JP2013224239A - Particle for formation of semiconductor layer, method of producing semiconductor layer and method of manufacturing photoelectric conversion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor layer and a photoelectric conversion device which have a high photoelectric conversion efficiency.SOLUTION: A particle for formation of a semiconductor layer mainly includes a metal chalcogenide and also includes an alkali metal element. A method of producing the semiconductor layer includes a process of forming a film containing the particles for formation of a semiconductor layer and a process of heating the film to form a semiconductor layer. A method of manufacturing a photoelectric conversion device 11 includes a process of forming a first semiconductor layer 3 on an electrode 2 by the method of producing the semiconductor layer and a process of forming a second semiconductor layer 4 having a type of conduction different from that of the first semiconductor layer 3 on the first semiconductor layer 3.

Description

  The present invention relates to particles for forming a semiconductor layer for forming a semiconductor layer containing a metal chalcogenide, a method for manufacturing a semiconductor layer using the particle, and a method for manufacturing a photoelectric conversion device.

As solar cells, I-III-VI group compounds such as CIS and CIGS, and I-II such as CZTS
There is one using a photoelectric conversion device including a semiconductor layer containing a -IV-VI group compound (for example, see Patent Document 1 and Patent Document 2).

  As a method for manufacturing such a semiconductor layer, Patent Document 1 describes that a semiconductor layer is formed by forming a coating layer using a solution containing metal chalcogenide fine particles and sintering the coating layer. .

JP 2011-11956 A JP 2007-269589 A

  In recent years, the demand for photoelectric conversion devices has been increasing, and further improvement in photoelectric conversion efficiency of the photoelectric conversion devices is desired. In order to increase the photoelectric conversion efficiency of the photoelectric conversion device, it is effective to promote crystallization of the semiconductor layer.

  Therefore, an object of the present invention is to provide a semiconductor layer and a photoelectric conversion device with high photoelectric conversion efficiency.

  The particles for forming a semiconductor layer according to an embodiment of the present invention mainly contain a metal chalcogenide and an alkali metal element.

  The manufacturing method of the semiconductor layer which concerns on one Embodiment of this invention comprises the process of forming the membrane | film | coat containing said particle | grains for semiconductor layer formation, and the process of heating this membrane | film | coat and making it a semiconductor layer.

  A method for manufacturing a photoelectric conversion device according to an embodiment of the present invention includes a step of manufacturing a first semiconductor layer on an electrode by the above-described method for manufacturing a semiconductor layer, and the first semiconductor layer on the first semiconductor layer. Forming a second semiconductor layer having a conductivity type different from that of the semiconductor layer.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide a semiconductor layer and a photoelectric conversion apparatus with high photoelectric conversion efficiency.

It is a perspective view which shows an example of a photoelectric conversion apparatus. It is sectional drawing of the photoelectric conversion apparatus of FIG.

  Hereinafter, a semiconductor layer forming particle, a semiconductor layer manufacturing method, and a photoelectric conversion device manufacturing method according to an embodiment of the present invention will be described in detail with reference to the drawings.

<(1) Particles for forming a semiconductor layer>
The semiconductor layer forming particles mainly contain a metal chalcogenide and an alkali metal element. The semiconductor layer forming particles are formed into a film and then fired, whereby the semiconductor layer forming particles bond to each other to crystallize or react with each other to crystallize to form a semiconductor layer. .

The metal chalcogenide is a compound of a metal element and a chalcogen element. The chalcogen element is S, Se, or Te among VI-B group elements (also referred to as group 16 elements). As the metal chalcogenide used for the semiconductor layer forming particles, a group I-VI compound or a group II-B element (also referred to as a group 12 element) which is a compound of a group IB element (also referred to as group 11 element) and a chalcogen element ) And chalcogen element II-VI group compound, III-B group element (also referred to as group 13 element) and chalcogen element compound III-VI group compound, IV-B group element (1
Group IV-VI compounds which are compounds of group 4 elements and chalcogen elements, Group I-III-VI compounds which are compounds of group IB elements III-B elements and chalcogen elements, and I- An I-II-IV-VI group compound that is a compound of a B group element, a II-VI group compound, an IV-B group element, and a chalcogen element may be employed.

The metal chalcogenide contained in the semiconductor layer forming particles may be the same as or different from the compound mainly contained in the semiconductor layer obtained by firing the semiconductor layer forming particles. For example, a semiconductor layer obtained by firing particles for forming a semiconductor layer is I-III-VI
In the case of a group compound, the particles for forming a semiconductor layer may include a group I-III-VI compound as a metal chalcogenide, or a group including a group I-VI compound or a group III-VI compound as a metal chalcogenide It may be. When the semiconductor layer obtained by firing the semiconductor layer forming particles is an I-II-IV-VI group compound, the semiconductor layer forming particles contain an I-II-IV-VI group compound as a metal chalcogenide. Alternatively, the metal chalcogenide may contain any of a group I-VI compound, a group II-VI compound, and a group IV-B compound.

When the semiconductor layer forming particles and the semiconductor layer obtained by firing the same are different compounds, the semiconductor layer forming particles can be mixed with another compound and fired to form a semiconductor layer. For example, when the semiconductor layer obtained by firing the semiconductor layer forming particles is an I-III-VI group compound such as CIGS, the III-VI group compound such as indium selenide or gallium selenide is used as the semiconductor layer forming particle. The semiconductor layer forming particles may be used as a mixture of an IB group element compound (for example, copper selenide, copper complex, etc.). Or III-VI
A group compound may be used as the semiconductor layer forming particles, and the semiconductor layer forming particles mixed with a group III-B element compound may be fired.

Further, when the semiconductor layer forming particles and the semiconductor layer obtained by firing the same are different compounds, the semiconductor layer forming particles made of different compounds can be mixed and fired to form a semiconductor layer. . For example, when the semiconductor layer obtained by firing the semiconductor layer forming particles is an I-III-VI group compound such as CIGS, the semiconductor layer forming particles mainly containing indium selenide and the gallium selenide mainly. You may bake what mixed the particle for semiconductor layer formation containing, and the semiconductor layer which mainly contains copper selenide.

The semiconductor layer forming particles mainly contain the metal chalcogenide and further contain an alkali metal element. That is, one particle of the semiconductor layer forming particles contains an alkali metal element in addition to the metal chalcogenide. In addition, an alkali metal element means what remove | excluded the hydrogen element among IA group elements (it is also called 1st group element). With such a configuration, when the semiconductor layer forming particles are fired, when the metal chalcogenide particles bond to each other and crystallize, or react with each other and crystallize, the alkali metal element has good crystallization. And a semiconductor layer with high photoelectric conversion efficiency is generated. That is, the alkali metal element is not added from the outside, but is contained in the particles for forming the semiconductor layer, so that the crystallization promoting effect by the alkali metal element is very high, and the reaction variation is small, A stable crystallization reaction occurs.

  As the semiconductor layer forming particles, particles having an average particle diameter of 20 nm to 200 nm may be used from the viewpoint of easily forming a dense and good semiconductor layer.

  Further, the content of the alkali metal element in the semiconductor layer forming particles is included in the semiconductor layer forming particles from the viewpoint of further enhancing the crystallization reaction and enabling favorable crystallization even at a relatively low temperature. When the total number of moles of the chalcogen element is 100 mol, it may be about 1 to 50 mol. From the viewpoint of improving the coatability by making the average particle diameter of the semiconductor layer forming particles as fine as several tens to several hundreds of nanometers, the content of the alkali metal element in the semiconductor layer forming particles is When the total number of moles of the chalcogen element contained in the particles for use is 100 mol%, it may be about 2 to 15 mol. As an elemental analysis method in the semiconductor layer forming particles, for example, EDS (Energy Dispersive Spectroscopy) analysis of SEM (Scanning Electron Microscope) is used.

<(2) Method for Producing Semiconductor Layer Forming Particle>
An example of a method for producing the semiconductor layer forming particles will be described below. First, a raw material solution containing a metal element, an alkali metal element, and a chalcogen element-containing organic compound constituting a metal chalcogenide is prepared.

  Various materials such as chlorides, nitrates, perchlorates, organic acid salts, organic complexes, and metal chalcogenides can be used as the metal element raw material, and these are dissolved in a solvent containing the chalcogen element-containing organic compound. . Similarly, various materials such as chlorides, nitrates, perchlorates, organic acid salts, organic complexes, metal chalcogenides, and the like can be used as the raw materials for alkali metal elements, and these include solvents containing chalcogen element-containing organic compounds. Dissolve in. The chalcogen element-containing organic 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 chalcogen element-containing organic compound include thiol, sulfide, disulfide, selenol, selenide, diselenide, tellurol, telluride, ditelluride and the like. Moreover, basic organic solvents, such as aniline and a pyridine, can be used as a solvent of a raw material solution. By preparing a raw material solution using the above metal element raw material, alkali metal element raw material, chalcogen element-containing organic compound and solvent, the metal element and alkali metal element are converted into the chalcogen element-containing organic compound in the raw material solution. Coordinated and stabilized.

  And this raw material solution is heated at 100-250 degreeC. As a result, semiconductor layer forming particles having an average particle diameter of 20 to 200 nm and mainly containing metal chalcogenide and containing an alkali metal element are produced. In other words, since the metal element and the alkali metal element dissolved in the raw material solution are in close proximity to each other through the chalcogen element-containing organic compound, the metal element chemically reacts with the chalcogen element contained in the chalcogen element-containing organic compound. At this time, the alkali metal element also chemically reacts with the chalcogen element and is well incorporated into the semiconductor layer forming raw material.

Specific examples of the process for producing the semiconductor layer forming particles are shown below. For example, a Cu metal, an In metal, and a Ga metal are prepared as raw materials for the metal element. Further, Na ₂ Se is prepared as a raw material for the alkali metal element. Moreover, phenyl selenol is prepared as a chalcogen element-containing organic compound. These are heated in aniline at 50 to 120 ° C. to dissolve Cu, In, Ga and Na ₂ Se, and then heated to 100 to 250 ° C. As a result, semiconductor forming particles mainly containing CIGS (Cu (In, Ga) Se ₂ ) having an average particle diameter of 20 to 200 nm and containing Na are generated.

Other specific examples of the process for producing the semiconductor layer forming particles are shown below. For example, Cu metal powder, Zn metal powder, and Sn metal powder are prepared as raw materials for the metal element. Further, as a raw material for the alkali metal element, providing a _Na 2 Se powder. Moreover, phenyl selenol is prepared as a chalcogen element-containing organic compound. And these are heated at 100-250 degreeC in aniline. Thereby, particles for forming a semiconductor mainly containing CZTSe (Cu ₂ ZnSnSe ₄ ) having an average particle diameter of 20 to 200 nm and containing Na are generated.

  Next, the semiconductor layer forming particles generated in the solution are taken out by centrifugation or the like and sufficiently washed. The washed particles for forming a semiconductor layer may be heated at 100 to 300 ° C. in order to further remove the organic component.

<(3) Configuration of photoelectric conversion device>
FIG. 1 is a perspective view showing an example of a photoelectric conversion device manufactured using semiconductor layer forming particles according to an embodiment of the present invention. FIG. 2 is an XZ sectional view of the photoelectric conversion device 11 of FIG. 1 and 2 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.

  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 is a semiconductor layer having 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 has a function as a light absorption layer and is a semiconductor layer mainly containing metal chalcogenide. The metal chalcogenide contained in the first semiconductor layer 3 includes an I-III-VI group compound, which is a compound of an IB group element, an III-B group element, and a VI-B group element, and an IB group element. I-II-IV-VI group compounds, etc., which are compounds of the group II-B group elements, the IV-B group elements and the VI-B group elements, may be employed.

Examples of the I-III-VI group compound include CuInSe ₂ (indium diselenide,
CIS), Cu (In, Ga) Se ₂ (also called copper indium selenide / gallium, CIGS) and the like. Examples of the I-II-IV-VI group compound include Cu ₂ ZnSnSe ₄ (also referred to as CZTSe).

The first semiconductor layer 3 can be manufactured as follows. First, a raw material solution in which the semiconductor layer forming particles are dispersed in a solvent is prepared. As the solvent used for the raw material solution, a solvent capable of dispersing the semiconductor layer forming particles can be used. For example, a basic organic solvent such as aniline or pyridine may be used. Then, on the substrate 1 having the first electrode layer 2, the raw material solution is applied by, for example, a spin coater, screen printing, dipping, spraying, or a die coater to form a film. And the 1st semiconductor layer 3 can be formed by heating this membrane | film | coat to 450-600 degreeC in inert gas atmosphere, such as nitrogen gas, and reducing gas atmosphere, such as hydrogen gas. In order to further promote the chalcogenization of the first semiconductor layer 3, a chalcogen element is contained in the heating atmosphere in the state of hydrogenated chalcogen such as H ₂ S or H ₂ Se, or sulfur vapor or selenium. You may mix in the state of steam, such as steam.

  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 electric charge collected by the current collecting electrode 7 and the upper electrode layer 5 passes through the connecting conductor 6 provided in the groove P that divides the first semiconductor layer 3 and the second semiconductor layer 4, and the adjacent photoelectric conversion cell 10. Is transmitted to. 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. Thus, in the photoelectric conversion device 11, one lower electrode layer 2 of the adjacent photoelectric conversion cell 10 and the other current collecting electrode 7 are electrically connected in series via the connection conductor 6 provided in the groove portion P. It is connected to the. 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.

  The semiconductor layer forming particles, the semiconductor layer manufacturing method, and the photoelectric conversion device manufacturing method were evaluated as follows. In this example, CIGS was used as the semiconductor layer.

<Preparation of semiconductor layer forming particles (sample 1)>
1 mmol of In solid, 1.5 mmol of Se powder, and 0.25 mmol of Na ₂ Se powder were put into a mixed solvent of 5 mmol of aniline and 5 mmol of phenylselenol and dissolved by heating at 80 ° C. And this mixed solvent was heated at 200 degreeC for 12 hours, and the semiconductor layer formation particle | grains as the sample 1 were produced. Then, the semiconductor layer forming particles as Sample 1 were taken out by centrifugation and washed with toluene.

  SEM observation and EDS analysis were performed on the particles for forming a semiconductor layer as Sample 1 produced as described above. As a result, the particles for forming a semiconductor layer as Sample 1 have an average particle diameter of 120 nm and contain Na, In, and Se, and their molar ratio Na: In: Se is 0.25: 1: 1.63 ( That is, it was found that the ratio Na / Se of the number of moles of Na to the number of moles of Se was 0.15).

<Preparation of semiconductor layer forming particles (sample 2)>
Further, the semiconductor layer forming particles as Sample 2 were prepared in the same manner as the preparation of the semiconductor layer forming particles as Sample 1 except that the Na ₂ Se powder was changed to 0.05 mmol.

  SEM observation and EDS analysis were performed on the particles for forming a semiconductor layer as Sample 2 produced as described above. As a result, the semiconductor layer forming particles as Sample 2 have an average particle diameter of 150 nm and contain Na, In, and Se, and their molar ratio Na: In: Se is 0.05: 1: 1.53 ( That is, it was found that the ratio of the number of moles of Na to the number of moles of Se, Na / Se, was 0.03).

<Preparation of semiconductor layer forming particles (sample 3)>
1 mmol Cu powder, 1 mmol In solid, 0.7 mmol Ga liquid, 0.3 mmol Se powder and 0.25 mmol Na ₂ Se powder were put into a mixed solvent of 5 mmol aniline and 5 mmol phenyl selenol. And dissolved at 80 ° C. And this mixed solvent was heated at 200 degreeC for 12 hours, and the semiconductor layer formation particle | grains as the sample 3 were produced. Then, the semiconductor layer forming particles as Sample 3 were taken out by centrifugation and washed with toluene.

  SEM observation and EDS analysis were performed on the semiconductor layer forming particles as Sample 3 produced as described above. As a result, the semiconductor layer forming particles as the sample 3 have an average particle diameter of 130 nm and contain Na, Cu, In, Ga, and Se, and their molar ratio Na: Cu: In: Ga: Se is 0.00. 25: 1: 0.7: 0.3: 2.13 (ie, the ratio of the number of moles of Na to the number of moles of Se, Na / Se is 0.12).

<Preparation of semiconductor layer forming particles (sample 4)>
Further, the semiconductor layer forming particles as Sample 4 were prepared in the same manner as the preparation of the semiconductor layer forming particles as Sample 3 except that the Na ₂ Se powder was changed to 0.05 mmol.

  SEM observation and EDS analysis were performed on the semiconductor layer forming particles as Sample 4 produced as described above. As a result, the semiconductor layer forming particles as the sample 4 have an average particle diameter of 130 nm and contain Na, Cu, In, Ga, and Se, and their molar ratio Na: Cu: In: Ga: Se is 0.00. 05: 1: 0.7: 0.3: 2.03 (ie, the ratio of the number of moles of Na to the number of moles of Se, Na / Se was 0.02).

<Preparation of semiconductor layer forming particles (Comparative Sample 1)>
Further, the semiconductor layer forming particles as the comparative sample 1 were prepared in the same manner as the preparation of the semiconductor layer forming particles as the sample 1 without using the Na ₂ Se powder.

  SEM observation and EDS analysis were performed about the particle for semiconductor layer formation as the comparative sample 1 produced as mentioned above. As a result, it was found that the semiconductor layer forming particles as the comparative sample 1 had an average particle diameter of 120 nm, contained In and Se, and a molar ratio In: Se of 1: 1.5.

<Preparation of Semiconductor Layer Forming Particles (Comparative Sample 2)>
Further, the semiconductor layer forming particles as the comparative sample 2 were prepared in the same manner as the preparation of the semiconductor layer forming particles as the sample 3 without using the Na ₂ Se powder.

  SEM observation and EDS analysis were performed about the particle for semiconductor layer formation as the comparative sample 2 produced as mentioned above. As a result, the semiconductor layer forming particles as the comparative sample 2 have an average particle diameter of 120 nm and contain Cu, In, Ga, and Se, and the molar ratio Cu: In: Ga: Se is 1: 0.7. : 0.3: 2.

<Production of photoelectric conversion device>
A raw material solution as Sample 1 was prepared by uniformly dispersing 0.1 mol of the semiconductor layer forming particles as Sample 1 and 0.9 mol of the semiconductor layer forming particles as Comparative Sample 2 in aniline.

  Further, 0.1 mol of the semiconductor layer forming particles as Sample 2 and 0.9 mol of the semiconductor layer forming particles as Comparative Sample 2 were uniformly dispersed in aniline to prepare a raw material solution as Sample 2.

  Further, 0.1 mol of the semiconductor layer forming particles as Sample 3 and 0.9 mol of the semiconductor layer forming particles as Comparative Sample 2 were uniformly dispersed in aniline to prepare a raw material solution as Sample 3.

  Further, 0.1 mol of the semiconductor layer forming particles as Sample 4 and 0.9 mol of the semiconductor layer forming particles as Comparative Sample 2 were uniformly dispersed in aniline to prepare a raw material solution as Sample 4.

  Moreover, the raw material solution as the comparative sample 1 is produced by uniformly dispersing 0.1 mol of the semiconductor layer forming particles as the comparative sample 1 and 0.9 mol of the semiconductor layer forming particles as the comparative sample 2 in aniline. did.

  Moreover, the raw material solution as the comparative sample 2 was produced by uniformly dispersing 1.0 mol of the semiconductor layer forming particles as the comparative sample 2 in aniline.

  Next, a film was formed on the lower electrode layer made of Mo of the soda lime glass substrate by the doctor blade method for each of the six types of raw material solutions.

  After the film formation, heat treatment was performed in a hydrogen gas atmosphere containing Se vapor. The heat treatment was performed by holding at 500 ° C. for 1 hour, and then naturally cooling to produce a first semiconductor layer having a thickness of 2 μm. From the X-ray diffraction result of the first semiconductor layer, it was confirmed that the obtained first semiconductor layer was CIGS when any of the six types of raw material solutions was used.

  Thereafter, cadmium acetate and thiourea were dissolved in aqueous ammonia, and the above sample was immersed therein to form a second semiconductor layer made of CdS having a thickness of 0.05 μm on each first semiconductor layer. Furthermore, an Al-doped zinc oxide film (upper electrode layer) was formed on the second semiconductor layer by a sputtering method, thereby manufacturing a photoelectric conversion device.

When the photoelectric conversion efficiency of this photoelectric conversion device was measured, the photoelectric conversion efficiency of the photoelectric conversion device produced using the raw material solution as the comparative sample 1 was 12.6%, and the raw material solution as the comparative sample 2 was used. The photoelectric conversion efficiency of the produced photoelectric conversion device was 12.4%. On the other hand, the photoelectric conversion efficiency of the photoelectric conversion device manufactured using the raw material solution as Sample 1 is 14.5, the photoelectric conversion efficiency of the photoelectric conversion device manufactured using the raw material solution as Sample 2 is 13.6%, and the sample The photoelectric conversion efficiency of the photoelectric conversion device manufactured using the raw material solution as 3 is 14.2, and the photoelectric conversion efficiency of the photoelectric conversion device manufactured using the raw material solution as the sample 4 is 13.3%. It was found to be superior to Comparative Sample 1 and Comparative Sample 2. From the above results, it was found that a photoelectric conversion device having high photoelectric conversion efficiency can be obtained by using particles for forming a semiconductor layer mainly containing metal chalcogenide and containing an alkali metal element.

  Note that the present invention is not limited to the above-described embodiment, and various modifications may be made without departing from the scope of the present invention.

1: Substrate 2: Lower electrode layer 3: First semiconductor layer 4: Second semiconductor layer 5: Upper electrode layer 6: Connection conductor 7: Current collecting electrode 10: Photoelectric conversion cell 11: Photoelectric conversion device

Claims (4)

  Semiconductor layer forming particles mainly containing a metal chalcogenide and containing an alkali metal element. 2. The semiconductor layer forming particle according to claim 1, wherein the metal chalcogenide contains at least one element selected from a group I-B element and a group III-B element as a metal element. Forming a film containing the semiconductor layer forming particles according to claim 1 or 2,
And a step of heating the film to form a semiconductor layer. A step of producing a first semiconductor layer on the electrode by the method for producing a semiconductor layer according to claim 3;
Forming a second semiconductor layer having a conductivity type different from that of the first semiconductor layer over the first semiconductor layer.

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