing a photoelectric conversion element according to the embodiment disclosed herein, the step of patterning the second conductive type amorphous semiconductor film is a step of patterning the second conductive type amorphous semiconductor film by laser ablation. And the step of patterning by laser ablation includes a step of forming a second conductive type amorphous semiconductor film on the semiconductor substrate and a second conductive type by irradiating the second conductive type amorphous semiconductor film with laser light. And removing a part of the type amorphous semiconductor film. Also in this case, the manufacturing cost can be reduced, and a highly reliable and high characteristic photoelectric conversion element can be manufactured.

Although the embodiment has been described as described above, it is also planned from the beginning to appropriately combine the configurations of the above-described embodiments.

The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

Embodiment disclosed here can be utilized for the manufacturing method of a photoelectric conversion element and a photoelectric conversion element, and may be suitably used for the manufacturing method of a solar cell and a solar cell, Especially preferably, it is hetero. There is a possibility that it can be used in a manufacturing method of a junction type back contact cell and a hetero junction type back contact cell.

1. Semiconductor substrate, 2. First i-type amorphous semiconductor film, 3. First conductivity-type amorphous semiconductor film, 3a edge, 3b end, 4. First i-type amorphous semiconductor film, 5. Second. Conductive amorphous semiconductor film, 5a edge, 5b edge, 7 first electrode, 8 second electrode, 10 etching resist ink, 10a cured etching resist ink, 11 etching paste, 11a etching paste after baking, 12 Lift-off ink, 13 laser light, 41 1st direction, 42 2nd direction, 51 1st conductivity type region, 52 2nd conductivity type region, 111 substrate, 112 i-type amorphous semiconductor layer, 113 i-type amorphous semiconductor Layer, 114 n-type amorphous semiconductor layer, 115 p-type amorphous semiconductor layer, 116 n-side electrode, 116a organic coating, 116b metal layer, 116c transparent conductive 117 p-side electrode, 117a organic coating, 117b metal layer, 117c transparent conductive layer, 119 i-type amorphous semiconductor layer, 120 n-type amorphous semiconductor layer, 121 insulating layer, 122 n-type region, 123 p-type region 124, protective film.

Claims

A semiconductor substrate;
A first conductive type amorphous semiconductor film extending in a first direction on the semiconductor substrate;
A second conductivity type amorphous semiconductor film extending in a second direction on the semiconductor substrate,
An edge of the second conductive type amorphous semiconductor film is located on an edge of the first conductive type amorphous semiconductor film;
A photoelectric conversion element in which at least one of an end portion of the edge portion of the first conductive type amorphous semiconductor film and an end portion of the edge portion of the second conductive type amorphous semiconductor film has undulations.
The photoelectric conversion element according to claim 1, wherein the end portion of the edge portion of the first conductive type amorphous semiconductor film has a undulation extending in the first direction.
3. The photoelectric conversion element according to claim 1, wherein the end portion of the edge portion of the second conductive type amorphous semiconductor film has a undulation extending in the second direction.
The photoelectric conversion element according to any one of claims 1 to 3, wherein the undulation curve degree is 1.03 or more.
The photoelectric conversion element according to any one of claims 1 to 4, wherein a curve degree of the undulation is 3.15 or less.
Patterning a first conductive type amorphous semiconductor film extending in a first direction on a semiconductor substrate;
Patterning a second conductive amorphous semiconductor film extending in a second direction on the semiconductor substrate;
In the step of patterning the second conductive type amorphous semiconductor film, the edge of the second conductive type amorphous semiconductor film is positioned on the edge of the patterned first conductive type amorphous semiconductor film. Patterning the second conductive type amorphous semiconductor film to include:
At least one of the end portion of the edge portion of the first conductive type amorphous semiconductor film after the patterning and the end portion of the edge portion of the second conductive type amorphous semiconductor film after the patterning has waviness. A method for producing a photoelectric conversion element.