WO2019230469A1 - Élément de batterie solaire - Google Patents

Élément de batterie solaire Download PDF

Info

Publication number
WO2019230469A1
WO2019230469A1 PCT/JP2019/019863 JP2019019863W WO2019230469A1 WO 2019230469 A1 WO2019230469 A1 WO 2019230469A1 JP 2019019863 W JP2019019863 W JP 2019019863W WO 2019230469 A1 WO2019230469 A1 WO 2019230469A1
Authority
WO
WIPO (PCT)
Prior art keywords
protective layer
semiconductor substrate
solar cell
cell element
region
Prior art date
Application number
PCT/JP2019/019863
Other languages
English (en)
Japanese (ja)
Inventor
順次 荒浪
宏明 ▲高▼橋
誠一郎 稲井
Original Assignee
京セラ株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 京セラ株式会社 filed Critical 京セラ株式会社
Priority to JP2020522108A priority Critical patent/JP7109539B2/ja
Publication of WO2019230469A1 publication Critical patent/WO2019230469A1/fr

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
    • H01L31/054—Optical elements directly associated or integrated with the PV cell, e.g. light-reflecting means or light-concentrating means
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
    • H01L31/054—Optical elements directly associated or integrated with the PV cell, e.g. light-reflecting means or light-concentrating means
    • H01L31/056—Optical elements directly associated or integrated with the PV cell, e.g. light-reflecting means or light-concentrating means the light-reflecting means being of the back surface reflector [BSR] type

Definitions

  • This disclosure relates to a solar cell element.
  • a solar cell element having a semiconductor substrate using crystalline silicon or the like is known.
  • the semiconductor substrate is made thinner in order to save resources, reduce the size, and reduce the weight.
  • the semiconductor substrate becomes thinner, the ratio of the light that is not absorbed by the semiconductor substrate and passes through the semiconductor substrate in the light irradiated to the semiconductor substrate increases, which may reduce the light use efficiency. is there.
  • a solar cell element has been proposed in which a white coating film is provided on the back side of a semiconductor substrate so that light transmitted through the semiconductor substrate is reflected toward the semiconductor substrate by the white coating film.
  • a white coating film is provided on the back side of a semiconductor substrate so that light transmitted through the semiconductor substrate is reflected toward the semiconductor substrate by the white coating film.
  • a solar cell element is disclosed.
  • the solar cell element includes a semiconductor substrate, a protective layer, and an electrode.
  • the semiconductor substrate performs photoelectric conversion.
  • the protective layer is located on the semiconductor substrate.
  • the electrode includes a first portion located on the protective layer and a second portion in a state of being electrically connected to the semiconductor substrate.
  • the protective layer includes a base material portion and a plurality of granular materials located in the base material portion.
  • the base material part includes a non-gap part and a plurality of gaps.
  • the protective layer has a first surface on the semiconductor substrate side and a second surface on the first portion side in the thickness direction of the protective layer. Each of the plurality of gaps is located in a partial region between the first surface and the second surface in the thickness direction of the protective layer.
  • the refractive index of the plurality of granular materials is different from the refractive index of the base material portion.
  • FIG.1 (a) is a top view which shows the external appearance seen from the 1st front side of an example of the solar cell element which concerns on 1st Embodiment.
  • FIG.1 (b) is a top view which shows the external appearance seen from the 1st back surface side of an example of the solar cell element which concerns on 1st Embodiment.
  • FIG. 2 is a cross-sectional view showing an example of the solar cell element according to the first embodiment, and is a view showing a virtual cut surface along the line II-II in FIGS. 1 (a) and 1 (b). is there.
  • FIG. 1 (a) is a top view which shows the external appearance seen from the 1st front side of an example of the solar cell element which concerns on 1st Embodiment.
  • FIG.1 (b) is a top view which shows the external appearance seen from the 1st back surface side of an example of the solar cell element which concerns on 1st Embodiment.
  • FIG. 2 is a cross-sectional view
  • FIG. 3 is a diagram showing a configuration example of the protective layer and its peripheral portion in the virtual cut surface portion of the example of the solar cell element according to the first embodiment in the III part of FIG. 2.
  • FIG. 4 is a diagram illustrating an example of a path of light incident on the solar cell element in the virtual cut surface portion of FIG. 2 in the example of the solar cell element according to the first embodiment.
  • FIG. 5A to FIG. 5D are cross-sectional views illustrating states in the middle of manufacturing the solar cell element according to the first embodiment.
  • FIG. 6 is a plan view showing an appearance of an example of the solar cell element according to the second embodiment viewed from the first back surface side.
  • FIG. 7 is a diagram showing a configuration example of the protective layer and its peripheral portion with respect to a virtual cut surface portion of an example of the solar cell element according to the third embodiment corresponding to the III portion of FIG. 2.
  • FIG. 8 is a diagram showing a configuration example of the protective layer and its peripheral portion with respect to a virtual cut surface portion of an example of the solar cell element according to the fourth embodiment corresponding to the III portion of FIG. 2.
  • FIG. 9 is a diagram illustrating a configuration example of a protective layer and its peripheral portion with respect to a virtual cut surface portion of an example of the solar cell element according to the fifth embodiment corresponding to the III portion of FIG. 2.
  • FIG. 10 is a diagram illustrating another configuration example of the protective layer and its peripheral portion with respect to a virtual cut surface portion of an example of the solar cell element according to the fifth embodiment corresponding to the III portion of FIG. 2.
  • FIG. 11 is a diagram showing a configuration example of the protective layer and its peripheral portion with respect to a virtual cut surface portion of an example of the solar cell element according to the sixth embodiment corresponding to the III portion of FIG. 2.
  • the semiconductor substrate is made thinner.
  • the proportion of light that is transmitted through the semiconductor substrate without being absorbed by the semiconductor substrate can increase.
  • a crystalline silicon semiconductor substrate easily transmits light in the infrared wavelength region.
  • light in a part of the wavelength region such as infrared rays of sunlight is difficult to be used for photoelectric conversion in the semiconductor substrate, and the photoelectric conversion efficiency of the solar cell element is difficult to improve.
  • visible light rays of about 400 nanometers (nm) to about 700 nm and infrared energy intensity in a wavelength region of about 700 nm to 1200 nm are high.
  • the temperature of the solar cell element rises, and the photoelectric conversion efficiency of the solar cell element may decrease.
  • a white coating film containing a white component having a high light reflectance such as barium sulfide, magnesium oxide, and titanium oxide may be disposed between the semiconductor substrate and the back electrode.
  • a white coating film is formed, for example, by applying a white coating film containing fine particles of a white component, a binder, and a solvent.
  • the white coating film there are gaps between the fine particles of the white component. For this reason, a water
  • a back electrode when a back electrode is formed by applying a metal paste containing a metal powder, glass frit, and an organic vehicle on a white coating film, the metal paste is applied to the white coating film through a gap between fine particles. Infiltration, metal powder may be interposed between the semiconductor substrate and the white coating film.
  • metal powder may be interposed between the semiconductor substrate and the white coating film.
  • the metal powder if an aluminum powder that easily absorbs light is used as the metal powder, reflection of light by the white coating film may be difficult to occur. As a result, for example, the photoelectric conversion efficiency of the solar cell element may be reduced.
  • PERC PassivatedivatEmitter and Rear Cell
  • a passivation film is located on the back surface of a semiconductor substrate
  • the glass component of the metal paste can penetrate the white coating film.
  • unintended firing of the passivation film may occur and the function of the passivation film may be deteriorated.
  • the photoelectric conversion efficiency of the solar cell element may be reduced.
  • the present inventors have created a technique for improving the photoelectric conversion efficiency of the solar cell element.
  • FIG. 1A to FIG. 11 a right-handed XYZ coordinate system is attached.
  • the direction along the pair of sides of the first front surface 1fs of the solar cell element 1 is the + X direction
  • the direction along the other pair of sides of the first front surface 1fs is the + Y direction
  • + X The normal direction of the first front surface 1fs that is orthogonal to both the direction and the + Y direction is the + Z direction.
  • the solar cell element 1 can convert light energy into electric energy, for example.
  • a solar cell element 1 includes a light receiving surface (also referred to as a first front surface) 1fs on which light is mainly incident, and a side opposite to the first front surface 1fs. 1bs which is a surface (also referred to as a first back surface).
  • the first front surface 1fs is in the + Z direction
  • the first back surface 1bs is in the -Z direction.
  • the + Z direction is set, for example, in a direction toward the sun going south.
  • the first front surface 1fs and the first back surface 1bs each have a rectangular shape.
  • the solar cell element 1 includes a semiconductor substrate 2, an antireflection film 3, a passivation film 4, a protective layer 5, and a front electrode 6. And a back electrode 7.
  • the front electrode 6 is located on a part of the first front surface 1fs side
  • the back electrode 7 is located on a substantially entire surface of the first back surface 1bs side.
  • the solar cell element 1 according to the first embodiment is a type of element that uses light incident on the first front surface 1fs for power generation.
  • the semiconductor substrate 2 has a second front surface 2fs, a second back surface 2bs, and an outer peripheral surface 2ss.
  • the second front surface 2fs is located on the first front surface 1fs side.
  • the second back surface 2bs is located on the side opposite to the second front surface 2fs.
  • the outer peripheral surface 2ss is located in a state where the second front surface 2fs and the second back surface 2bs are connected.
  • the second front surface 2fs is positioned in the + Z direction
  • the second back surface 2bs is positioned in the -Z direction.
  • the semiconductor substrate 2 can perform photoelectric conversion according to, for example, light irradiation.
  • the semiconductor substrate 2 includes, for example, a region (also referred to as a first semiconductor region) 21 having a first conductivity type, and a region (also referred to as a second semiconductor region) 22 having a second conductivity type opposite to the first conductivity type.
  • the first semiconductor region 21 is located on the second back surface 2bs side of the semiconductor substrate 2, for example.
  • the second semiconductor region 22 is located in the surface layer portion of the semiconductor substrate 2 on the second front surface 2fs side.
  • the semiconductor substrate 2 has a pn junction located at the interface between the first semiconductor region 21 and the second semiconductor region 22.
  • a p-type silicon substrate can be manufactured.
  • the n-type second semiconductor region 22 can be generated by diffusing an impurity such as phosphorus as an n-type dopant in the surface layer portion on the second front surface 2fs side of the p-type silicon substrate.
  • the semiconductor substrate 2 in which the p-type first semiconductor region 21 and the n-type second semiconductor region 22 are stacked in the order of description can be formed.
  • the second front surface 2fs of the semiconductor substrate 2 may have, for example, a fine concavo-convex structure (texture) for reducing reflection of irradiated light.
  • a third semiconductor region 23 having the same first conductivity type as the first semiconductor region 21 may exist in the surface layer portion of the semiconductor substrate 2 on the second back surface 2bs side.
  • the third semiconductor region 23 if the dopant concentration in the third semiconductor region 23 is higher than the dopant concentration in the first semiconductor region 21, the third semiconductor region 23 generates an internal electric field on the second back surface 2 bs side of the semiconductor substrate 2. It plays a role as a BSF (Back-Surface-Field) layer to be formed.
  • BSF Back-Surface-Field
  • the third semiconductor region 23 can be generated, for example, by diffusing a dopant element such as aluminum in the surface layer portion of the semiconductor substrate 2 on the second back surface 2bs side.
  • the antireflection film 3 is located on the second front surface 2fs side of the semiconductor substrate 2, for example. In the example of FIG. 1A and FIG. 2, the antireflection film 3 is located on the second front surface 2fs.
  • the antireflection film 3 can reduce the reflectance of light irradiated on the first front surface 1 fs of the solar cell element 1.
  • the material of the antireflection film 3 for example, silicon oxide, aluminum oxide, silicon nitride, or the like can be employed.
  • the refractive index and the thickness of the antireflection film 3 are, for example, a condition where the reflectance is low with respect to light in a wavelength region that can be absorbed by the semiconductor substrate 2 and contribute to power generation in sunlight (also referred to as a low reflection condition) ) Is appropriately set to a value capable of realizing.
  • the refractive index of the antireflection film 3 is about 1.8 to 2.5
  • the thickness of the antireflection film 3 is about 20 nm to 120 nm.
  • the antireflection film 3 can be formed by using, for example, a plasma enhanced chemical vapor deposition (PECVD) method or a sputtering method.
  • PECVD plasma enhanced chemical vapor deposition
  • the passivation film 4 is located on at least the second back surface 2bs of the semiconductor substrate 2. In the first embodiment, the passivation film 4 is in contact with the second back surface 2bs of the semiconductor substrate 2. For example, the passivation film 4 can reduce recombination of minority carriers generated by photoelectric conversion in response to light irradiation in the semiconductor substrate 2.
  • the material of the passivation film 4 for example, one or more materials selected from aluminum oxide, zirconium oxide, hafnium oxide, silicon oxide, silicon nitride, silicon oxynitride, and the like are employed.
  • the passivation film 4 may be, for example, a single layer film of one kind of material, or may be a state in which two or more layers of different materials are laminated.
  • a single layer film of aluminum oxide may be employed, or a film in which a silicon oxide film and an aluminum oxide film are stacked in this order is employed. May be.
  • the passivation film 4 can be formed by, for example, an atomic layer deposition (ALD) method.
  • ALD atomic layer deposition
  • the passivation film 4 can reduce minority carrier recombination by, for example, termination of dangling bonds on the second back surface 2bs of the semiconductor substrate 2 and field effect.
  • the aluminum oxide when aluminum oxide is adopted as the material for the passivation film 4, the aluminum oxide has a negative fixed charge. Therefore, minority carriers (electrons in this case) generated in the region on the second back surface 2bs side of the semiconductor substrate 2 due to the field effect are converted into the interface (second back surface 2bs) between the p-type first semiconductor region 21 and the passivation film 4. ). Thereby, recombination of minority carriers in the vicinity of the second back surface 2bs of the semiconductor substrate 2 can be reduced. As a result, the photoelectric conversion efficiency of the solar cell element 1 can be improved.
  • the thickness of the passivation film 4 is, for example, about 10 nm to 60 nm.
  • the passivation film 4 may be located on the second front surface 2 fs of the semiconductor substrate 2 or may be located on the outer peripheral surface 2 ss of the semiconductor substrate 2.
  • the protective layer 5 is located, for example, on the second back surface 2bs side of the semiconductor substrate 2. In other words, the protective layer 5 is located on the semiconductor substrate 2, for example. In the first embodiment, the protective layer 5 is located on the passivation film 4 located on the second back surface 2bs of the semiconductor substrate 2, for example. From another point of view, the passivation film 4 is located between the semiconductor substrate 2 and the protective layer 5. The protective layer 5 is in a state of covering the passivation film 4 on the passivation film 4. Thereby, the protective layer 5 can protect the passivation film 4, for example.
  • the protective layer 5 may be formed also on the outer peripheral surface 2ss of the semiconductor substrate 2, for example.
  • the protective layer 5 can be formed directly on the antireflection film 3 or on the passivation film 4, for example, on the outer peripheral surface 2 ss of the semiconductor substrate 2. For example, due to the presence of the protective layer 5, a leak current hardly occurs in the solar cell element 1.
  • the protective layer 5 has a desired pattern on the passivation film 4.
  • the protective layer 5 has a plurality of holes 5h positioned so as to penetrate the protective layer 5 in the thickness direction (here, + Z direction).
  • the plurality of hole portions 5h penetrates the protective layer 5 among the plurality of hole portions (also referred to as through-holes) 45h that continuously penetrate the protective layer 5 and the passivation film 4. It is a part in.
  • Each hole 5h and each through-hole 45h may be a through-hole whose periphery along the second back surface 2bs is closed, or at least a part of the periphery along the second back surface 2bs is opened.
  • each hole 5h may be any of a dot shape, a belt shape, and a line shape.
  • the diameter or width of the hole 5h is, for example, about 10 ⁇ m to 500 ⁇ m.
  • the pitch of the holes 5h is, for example, about 0.3 millimeters (mm) to about 3 mm.
  • the pitch of the hole portions 5h is, for example, the distance between the centers of the adjacent hole portions 5h when the protective layer 5 is viewed through.
  • the combination of the size, shape, and number of each hole 5h can be adjusted as appropriate. For this reason, the number of the hole parts 5h should just be one or more, for example.
  • the protective layer 5 is formed such that, for example, the insulating paste has a desired pattern on the passivation film 4 formed on the second back surface 2bs of the semiconductor substrate 2 by a coating method such as a spray method, a coater method, or a screen printing method. It is formed by being coated and dried.
  • a coating method such as a spray method, a coater method, or a screen printing method. It is formed by being coated and dried.
  • the first metal paste is applied on the protective layer 5 so as to have a desired shape and baked.
  • the first metal paste is, for example, a conductive paste (Al paste) containing a metal powder mainly composed of aluminum, a glass component, and an organic vehicle.
  • the main component means a component having the largest content ratio (also referred to as content) among the contained components.
  • the first metal paste applied directly on the passivation film 4 in the hole 5 h of the protective layer 5 causes the passivation film 4 to be fired and penetrated, and the second current collecting electrode 7 b is formed on the second back surface 2 bs of the semiconductor substrate 2. Are connected directly.
  • the passivation film 4 and the protective layer 5 have a plurality of through-holes 45 h that are positioned in a state of continuously passing through the passivation film 4 and the protective layer 5.
  • the aluminum contained in the first metal paste located in the plurality of through holes 45h diffuses into the surface layer portion of the second back surface 2bs of the semiconductor substrate 2, so that the third semiconductor region 23 is formed.
  • the thickness of the protective layer 5 is sufficiently larger than the thickness of the passivation film 4, the portion of the passivation film 4 covered with the protective layer 5 causes the first metal due to the presence of the protective layer 5. The paste is unlikely to cause firing through the passivation film 4.
  • the function of the passivation film 4 is unlikely to deteriorate.
  • the photoelectric conversion efficiency of the solar cell element 1 can be improved.
  • the passivation film 4 can be left on the second back surface 2 bs of the semiconductor substrate 2 in a desired pattern corresponding to the pattern of the protective layer 5.
  • the thickness of the protective layer 5 is, for example, about 0.5 ⁇ m to 10 ⁇ m. Thereby, for example, the performance of protecting the semiconductor substrate 2 and the passivation film 4 by the protective layer 5 can be ensured. In addition, for example, the protective layer 5 becomes too thick to cause a problem of cracking, and the performance of protecting the semiconductor substrate 2 and the passivation film 4 by the protective layer 5 is unlikely to deteriorate.
  • the thickness of the protective layer 5 is, for example, the composition of the insulating paste for forming the protective layer 5, the shape of the second back surface 2bs of the semiconductor substrate 2, and the firing conditions when forming the second current collecting electrode 7b described later. It may be set appropriately according to the above.
  • the front electrode 6 is located on the second front surface 2 fs side of the semiconductor substrate 2, for example. In the first embodiment, the front electrode 6 is located on the second front surface 2 fs of the semiconductor substrate 2.
  • the front electrode 6 includes, for example, a first output extraction electrode 6a and a first current collecting electrode 6b.
  • the first output extraction electrode 6a can extract, for example, carriers obtained by photoelectric conversion in response to light irradiation on the semiconductor substrate 2 to the outside of the solar cell element 1.
  • three first output extraction electrodes 6 a exist on the second front surface 2 fs side of the semiconductor substrate 2.
  • Each first output extraction electrode 6a has a longitudinal direction along the second front surface 2fs. This longitudinal direction is the + Y direction.
  • the length (also referred to as width) of the first output extraction electrode 6a in the short direction is, for example, about 1.3 mm to 2.5 mm. At least a part of the first output extraction electrode 6a is in a state of being electrically connected across the first collector electrode 6b.
  • the first current collecting electrode 6b can collect, for example, carriers obtained by photoelectric conversion according to light irradiation on the semiconductor substrate 2.
  • a plurality of first current collecting electrodes 6 b exist on the second front surface 2 fs side of the semiconductor substrate 2.
  • Each first current collecting electrode 6b has a longitudinal direction along the second front surface 2fs. This longitudinal direction is the + X direction.
  • the plurality of first current collecting electrodes 6b have a so-called finger shape.
  • Each first current collecting electrode 6b is a linear electrode having a width of about 20 ⁇ m to 200 ⁇ m, for example.
  • the width of each first current collecting electrode 6b is smaller than the width of the first output extraction electrode 6a.
  • the plurality of first current collecting electrodes 6b are positioned, for example, in a state where they are aligned with an interval of about 1 mm to 3 mm.
  • the thickness of the front electrode 6 is, for example, about 10 ⁇ m to 40 ⁇ m.
  • the front electrode 6 having the above-described configuration can be formed by, for example, applying the second metal paste into a desired shape by screen printing or the like and then firing the second metal paste.
  • the second metal paste is, for example, a conductive paste (also referred to as a silver paste) containing silver-based metal particles, an organic vehicle, and glass frit.
  • the second metal paste is applied on the antireflection film 3 in a desired shape. And when this 2nd metal paste is baked, this 2nd metal paste produces the baking penetration of the anti-reflective film 3.
  • FIG. Thereby, the front electrode 6 in a state of being connected to the second front surface 2fs of the semiconductor substrate 2 can be formed.
  • the front electrode 6 may have, for example, an auxiliary electrode 6c having the same shape as the first current collecting electrode 6b.
  • the auxiliary electrode 6c is located along each of the end in the + X direction and the end in the ⁇ X direction of the semiconductor substrate 2 so that the first current collecting electrodes 6b can be electrically connected to each other. .
  • the back surface electrode 7 is located on the second back surface 2 bs side of the semiconductor substrate 2, for example.
  • the protective layer 5 is located between the passivation film 4 and the back electrode 7.
  • the back electrode 7 includes, for example, a second output extraction electrode 7a and a second current collecting electrode 7b.
  • the second output extraction electrode 7a can extract, for example, carriers obtained by photoelectric conversion according to light irradiation on the semiconductor substrate 2 to the outside of the solar cell element 1.
  • three second output extraction electrodes 7 a exist on the protective layer 5 on the second back surface 2 bs side of the semiconductor substrate 2.
  • Each second output extraction electrode 7a has a longitudinal direction along the second back surface 2bs. This longitudinal direction is the + Y direction.
  • Each second output extraction electrode 7a is composed of N (N is an integer of 2 or more) island-like electrode portions (also referred to as island-like electrode portions) arranged along the + Y direction as the longitudinal direction. Yes.
  • N is four.
  • the second output extraction electrode 7a has a width direction perpendicular to the longitudinal direction. This width direction is the + X direction.
  • the thickness of the second output extraction electrode 7a is, for example, about 10 ⁇ m to 40 ⁇ m.
  • the width of the second output extraction electrode 7a is, for example, about 1.3 mm to 7 mm. At least a part of the second output extraction electrode 7a is in contact with and electrically connected to the second collector electrode 7b.
  • the second output extraction electrode 7a can be formed, for example, by applying the third metal paste in a desired shape by screen printing or the like and then firing the third metal paste.
  • the third metal paste is applied in a desired shape on the protective layer 5.
  • the third metal paste is, for example, a conductive paste (also referred to as a silver paste) containing silver-based metal particles, an organic vehicle, and glass frit.
  • the second collector electrode 7b can collect, for example, carriers obtained by photoelectric conversion according to light irradiation on the semiconductor substrate 2.
  • the second current collecting electrode 7b is present over substantially the entire surface of the first back surface 1bs.
  • the second current collecting electrode 7b includes, for example, a first portion 7b1 and a second portion 7b2.
  • the first portion 7 b 1 is a portion located on the protective layer 5.
  • the second portion 7 b 2 is a portion that is in a state of being electrically connected to the semiconductor substrate 2.
  • the second portion 7b2 is located in a state where it is electrically connected to the semiconductor substrate 2 in each of the plurality of through holes 45h that continuously penetrates the protective layer 5 and the passivation film 4.
  • the thickness of the first portion 7b1 is, for example, about 10 ⁇ m to 40 ⁇ m.
  • the first portion 7b1 and the second portion 7b2 are in an electrically connected state.
  • the second current collecting electrode 7b having the above-described configuration can be formed, for example, by baking the first metal paste after applying the above-described first metal paste to a desired shape by screen printing or the like.
  • the first metal paste is applied on the protective layer 5 and in the plurality of holes 5 h of the protective layer 5. And when this 1st metal paste is baked, the 1st metal paste in the some hole 5h of the protective layer 5 produces baking penetration of the passivation film 4.
  • FIG. Thereby, the 2nd part 7b2 in the state located in the some through-hole 45h can be formed.
  • the first metal paste located on the protective layer 5 does not cause firing of the passivation film 4 due to the presence of the protective layer 5, and the first portion 7 b 1 can be formed on the protective layer 5. As a result, the back electrode 7 can be formed.
  • connection between solar cell elements For example, when a solar cell module is manufactured by arranging a plurality of solar cell elements 1, the first output extraction electrode of one solar cell element 1 as shown in FIGS. 1 (a) and 1 (b). 6a and the second output extraction electrode 7a of one solar cell element 1 adjacent to the one solar cell element 1 are electrically connected by the wiring material W1.
  • the outer edge of the wiring member W1 attached to each solar cell element 1 is virtually drawn with a two-dot chain line.
  • a metal having a linear or belt-like conductivity is applied for example.
  • a copper foil having a thickness of about 0.1 mm to 0.2 mm and a width of about 1 mm to 2 mm and having the entire surface covered with solder is applied to the wiring member W1.
  • the wiring member W1 is electrically connected to the first output extraction electrode 6a and the second output extraction electrode 7a by soldering.
  • the protective layer 5 includes a base material portion (also referred to as a base material portion) 5a and a plurality of granular materials 5b located in the base material portion 5a.
  • the plurality of granular bodies 5b are positioned in a moderately dispersed state within the base material portion 5a.
  • the base material portion 5a includes a portion (also referred to as a non-void portion) 5a1 that is not a void, and a plurality of void portions (also referred to as void portions) 5a2 existing inside the non-void portion 5a1.
  • the plurality of gaps 5a2 are located in a state where the gaps 5a2 are appropriately dispersed inside and on the surface of the non-gap part 5a1.
  • the gap 5a2 may be positioned so as to be in contact with the granular body 5b, may be positioned around the granular body 5b, or is positioned in a state separated from the granular body 5b. Also good.
  • the gap 5a2 is at least one of the passivation film 4 as a layer adjacent to the protective layer 5 and the first portion 7b1 of the second collector electrode 7b. It may be in contact with the layer. Also in this case, for example, the protective layer 5 is located in the entire region between the passivation film 4 as a layer adjacent to the protective layer 5 and the first portion 7b1.
  • the protective layer 5 includes a surface (also referred to as a first surface) Sf1 on the semiconductor substrate 2 side in the thickness direction (here, + Z direction) of the protective layer 5 and the second collector electrode 7b. 1 part 7b1 side surface (it is also called 2nd surface) Sf2.
  • each of the plurality of gaps 5a2 is located in a partial region between the first surface Sf1 and the second surface Sf2 in the thickness direction of the protective layer 5.
  • the gaps 5 a 2 do not exist so as to penetrate the protective layer 5 in the thickness direction of the protective layer 5.
  • the diameter of each gap 5a2 is smaller than the thickness of the protective layer 5, for example.
  • the base material portion 5a is positioned between the plurality of granular bodies 5b.
  • a portion located closer to the semiconductor substrate 2 than the protective layer 5 can be sufficiently protected by the protective layer 5.
  • the presence of such a protective layer 5 makes it difficult for moisture to reach the passivation film 4 and the semiconductor substrate 2 from the outside of the solar cell element 1.
  • the photoelectric conversion efficiency of the solar cell element 1 can be improved.
  • silicon oxide is applied as the material of the non-void portion 5a1.
  • a siloxane resin or the like is applied to the material of the non-voided portion 5a1.
  • a siloxane resin is a siloxane compound having a Si—O—Si bond (also referred to as a siloxane bond).
  • the protective layer 5 can be easily formed by applying an insulating paste on the passivation film 4 so as to have a desired pattern by a coating method such as a spray method, a coater method, or a screen printing method, followed by drying. Can be formed.
  • an insulating paste for example, an insulating paste including a siloxane resin that is a raw material of the non-void portion 5a1, an organic solvent, and a large number of particles is applied.
  • the siloxane resin for example, a low molecular weight resin having a molecular weight of 15,000 or less, which is produced by hydrolysis and condensation polymerization of alkoxysilane or silazane, is applied.
  • the organic solvent for example, a siloxane resin and a solvent in which a large number of particles are dispersed are applied.
  • a large number of particles include, for example, at least a plurality of granular materials 5b.
  • the large number of particles may contain, for example, a filler of an inorganic material such as silicon oxide, aluminum oxide, or titanium oxide as a filler (also referred to as a viscosity adjusting filler) for adjusting the viscosity of the insulating paste.
  • the average particle diameter of the large number of particles is, for example, 1 ⁇ m or less.
  • the average particle size here may be the average particle size of the primary particles or the average particle size of the secondary particles in which the primary particles are aggregated.
  • the insulating paste can be applied onto the passivation film 4 in a desired pattern having a plurality of holes 5h.
  • a large number of particles may separately include a plurality of granules 5b and a viscosity adjusting filler, and the plurality of granules 5b have a function as a viscosity adjusting filler. You may do it.
  • the shape of a large number of particles may be any of, for example, a particle shape, an elliptical shape, a right cylindrical shape, a needle shape, a layer shape, a flat shape, a hollow structure shape, and a fibrous shape.
  • the gap portion 5a2 is a portion where a gas such as air is located, for example.
  • a gas such as air
  • the organic material granules disappear due to thermal decomposition, so that the organic material granules
  • the void portion 5a2 can be formed as a trace of the region where the disappearance occurs.
  • the thermal decomposition of the granular material of the organic material occurs, for example, when the insulating paste is dried.
  • the lower limit value of the particle diameter capable of producing a granular material of an organic material is 10 nm
  • the lower limit value of the diameter of the gap 5a2 may be 10 nm.
  • the upper limit value of the diameter of the gap 5 a 2 may be less than the thickness of the protective layer 5.
  • the protective layer 5 is cracked when the insulating paste for forming the protective layer 5 is applied and dried. It is difficult to reduce the performance of protecting the semiconductor substrate 2 and the passivation film 4 by the protective layer 5.
  • the upper limit of the thickness of the protective layer 5 is 10 ⁇ m
  • the diameter of the gap 5a2 can be about 10 nm to 5 ⁇ m.
  • the granular material of the organic material may have a function of a viscosity adjusting filler.
  • the light Lt1 irradiated to the first front surface 1fs is directed from the first front surface 1fs toward the first back surface 1bs.
  • the light Lt2 that passes through the semiconductor substrate 2 can be generated in the thickness direction of the semiconductor substrate 2.
  • the semiconductor substrate 2 is a silicon substrate, infrared light as light in a specific wavelength region of sunlight is likely to pass through the semiconductor substrate 2 in accordance with the light absorption coefficient of silicon.
  • the second current collecting electrode 7b containing aluminum as a main component is located in a wide range on the first back surface 1bs side of the solar cell element 1, the second current collecting electrode 7b is It can generate heat by absorbing about half of the infrared rays from the semiconductor substrate 2 side. Further, even if the second collector electrode 7b simply reflects the remaining half of the infrared rays from the semiconductor substrate 2 side toward the semiconductor substrate 2, the semiconductor substrate 2 that has been reduced in thickness has sufficient infrared rays. May be transmitted without being absorbed.
  • the protective layer 5 has a region in which a part of the plurality of voids 5a2 is located closest to the semiconductor substrate 2 of the protective layer 5, the semiconductor The light transmitted through the substrate 2 is not easily incident on this region and is easily reflected due to a rapid decrease in the refractive index.
  • some of the plurality of voids 5a2 are positioned so as to be in contact with the passivation film 4 that is a layer located on the semiconductor substrate 2 side of the protective layer 5. May be.
  • the gap 5a2 is positioned so as to be in contact with the passivation film 4 that is the layer on the semiconductor substrate 2 side of the protective layer 5, at the interface between the passivation film 4 and the gap 5a2, Due to the drop in the refractive index, the light transmitted through the semiconductor substrate 2 is easily reflected. Thereby, for example, light transmitted through the semiconductor substrate 2 is easily absorbed by the semiconductor substrate 2. Further, for example, the light transmitted through the semiconductor substrate 2 does not easily reach the back electrode 7, and the back electrode 7 is unlikely to generate heat. As a result, for example, a decrease in output characteristics due to overheating of the solar cell element 1 hardly occurs. Therefore, for example, the photoelectric conversion efficiency of the solar cell element 1 can be improved.
  • the protective layer 4 including the plurality of granular materials 5b can emit more light in the infrared wavelength region than in the visible wavelength region. Many can be scattered and reflected. In this case, for example, infrared rays transmitted through the semiconductor substrate 2 are likely to be scattered and reflected by the protective layer 4 including the plurality of granular bodies 5b.
  • the protective layer 5 is cracked when the insulating paste for forming the protective layer 5 is applied and dried. Hard to occur. As a result, for example, the performance of protecting the semiconductor substrate 2 and the passivation film 4 by the protective layer 5 is unlikely to deteriorate. Further, for example, when the protective layer 5 is seen through, the area where the granular material 5b is present can be increased. Thereby, in the protective layer 5, the infrared light transmitted through the semiconductor substrate 2 is easily scattered and reflected. As a result, for example, the photoelectric conversion efficiency of the solar cell element 1 can be improved.
  • the total volume of the plurality of granular bodies 5b may be about 3 to 90, or about 5 to 85.
  • the volume ratio of the plurality of granular bodies 5b in the protective layer 5 is obtained by, for example, observing a plurality of cut surfaces of the protective layer 5 with an SEM or the like, It can be calculated from the ratio of the flat area of the granular material 5b.
  • the volume ratio of the plurality of granular bodies 5b in the protective layer 5 is calculated, for example, by subtracting the volume of the plurality of granular bodies 5b from the volume of the protective layer 5 to calculate the volume of the base material part 5a.
  • the volume of the protective layer 5 is determined by, for example, imaging and image processing after removing the back electrode 7 of the solar cell element 1 by etching using hydrochloric acid or the like with the thickness of the protective layer 5 measured with a stylus or an ellipsometer. It can be obtained by calculating the product of the measured flat area of the protective layer 5.
  • the volume of the plurality of granules 5b is, for example, a plurality of granules extracted by removing the back electrode 7 of the solar cell element 1 by etching using hydrochloric acid or the like and then removing the protective layer 5 using hydrofluoric acid or the like. For 5b, it can be calculated by measuring the particle size distribution.
  • the volume of the base material portion 5a is set to 100, and the oxidation as the plurality of granular materials 5b is performed.
  • the volume of the titanium granular material can be about 5 to 25.
  • fine particles of SiO 2 having a particle diameter of about 10 nm having a volume of about 50 to 60 may be further present in the protective layer 5.
  • the volume ratio of the plurality of gaps 5a2 in the base material part 5a is obtained by, for example, observing a plurality of cut surfaces of the protective layer 5 with an SEM or the like, and a plurality of flat areas of the base material part 5a. It can be calculated from the ratio of the flat area of the void 5a2.
  • a mixed solution is prepared by mixing a siloxane resin precursor, water, a catalyst, an organic solvent, and a large number of fillers.
  • silane compound having a Si—O bond or a silazane compound having a Si—N bond can be employed as the precursor of the siloxane resin. These compounds have a property of causing hydrolysis (also referred to as hydrolyzability). Further, the precursor of the siloxane resin becomes a siloxane resin by hydrolysis and condensation polymerization.
  • the silane compound is represented by the following general formula 1.
  • N in the general formula 1 is an integer of any one of 0, 1, 2, and 3.
  • R1 and R2 in the general formula 1 represent a hydrocarbon group such as an alkyl group such as a methyl group and an ethyl group or a phenyl group.
  • the silane compound includes, for example, a silane compound in which at least R1 includes an alkyl group (also referred to as an alkyl group-based silane compound).
  • alkyl group-based silane compound for example, methyltrimethoxysilane, dimethyldimethoxysilane, triethoxymethylsilane, diethoxydimethylsilane, trimethoxypropylsilane, triethoxypropylsilane, hexyltrimethoxysilane, Examples include triethoxyhexylsilane, triethoxyoctylsilane, and decyltrimethoxysilane.
  • the silazane compound may be either an inorganic silazane compound or an organic silazane compound.
  • polysilazane is applied to the inorganic silazane compound.
  • hexamethyldisilazane, tetramethylcyclodisilazane, or tetraphenylcyclodisilazane is applied to the organic silazane compound.
  • Water is a liquid for hydrolyzing the precursor of the siloxane resin.
  • pure water is used as water.
  • water reacts with a Si—OCH 3 bond of a silane compound a Si—OH bond and HO—CH 3 (methanol) are generated.
  • the organic solvent is a solvent for producing a paste containing a siloxane resin from a siloxane resin precursor. Moreover, the organic solvent can mix the precursor of a siloxane resin, and water.
  • the organic solvent include diethylene glycol monobutyl ether, methyl cellosolve, ethyl cellosolve, ethyl alcohol, 2- (4-methylcyclohex-3-enyl) propan-2-ol, and 2-propanol.
  • any one of these organic solvents and an organic solvent obtained by mixing two or more organic solvents may be used.
  • the catalyst can control the rate of reaction as the siloxane resin precursor undergoes hydrolysis and condensation polymerization.
  • the Si—OR bond for example, R is an alkyl group
  • the rate of the reaction yielding water
  • the catalyst for example, one or more inorganic acids or one or more organic acids of hydrochloric acid, nitric acid, sulfuric acid, boric acid, phosphoric acid, hydrofluoric acid and acetic acid are applied.
  • one or more inorganic bases or one or more organic bases among ammonia, sodium hydroxide, potassium hydroxide, barium hydroxide, calcium hydroxide, and pyridine may be applied to the catalyst.
  • the catalyst may be, for example, a combination of an inorganic acid and an organic acid, or a combination of an inorganic base and an organic base.
  • the filler is for adjusting the viscosity of the mixed solution.
  • the filler for example, an inorganic material filler containing silicon oxide, aluminum oxide, titanium oxide, or the like is used.
  • the concentration of the precursor of the siloxane resin is 7% by mass to 60% by mass, and the concentration of water is 5% by mass.
  • % To 40% by mass (may be 10% to 20% by mass) the catalyst concentration is 1 ppm to 1000 ppm, the organic solvent concentration is 5% to 50% by mass, and the concentration of fillers of many inorganic materials is It is adjusted to be 3% by mass to 30% by mass.
  • a siloxane resin produced by hydrolysis and condensation polymerization of a siloxane resin precursor can be contained in the insulating paste at an appropriate concentration.
  • an excessive increase in viscosity due to gelation hardly occurs in the insulating paste.
  • the mixed solution is stirred.
  • the mixed solution is stirred using, for example, a mix rotor or a stirrer.
  • the hydrolysis of the precursor of the siloxane resin further proceeds.
  • the hydrolyzed siloxane resin precursor undergoes condensation polymerization, and the siloxane resin continues to be produced.
  • a stirring condition is employed in which the rotation speed of the rotating roller of the mix rotor is about 400 rpm to 600 rpm and the stirring time is about 30 minutes to 90 minutes.
  • the precursor of siloxane resin, water, catalyst, organic solvent, and fillers of many inorganic materials can be uniformly mixed.
  • the by-product includes, for example, an organic component such as an alcohol generated by a reaction between a siloxane resin precursor and water.
  • the processing temperature is about room temperature to 90 ° C. (may be about 50 ° C. to 90 ° C.) and the processing time is about 10 minutes to 600 minutes,
  • the mixed solution after stirring is treated.
  • By-products can be removed if the processing temperature is within the above temperature range.
  • productivity can be improved by shortening the processing time.
  • the many granular materials include, for example, a large number of inorganic material granular materials that form the plurality of granular materials 5b described above, and a large number of organic material granular materials for forming the plurality of void portions 5a2.
  • the granular material of the organic material for example, a material containing as a main component a material that causes thermal decomposition below the temperature at which the insulating paste is dried when the protective layer 5 is formed.
  • the temperature at which the granular material of the organic material undergoes thermal decomposition is, for example, 350 ° C. or less.
  • the mixed solution to which many granular materials are added is stirred.
  • the mixed solution is stirred using, for example, a mix rotor or a stirrer.
  • an insulating paste can be produced.
  • a number of inorganic material fillers, a number of inorganic material granules, and a number of organic material granules can constitute a number of particles.
  • the viscosity of the insulating paste may be adjusted by a large number of inorganic material particles and a large number of organic material particles without including an inorganic material filler in the mixed solution.
  • the semiconductor substrate 2 is prepared.
  • the semiconductor substrate 2 has a second front surface 2fs and a second back surface 2bs facing in the opposite direction to the second front surface 2fs.
  • the semiconductor substrate 2 can be formed using, for example, an existing Czochralski (CZ) method or a casting method.
  • CZ Czochralski
  • a casting method an example using a p-type polycrystalline silicon ingot produced by a casting method will be described.
  • the ingot is sliced to a thickness of 250 ⁇ m or less, for example, and the semiconductor substrate 2 is manufactured.
  • an aqueous solution such as sodium hydroxide, potassium hydroxide, hydrofluoric acid, or hydrofluoric acid, mechanical damage to the cut surface of the semiconductor substrate 2 occurs.
  • the received layer and the contaminated layer can be removed.
  • a part of the texture described above may be formed on the second front surface 2fs of the semiconductor substrate 2.
  • a texture is formed on the second front surface 2 fs of the semiconductor substrate 2.
  • the texture can be formed by, for example, wet etching using an alkaline aqueous solution such as sodium hydroxide or an acidic aqueous solution such as hydrofluoric acid, or dry etching using a reactive ion etching (RIE) method or the like.
  • RIE reactive ion etching
  • a second semiconductor region 22 that is an n-type semiconductor region is formed in the surface layer portion of the textured semiconductor substrate 2 on the second front surface 2fs side.
  • the second semiconductor region 22 is formed into a gaseous state, for example, by applying a paste-like phosphorous pentoxide (P 2 O 5 ) to the second front surface 2fs of the semiconductor substrate 2 to thermally diffuse phosphorus. It can be formed using a vapor phase thermal diffusion method using phosphorus oxychloride (POCl 3 ) as a diffusion source.
  • the second semiconductor region 22 is formed to have a depth of about 0.1 ⁇ m to 2 ⁇ m and a sheet resistance value of about 40 ⁇ / ⁇ to 200 ⁇ / ⁇ , for example.
  • the semiconductor substrate 2 is subjected to heat treatment for about 5 minutes to 30 minutes at a temperature of about 600 ° C. to 800 ° C. in an atmosphere having a diffusion gas mainly containing phosphorus oxychloride.
  • Phosphorous glass is formed on the surface of the semiconductor substrate 2.
  • heat treatment is performed on the semiconductor substrate 2 for about 10 minutes to 40 minutes at a relatively high temperature of about 800 ° C. to 900 ° C. in an atmosphere of an inert gas such as argon or nitrogen.
  • an inert gas such as argon or nitrogen.
  • the second semiconductor region formed on the second back surface 2bs side is removed by etching.
  • the second semiconductor region formed on the second back surface 2bs side can be removed by immersing the portion of the semiconductor substrate 2 on the second back surface 2bs side in an aqueous solution of hydrofluoric acid. Thereby, the region having the p-type conductivity can be exposed on the second back surface 2bs of the semiconductor substrate 2. Thereafter, the phosphorus glass adhering to the second front surface 2fs side of the semiconductor substrate 2 when the second semiconductor region 22 is formed is removed by etching.
  • the second semiconductor region formed on the second back surface 2bs side is removed by etching with the phosphor glass remaining on the second front surface 2fs side, the second semiconductor region 22 on the second front surface 2fs side is removed. Removal and damage can be reduced. At this time, the second semiconductor region formed on the outer peripheral surface 2ss of the semiconductor substrate 2 may also be removed. Also, here, for example, a diffusion mask is formed in advance on the second back surface 2bs side of the semiconductor substrate 2, the second semiconductor region 22 is formed by a vapor phase thermal diffusion method, and then the diffusion mask is removed. Also good. In this case, since the second semiconductor region is not formed on the second back surface 2bs side, the step of removing the second semiconductor region on the second back surface 2bs side is not necessary.
  • the semiconductor substrate 2 including the first semiconductor region 21 in which the second semiconductor region 22, which is an n-type semiconductor layer, is located on the second front surface 2 fs side and has a texture on the second front surface 2 fs can be prepared.
  • a passivation film 4 and an antireflection film 3 are formed.
  • the passivation film 4 is formed on at least the second back surface 2bs of the semiconductor substrate 2
  • the antireflection film 3 is formed on at least the second front surface 2fs of the semiconductor substrate 2.
  • the antireflection film 3 may be formed on the passivation film 4 formed on the second front surface 2fs of the semiconductor substrate 2, for example.
  • the passivation film 4 mainly containing aluminum oxide is formed on the second back surface 2 bs of the semiconductor substrate 2.
  • an antireflection film 3 is formed on the second front surface 2 fs of the semiconductor substrate 2.
  • the antireflection film 3 is made of, for example, a silicon nitride film.
  • Step A An aluminum raw material such as trimethylaluminum (TMA) is supplied onto the semiconductor substrate 2 together with a carrier gas such as argon gas or nitrogen gas. As a result, the aluminum material is adsorbed around the entire periphery of the semiconductor substrate 2.
  • the TMA supply time is, for example, about 15 milliseconds to 3000 milliseconds.
  • the surface of the semiconductor substrate 2 may be terminated with an OH group. In other words, the surface of the semiconductor substrate 2 may have a Si—O—H structure. This structure can be formed, for example, by treating the semiconductor substrate 2 with dilute hydrofluoric acid and then washing with pure water.
  • Step B The inside of the chamber of the film forming apparatus is cleaned with nitrogen gas to remove the aluminum material in the chamber. Furthermore, aluminum materials other than the components chemically adsorbed at the atomic layer level are removed from the aluminum materials physically and chemically adsorbed on the semiconductor substrate 2.
  • the cleaning time in the chamber with nitrogen gas is, for example, about 1 second to several tens of seconds.
  • Step C By supplying an oxidizing agent such as water or ozone gas into the chamber of the film forming apparatus, the alkyl group of TMA is removed and replaced with an OH group. Thereby, an atomic layer of aluminum oxide is formed on the semiconductor substrate 2.
  • the supply time of the oxidizing agent into the chamber is, for example, about 750 milliseconds to 1100 milliseconds. For example, if hydrogen is supplied into the chamber together with the oxidizing agent, more hydrogen atoms are easily contained in the aluminum oxide.
  • Step D The inside of the chamber of the film forming apparatus is cleaned with nitrogen gas to remove the oxidizing agent in the chamber.
  • the purification time in the chamber with nitrogen gas is, for example, about 1 second to several tens of seconds.
  • the preheating temperature of the semiconductor substrate 2 is set to about 50 ° C. higher than the film formation temperature. Further, a frequency of about 10 kHz to 500 kHz is employed as the frequency of the high frequency power source necessary for glow discharge.
  • the gas flow rate is appropriately determined according to the size of the reaction chamber. For example, the gas flow rate is in the range of about 150 ml / min (sccm) to about 6000 ml / min (sccm).
  • the value (B / A) obtained by dividing the flow rate B of ammonia gas by the flow rate A of silane gas is in the range of 0.5 to 15.
  • the protective layer 5 is formed.
  • an insulating paste is applied to substantially the entire surface of the passivation film 4 and the insulating paste is dried, and then the dried insulating paste is used.
  • the protective layer 5 is formed by irradiating laser light to form a plurality of holes 5h.
  • the protective layer 5 which has the base material part 5a containing the non-gap part 5a1 and the several space
  • Such a protective layer 5 can be formed by the following process, for example.
  • a plurality of holes 5h are formed by irradiating a desired position of the insulating paste after drying with laser light.
  • a plurality of through-holes 45h are formed which are positioned in a state of continuously passing through the passivation film 4 and the protective layer 5.
  • the protective layer 5 having the hole 5 h is formed on at least a part of the passivation film 4.
  • an insulating paste is applied so as to have a pattern including a plurality of holes 5h on the passivation film 4, and the insulating paste is dried.
  • the protective layer 5 may be formed.
  • the front electrode 6 is produced using, for example, the above-described second metal paste (silver paste).
  • the second metal paste Pa ⁇ b> 2 is applied to the second front surface 2 fs side of the semiconductor substrate 2.
  • the second metal paste Pa2 is applied on the antireflection film 3 formed on the passivation film 4 on the second front surface 2fs.
  • coating of 2nd metal paste Pa2 is implement
  • the second metal paste Pa2 may be dried by evaporating the solvent in the second metal paste Pa2 at a predetermined temperature.
  • the second metal paste Pa2 is applied by screen printing, for example, the first output extraction electrode 6a, the first current collecting electrode 6b, and the auxiliary electrode 6c in the front electrode 6 can be formed in one step. Thereafter, for example, the second metal paste Pa2 is fired under the condition that the maximum temperature is 600 ° C. to 850 ° C. and the heating time is about several tens of seconds to several tens of minutes in the firing furnace.
  • a front electrode 6 as shown in (a) and FIG. 2 can be formed.
  • the second output extraction electrode 7a of the back electrode 7 is produced using, for example, the above-described third metal paste (silver paste).
  • the third metal paste Pa ⁇ b> 3 is applied to the second back surface 2 bs side of the semiconductor substrate 2.
  • 3rd metal paste Pa3 is apply
  • coating of 3rd metal paste Pa3 is implement
  • the third metal paste Pa3 may be dried by evaporating the solvent in the third metal paste Pa3 at a predetermined temperature.
  • 2nd current collection electrode 7b of back electrode 7 is produced using the 1st metal paste (aluminum paste) mentioned above, for example.
  • the first metal paste Pa ⁇ b> 1 is applied to the second back surface 2 bs side of the semiconductor substrate 2.
  • the first metal paste Pa1 is applied so as to be in contact with a part of the third metal paste previously applied.
  • the first metal paste Pa1 is applied on the protective layer 5 formed on the second back surface 2bs side and in the plurality of through holes 45h.
  • a plurality of hole portions 5h are formed in the protective layer 5 without previously forming a plurality of through holes 45h that are respectively positioned in a state of continuously passing through the passivation film 4 and the protective layer 5. If it does, 1st metal paste Pa1 will be apply
  • 1st metal paste Pa1 After application
  • a second collector electrode 7b having a portion 7b1 and a second portion 7b2 is formed on the second back surface 2bs side of the semiconductor substrate 2.
  • the first metal paste Pa1 is applied in the plurality of through holes 45h formed in advance, the first metal paste Pa1 applied in the plurality of through holes 45h is simply fired, A second portion 7b2 is formed so as to be connected to the second back surface 2bs of the semiconductor substrate 2.
  • the plurality of holes 5h are formed in the protective layer 5 without forming the plurality of through holes 45h in advance, the first metal paste Pa1 is fired in each hole 5h. In doing so, firing of the passivation film 4 is caused to electrically connect with the first semiconductor region 21.
  • the solar cell element 1 as shown in FIG. 1A to FIG. 2 can be formed by forming the back surface electrode 7.
  • the second output extraction electrode 7a may be formed after the second collector electrode 7b is formed.
  • the passivation film 4 exists between the second output extraction electrode 7 a and the semiconductor substrate 2. It may not be in contact.
  • the front electrode 6 and the back electrode 7 may be formed by applying the respective metal pastes and firing them simultaneously. Thereby, the productivity of the solar cell element 1 can be improved. Further, in this case, since the thermal history applied to the semiconductor substrate 2 is reduced, the output characteristics of the solar cell element 1 can be improved.
  • the mixed solution was stirred using a rotation / revolution mixer under the conditions that the rotation speed was 850 rpm and the stirring time was 8 minutes.
  • the mixed solution having about 2.5 volume% of SiO 2 granules was used as the insulating paste according to Reference Example R1, Reference Example R4, and Reference Example R7.
  • a mixed solution having about 7.5% by volume of SiO 2 granules was used as the insulating paste according to Reference Example R2, Reference Example R5, and Reference Example R8.
  • a mixed solution having about 12.5% by volume of SiO 2 granules was used as the insulating paste according to Reference Example R3, Reference Example R6, and Reference Example R9.
  • a mixed solution having about 12.5% by volume of TiO 2 granules and about 7.5% by volume of acrylic resin granules was prepared as Example A3, Example A6, Example A9, Example A12, and Example. Insulating pastes according to A15 and Example A18 were obtained.
  • TiO 2 granules, SiO 2 granules, and acrylic resin granules were added to each of the mixed solutions according to Examples C1 to C27. Specifically, in each of the mixed solutions according to Example C1 to Example C9, TiO 2 granules having an average particle diameter of about 0.5 ⁇ m, SiO 2 granules having an average particle diameter of about 10 nm, and Acrylic resin granules having an average particle size of about 100 nm were added.
  • Example C21 An insulating paste according to Example C21.
  • a mixed solution having about 2.5 volume percent TiO 2 granules, about 27.5 volume percent SiO 2 granules, and about 7.5 volume percent acrylic resin granules was prepared as Example C4. Insulating pastes according to Example C13 and Example C22 were obtained.
  • a mixed solution having about 7.5% by volume TiO 2 granules, about 27.5% by volume SiO 2 granules and about 7.5% by volume acrylic resin granules was prepared as Example C5. Insulating pastes according to Example C14 and Example C23 were obtained.
  • the surface of the semiconductor substrate 2 was subjected to a very small amount of etching with an aqueous sodium hydroxide solution to remove the mechanically damaged layer and the contaminated layer on the cut surface of the semiconductor substrate 2. Thereafter, the semiconductor substrate 2 was washed.
  • an aluminum oxide layer was formed as a passivation film 4 on the entire surface including the second back surface 2bs of the semiconductor substrate 2 by using the ALD method.
  • the surface temperature of the semiconductor substrate 2 placed in the chamber of the film forming apparatus is maintained at about 200 ° C.
  • TMA is used as an aluminum material
  • ozone gas is used as an oxidant, so that the thickness is about 30 nm.
  • An aluminum oxide layer was formed.
  • Example A1 to Example A18 Example B1 to Example B9, and Example C1 to Example C27 having a film thickness of about 10 ⁇ m was formed, respectively, and Reference Example R0 and The protective layers according to Reference Example R1 to Reference Example R9 were formed.
  • the second protective layer and the protective layer 5 are laminated instead of the single protective layer 5 using the insulating paste according to Example D1 to Example D18.
  • solar cell elements 1 of Example D1 to Example D18 were produced.
  • a silicon nitride film as a second protective layer having a thickness of about 200 nm was formed on the passivation film 4 formed on the second back surface 2bs using the PECVD method.
  • each of the insulating pastes according to Examples D1 to D18 was applied on the second protective layer by screen printing. And the insulating paste after application
  • the protective layer 5 according to Example D1 to Example D18 having a film thickness of about 9.8 ⁇ m was formed. Thereafter, a plurality of holes 5h penetrating the protective layer 5 and the second protective layer were formed by irradiating with laser light. At this time, a plurality of through holes 45h penetrating the protective layer 5, the second protective layer, and the passivation film 4 were formed.
  • a plurality of particles in the protective layer 5 are targeted for each solar cell element 1 of Example A1 to Example A18, Example B1 to Example B9, Example C1 to Example C27, and Example D1 to Example D18.
  • the volume ratio of the body 5b and the volume ratio of the plurality of voids 5a2 in the base material part 5a were measured.
  • the volume ratio of the plurality of granular materials 5b in the protective layer 5 is determined by observing the five cut surfaces of the protective layer 5 with the SEM, and the planar area of the base material portion 5a and the plurality of granular materials. It was obtained by calculation using the ratio of the sum of the flat areas of 5b.
  • the volume ratio of the plurality of gaps 5a2 in the base material part 5a is obtained by observing the five cut surfaces of the protective layer 5 with the SEM, and the plane area of the base material part 5a and the plurality of gaps It was obtained by calculation using the ratio of the sum of the flat areas of 5a2.
  • the volume ratio of the plurality of TiO 2 granules as the plurality of granules 5b is: About 25% by volume.
  • the volume ratio of the plurality of TiO 2 granules is about 5% by volume, and the plurality of SiO 2 The volume ratio of the fine particles was about 50% by volume.
  • the volume ratio of the plurality of TiO 2 granules is about 15% by volume, and the volume ratio of the plurality of SiO 2 fine particles is about It was 50% by volume.
  • the volume ratio of the plurality of TiO 2 granules is about 25% by volume, and the volume ratio of the plurality of SiO 2 fine particles is about It was 50% by volume.
  • the volume ratio of the plurality of TiO 2 granules is about 5% by volume, and the volume ratio of the plurality of SiO 2 fine particles is about It was 55% by volume.
  • the volume ratio of the plurality of TiO 2 granules is about 15% by volume, and the volume ratio of the plurality of SiO 2 fine particles is about It was 55% by volume.
  • the volume ratio of the plurality of TiO 2 granules is about 25% by volume, and the volume ratio of the plurality of SiO 2 fine particles is about It was 55% by volume.
  • the volume ratio of the plurality of TiO 2 granules is about 5% by volume, and the volume ratio of the plurality of SiO 2 fine particles is about It was 60% by volume.
  • the volume ratio of the plurality of TiO 2 granules is about 15% by volume, and the volume ratio of the plurality of SiO 2 fine particles is about It was 60% by volume.
  • the volume ratio of the plurality of TiO 2 granules is about 25% by volume, and the volume ratio of the plurality of SiO 2 fine particles is about It was 60% by volume.
  • Example D1 As shown in Table 4, in each protective layer 5 according to Example D1, Example D4, Example D7, Example D10, Example D13, and Example D16, a plurality of TiO 2 as a plurality of granular bodies 5b.
  • the volume fraction of the granules was about 5% by volume.
  • the volume ratio of the plurality of TiO 2 granules as the plurality of granules 5b is: About 15% by volume.
  • the volume ratio of the plurality of granular materials in the protective layer and the volume ratio of the plurality of voids in the base material portion were also measured.
  • this measuring method the same measuring method as that of each of the solar cell elements 1 according to Example A1 to Example A18 described above was used.
  • the volume ratio of the plurality of granular materials and the volume ratio of the plurality of void portions in the base material portion were 0 (zero) volume%.
  • the volume ratio of the SiO 2 granules as the plurality of granules was about 5% by volume.
  • the volume ratio of the plurality of SiO 2 granules as the plurality of granules was about 15% by volume.
  • the volume ratio of the plurality of SiO 2 granules as the plurality of granules was about 25% by volume.
  • the volume ratio of the plurality of voids in the base material portion was 0 (zero) volume%.
  • each Pm obtained by the measurement is represented by a value obtained by normalizing Pm in the solar cell element of Reference Example R0, in which neither a granular material nor a void exists in the protective layer, as a reference value of 1.00. .
  • Pm in each solar cell element of Reference Example R1 to Reference Example R9 was 1.00, which is substantially the same as Pm in the solar cell element of Reference Example R0.
  • the base material portion and the plurality of granular materials were made of the same silicon oxide in the protective layer, and no void portion was present.
  • there is almost no difference in refractive index between the base material portion and the plurality of granular materials there is almost no difference in refractive index between the base material portion and the plurality of granular materials, and the infrared rays transmitted through the semiconductor substrate 2 are scattered by the protective layer and It was estimated that reflection was difficult to occur and the conversion efficiency of the solar cell element did not increase.
  • Pm in each solar cell element of Example B1 to Example B9 was 1.01, which is higher than Pm in the solar cell element of Reference Example R0.
  • the non-voided part 5a1 of the base material part 5a and the plurality of granular bodies 5b in the protective layer 5 were composed of the same silicon oxide.
  • a plurality of gaps 5a2 existed in the base material part 5a.
  • the refractive index of the base material portion 5a is lower than the refractive index of the plurality of granular bodies 5b due to the presence of the plurality of gap portions 5a2, so that the infrared rays transmitted through the semiconductor substrate 2 are scattered and reflected by the protective layer 5. It was estimated that the conversion efficiency of the solar cell element 1 was increased.
  • Pm in each solar cell element of Example C1 to Example C27 is also similar to Pm in the solar cell element of Reference Example R0, similarly to each solar cell element of Example A1 to Example A18. Also, it was 1.01 to 1.02.
  • the non-voided part 5a1 of the base material part 5a is made of silicon oxide, and at least a part of the plurality of granular bodies 5b is formed. It was composed of TiO 2.
  • the refractive index (1.45 to 1.5) of silicon oxide in the non-voided portion 5a1 and the refractive index (2.52 to 2.71) of TiO 2 of the plurality of granular materials 5b are clearly different. It was in a state. Thereby, it was estimated that the infrared rays which permeate
  • Pm in each solar cell element of Example D1 to Example D18 is also similar to Pm in the solar cell element of Reference Example R0, similarly to each solar cell element of Example A1 to Example A18. Also, it was 1.01 to 1.02.
  • the non-gap part 5a1 of the base material part 5a is made of silicon oxide, and the plurality of granular materials 5b are made of TiO 2 . It had been.
  • the refractive index (1.45 to 1.5) of silicon oxide in the non-voided portion 5a1 and the refractive index (2.52 to 2.71) of TiO 2 of the plurality of granular materials 5b are clearly different. It was in a state. Thereby, it was estimated that the infrared rays which permeate
  • the protective layer 5 includes a base material portion 5a including a non-void portion 5a1 and a plurality of void portions 5a2 present inside the non-void portion 5a1, And a plurality of granular materials 5b located in the base material portion 5a.
  • the infrared rays transmitted through the semiconductor substrate 2 are present in the protective layer 5. Can be scattered and reflected by. Thereby, for example, infrared light transmitted through the semiconductor substrate 2 can re-enter the semiconductor substrate 2 at various angles.
  • infrared light that has once transmitted through the semiconductor substrate 2 is easily absorbed by the semiconductor substrate 2.
  • infrared rays that have passed through the semiconductor substrate 2 are unlikely to reach the back electrode 7, and the back electrode 7 is unlikely to generate heat.
  • the output characteristics are hardly deteriorated due to overheating of the solar cell element 1. Therefore, for example, the photoelectric conversion efficiency of the solar cell element 1 can be improved.
  • each gap portion 5a2 is a part of the protective layer 5 between the first surface Sf1 on the semiconductor substrate 2 side in the thickness direction and the second surface Sf2 on the first portion 7b1 side. Since it is located in a field, it is located so that base material part 5a may be filled between a plurality of granular materials 5b. Thereby, for example, a portion located closer to the semiconductor substrate 2 than the protective layer 5 can be sufficiently protected by the protective layer 5. Further, for example, if the base material part 5a is positioned between the plurality of granular bodies 5b, the protective layer is formed when the back electrode 7 is formed by applying a metal paste on the protective layer 5. 5 is difficult to penetrate the metal paste.
  • the light that has passed through the semiconductor substrate 2 is not easily blocked into the protective layer 5, and the light that has passed through the semiconductor substrate 2 is likely to be scattered and reflected within the protective layer 5.
  • light transmitted through the semiconductor substrate 2 is easily absorbed by the semiconductor substrate 2.
  • the protective layer 5 and the back electrode 7 Even if a stress corresponding to the difference in thermal expansion is generated in this, this stress can be relaxed by the plurality of gaps 5a2. Thereby, for example, even if a plurality of granular materials 5b are present, the protective layer 5 is not easily cracked. In this case, for example, the performance of protecting the semiconductor substrate 2 by the protective layer 5 including the base material portion 5a and the plurality of granular bodies 5b can be improved. As a result, for example, the photoelectric conversion efficiency of the solar cell element 1 can be improved.
  • each second current collecting electrode 7b has a longitudinal direction along the second back surface 2bs. In the example of FIG. 6, this longitudinal direction is the + X direction.
  • the plurality of second current collecting electrodes 7b may have a so-called finger shape like the plurality of first current collecting electrodes 6b described above.
  • Each second current collecting electrode 7b is a linear electrode having a width of about 50 ⁇ m to 200 ⁇ m, which is smaller than the width of the second output extraction electrode 7a, for example.
  • the plurality of second current collecting electrodes 7b are located, for example, in a state where they are aligned with an interval of about 1 mm to 3 mm.
  • the solar cell element 1 according to the second embodiment having such a configuration, the light irradiated on the first back surface 1bs can also be incident on the semiconductor substrate 2.
  • the solar cell element 1 according to the second embodiment is an element that uses light incident on both the first front surface 1fs and the first back surface 1bs for power generation. For this reason, the photoelectric conversion efficiency of the solar cell element 1 can be improved.
  • the plurality of granular bodies 5b includes the first granular body 5b1 containing the first material and the second containing the second material different from the first material.
  • the granular material 5b2 may be included.
  • different materials among SiO 2 , Al 2 O 3 , TiO 2 , Fe 2 O 3 , Cu 2 O, Nb 2 O 5 , ZrO 2 , HfO 2 , ZnO, ZnS, SiC, and SiN. Can be employed as the material of the first granule 5b1 and the material of the second granule 5b2.
  • the plurality of granular materials 5b in the insulating paste have different hydrogen ion exponents (pH) that easily aggregate according to the material.
  • the plurality of granular bodies 5b include a plurality of first granular bodies 5b1 and a plurality of second granular bodies 5b2 of materials having different pHs that are likely to aggregate with each other, a plurality of granular bodies 5b are included in the insulating paste.
  • the granular material 5b is difficult to aggregate. Thereby, for example, in the protective layer 5, the plurality of granular materials 5 b can be appropriately dispersed without being aggregated.
  • the protective layer 5 As a result, for example, light transmitted through the semiconductor substrate 2 is easily scattered and reflected by the protective layer 5, and light transmitted through the semiconductor substrate 2 is easily absorbed by the semiconductor substrate 2. Further, for example, when the front electrode 6 and the back electrode 7 are formed by applying and baking a metal paste, a large stress is generated due to a difference in thermal expansion between the base material portion 5a and the plurality of granular bodies 5b. Hard to become. Thereby, for example, even if a plurality of granular materials 5b are present in the protective layer 5, the protective layer 5 is hardly cracked, and the performance of protecting the semiconductor substrate 2 and the passivation film 4 by the protective layer 5 can be improved.
  • the portion where the granular body 5b of the same material is in contact is different. Even in the portion where the first granular body 5b1 and the second granular body 5b2 are in contact with each other, infrared scattering and reflection can occur due to the difference in refractive index. Therefore, for example, the photoelectric conversion efficiency of the solar cell element 1 can be improved.
  • the protective layer 5 includes a first region 51 located on the semiconductor substrate 2 side from the central portion 5 ct in the thickness direction of the protective layer 5, And a second region 52 located on the first portion 7b1 side from the central portion 5ct.
  • the existence density of the plurality of granular bodies 5 b in the first area 51 may be larger than the existence density of the plurality of granular bodies 5 b in the second area 52.
  • the protective layer 5 having such a configuration is, for example, for forming an insulating paste (also referred to as a first insulating paste) for forming the first region 51 and a second region 52 on the passivation film 4.
  • Insulating paste (also referred to as second insulating paste) is applied in the order of description.
  • the first insulating paste only needs to have a plurality of granular bodies 5b at a higher density than the second insulating paste.
  • the said structure is employ
  • the second region 52 may or may not include a plurality of granular bodies 5b.
  • the second region 52 includes a plurality of granular materials 5b, if the second region 52 includes the non-voided portion 5a1, the protective layer 5 is not easily cracked.
  • the protective layer 5 is located in the thickness direction of the protective layer 5 in order, the first region 51 and a second region 52 may be included.
  • the second region 52 is located between the semiconductor substrate 2 and the first region 51 and includes at least the non-gap portion 5a1.
  • the 1st field 51 contains base material part 5a and a plurality of granular materials 5b, for example.
  • the first region 51 and the second region 52 may be, for example, the same material of the base material part 5a, or the first protective layer and the second material in which the material of the base material part 5a is different from each other. It may be a protective layer.
  • the protective layer 5 having such a configuration forms a second region 52 by applying a second insulating paste on the passivation film 4 and drying it, and the first insulating paste is formed on the second region 52. It can be realized by forming the first region 51 by applying and drying.
  • the second region 52 can be a dense layer.
  • the function of protecting the semiconductor substrate 2 and the passivation film 4 by the second region 52 can be improved.
  • the second region 52 can be a denser layer.
  • the passivation film 4 is hardly damaged by the granular material 5b.
  • the second region 52 includes a plurality of granules 5 b, and the presence density of the plurality of granules 5 b in the second region 52 is the first region 51. It may be smaller than the existence density of the plurality of granular materials 5b. In this case, for example, the difference in refractive index between the base material portion 5a and the plurality of granular materials 5b can be made different between the first region 51 and the second region 52. Thereby, for example, light transmitted through the semiconductor substrate 2 is easily scattered and reflected by the protective layer 5. In this case, for example, the second region 52 can be a denser layer than the first region 51.
  • the second region 52 is made to be more than the first region 51 by reducing the existence density of the plurality of granular bodies 5 b and the existence density of the plurality of gaps 5 a 2 in the second region 52. It can be a dense layer. In this case, for example, when the second insulating paste is applied to form the second region 52, the passivation film 4 is not easily damaged by the granular material 5b.
  • the plurality of granules 5b include a granule in which a metal reflective film (also referred to as a metal reflective film) 5c is located on a part of the surface. It may be.
  • a metal thin film such as aluminum is formed on the surface of the granular materials by sputtering or the like.
  • Granules 5b in which 5c is located on a part of the surface can be formed.
  • the metal reflective film 5c is present on the surface of the granular body 5b, the light that travels through the granular body 5b toward the back electrode 7 can be reflected by the metal reflective film 5c.
  • the ratio of light scattered and reflected toward the semiconductor substrate 2 by the protective layer 5 in the light transmitted through the semiconductor substrate 2 can be increased.
  • the photoelectric conversion efficiency of the solar cell element 1 can be improved.
  • each granular body 5b covers a main body portion made of the same material as the non-voided portion 5a1 of the base material portion 5a and the surface of the main body portion.
  • the non-gap part 5a1 and the covering part made of a different material may be included.
  • each granular body 5b is positioned so as to cover the main body portion made of SiO 2 and the surface of the main body portion. a covering portion formed of TiO 2, a configuration having the contemplated.
  • each granular material 5b can be prepared by, for example, forming a TiO 2 film on the surface of the SiO 2 grains in advance using sputtering or the like when manufacturing an insulating paste.
  • the insulating paste may contain SiO 2 granules having an average particle diameter of about 1 ⁇ m and a large number of fine particles of TiO 2 having an average particle diameter of about 10 nm to 50 nm.
  • the semiconductor substrate 2 may be a silicon substrate using amorphous silicon, for example, instead of single crystal or polycrystalline silicon.
  • the semiconductor substrate 2 is not a silicon substrate, for example, four types of elements of copper, indium, gallium and selenium, or two types of elements of cadmium and tellurium, etc. It may be a substrate having a compound semiconductor using In this case, for example, depending on the material of the semiconductor substrate 2, the wavelength range of the light that easily passes through the semiconductor substrate 2 is different. For this reason, for example, the particle diameters of the plurality of granular bodies 5b may be set so that light scattering is likely to occur in the wavelength range of light that easily passes through the semiconductor substrate 2.
  • the passivation film 4 is damaged by the application of the insulating paste. Hateful.
  • the refractive index of the material of the plurality of granular bodies 5b may be lower than the refractive index of the material of the non-voided portion 5a1 of the base material portion 5a.
  • the refractive index only needs to be different between the material of the non-gap part 5a1 of the base material part 5a and the material of the plurality of granular bodies 5b.
  • the material of the non-gap portion 5a1 of the base material portion 5a may be, for example, other materials such as aluminum oxide or titanium oxide instead of silicon oxide.
  • one or more kinds of materials may be applied to the material of the non-gap part 5a1 of the base material part 5a.
  • the granular material of the organic material contained in the insulating paste does not thermally decompose at a temperature at which the insulating paste is dried to form the protective layer 5, for example.
  • the metal paste may be pyrolyzed at a temperature for firing.
  • Such a configuration appropriately adjusts, for example, the material constituting the organic material granular material included in the insulating paste and the temperature at which the coated insulating paste is dried to form the protective layer 5. This can be realized. If such a configuration is employed, for example, when the metal paste is baked to form the back electrode 7, the protective layer 5 becomes denser, and the passivation film 4 is baked and penetrated by the first metal paste. Hateful.
  • the solar cell element 1 is not a PERC type solar cell element.
  • the IBC Interdigitated Back Contact
  • MWT Metal Wrap Through
  • EWT Emitter Wrap
  • a back contact type solar cell element having a structure such as “through” may be used.
  • the passivation film 4 may not exist, and at least the protective layer 5 and the electrode on the back surface side exist on the second back surface 2 bs of the semiconductor substrate 2.
  • the gap 5a2 is the first portion of the semiconductor substrate 2 and the second current collecting electrode 7b as a layer adjacent to the protective layer 5.
  • 7b1 may be in contact with at least one of the layers.
  • the protective layer 5 is located in the entire region between the semiconductor substrate 2 as a layer adjacent to the protective layer 5 and the first portion 7b1.
  • the second output extraction electrode 7 a may be positioned on the semiconductor substrate 2 without being positioned on the protective layer 5.
  • a hole penetrating in the thickness direction of the protective layer 5 is present in a portion where the second output extraction electrode 7a is formed.
  • the structure which forms the protective layer 5 can be considered.
  • a portion where the protective layer 5 exists and a protective layer 5 exist depending on the presence or absence of light scattering according to the presence of the plurality of granular bodies 5 b. It may be possible to distinguish the parts that are not.
  • the second output extraction electrode 7a is accurately formed on the second back surface 2bs side of the semiconductor substrate 2 in accordance with the region where the protective layer 5 does not exist by using imaging and image processing. Can do.
  • the second output extraction electrode 7a is directly connected to the semiconductor substrate 2, and therefore the second output extraction electrode 7a is unlikely to peel off.

Landscapes

  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Electromagnetism (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Photovoltaic Devices (AREA)

Abstract

La présente invention concerne un élément de batterie solaire pourvu : d'un substrat semi-conducteur ; d'une couche de protection ; et d'une électrode. Le substrat semi-conducteur effectue une conversion photoélectrique. La couche de protection est située sur le substrat semi-conducteur. L'électrode a une première partie qui est située sur la couche de protection et une seconde partie qui est dans un état où elle va être électriquement connectée au substrat semi-conducteur. La couche de protection comprend une partie de matériau de base et une pluralité de granules situées à l'intérieur de la partie de matériau de base. La partie de matériau de base comprend une partie non vide et une pluralité de parties vides. La couche de protection a, dans la direction de l'épaisseur de la couche de protection, une première face sur le côté du substrat semi-conducteur et une seconde face sur le côté de la première partie. Chaque partie vide de la pluralité de parties vides est située dans une partie de la région de la couche de protection entre la première face et la seconde face dans la direction de l'épaisseur de la couche de protection. La pluralité de granules a un indice de réfraction qui est différent de l'indice de réfraction de la partie de matériau de base.
PCT/JP2019/019863 2018-05-29 2019-05-20 Élément de batterie solaire WO2019230469A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2020522108A JP7109539B2 (ja) 2018-05-29 2019-05-20 太陽電池素子

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2018102731 2018-05-29
JP2018-102731 2018-05-29

Publications (1)

Publication Number Publication Date
WO2019230469A1 true WO2019230469A1 (fr) 2019-12-05

Family

ID=68698118

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2019/019863 WO2019230469A1 (fr) 2018-05-29 2019-05-20 Élément de batterie solaire

Country Status (2)

Country Link
JP (1) JP7109539B2 (fr)
WO (1) WO2019230469A1 (fr)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009231505A (ja) * 2008-03-21 2009-10-08 Sanyo Electric Co Ltd 太陽電池
JP2011071523A (ja) * 2009-09-28 2011-04-07 Schott Solar Ag ソーラーセル
JP2014135446A (ja) * 2013-01-11 2014-07-24 Mitsubishi Heavy Ind Ltd 光電変換装置及び光電変換装置の製造方法
WO2014185356A1 (fr) * 2013-05-14 2014-11-20 三菱電機株式会社 Elément photovoltaïque et son procédé de fabrication
US20160035916A1 (en) * 2013-03-15 2016-02-04 The Trustees Of Dartmouth College Multifunctional Nanostructured Metal-Rich Metal Oxides
WO2017207558A1 (fr) * 2016-05-30 2017-12-07 Bright New World Ab Panneau de cellules photovoltaïques réparties

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TWI505486B (zh) * 2014-03-07 2015-10-21 Motech Ind Inc 太陽能電池及其模組

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009231505A (ja) * 2008-03-21 2009-10-08 Sanyo Electric Co Ltd 太陽電池
JP2011071523A (ja) * 2009-09-28 2011-04-07 Schott Solar Ag ソーラーセル
JP2014135446A (ja) * 2013-01-11 2014-07-24 Mitsubishi Heavy Ind Ltd 光電変換装置及び光電変換装置の製造方法
US20160035916A1 (en) * 2013-03-15 2016-02-04 The Trustees Of Dartmouth College Multifunctional Nanostructured Metal-Rich Metal Oxides
WO2014185356A1 (fr) * 2013-05-14 2014-11-20 三菱電機株式会社 Elément photovoltaïque et son procédé de fabrication
WO2017207558A1 (fr) * 2016-05-30 2017-12-07 Bright New World Ab Panneau de cellules photovoltaïques réparties

Also Published As

Publication number Publication date
JP7109539B2 (ja) 2022-07-29
JPWO2019230469A1 (ja) 2021-05-13

Similar Documents

Publication Publication Date Title
JP4481869B2 (ja) 太陽電池の製造方法及び太陽電池並びに半導体装置の製造方法
JP6229099B1 (ja) 絶縁性ペースト、絶縁性ペーストの製造方法、太陽電池素子の製造方法および太陽電池素子
CN112993064B (zh) 太阳能电池及其制备方法、光伏组件
JP6807433B2 (ja) 太陽電池素子
US10749047B2 (en) Solar cell element and method for manufacturing solar cell element
EP3306674B1 (fr) Élément de cellule solaire et son procédé de fabrication
JPWO2017146214A1 (ja) 太陽電池素子
JP6863853B2 (ja) 太陽電池素子および太陽電池モジュール
WO2019230469A1 (fr) Élément de batterie solaire
JP2017069247A (ja) 絶縁性ペーストおよびその製造方法並びに太陽電池素子の製造方法
WO2019230686A1 (fr) Élément de batterie solaire et module de batterie solaire
JP6539010B1 (ja) 太陽電池素子
US20190245107A1 (en) Solar cell element
KR20110091427A (ko) 질화규소 반사방지막의 제조 방법 및 이를 이용한 실리콘 태양전지
JP6971769B2 (ja) 太陽電池素子
JP6893438B2 (ja) 太陽電池素子を製造する際に保護層の形成に用いられる絶縁性ペースト
TWI753179B (zh) 高效率內面電極型太陽電池及其製造方法

Legal Events

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

Ref document number: 19811641

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2020522108

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 19811641

Country of ref document: EP

Kind code of ref document: A1