JP5006245B2 - Method and apparatus for manufacturing chalcopyrite thin film solar cell - Google Patents

Description

  The present invention relates to a method for manufacturing a thin film solar cell, and more particularly, to a method for forming a buffer layer in a thin film solar cell in which a buffer layer is formed between a light absorption layer and a transparent electrode layer and an apparatus therefor.

  A chalcopyrite thin film solar cell belongs to a thin film type, and is a Cu—In—Ga—Se (hereinafter abbreviated as CIGS) composed of a chalcopyrite compound containing elements of Group I, Group III, and Group VI as constituent components. A layer) as a p-type light absorption layer.

  A chalcopyrite thin film solar cell has a back electrode layer, which is a positive electrode made of a Mo metal layer, a CIGS light absorption layer, an n-type buffer layer, and an outermost surface layer made of a transparent electrode layer, which is a negative electrode, on a glass substrate. It is composed of a multilayered laminated structure. When irradiation light such as sunlight enters from the surface light receiving portion of this multilayer laminated structure, it is excited near the pn junction of the multilayer laminated structure by the irradiation light having energy greater than or equal to the band gap, and a pair of electrons and positive electrons. A hole is formed. The excited electrons and holes reach the pn junction by diffusion, and the electrons are collected in the n region and the holes are separated in the p region due to the internal electric field of the junction. As a result, the n region is negatively charged, the p region is positively charged, and a potential difference is generated between the electrodes provided in each region. Then, when this potential difference is used as an electromotive force, a photocurrent is obtained when the electrodes are connected by a conductive wire.

  As a buffer layer in such a compound thin film solar cell, a plurality of substrates are reacted with a reaction solution by a dip bath deposition (hereinafter sometimes abbreviated as CBD) method on a substrate on which a CIGS light absorption layer is laminated. The film is immersed in CdS, ZnO, InS, etc., which are n-type semiconductor materials (see, for example, Patent Document 1).

  Further, in order to promote the film formation reaction, the reaction solution layer is provided with a plurality of vibrators from the viewpoint that it is necessary to always bring a fresh reaction solution into contact with the film formation region on the upper surface of the substrate. What is comprised so that stirring may be performed is known (for example, refer patent document 2).

  However, in such a batch-type film forming method, there is a concern that when the substrates are enlarged, the substrates adhere to each other when the plurality of substrates are pulled up from the tank. Even if the heated solution is circulated by a pump mechanism or a vibration is applied to the solution tank, it is difficult to keep the solution temperature uniform in the tank, and if a temperature difference occurs, there is a difference in the deposition rate of the buffer film. This causes uneven thickness of the buffer film. In addition, when heating the temperature of the solution, it is necessary to increase the temperature of the entire chemical solution in the tank and the circulation system, so the heat capacity of the solution increases, and it takes a long time to raise and lower the temperature, resulting in a longer processing time. was there.

  In addition, since the solution is circulated and stored in a solution tank for film formation, the larger the substrate, the larger the amount of solution required, and the greater the amount of solution discarded. Since it is necessary to fill the pump piping and tank with the solution, too much solution is required with respect to the substrate surface area, and the reaction is generated and consumed even in the place unnecessary for film formation, so the material utilization rate is low. It was. In particular, since the back surface of the substrate is also in contact with the solution to form a film, it is necessary to add a step for removing the layer later.

  In order to reduce the amount of the reaction solution used, a method of reducing the amount of the solution to be used by providing a reaction solution layer only on the side on which the substrate is formed has been considered (for example, see Patent Document 3). However, in order to maintain the solution at the reaction temperature, a constant temperature bath having a capacity sufficient to accommodate the substrate and the solution bath is required, and the equipment becomes large. Further, even if the temperature of the thermostatic bath is kept constant, it takes time until the temperature of the reaction solution is increased to the reaction temperature after the substrate is introduced.

  As a method for solving the problem of the method of immersing the substrate in the reaction solution tank as described above, the substrate is directly placed on a base with a built-in heater for heating, and a carrier gas is formed thereon. There is disclosed a method in which a reaction solution mixed with is reacted with a drug in a gas phase to form solid fine particles and then deposited (see, for example, Patent Document 4). According to this method, there is an advantage that only a necessary amount of the reaction solution is used.

  However, since the surface of the light absorbing layer has many minute irregularities, when the reaction component is sprayed as solid fine particles, the reaction component may adhere only to the physically reachable surface layer portion and completely penetrate into the recess. Have difficulty. Therefore, there is a problem that a portion where a pn junction does not occur is formed.

JP 2006-196771 A Japanese Patent Laid-Open No. 11-330509 Japanese Patent Laid-Open No. 11-330100 JP 11-87747 A

  The present invention has been made in view of the above problems, and in the formation of a buffer layer in the production of solar cells, it corresponds to a large-sized substrate, and it is possible to reduce cost and reduce film thickness uniformity by reducing the amount of material solution used. Provided is a film forming method for obtaining an excellent high quality buffer layer.

The apparatus for manufacturing a chalcopyrite thin film solar cell of the present invention has a built-in heater for supporting and heating a substrate on which a back electrode layer on which a p-type light absorption layer containing at least a group I, group III and group VI element is formed is formed. A susceptor, a heating means for additionally heating the heater built-in susceptor, a chemical liquid mixing means for mixing the reducing chemical and the raw material chemical and sending the mixed chemical liquid to the chemical liquid introduction nozzle, and a chemical liquid introduction for dropping the mixed chemical liquid onto the substrate surface A nozzle and a reaction tank for holding the dropped mixed chemical solution , and the chemical solution is heated in contact with the substrate heated by the heater, whereby the buffer layer is formed on the light absorption layer of the substrate. It is possible to be performed .

  The heating means is composed of a plurality of infrared lamps, the susceptor supporting the substrate is made of a material having excellent thermal conductivity, and the heating means is to maintain the substrate temperature uniformly by controlling the infrared lamps individually. This is a preferred embodiment.

The method for producing a chalcopyrite thin film solar cell of the present invention comprises a step of forming a p-type light absorption layer containing at least a group I, group III and group VI element on a back electrode layer formed on a substrate; And a step of forming an n-type buffer layer on the light absorption layer and a step of forming a transparent electrode layer on the buffer layer, and the step of forming the buffer layer comprises a step of forming a substrate on which the light absorption layer is formed. Placing on the susceptor, heating the substrate on the susceptor , dropping and holding a solution prepared by mixing the raw chemical and the reducing chemical on the heated substrate, and further supplying the solution intermittently ; It is characterized by providing .

  The step of forming the buffer layer is preferably performed by continuously performing a low temperature process for covering the surface and a high temperature process for obtaining a desired film thickness.

  If the manufacturing method of the buffer layer of the solar cell by this invention is used, since only a required amount of solution will be dripped at the substrate surface, a solution usage-amount can be reduced significantly compared with a tank system. In addition, since the film formation is performed by the wet method, the buffer layer can be formed all over the CIGS light absorption layer with many irregularities. Since the susceptor with excellent thermal conductivity that holds the substrate is directly heated, it is possible to control the temperature distribution of the substrate with high accuracy, and the process with excellent film thickness distribution and film quality distribution and reduced film formation speed. It can be carried out.

Hereinafter, the best embodiment of the present invention will be described in detail with reference to the drawings.
Problems of Conventional CBD Process FIG. 1 is a schematic diagram showing a batch type CBD process using a conventional large tank. As shown in FIG. 1 (a), the reaction tank 11 is filled with a raw chemical solution and a reducing chemical solution to form a reaction solution 2, and dozens of solar cell substrates 3 are batch-fitted in a batch system. Then, the reaction solution 2 is circulated by the pump 13 while heating, and a film forming reaction is performed on the surface of the solar cell substrate 3.

  In this step, since the reaction solution 2 is circulated through the reaction tank 11, the solution holding tank 1, the pipe 12 and the pump 13, a larger amount of solution is required as the substrate becomes larger. In addition, since a reaction occurs even at a place unnecessary for film formation, a large amount of material is consumed, the amount of the solution to be discarded becomes large, and the material utilization rate is low. In particular, since the back surface of the substrate is also in contact with the solution to form a film, it is necessary to add a step for removing the layer later.

  In addition, although the heated reaction solution is circulated by a pump, it is difficult in principle to obtain a uniform temperature distribution in the tank (especially in the vertical direction). This causes film thickness unevenness. Furthermore, when heating the temperature of the solution, it is necessary to raise the temperature of the entire chemical solution in the tank and the circulation system, so that the heat capacity of the solution becomes large, and it takes a long time to raise and lower the temperature, resulting in a longer processing time.

  As shown in FIG. 1B, after the film formation reaction is completed, the solar cell substrates 3 are pulled up collectively. It is possible to increase the number of substrates that can be processed in a reaction tank of a certain size as the space between the substrates is narrowed, which is advantageous as a production cost, but if the space between the substrates is too narrow, When the reaction solution remaining between the substrates is dropped, the substrates on both sides are pulled by surface tension, so that a phenomenon may occur in which the substrates on both sides stick to each other as shown in FIG. In this case, the substrate cannot be transported and the apparatus is stopped, so that productivity is deteriorated.

Principle of the Invention FIG. 2 shows the reaction chamber supply mechanism of the film forming chamber M1 of the present invention. A necessary amount of the reducing chemical 21 in the reducing chemical tank 15 and the raw chemical 22 in the raw material tank 16 are previously measured by the measuring nozzle 4 and supplied to the stirring container 17. The reducing chemical 21 and the raw chemical 22 are agitated by the agitating means 5 incorporated in the agitating vessel 17 to become the reaction solution 2 and sent to the shower head 18 (chemical solution introduction nozzle) of the film forming chamber M1.

  Below the shower head 18, the solar cell substrate 3 is placed on a susceptor 6 containing a heater for heating (not shown) and is surrounded and held by a reaction vessel 19. The reaction solution 2 dropped from the shower head 18 is held in the reaction vessel 19, and the solar cell substrate 3 is immersed in the reaction solution 2. In the present invention, the substrate is directly heated from the back surface through the susceptor, and the reaction solution is dropped onto the film formation surface of the substrate to form the buffer layer. Here, when the heating of the solar cell substrate 3 is started by the heater built in the susceptor 6, the reaction is started in the portion of the reaction solution 2 in contact with the substrate, and the film formation of the buffer layer proceeds.

  Further, as an auxiliary heating means, as shown in the figure, a heater by a lamp system 61 or the like is disposed at the lower part of the susceptor to provide an additional heating means that can be individually controlled, so that temperature distribution control is possible.

  The reaction solution is dropped several times on the heated substrate to advance the chemical reaction, thereby forming a buffer layer. After repeating a plurality of times, cleaning is performed with pure water or the like, and the substrate is dried with an air knife to complete the film formation.

  Since the present invention is a single wafer processing method in which processing is performed one by one, there is no sticking between substrates, which has been a problem in conventional batch processing. In addition, since the conventional method of spraying the reaction component as solid fine particles is a physical method, there is a concern that the reaction solid particles are not coated on the recesses on the surface of the light absorption layer, and the diode interface leaks. According to this embodiment, since it is a wet system in which the substrate is completely immersed, the reaction solution penetrates into the recess.

  In the present invention, since the reaction solution is not heated, but the substrate itself is heated, the film formation reaction reacts most strongly in the vicinity of the substrate surface, and the reaction hardly occurs at a position away from the substrate. For this reason, by stopping the heating of the substrate, the reaction quickly converges and unnecessary continuation of the film forming reaction is suppressed. The heater built in the susceptor is preferably a multi-channel heater. By adjusting the output of each heater, the temperature distribution on the large substrate can be controlled.

The material constituting the susceptor is preferably a material having excellent thermal conductivity. Examples of such a material include carbon materials, carbon compounds such as SiC, and corrosion-resistant coated metals (Al, Cu, Fe), and the like. Examples of the coating material include AlN, Al ₂ O _{3, and the} like. By incorporating a heater in such a material, the thermal uniformity of the entire susceptor can be improved.

  The lamp system 61 serving as auxiliary heating means preferably includes an infrared lamp 62, and more preferably a plurality of infrared lamps that can be individually controlled. By efficiently absorbing infrared rays into the susceptor, it is possible to cope with rapid temperature rise. As shown in the graph of FIG. 3, when a lamp system is used in combination with a heater with a built-in susceptor, the substrate can be heated more quickly.

  Moreover, the lamp reflector 63 surrounding each infrared lamp can be provided. The lamp reflector 63 can be adjusted such that an optimum temperature distribution can be obtained by adjusting the infrared irradiation range by adjusting the angle. Moreover, the whole lamp system 61 can make the infrared irradiation range with respect to a susceptor uniform by adding a rotation function. In this case, the rotational speed is usually adjusted within a range of 0 to 200 rpm.

  A quartz glass 64 is preferably provided above the lamp system 61. The material is not limited to quartz glass, and may be any material that has excellent heat resistance (up to about 300 ° C.), high light transmittance, and high strength. Further, it is preferable that a reflector 65 is provided around the lamp system 61 and the quartz glass 64. Examples of the material of the reflector include metals such as gold and aluminum having a high reflectance with respect to infrared rays.

  As the reaction solution supplied from the shower head, a solution obtained by mixing and stirring a reducing chemical and a raw material chemical immediately before dropping the solution is used. It is preferable that only a necessary amount (surface tension level) is intermittently supplied from the dropping means formed in a shower shape so as to cover at least the substrate surface. By intermittently supplying a small amount of the reaction solution while judging the progress of the film formation reaction on the substrate surface, it is possible to supply the optimum amount necessary for obtaining a desired film thickness and film formation rate. For this reason, generation | occurrence | production of the unnecessary reaction which arises by extra material supply is prevented, and material usage-amount can be suppressed.

  As an example of the reaction solution, when forming a film of indium sulfide, thioacetamide is used as a reducing chemical, and indium chloride is used as a raw material chemical. In the case of forming a zinc sulfide film, a mixed chemical solution of thioacetamide, ammonia and zinc chloride is used. In the case of forming a multi-element sulfide buffer layer such as InAlS, raw material chemicals of a plurality of elements such as indium chloride and aluminum chloride are respectively prepared and quantified, and then mixed with a reducing chemical thioacetamide.

  As another example of the reaction solution, when forming a film of cadmium sulfide (CdS), a mixed chemical solution of cadmium chloride, thiourea, and ammonia is used.

  As the stirring container 17 and the stirring means 5, known means such as a stirrer having a structure for rotating a propeller, ultrasonic stirring, or a static method can be used.

  The step of forming the buffer layer includes a step of controlling the relatively low temperature to form the first buffer layer, and a step of controlling the relatively high temperature to form the second buffer layer so as to overlap the first buffer layer. It is preferable.

  Since the first buffer layer is intended to form a film with high film quality and coverage, it is preferable to form the film while maintaining the reaction temperature at a low temperature. At low holding temperatures, the chemical reaction of the dropped chemical solution is in the reaction rate-determining region. The film can be formed and high film quality can be obtained. In addition, since the film formation rate is low and the temperature of the chemical solution is kept at a low temperature, the reaction reliably proceeds inside the surface recesses of the absorption layer, and good coverage with respect to the surface unevenness of the absorption layer can be obtained. . On the other hand, it is preferable to form the second buffer layer while keeping the reaction temperature at a high temperature in order to shorten the processing time. At a high holding temperature, when the chemical solution is dropped, it is immediately heated and has sufficient reactivity, so that the film formation rate is increased and the processing time can be shortened. In addition, since the chemical reaction proceeds in the supply rate-determining region, the film formation rate depends on the chemical supply amount and is not affected by temperature variations due to the lamp heating mechanism, and the film formation rate is kept uniform by uniform chemical supply.

  The film forming chamber M1 described above can be formed into a multi-stage stacked film forming chamber M2 by stacking in a plurality of stages as shown in FIG. In this way, the film forming chamber M1 has a plurality of stages, the solar cell substrate 3 is continuously transferred to the film forming chamber M1 by a transport unit (not shown), and the mixed chemical solution is supplied by a chemical solution supply unit (not shown). The buffer layer forming equipment can be used effectively.

Specific Embodiments Next, specific embodiments of the present invention will be described in more detail. FIG. 5 is a schematic plan view showing a film forming apparatus M3 according to an embodiment of the present invention. The film forming apparatus M3 includes a plurality of multi-layer stacked film forming chambers M2 shown in FIG. The transfer means 7 is a means for carrying in the unformed solar cell substrate 3 from the outside and carrying out the formed solar cell substrate 3 to the outside. The gripping means 8 is for holding the loaded solar cell substrate 3. Then, it is a means for supplying to any one of the multi-layer stacked film forming chambers M2 and holding and taking out the solar cell substrate 3 from the multi-stage stacked film forming chamber M2 after the film forming reaction is completed. Each multi-stage film forming chamber M2 (M2a to M2c) includes a chemical supply system including a reducing chemical tank 15, a raw chemical tank 16, a stirring container 17, and a stirring means 5, as schematically shown in FIG. As described above, these are supplied as mixed chemicals to each film forming chamber M1.

  Next, in the film forming apparatus M3 in FIG. 5, the steps shown in the following Table 1 are performed by taking as an example a case where film formation is performed by operating only one film forming chamber M1 of one multistage stacked film forming chamber M2a. The description will be given with reference.

  First, in the first step, the gripping means 8 receives the solar cell substrate 3 from the transport means 7. At the same time, in the chemical supply system, the metering nozzle 4 determines the reducing chemical 21 for forming the first buffer layer and the raw chemical 22 and injects two liquids into the stirring container 17. In the heating system, the built-in heater of the susceptor 6 is turned on, and heating of the susceptor 6 is started.

  In the second step, the gripping means 8 inserts the solar cell substrate 3 into the susceptor 6 of the film forming chamber M1. Since the heating of the susceptor 6 has already been started, the temperature rise of the solar cell substrate 3 itself is also started. In the chemical supply system, the reducing chemical 21 and the raw chemical 22 injected into the stirring container 17 are stirred by the stirring means 5 to become the reaction solution 2.

  In the third step, the reaction solution 2 for forming the first buffer layer is quantitatively dropped onto the solar cell substrate 3 through the shower head 18.

  Since the solar cell substrate 3 has already been heated by the built-in heater of the susceptor, in the fourth step, the reaction solution comes into contact with the substrate, and the film formation reaction of the first buffer layer occurs immediately at that portion. In parallel with this, in the chemical supply system, the metering nozzle 4 quantifies the reducing chemical 21 for forming the second buffer layer and the raw chemical 22 and injects two liquids into the stirring container 17.

  In the fifth step, the film formation reaction of the first buffer layer is ongoing. In parallel with this, in the chemical supply system, the reducing chemical 21 and the raw chemical 22 injected into the stirring vessel 17 are stirred by the stirring means 5. The reaction solution 2 is obtained.

  In the sixth step, the reaction solution 2 for forming the second buffer layer is quantitatively dropped onto the solar cell substrate 3 through the shower head 18. In parallel with this, in the heating system, the heater with built-in susceptor is turned off and the lamp system 61 is turned on, and additional heating of the susceptor 6 is started. Thereby, the susceptor 6 and the solar cell substrate 3 are further heated, and a film forming reaction of the second buffer layer occurs. Since the second buffer layer is formed at a higher temperature than that of the first buffer layer, the film formation rate is high.

  In the seventh step, since the film formation of the second buffer layer is completed, the temperature increase of the lamp system 61 is completed. In addition, by repeating the sixth step and the seventh step, it is possible to advance a further film formation reaction and increase the thickness of the buffer layer.

  In the eighth step, the chemical supply system is completely stopped, and in the heating system, the lamp system 61 is turned off while the built-in heater of the susceptor 6 is turned on. Pure water is dropped on the solar cell substrate 3 and replaced with the remaining reaction solution by overflow rinsing.

  In the ninth step, the remaining pure water is removed by a drying means such as an air knife, and the solar cell substrate 3 is dried.

  In the tenth step, the gripping means 8 grips the solar cell substrate 3 in the film formation chamber M1 and carries it out to the transport means 7, thereby obtaining a solar cell substrate on which the buffer layer deposition is completed.

  The series of processes described above is an example of a film forming process when one film forming chamber M1 is operated. By using a multi-layer stacked film forming chamber M2 as shown in FIG. Battery substrates can be accommodated in a plurality of stages, and film formation reactions can proceed simultaneously.

  In addition, as shown in FIG. 5, a plurality of multi-layer stacked film forming chambers M2 (M2a to M2c) are provided, for example, while the film forming reaction proceeds in the film forming chamber M2a, If the battery substrate is carried in, the reducing chemical and the raw chemical are mixed, the film formation in M2b is started after the film formation in M2a is completed, and the film formation reaction is performed in the film formation chamber M2c in the same manner. M2a → M2b → M2c → M2a is preferable because the film formation reaction can be continuously performed. In FIG. 5, although the film forming chambers M2 are provided at three locations, this number is arbitrary and does not limit the present invention.

The following improvements could be achieved by the buffer layer deposition CBD process of the CIGS solar cell according to the present invention.
1. The substrate sticking trouble that occurs when taking out from a large tank that has occurred in the batch method with substrate sticking does not occur in principle because of the single wafer type.
2. Since only a necessary amount of the chemical solution is dropped only on the substrate surface on which the chemical solution use amount buffer film is formed, it is possible to greatly reduce the use amount of the chemical solution with respect to the large tank system.
3. The temperature distribution of the substrate can be controlled with high accuracy by the advantage of the single wafer type susceptor structure in which the film thickness is in direct contact with the substrate and the temperature distribution control mechanism using a divided heater built in the susceptor. By controlling the temperature distribution, it is possible to suppress variations in the film formation rate between substrates and within the substrate, thereby improving the film thickness distribution.
4). Since the selective film forming chemical can be selectively dropped onto the substrate surface, film formation occurs only on the substrate surface.
5. Speeding up the processing time In addition to the heater built in the susceptor, a lamp heating mechanism is provided to achieve rapid temperature rise of the substrate. It is possible to shorten the temperature raising time required for temperature switching between steps, and shorten the process processing time.

  In the buffer layer forming step in the manufacture of the chalcopyrite thin film solar cell, it is possible to reduce the environmental load, and to achieve cost reduction and high quality.

It is a schematic cross section which shows the conventional batch type buffer layer film-forming process. It is a schematic cross section which shows the film-forming chamber of the single-wafer | sheet-fed buffer layer film-forming process of this invention. It is the graph which compared the heating by the conventional heating and the lamp system of this invention. It is a perspective view which shows the multistage laminated film-forming chamber of the film-forming chamber of this invention. It is a top view which shows one Embodiment of the film-forming apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Solution holding tank, 11 ... Reaction tank, 12 ... Piping, 13 ... Pump, 15 ... Reducing chemical tank,
16 ... Raw material chemical tank, 17 ... Stirring vessel, 18 ... Shower head, 19 ... Reaction tank,
2 ... Reaction solution, 21 ... Reducing chemical, 22 ... Raw material chemical, 3 ... Solar cell substrate, 4 ... Metering nozzle,
5 ... Stirring means, 6 ... Susceptor, 61 ... Lamp system, 62 ... Infrared lamp,
63 ... Lamp reflector, 64 ... Quartz glass, 65 ... Reflector, 7 ... Conveying means,
8 ... Grasping means, M1 ... Film forming chamber, M2 ... Multi-layered film forming chamber, M3 ... Film forming apparatus

Claims (5)

A heater built-in susceptor that supports and heats a substrate on which a back electrode layer on which a p-type light absorption layer containing at least a group I, group III, and group VI element is formed;
Heating means for additionally heating the heater built-in susceptor;
A chemical mixing means for mixing the reducing chemical and the raw chemical and sending the mixed chemical to the chemical introduction nozzle;
A chemical introduction nozzle that drops the mixed chemical on the substrate surface;
A reaction tank for holding the dropped mixed chemical solution ,
The chemical solution is heated in contact with the substrate heated by the heater, so that a buffer layer can be formed on the light absorption layer of the substrate. An apparatus for producing a chalcopyrite thin film solar cell.   The heating means is composed of a plurality of infrared lamps, and the susceptor supporting the substrate is made of a material having excellent thermal conductivity. The heating means keeps the substrate temperature uniform by controlling the infrared lamps individually. The apparatus for manufacturing a chalcopyrite thin film solar cell according to claim 1.   3. The apparatus for manufacturing a chalcopyrite thin film solar cell according to claim 2, wherein the material constituting the susceptor is a material selected from carbon, a carbon compound, and a metal subjected to corrosion resistance treatment. Forming a p-type light absorption layer containing at least a group I, group III and group VI element on a back electrode layer formed on the substrate;
Forming an n-type buffer layer on the light absorption layer;
Forming a transparent electrode layer on the buffer layer ,
The step of forming the buffer layer includes:
Placing the substrate on which the light absorption layer is formed on a susceptor;
Heating the substrate on the susceptor;
Raw chemicals and a mixed solution of a reducing chemical in advance was dropped was held on a heated the substrate, method of manufacturing a chalcopyrite-type thin film solar cell, characterized by and a intermittent supplying step the solution . The step of forming the buffer layer is controlled to a temperature at which the first buffer layer is formed by the reaction rate-limiting region and a temperature at which the second buffer layer by the supply rate-limiting region is formed to overlap the first buffer layer. The method for producing a chalcopyrite solar cell according to claim 4, further comprising a step.

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