JP2013239618A - Photoelectric conversion device manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase photoelectric conversion efficiency in a photoelectric conversion device.SOLUTION: A manufacturing method of a photoelectric conversion device 11 comprises the steps of: forming on an electrode layer 2, a first film 3a containing a group I-B element, an In element and a Ga element; forming on the first film 3a, a second film 3b containing a group I-B element, an In element, an organic compound and a Ga element having a concentration higher than that of the first film 3a to form a layered film 3x in which the first film 3a and the second film 3b are layered; making the laminated film 3x be a thermally-decomposed film by heating the laminated film 3x at a first temperature to thermally decompose the organic compound; and making the thermally-decomposed film be a semiconductor layer 3 containing a group I-III-VI compound by heating the thermally-decomposed film at a second temperature lower than the first temperature and subsequently at a third temperature higher than the first temperature in a chalcogen element-containing atmosphere.

Description

The present invention relates to a method for manufacturing a photoelectric conversion device using a semiconductor layer containing an I-III-VI group compound.

As a photoelectric conversion device used for solar power generation or the like, there is one in which a light absorption layer is formed of an I-III-VI group compound such as CIS or CIGS. Such a photoelectric conversion device is described in Patent Document 1, for example.

A photoelectric conversion device using such an I-III-VI group compound has a configuration in which a plurality of photoelectric conversion cells are arranged side by side in a plane. Each photoelectric conversion cell has a substrate such as glass, a lower electrode such as a metal electrode, a photoelectric conversion layer including a light absorption layer and a buffer layer, and an upper electrode such as a transparent electrode and a metal electrode in this order. It is constructed by stacking. In addition, the plurality of photoelectric conversion cells are electrically connected in series by electrically connecting the upper electrode of one adjacent photoelectric conversion cell and the lower electrode of the other photoelectric conversion cell by a connecting conductor. Yes.

  Such a light absorption layer containing an I-III-VI group compound is formed by forming a film containing a raw material of an I-III-VI group compound on the lower electrode and heat-treating the film.

  As a raw material for the I-III-VI group compound, a salt or a complex of an element constituting the I-III-VI group compound is used. For example, Patent Document 2 describes that a single source precursor in which Cu, Se, In, or Ga is present in one organic compound is used as a raw material for metal chalcogenide. Yes.

JP 2000-299486 A US Pat. No. 6,992,202

The photoelectric conversion device containing the I-III-VI group compound is always required to improve the photoelectric conversion efficiency. This photoelectric conversion efficiency indicates the rate at which sunlight energy is converted into electric energy in the photoelectric conversion device. For example, the value of the electric energy output from the photoelectric conversion device is the amount of sunlight incident on the photoelectric conversion device. Divided by the value of energy and derived by multiplying by 100.

  This invention is made | formed in view of the said subject, and aims at the improvement of the photoelectric conversion efficiency in a photoelectric conversion apparatus.

  A method for manufacturing a photoelectric conversion device according to an embodiment of the present invention includes a step of forming a first film containing a group IB element, an In element, and a Ga element on an electrode layer; A second film containing a IB group element, an In element, an organic compound, and a Ga element having a higher concentration than the first film is formed, and the first film and the second film are laminated. A step of producing a laminated film, a step of heating the laminated film at a first temperature to thermally decompose the organic compound, thereby converting the laminated film into a thermally decomposed film, and an atmosphere containing a chalcogen element The pyrolysis film is heated at a second temperature lower than the first temperature, and then heated at a third temperature higher than the first temperature to make the pyrolysis film a group I-III-VI And a step of forming a semiconductor layer containing a compound.

  According to the embodiment of the present invention, a photoelectric conversion device with high photoelectric conversion efficiency can be provided.

It is a perspective view which shows an example of embodiment of the photoelectric conversion apparatus produced using the manufacturing method of the photoelectric conversion apparatus which concerns on one Embodiment of this invention. It is sectional drawing of the photoelectric conversion apparatus of FIG. It is sectional drawing which shows typically the mode in the middle of manufacture of a photoelectric conversion apparatus. It is sectional drawing which shows typically the mode in the middle of manufacture of a photoelectric conversion apparatus. It is sectional drawing which shows typically the mode in the middle of manufacture of a photoelectric conversion apparatus. It is sectional drawing which shows typically the mode in the middle of manufacture of a photoelectric conversion apparatus. It is sectional drawing which shows typically the mode in the middle of manufacture of a photoelectric conversion apparatus. It is sectional drawing which shows typically the mode in the middle of manufacture of a photoelectric conversion apparatus. It is sectional drawing which shows typically the mode in the middle of manufacture of a photoelectric conversion apparatus. It is sectional drawing which shows typically the mode in the middle of manufacture of a photoelectric conversion apparatus. It is sectional drawing which shows typically the mode in the middle of manufacture of a photoelectric conversion apparatus. It is sectional drawing which shows typically the mode in the middle of manufacture of a photoelectric conversion apparatus. It is a graph which shows an example of the composition distribution of the thickness direction of a 1st semiconductor layer. It is a graph which shows the other example of the composition distribution of the thickness direction of a 1st semiconductor layer.

  Hereinafter, a method for manufacturing a photoelectric conversion device according to an embodiment of the present invention will be described with reference to the drawings. In the drawings, parts having similar configurations and functions are denoted by the same reference numerals, and redundant description is omitted in the following description. Further, the drawings are schematically shown, and the sizes, positional relationships, and the like of various structures in the drawings are not accurately illustrated.

<(1) Configuration of photoelectric conversion device>
FIG. 1 is a perspective view showing an example of a photoelectric conversion device 11 manufactured by using a method for manufacturing a photoelectric conversion device according to an embodiment of the present invention. FIG. 2 is an XZ sectional view of the photoelectric conversion device 11 of FIG. 1 to 12 are provided with a right-handed XYZ coordinate system in which the arrangement direction of photoelectric conversion cells 10 (the horizontal direction in the drawing in FIG. 1) is the X-axis direction.

  The photoelectric conversion device 11 has a configuration in which a plurality of photoelectric conversion cells 10 are arranged in parallel on a substrate 1. In FIG. 1, only two photoelectric conversion cells 10 are shown for convenience of illustration, but an actual photoelectric conversion device 11 has a large number of photoelectric conversion cells in the X-axis direction of the drawing or further in the Y-axis direction of the drawing. The conversion cells 10 are arranged two-dimensionally (two-dimensionally).

  Each photoelectric conversion cell 10 mainly includes a lower electrode layer 2, a first semiconductor layer 3, a second semiconductor layer 4, an upper electrode layer 5, and a collecting electrode 7. In the photoelectric conversion device 11, the main surface on the side where the upper electrode layer 5 and the collecting electrode 7 are provided is a light receiving surface. In addition, the photoelectric conversion device 11 is provided with three types of groove portions such as first to third groove portions P1, P2, and P3.

The substrate 1 supports the plurality of photoelectric conversion cells 10 and is made of, for example, a material such as glass, ceramics, resin, or metal. As a specific example, for example, a blue plate glass (soda lime glass) having a thickness of about 1 to 3 mm may be used as the substrate 1.

  The lower electrode layer 2 is a conductive layer provided on one main surface of the substrate 1. For example, molybdenum (Mo), aluminum (Al), titanium (Ti), tantalum (Ta), or gold (Au). Or a laminated structure of these metals. The lower electrode layer 2 has a thickness of about 0.2 to 1 μm and is formed by a known thin film forming method such as a sputtering method or a vapor deposition method.

The first semiconductor layer 3 as the light absorption layer is provided with a first conductivity type (here, p-type conductivity type) provided on the main surface (also referred to as one main surface) on the + Z side of the lower electrode layer 2. ) And has a thickness of about 1 to 3 μm. The first semiconductor layer 3 is a compound of a group IB element (also referred to as a group 11 element), a group III-B element (also referred to as a group 13 element) including an In element and a Ga element, and a chalcogen element. , I-III-VI group compounds. The chalcogen element refers to S, Se, or Te among VI-B group elements (also referred to as group 16 elements). As such an I-III-VI group compound, for example, Cu (In, Ga) Se ₂ (also called copper indium gallium selenide, CIGS), Cu (In, Ga) (Se, S) ₂ ( Diselenium, copper indium sulphide, indium gallium, also referred to as CIGSS).

  Further, the first semiconductor layer 3 has a Ga element concentration (Ga element relative to the sum of In element and Ga element) on the surface portion opposite to the lower electrode layer 2, that is, on the surface portion on the second semiconductor layer 4 side. The ratio increases gradually or stepwise as it approaches the surface of the second semiconductor layer 4 side. With such a configuration, it is possible to increase the band gap at the surface portion on the second semiconductor layer 4 side and increase the open-circuit voltage. As a result, the photoelectric conversion efficiency of the photoelectric conversion device 11 can be increased. . The thickness of the site where the Ga element concentration is inclined in the surface portion of the first semiconductor layer 3 on the second semiconductor layer 4 side may be about 100 to 1000 nm, for example. FIG. 13 is a graph showing an example of the composition distribution in the thickness direction of the first semiconductor layer 3 when the first semiconductor layer 3 is CIGS having a thickness of 2 μm. As shown in FIG. 13, in the surface portion of the first semiconductor layer 3 on the second semiconductor layer 4 side, the concentration of Ga element increases as it approaches the surface on the second semiconductor layer 4 side.

  Further, the first semiconductor layer 3 may be gradually or stepwise increased as the Ga element concentration further approaches the surface on the lower electrode layer 2 side. In other words, the Ga semiconductor concentration has a minimum value inside the first semiconductor layer 3 in the thickness direction, and the Ga element concentration increases as it approaches the surface on the second semiconductor layer 4 side from the portion exhibiting the minimum value. In addition, the concentration of the Ga element may increase as it approaches the surface on the lower electrode layer 2 side from the portion showing the minimum value. With such a configuration, the band gap of the first semiconductor layer 3 can have a double graded structure, and the photoelectric conversion efficiency of the photoelectric conversion device 11 becomes higher. FIG. 14 is a graph showing another example of the composition distribution in the thickness direction of the first semiconductor layer 3 when the first semiconductor layer 3 is CIGS having a thickness of 2 μm. As shown in FIG. 14, the concentration of Ga element shows a minimum value at a portion of the first semiconductor layer 3 near the second semiconductor layer 4, and from the portion showing the minimum value to the surface on the second semiconductor layer 4 side. The closer to the surface, the higher the Ga element concentration, and the closer to the surface on the lower electrode layer 2 side from the portion showing the minimum value, the higher the Ga element concentration.

As a specific example of the concentration distribution of the Ga element in the first semiconductor layer 3, for example, in a portion showing the minimum value of the Ga element inside the thickness direction of the first semiconductor layer 3, the Ga element and the In element The ratio of the number of moles of Ga element to the total number of moles is 0.05 to 0.25. On the other hand, in the vicinity of the surface of the first semiconductor layer 3 on the second semiconductor layer 4 side (region within 100 nm from the interface with the second semiconductor layer 4), Ga element relative to the total number of moles of Ga element and In element. The ratio of the number of moles is 1.2 to 6 times the ratio of the number of moles of Ga element at the minimum value. Further, in the vicinity of the surface of the first semiconductor layer 3 on the lower electrode layer 2 side (region within 100 nm from the interface with the lower electrode layer 2), the number of moles of Ga element relative to the total number of moles of Ga element and In element The ratio is 1 to 12 times the ratio of the number of moles of Ga element at the minimum value.

  The content of each element in the first semiconductor layer 3 is determined by secondary ion mass spectrometry (SIMS), Auger Electron Spectroscopy (AES), or X-ray photoelectron spectroscopy (XPS). X-ray Photoelectron Spectroscopy) can be used.

  The second semiconductor layer 4 is a semiconductor layer provided on one main surface of the first semiconductor layer 3. The second semiconductor layer 4 has a conductivity type (here, n-type conductivity type) different from that of the first semiconductor layer 3. By joining the first semiconductor layer 3 and the second semiconductor layer 4, positive and negative carriers generated by photoelectric conversion in the first semiconductor layer 3 are favorably separated. Note that semiconductors having different conductivity types are semiconductors having different conductive carriers. Further, when the conductivity type of the first semiconductor layer 3 is p-type as described above, the conductivity type of the second semiconductor layer 4 may be i-type instead of n-type. Furthermore, there may be a mode in which the conductivity type of the first semiconductor layer 3 is n-type or i-type and the conductivity type of the second semiconductor layer 4 is p-type.

The second semiconductor layer 4 includes, for example, cadmium sulfide (CdS), indium sulfide (In ₂ S ₃ ), zinc sulfide (ZnS), zinc oxide (ZnO), indium selenide (In ₂ Se ₃ ), In (OH , S), (Zn, In) (Se, OH), and (Zn, Mg) O. From the viewpoint of reducing current loss, the second semiconductor layer 4 can have a resistivity of 1 Ω · cm or more. The second semiconductor layer 4 is formed by, for example, a chemical bath deposition (CBD) method or the like.

  The second semiconductor layer 4 has a thickness in the normal direction of one main surface of the first semiconductor layer 3. This thickness is set to, for example, 10 to 200 nm.

  The upper electrode layer 5 is a transparent conductive film having an n-type conductivity provided on the second semiconductor layer 4, and is an electrode for extracting charges generated in the first semiconductor layer 3. The upper electrode layer 5 is made of a material having a lower resistivity than the second semiconductor layer 4. The upper electrode layer 5 includes what is called a window layer, and when a transparent conductive film is further provided in addition to the window layer, these may be regarded as an integrated upper electrode layer 5.

The upper electrode layer 5 mainly includes a material having a wide forbidden band, transparent, and low resistance. As such a material, for example, a metal oxide semiconductor such as ZnO, In ₂ O ₃ and SnO ₂ can be adopted. These metal oxide semiconductors may contain any element of Al, B, Ga, In, F, and the like. Specific examples of the metal oxide semiconductor containing such an element include, for example, AZO (Aluminum Zinc Oxide), GZO (Gallium Zinc Oxide),
Examples include IZO (Indium Zinc Oxide), ITO (Indium Tin Oxide), and FTO (Fluorine tin Oxide).

  The upper electrode layer 5 is formed to have a thickness of 0.05 to 3.0 μm by sputtering, vapor deposition, chemical vapor deposition (CVD), or the like. Here, from the viewpoint of good charge extraction from the first semiconductor layer 3, the upper electrode layer 5 has a resistivity of less than 1 Ω · cm and a sheet resistance of 50Ω / □ or less. Can do.

The second semiconductor layer 4 and the upper electrode layer 5 may be made of a material having a property (also referred to as light transmission property) that allows light to easily pass through the wavelength region of light absorbed by the first semiconductor layer 3.
Thereby, a decrease in light absorption efficiency in the first semiconductor layer 3 caused by providing the second semiconductor layer 4 and the upper electrode layer 5 is reduced.

  In addition, from the viewpoint of improving the light transmittance, the effect of preventing loss of light reflection and the light scattering effect, and further transmitting the current generated by the photoelectric conversion, the upper electrode layer 5 can have a thickness of 0.05 to 0.5 μm. Further, from the viewpoint of reducing the light reflection loss at the interface between the upper electrode layer 5 and the second semiconductor layer 4, the absolute refractive index is substantially between the upper electrode layer 5 and the second semiconductor layer 4. It can be made the same.

  The collecting electrodes 7 are spaced apart in the Y-axis direction, and each extend in the X-axis direction. The collector electrode 7 is an electrode having conductivity, and is made of a metal such as silver (Ag), for example.

  The collecting electrode 7 plays a role of collecting charges generated in the first semiconductor layer 3 and taken out in the upper electrode layer 5. If the current collecting electrode 7 is provided, the upper electrode layer 5 can be thinned.

  The charges collected by the collector electrode 7 and the upper electrode layer 5 are transmitted to the adjacent photoelectric conversion cell 10 through the connection conductor 6 provided in the second groove portion P2. For example, the connection conductor 6 is constituted by a portion extending in the Y-axis direction of the current collecting electrode 7 as shown in FIG. Thereby, in the photoelectric conversion apparatus 11, one lower electrode layer 2 of the adjacent photoelectric conversion cell 10 and the other collector electrode 7 are electrically connected via the connection conductor 6 provided in the second groove portion P2. Connected in series. In addition, the connection conductor 6 is not limited to this, You may be comprised by the extension part of the upper electrode layer 5. FIG.

  The current collecting electrode 5 has a width of 50 to 400 μm so that good conductivity is ensured and a decrease in the light receiving area that affects the amount of light incident on the first semiconductor layer 3 is minimized. Can be.

<(2) Method for Manufacturing Photoelectric Conversion Device>
3 to 10 are cross-sectional views schematically showing a state during the manufacture of the photoelectric conversion device 11. Each of the cross-sectional views shown in FIGS. 3 to 10 shows a state in the middle of manufacturing a portion corresponding to the cross-section shown in FIG.

  First, as shown in FIG. 3, a lower electrode layer 2 made of Mo or the like is formed on substantially the entire surface of the cleaned substrate 1 using a sputtering method or the like. Then, the first groove portion P1 is formed from the linear formation target position along the Y direction on the upper surface of the lower electrode layer 2 to the upper surface of the substrate 1 immediately below the formation position. The first groove portion P1 can be formed by, for example, a scribe process in which a groove process is performed by irradiating a formation target position while scanning a laser beam by a YAG laser or the like. FIG. 4 is a diagram illustrating a state after the first groove portion P1 is formed.

  After forming the first groove P1, a first film 3a containing a group IB element, an In element, and a Ga element is formed on the lower electrode layer 2. The manufacturing method of the 1st membrane | film | coat 3a is not specifically limited, For example, you may produce by the process called what is called the apply | coating method or the printing method, using the raw material solution mentioned later. In addition, the 1st membrane | film | coat 3a may consist of multiple layers. FIG. 5 is a diagram illustrating a state after the first film 3a is formed.

  Next, a second film 3b containing a group I-B element, an In element, an organic compound, and a Ga element having a higher concentration than the first film 3a is formed on the first film 3a. A laminated film 3x in which the film 3a and the second film 3b are laminated is prepared.

  Such a 2nd membrane | film | coat 3b can be produced as follows. First, a raw material solution containing an IB group element, an In element, a Ga element, and an organic compound is prepared. At this time, the Ga element concentration is adjusted to be higher than the Ga element concentration in the first coating 3a. As such a raw material solution, a solution obtained by dissolving an organic complex in which an organic compound is bonded to a metal element in an organic solvent or the like can be used. Note that the organic complex includes a compound in which an organic compound is coordinated or ionically bonded to a metal element, and a salt of an organic acid and the metal element is also included in the organic complex. The raw material solution may contain a chalcogen element. When the raw material solution contains a chalcogen element, the metal element can be well chalcogenized and the I-III-VI group compound can be formed well.

  As the organic complex, a complex of an IB group element and an organic ligand, a complex of an In element and an organic ligand, a complex of a Ga element and an organic ligand, an IB group element and an In element, A single source complex in which an organic ligand forms one complex compound (see Patent Document 2) and a single source in which a IB group element, a Ga element, and an organic ligand form one complex compound And a complex (see Patent Document 2). The concentrations of the IB group element, In element, and Ga element can be adjusted to a desired concentration ratio by appropriately mixing the organic complex.

As an organic ligand used for the organic complex, various compounds such as acetylacetonate and organic acid can be used. From the viewpoint of forming the I-III-VI group compound satisfactorily, an organic chalcogen compound may be used. An organic chalcogen compound is an organic compound containing a chalcogen element, and is an organic compound having a covalent bond between a carbon element and a chalcogen element. Examples of the organic chalcogen compound include thiol, sulfide, disulfide, selenol, selenide, diselenide, tellurol, telluride, ditelluride and the like.

  Using the raw material solution as described above, the second film 3b is formed on the first film 3a by a process called a so-called coating method or printing method, and the first film 3a and the second film 3b are formed. Is formed. By such a method, the Ga element concentration gradient is increased at the surface portion of the multilayer coating 3z opposite to the lower electrode layer 2 as the Ga element concentration is closer to the surface opposite to the lower electrode layer 2. It will have. The second coating 3b may be composed of a plurality of layers, and the concentration gradient of Ga element may be made in multiple stages by using a plurality of raw material solutions in which the concentration of Ga element is changed. FIG. 6 is a diagram illustrating a state after the multilayer coating 3x is formed.

Next, the laminated film 3x is heated at a first temperature to thermally decompose the organic compound in the laminated film 3x (the laminated film 3x after the thermal decomposition is referred to as a pyrolytic film). The first temperature is a temperature at which the organic compound in the second film 3b can be thermally decomposed, and is generated by the reaction of the group IB element, In element, and Ga element in the multilayer film 3x. The temperature is such that the production rate of the I-III-VI group compound is low. As a specific example, for example, the first temperature is 100 to 350 ° C. The atmosphere at the time of heating at the first temperature may be an inert gas atmosphere such as nitrogen or a reducing gas atmosphere such as hydrogen. The Ga element in the pyrolysis film formed in this way maintains the Ga element concentration gradient in the laminated film 3x to some extent.

  Next, the pyrolysis film is heated at a second temperature lower than the first temperature in an atmosphere containing a chalcogen element, and then heated at a third temperature higher than the first temperature to perform the pyrolysis. The film is formed into the first semiconductor layer 3 containing the I-III-VI group compound.

The atmosphere containing a chalcogen element is an atmosphere containing the chalcogen element as a chalcogen compound such as H ₂ S or H ₂ Se, or a vapor of a chalcogen alone such as sulfur vapor or selenium vapor. This atmosphere may contain an inert gas such as nitrogen or a reducing gas such as hydrogen. When the inert gas or reducing gas is contained in the atmosphere, the chalcogenation reaction can be allowed to proceed slowly, and the Ga element concentration gradient can be maintained better.

  The second temperature is, for example, 30 to 70 ° C. lower than the first temperature, and is in the range of 70 to 320 ° C., for example. The heating time at the second temperature is 60 to 120 minutes. In the heating at the second temperature, the second temperature may vary within a temperature range lower than the first temperature.

The third temperature is higher than the first temperature, and is a temperature at which the pyrolysis film can be made into a polycrystalline body mainly containing the I-III-VI group compound. Such 3rd temperature is 450-600 degreeC, for example, and the heating time in 3rd temperature is 1 to 5 hours, for example.

  By such a method, it is possible to satisfactorily produce the first semiconductor layer 3 in which the Ga element concentration increases gradually or stepwise as it approaches the surface opposite to the lower electrode layer 2. That is, when the pyrolysis film is heated in an atmosphere containing a chalcogen element, the Ga element is particularly likely to move to the lower electrode layer 2 side, and it is difficult to maintain the Ga element concentration gradient. On the other hand, by heating at the second temperature for a certain period of time as described above, the reaction is allowed to proceed to some extent while suppressing the movement speed of the Ga element, and then the temperature is raised to the third temperature, whereby the Ga element concentration gradient is increased to some extent. Can be maintained. FIG. 7 is a view showing a state after the first semiconductor layer 3 is formed.

  From the viewpoint of more easily maintaining the Ga element concentration gradient, in the step of thermally decomposing the organic compound in the second film 3b to produce a pyrolytic film, water vapor having a partial pressure ratio of 50 to 300 ppmv in the atmosphere. Or you may make it contain oxygen and to oxidize some metal elements of the 2nd membrane | film | coat 3b. As a result, the bonding force between the compounds constituting the pyrolysis film is increased, and during the subsequent heating at the second temperature and the third temperature, the movement speed of the Ga element is further suppressed, and the concentration of the Ga element is increased. The inclination can be maintained better. As a result, for example, the first semiconductor layer 3 becomes higher as the Ga element as shown in FIG. 13 approaches the surface opposite to the lower electrode layer 2.

  After the formation of the first semiconductor layer 3, the second semiconductor layer 4 and the upper electrode layer 5 are sequentially formed on the first semiconductor layer 3.

  The second semiconductor layer 4 can be formed by a solution growth method (also referred to as a CBD method). For example, cadmium acetate and thiourea are dissolved in ammonia water, and the substrate 1 that has been formed up to the formation of the first semiconductor layer 3 is immersed in the second semiconductor layer 3 so as to contain the second CdS on the first semiconductor layer 3. The semiconductor layer 4 can be formed.

  The upper electrode layer 5 is a transparent conductive film containing, for example, indium oxide (ITO) containing Sn as a main component, and can be formed by a sputtering method, a vapor deposition method, a CVD method, or the like. FIG. 8 is a diagram illustrating a state after the second semiconductor layer 4 and the upper electrode layer 5 are formed.

After the upper electrode layer 5 is formed, the second groove portion P2 is formed from the linear formation target position along the Y direction on the upper surface of the upper electrode layer 5 to the upper surface of the lower electrode layer 2 immediately below it. . The second groove portion P2 is formed, for example, by performing scribing using a scribe needle having a scribe width of about 40 to 50 μm continuously several times while shifting the pitch. Further, the second groove portion P2 may be formed by scribing after the tip shape of the scribe needle is expanded to an extent close to the width of the second groove portion P2. Alternatively, the second groove portion P2 may be formed by fixing two or more than two scribe needles in contact with or in close proximity to each other, and performing one to several scribes. FIG. 9 is a diagram illustrating a state after the second groove portion P2 is formed. The second groove portion P2 is formed at a position slightly shifted in the X direction (in the drawing, + X direction) from the first groove portion P1.

  After the second groove portion P2 is formed, the current collecting electrode 7 and the connection conductor 6 are formed. For the collector electrode 7 and the connection conductor 6, for example, a conductive paste (also referred to as a conductive paste) in which a metal powder such as Ag is dispersed in a resin binder or the like is printed so as to draw a desired pattern, This is formed by drying and solidifying. The solidified state is the solidified state after melting when the binder used in the conductive paste is a thermoplastic resin, and the curing when the binder is a curable resin such as a thermosetting resin or a photocurable resin. Includes both later states. FIG. 10 is a diagram showing a state after the collecting electrode 7 and the connecting conductor 6 are formed.

  After the current collecting electrode 7 and the connection conductor 6 are formed, the third groove portion P3 is formed from the linear formation target position on the upper surface of the upper electrode layer 5 to the upper surface of the lower electrode layer 2 immediately below the formation position. The width of the third groove portion P3 is preferably about 40 to 1000 μm, for example. Further, the third groove portion P3 is preferably formed by mechanical scribing similarly to the second groove portion P2. In this way, the photoelectric conversion device 11 shown in FIGS. 1 and 2 is manufactured by forming the third groove portion P3.

<(3) Other Examples of Manufacturing Method of Photoelectric Conversion Device>
The present invention is not limited to the above-described embodiment, and various changes and improvements can be made without departing from the scope of the present invention.

  For example, in the manufacturing method of the photoelectric conversion device 11 described above, the multilayer coating 3x may have a high concentration of Ga element on the lower electrode layer 2 side. That is, the steps shown in FIGS. 5 and 6 in the above manufacturing method may be replaced with the steps shown in FIGS. In FIG. 11, a third film 3 c having a Ga element concentration higher than that of the first film 3 a is further formed between the first film 3 a and the lower electrode layer 2. As a result, as shown in FIG. 12, the laminated film 13x is formed by sequentially laminating the third film 3c, the first film 3a, and the second film 3b. The multilayer coating 13x has a portion where the Ga element is relatively high, a low portion, and a high portion in order from the lower electrode layer 2 side. By forming the first semiconductor layer 3 using such a laminated film 13x, for example, the Ga element as shown in FIG. 14 becomes higher as it approaches both the second semiconductor layer 4 side and the lower electrode layer 2 side. This makes it easier to form the double graded structure.

1: Substrate 2: Lower electrode layer 3: First semiconductor layer 3a: First coating 3b: Second coating 3c: Third coating 3x, 13x: Multilayer coating 4: Second semiconductor layer 5: Upper electrode Layer 6: Connection conductor 7: Current collecting electrode 10: Photoelectric conversion cell 11: Photoelectric conversion device

Claims (5)

Producing a first film containing a group IB element, an In element and a Ga element on the electrode layer;
On the first film, a second film containing a group I-B element, an In element, an organic compound, and a Ga element having a higher concentration than the first film is formed. A step of producing a laminated film in which two films are laminated;
Heating the laminated film at a first temperature to thermally decompose the organic compound, thereby turning the laminated film into a thermally decomposed film;
After heating the pyrolysis film at a second temperature lower than the first temperature in an atmosphere containing a chalcogen element, the pyrolysis film is heated at a third temperature higher than the first temperature. And a process for producing a semiconductor layer containing a group I-III-VI compound.   The method for manufacturing a photoelectric conversion device according to claim 1, wherein the atmosphere includes at least one of an inert gas and a hydrogen gas.   3. The method for manufacturing a photoelectric conversion device according to claim 1, wherein the first film is formed such that the concentration of the Ga element increases as it approaches the surface on the electrode layer side.   The method for manufacturing a photoelectric conversion device according to claim 1, wherein water is included in the atmosphere when the laminated film is heated at the first temperature.   The method for manufacturing a photoelectric conversion device according to claim 1, wherein an organic chalcogen compound is used as the organic compound.

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