KR20190029336A - Solar cell and method of manufacturing the same - Google Patents

Abstract

The present invention relates to a method for manufacturing a solar cell, and more particularly, to a new method for manufacturing a precursor solution for a seed layer of a perovskite thin film at room temperature, and to a perovskite solar cell and a tandem solar cell applied therewith. According to the present invention, the method comprises the processes of: preparing a precursor solution by dissolving (bPbX_2 + (1-b)PbX_2′ + AX) in a solvent; coating a substrate with the precursor solution; and applying cAX + (1-c)AX′ to a coated precursor layer. Therefore, a precursor solution for a seed layer having uniform and high solubility even at room temperature can be prepared. As a result, the reflectivity of solar rays in a solar cell, particularly, a tandem solar cell, is reduced to greatly increase light conversion efficiency.

Description

SOLAR CELL AND METHOD OF MANUFACTURING THE SAME [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar cell and a method of manufacturing a solar cell, and more particularly, to a new manufacturing method for manufacturing the perovskite absorption layer in a solar cell including a perovskite absorption layer and a solar cell will be.

Crystalline silicon (c-Si) solar cells are a typical single-junction solar cell and are now widely used as commercial solar cells.

However, due to the low photoelectric conversion efficiency of crystalline silicon solar cells and relatively high manufacturing costs compared to other solar cells, the development of new solar cells is continuously required.

Accordingly, perovskite solar cells using a material having a relatively high efficiency and a relatively low manufacturing cost and having a perovskite structure have recently attracted attention.

Furthermore, development of a tandem solar cell constituting one solar cell by connecting a single junction solar cell including an absorption layer having different band gaps has been actively progressed.

FIG. 1 schematically shows a cross section of a typical two-terminal tandem solar cell among the tandem solar cells.

Referring to FIG. 1, a solar cell includes a single junction solar cell including an absorption layer having a relatively large band gap and a single junction solar cell including an absorption layer having a relatively small band gap. The single junction solar cell includes an intermediate layer (or a junction layer, inter-layer "). < / RTI >

Of these, a perovskite / crystalline silicon tandem solar cell using a single junction solar cell including an absorbing layer having a relatively large band gap as a perovskite solar cell achieves a photoelectric efficiency as high as 30% or more I can get a lot of attention.

The perovskite absorption layer in a conventional perovskite solar cell was formed by forming a single coating layer using a single solution coating method and then converting it into a perovskite thin film. However, the single coating method has a problem that the perovskite thin film is uneven and large pores are generated.

Accordingly, in order to improve the above-mentioned single coating method, the inorganic seed layer is first coated in a first step, and then the seed layer is dipped in an organic solution or heat treatment is performed in an organic material atmosphere to convert it into a perovskite thin film A two-step method was used.

The solution used for coating the seed layer in step 1 is prepared by first dissolving PbI ₂ (lead (II) iodide) precursor in a solvent such as DMF (di-methyl-formamide). However, the PbI ₂ precursor is used by dissolving, because completely soluble in DMF at room temperature, typically at least 70 ℃ PbI ₂ precursor to a high temperature.

Therefore, due to the low solubility of PbI ₂ precursor to the solvent it is, if you are not maintained so uniform the temperature of the solution and reproducible PbI ₂ precursor in the solution is re-crystallization (precipitation) in the formation layer step 1 seed uniformly the resulting solution There is a problem that it is difficult to maintain a concentration.

The spray coating method and the slot die coating method which can form a conformal coating on the step-like seed layer and the concavo-convex substrate can be used as a coating solution of the solution There is a disadvantage that there is a restriction in use due to a very high possibility that the temperature is changed.

It is another object of the present invention to provide a novel process for producing a precursor solution for a seed layer of a perovskite thin film in a solar cell at room temperature and a perovskite solar cell and a tandem solar cell using the same.

According to an aspect of the present invention, there is provided a process for preparing a solution of a precursor solution (bBX ₂ + (1-b) BX ₂ '+ AX) ≪ RTI ID = 0.0 > a < / RTI > perovskite composition can be provided. (Wherein X and X 'each independently represent a halogen group, A includes one or more of a C _1-20 alkyl group, an amine group-substituted alkyl group, and an organic amidinium group, and B represents a +2 valent Pb ^{2 +, Sn 2 +, Cu 2+} , Ca 2 +, Sr 2 +, Cd 2 +, Ni 2 +, Mn 2 +, Fe 2 +, Co 2 +, Pd 2 +, Ge 2 +, Yb 2 +, Eu < ^{2 +} >).

Preferably, the process for making the solution further comprises an alkali halide (aA'X), wherein a process for producing a perovskite composition is provided. (Wherein A < 1 > includes an alkaline group of +1 valency)

In this case, the solution may be completely dissolved at room temperature. The method for producing the perovskite composition may be provided.

On the other hand, the present invention provides a process for producing a perovskite composition, which is characterized in that A ': A = (0.05 to 0.3) :( 0.95 to 0.7).

Preferably, the solvent is one or more of DMF, DMSO, NMP, and GBL. A process for preparing the perovskite composition may be provided.

According to another aspect of the present invention, there is provided a process for producing a semiconductor device, comprising the steps of: (bBX ₂ + (1-b) BX ₂ '+ AX) as a solute in a solvent to form a seed layer by coating a dissolved precursor solution on a substrate; And a step of applying cax + (1-c) AX 'onto the coated seed layer to convert into a perovskite layer. (Wherein X and X 'each independently represent a halogen group, A includes one or more of a C _1-20 alkyl group, an amine group-substituted alkyl group, and an organic amidinium group, and B represents a +2 valent Pb ^{2 +, Sn 2 +, Cu 2} +, Ca 2+, Sr 2 +, Cd 2 +, Ni 2 +, Mn 2 +, Fe 2 +, Co 2 +, Pd 2 +, Ge 2 +, Yb 2 +, Eu < ^{2 +} >).

Preferably, a process for producing a solar cell, which further comprises an alkali halide (aA'X) in the process for producing the solution, can be provided. (Wherein A < 1 > includes an alkaline group of +1 valency)

In this case, the solution may be completely dissolved at room temperature. The method for producing the perovskite composition may be provided.

Particularly, they are present in a ratio of A ': A = (0.05 to 0.3) :( 0.95 to 0.7); A method of manufacturing a solar cell can be provided.

Preferably, the solvent is one or more of DMF, DMSO, NMP and GBL.

Preferably, the substrate is any one of glass, polymer, and crystalline silicon.

At this time, a first intrinsic amorphous silicon layer (ia-Si: H) is formed on the first surface of the crystalline silicon substrate and a second intrinsic amorphous silicon (ia-Si: H) layer is formed on the second surface of the crystalline silicon substrate Respectively; Forming a first conductive amorphous silicon layer on the first intrinsic amorphous silicon layer; Forming a second conductive amorphous silicon layer on the second intrinsic amorphous silicon layer; The method of manufacturing a solar cell according to the present invention can be provided.

In particular, the method may further include forming a texturing pattern by texturing at least one of the first surface and the second surface before the step of forming the intrinsic amorphous silicon (ia-Si: H) A method of manufacturing a solar cell can be provided.

Forming an emitter layer on the first surface of the crystalline silicon substrate; Forming a whole layer formed on a second surface of the crystalline silicon substrate; The method of manufacturing a solar cell according to the present invention can be provided.

And forming a texturing pattern by texturing at least one or more of the first and second surfaces of the crystalline silicon substrate prior to the step of forming the emitter layer and the whole layer of the crystalline silicon substrate A method of manufacturing a solar cell can be provided.

Particularly, the perovskite absorption layer may be a component of FA _{1 x} Cs _x PbBr _y I _{3 -y} (wherein 0? X? 1, 0.8 < y? 2.8).

Preferably, a step of forming an electron transport layer or a hole transport layer on the substrate before the coating step is provided.

Preferably, the coating process is a conformal coating; A method of manufacturing a solar cell can be provided.

Preferably, the coating process is any one of a spray process, an electro-deposition process, an ink jet process, and an aerosol process. Can be provided.

Preferably, the method further comprises a step of hydrophilizing the substrate prior to the coating step.

Preferably, the step of drying at a temperature of 100 ° C or lower within 60 minutes after the coating step can be provided.

Preferably, the process is one of a spray process, a slot die process, a dipping process, a drop cast process, and a printing process.

Preferably, the process is one of a chemical vapor deposition, a physical vapor deposition, a thermal evaporation process, and a vapor annealing process. Can be provided.

Preferably, the method further includes a step of post-heat treatment at 200 ° C or less for 120 minutes or less after the switching step.

In particular, the post-heat treatment step may include a solvent treatment step of flowing the solvent in the chamber.

According to another aspect of the present invention, And a perovskite absorption layer on the substrate, wherein the perovskite absorption layer is a FA _{1 x} Cs _x PbBr _y I _{3 -y} component. (Where 0? X? 1, 0.8 <y? 2.8)

Preferably, the substrate is any one of glass, polymer, or crystalline silicon; May be provided.

In particular, a first intrinsic amorphous silicon layer (i-a-Si: H) located on a first side of the crystalline silicon substrate; A second intrinsic amorphous silicon (i-a-Si: H) layer located on the rear surface of the second surface of the crystalline silicon substrate; A first conductive amorphous silicon layer located on the first intrinsic amorphous silicon layer; And a second conductive amorphous silicon layer located on the rear surface of the second intrinsic amorphous silicon layer.

An emitter layer located on a first side of the crystalline silicon substrate; And a front layer located on the rear surface of the second surface of the crystalline silicon substrate.

According to the present invention, the solubility of the precursor solution can be greatly increased by including a + 1 -valent organic ammonium or organic amidinium halide in the preparation of the precursor solution for the seed layer of the perovskite thin film.

This makes it possible to prepare a precursor solution for a seed layer having uniform and complete solubility even at room temperature.

Also, because of the high and stable solubility of the precursor solution at room temperature, the seed layer is coated on the substrate using a liquid drop, which can change the temperature of the solution during the process, such as a spray process among solution processes .

As a result, a conformal coating of the perovskite thin film can be realized even if the substrate has irregularities. Therefore, solar cells, especially tandem solar cells, can reduce the reflectance of sunlight, thus greatly increasing the light conversion efficiency.

Further, according to the present invention, it is possible to control the band gap of the perovskite thin film more widely. More specifically, the solar cell of the present invention can make the band gap of the perovskite thin film larger.

As a result, the bandgap perovskite layer absorbs light of a short wavelength compared to the conventional silicon solar cell, thereby reducing the thermal loss caused by the difference between the photon energy and the bandgap, thereby generating a high voltage, The conversion efficiency can be further increased.

1 is a schematic diagram schematically showing a general tandem solar cell.
2 is a process diagram showing a method of manufacturing a perovskite absorption layer according to a conventional example.
3 is a photograph showing a precursor solution of a perovskite absorption layer prepared according to a conventional example.
4 is a process diagram showing a method for manufacturing a perovskite absorbing layer according to one embodiment of the present invention.
5 is a photograph illustrating a precursor solution of a perovskite absorption layer produced according to an embodiment of the present invention.
6 to 13 are cross-sectional views illustrating a method of manufacturing a tandem solar cell according to an embodiment of the present invention.
Fig. 14 is a diagram showing a simulation result of the efficiency calculated according to the bandgap of the upper solar cell in the two-junction tandem solar cell.
Fig. 15 is a diagram showing the change in band gap of the FA-based perovskite absorption layer depending on the Br content.

Hereinafter, a solar cell according to a preferred embodiment of the present invention and a method of manufacturing the same will be described in detail with reference to the drawings attached hereto.

It is to be understood that the present invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, It is provided to inform.

In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification. Further, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In the drawings, like reference numerals are used to denote like elements throughout the drawings, even if they are shown on different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In describing the components of the present invention, the terms first, second, A, B, (a), (b), and the like can be used. These terms are intended to distinguish the components from other components, and the terms do not limit the nature, order, order, or number of the components. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected or connected to the other component, Quot; intervening " or that each component may be " connected, " " coupled, " or " connected " through other components.

The present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. As shown in FIG.

FIG. 2 is a process diagram showing a method of manufacturing a perovskite absorption layer according to a conventional example, and FIG. 3 is a photograph illustrating a precursor solution of a perovskite absorption layer produced according to a conventional method.

As shown in FIG. 2, the conventional perovskite absorbing layer is formed by first adding a perovskite (PbI ₂₎ and an optional alkali halide such as CsI to a solvent such as DMF (di-methyl-formamide) A solution for the precursor of the seed layer is prepared. Then, the precursor solution is coated on the substrate, then the organic halide is coated on the substrate, and then the heat treatment is performed to form an absorption layer having a perovskite crystal structure.

However, the solubility of PbI ₂ in polar solvents is very low. FIG. 3 shows a solution prepared by dissolving 1 M of PbI ₂ in DMF solvent at room temperature. As can be seen in FIG. 3, the solute PbI ₂ in the solvent DMF was not completely dissolved at room temperature, and as a result, the colloid-type solute PbI ₂ is present in the solution.

Of course, the solubility of PbI ₂ in the precursor solution of the prior art also increases with increasing solution temperature or process temperature. Therefore, the precursor solution is usually used at a temperature of about 70 캜 or higher.

However, if the solution undergoes an adiabatic expansion process during the process, such as spraying or slot die processes, the temperature of the solution will drop during the process, even if the initial temperature of the precursor solution is maintained above 70 ° C. When the precursor solution is coated on the substrate using such a process, it is impossible to uniformly apply the solution on the substrate due to the lowering of the solution temperature during the coating. As a result, it is difficult to uniformly form the precursor and the perovskite absorption layer there is a problem.

On the other hand, if the precursor solution is coated on the substrate using a solution process such as a spin coating process or a dipping process, the initial temperature of the precursor solution can be maintained as it is during the process, and uniformity of the precursor solution One application may be possible.

On the other hand, such a spin coating or dipping process has a problem that it is difficult to form a conformal coating on the substrate due to the leveling characteristic peculiar to the solution process. In particular, in a tandem solar cell using a lower substrate as a silicon solar cell, attempts to suppress the reflection of sunlight by forming irregularities on the substrate surface through a texturing process are widely used. In such a tandem solar cell, the fact that it can not use a coating conforming to the concavo-convex of the substrate is a very serious problem in the tandem solar cell.

Unlike the conventional example described above, the precursor solution according to one embodiment of the present invention has an advantage that a high solubility can be obtained with respect to a metal halide such as PbI ₂ .

FIG. 4 is a process diagram showing a method of manufacturing a perovskite absorption layer according to an embodiment of the present invention, and FIG. 5 is a photograph illustrating a precursor solution of a perovskite absorption layer produced according to the embodiment of FIG.

4, the perovskite absorption layer in the present invention is formed by first adding PbI ₂ and an organic halide (more specifically, a +1 organic ammonium or organic halide) to a solvent such as DMF (di-methyl-formamide) Amidinium halide) is added to prepare a solution for the precursor of the perovskite seed layer. Then, the precursor solution is coated on the substrate using a spray process or the like, and then heat treatment is performed thereon in an organic halide vapor atmosphere, or an organic halide solution is coated thereon, followed by heat treatment to form a perovskite crystal structure Thereby forming an absorbing layer.

In the present invention, it has been found that the solubility of PbI ₂ in a solvent is drastically increased when an organic halogen material is added, in contrast to the prior art, in preparing a precursor solution.

Figure 5 is a photograph of a solution for a precursor prepared in one embodiment of the present invention. The solution of FIG. 5 is obtained by adding only 30 mol% of MAI (methylammonium iodide) to the solution of the conventional example of FIG. 4. Unlike the conventional example of FIG. 4, PbI ₂ and MAI, which are solutes, are completely dissolved even at room temperature Respectively.

Accordingly, the precursor solution of the present invention can be used at room temperature, is very easy to store and maintain, and has an advantage of easily maintaining solubility in a coating process.

On the other hand, in the present invention, it is preferable to further include an alkali halide in the step of producing the precursor solution. In particular, when the organic halide includes a (Formamidinium) component, it is more preferable that an alkali metal, among which Cs is included. This is because the FA-based perovskite absorbing layer is superior in high-temperature stability to the MA-based compound, and can inhibit the generation of undesired delta (δ) -based FA compounds due to addition of Cs.

In the perovskite structure of the ABX ₃ formula, it is generally known that it has a stable alpha-phase perovskite structure when the Goldschmidt tolerance factor is 0.8 to 1.0. If A is present only as FA in the perovskite ABX ₃ formula, the factor has a value of about 0.98. On the other hand, when A is present only as Cs, the factor has a value of about 0.80. Therefore, in both of the above cases, the alpha phase perovskite is almost on the boundary line of the stable factor value.

In this case, it is more preferable that the alkali halide is added in an amount of 5 to 30 mol% with respect to the organic halide. When the addition amount of Cs is less than 5 mol%, there is a problem in that a decrease in the factor value due to the addition of Cs (in other words, a suppression effect on the delta phase) is not large. On the other hand, it has been reported that when the addition amount of Cs exceeds 30 mol%, a delta-phase perovskite absorption layer starts to be generated.

On the other hand, the solvent for preparing the precursor solution in the present invention may be a solvent capable of dissolving the metal halide. However, in view of the fact that the metal halides for forming the perovskite absorbing layer are ion-binding compounds composed of metal and a halogen group, the solvents are preferably polar solvents. Among the polar solvents, polar solvents such as DMF (di-methyl-formamide), DMSO (di-methyl-sulfoxide), NMP (n-methyl-pyrrolidone) and GBL (gamma-butyro-lactone) .

The precursor solution of the perovskite absorption layer formed by the method of the present invention can be coated on the substrate using a process using a liquid drop, such as a spray process. This means that the stability of the solution can be maintained even if the temperature of the solution is decreased during the process of forming droplets. As a result, the concentration of the precursor coated on the substrate is maintained uniform, so that the uniformity of the perovskite absorption layer and the solar cell can be greatly improved.

The precursor solution of the present invention is applicable to all solar cells including a perovskite absorption layer. As a specific example thereof, the perovskite absorption layer using the precursor solution in the present invention can be applied to both a normal perovskite solar cell and an inverted perovskite solar cell.

Hereinafter, a method of manufacturing a tandem solar cell including a perovskite absorption layer manufactured using the precursor solution in the present invention will be described in detail.

FIGS. 6 to 13 show a method of manufacturing a normal tandem solar cell 100. FIG. The normal tandem solar cell 100 described as a specific embodiment in the present invention is substantially the same as the method of manufacturing an inverted tandem solar cell basically, different.

The perovskite absorption layer produced using the precursor solution of the present invention can also be applied to a perovskite solar cell. The perovskite solar cell may be used as an upper solar cell of a tandem solar cell. Accordingly, by examining a method of manufacturing a tandem solar cell, representative solar cells to which a perovskite absorbing layer manufactured using the precursor solution of the present invention is applied can be described at the same time.

In preparing the solar cell of the present invention, a substrate on which a tandem solar cell is stacked is prepared. For example, a substrate in a perovskite solar cell corresponds to a glass substrate, while a substrate in a tandem solar cell corresponds to a crystalline silicon solar cell.

At this time, in the case of a glass substrate for a perovskite solar cell, a soda lime glass substrate having a desired sheet resistance is cleaned using an organic solvent such as ethanol and DI water as necessary. At this time, the iron (Fe) content in the glass substrate is preferably as small as possible.

On the other hand, in order to manufacture a tandem solar cell, a crystalline silicon solar cell is first prepared.

6, first, the first and second surfaces of the crystalline silicon substrate 111 are planarized, and at least one of the first and second surfaces is textured to form a texturing pattern .

At this time, the introduction of the texture structure of the crystalline silicon substrate 111 can be performed by any one of a wet chemical etching method, a dry chemical etching method, an electrochemical etching method, and a mechanical etching method, but is not limited thereto. As an example, at least one of the first and second surfaces of the crystalline silicon substrate 111 may be etched in a basic aqueous solution to introduce the texture structure.

More specifically, first, an n-type silicon single crystal substrate sliced along the (100) plane and having a thickness of several hundreds to several thousands of micrometers is prepared. Next, an aqueous solution containing 1 to 5% by weight of an aqueous solution of sodium hydroxide (NaOH) or an aqueous solution of potassium hydroxide (KOH) at a temperature ranging from room temperature to 150, containing additives such as organic solvent, phosphate, reaction regulator and / The substrate surface is etched.

The organic solvent may be 2-methyl-2,4-pentanediol, propylene glycol, 2,2,4-trimethyl-1,3-pentanediol (2, 2,4-trimethyl-1,3-pentanediol, 1,3-butanediol, 1,4-butanediol, 1,6- hexanediol, 2,2-dimethyl-1,3-propanediol, hydroquinone, 1,4-cyclohexanediol, And N-methyl proline may be used.

The phosphate may be at least one of K ₃ PO ₄ and K ₂ HPO ₄ .

Through the etching, a texture having pyramidal irregularities is formed on the silicon single crystal substrate. Since the silicon single crystal has a diamond cubic structure, the {111} plane is the most proximal plane and chemically stable plane. As a result, the etch rate for the aqueous solution of sodium hydroxide becomes the slowest for the {111} plane, resulting in anisotropic etching along the {111} plane of the silicon substrate after etching. As a result, a texture having a depth of 0.1 to 10 탆 is uniformly formed on the entire surface of the silicon substrate.

Next, the second conductivity type layer 114 is formed on the second surface of the crystalline silicon substrate 111 having the first conductivity type. After the second conductive type layer 114 is formed, a first conductive type layer 115 having the same conductivity type as that of the silicon substrate may be further formed on the first surface of the crystalline silicon substrate 111 7).

In the case of a heterogeneous silicon solar cell, the crystalline silicon solar cell comprises a crystalline silicon substrate 111 having a textured structure on the first and / or second surface, a first and a second surface, respectively, on the first and second surfaces of the crystalline silicon substrate, A first intrinsic amorphous silicon layer (ia-Si: H) 113 and a second intrinsic amorphous silicon layer (ia-Si: H) 112; A first conductive amorphous silicon layer 115 located on the rear surface of the first intrinsic amorphous silicon layer 113; And a second conductive amorphous silicon layer (114) located on the front surface of the second intrinsic amorphous silicon layer (112).

For example, first a very thin amorphous silicon (ia-Si: H) is formed as a passivation layer on the first and second surfaces of an n-type crystalline silicon substrate, and a p-type high-concentration amorphous silicon (n ⁺ -a-Si: H) layer is formed on the second surface by the second conductive type layer 114 and a high-concentration amorphous silicon (n ⁺ -a-Si: H) . &Lt; / RTI &gt;

Generally, the amorphous silicon layer has a large energy band gap of about 0.6 to 0.7 eV as compared with a crystalline silicon layer having an energy band gap of about 1.1 eV, and is also advantageous in that it can be formed very thin during the deposition process. The advantage of such an amorphous silicon layer is that the light absorption loss in the short wavelength region can be minimized and the light utilization factor can be increased and the high open circuit voltage and the back electric field effect can be obtained.

In addition, in the case of heterogeneous junctions having different band gaps in general, there is a high possibility that lattice mismatch between different materials occurs. However, when the amorphous silicon layer is used, the crystal lattice mismatching does not occur because the crystal lattice is made irregular, unlike the crystalline one. As a result, when the intrinsic amorphous silicon layer (i-a-Si) is deposited on the crystalline silicon substrate, the recombination of the surface of the silicon substrate can be effectively reduced.

The intrinsic amorphous silicon layer in the present invention is more preferably a hydrogenated intrinsic amorphous silicon layer (i-a-Si: H). This is because hydrogen can enter the amorphous silicon by a hydrogenation reaction to reduce the dangling bond of the amorphous silicon and the localized energy state in the energy bandgap.

However, when the hydrogenated intrinsic amorphous silicon layer (i-a-Si: H) is used, the subsequent process temperature is limited to 250 or less, more preferably 200 or less. This is because when the process temperature is higher than 200, the hydrogen bonds inside the amorphous silicon are destroyed.

Therefore, there is a restriction that firing in a subsequent process, particularly a process for forming a grid electrode of a metal material, should proceed at a low temperature. On the other hand, there is an additional advantage that the subsequent process temperature is low, thereby reducing thermal damage.

In a heterojunction silicon solar cell, an amorphous intrinsic silicon (ia-Si: H) layer is first formed as a passivation layer 112 and 113 on both sides of an n-type silicon crystalline substrate 111 having a uniform texture, SiH ₄ , Si ₂ H _6, etc.) and hydrogen (H ₂ ). The PECVD method has a merit that the process temperature can be lowered compared to a general CVD method, and is thus particularly preferable as a method for producing a heterojunction silicon solar cell.

Next, a second conductive type layer 114 doped with a conductive impurity opposite to that of the silicon crystalline substrate and a first conductive type layer 115 doped with the same conductivity type impurity as the silicon crystalline substrate are formed. Specifically, by using the PECVD process, at least one gas selected from the group consisting of SiH ₄ , Si ₂ H ₆ , SiHCl ₃ and SiH ₂ Cl ₂ and H ₂ gas, and B ₂ H ₆ or PH _{3 Use the} gas as the reactant. At this time, the temperature and pressure conditions of the PECVD process can be said to be the same as the PECVD conditions of the amorphous intrinsic silicon layer.

Alternatively, in the case of a homojunction silicon solar cell, the second conductivity type layer 114 and the first conductivity type layer 115 may be formed through an implant process without a passivation layer. The second conductive type layer 114 is doped with boron as an impurity and the first conductive type layer 115 is phosphorus-doped as an impurity.

When the second conductive type layer 114 and the rear surface first conductive type layer 115 are formed by the implant process, it is preferable to carry out the heat treatment of 700 to 1,200 to activate the impurities. Alternatively, the second conductivity type layer 114 and the first conductivity type layer 115 may be formed through a high-temperature diffusion process using BBr ₃ or PCl ₃ instead of the implant process.

As shown in FIG. 8, a first electrode 140 is formed on a first surface of a crystalline silicon substrate 111.

In the case of the heterojunction silicon solar cell, the process temperature of the first electrode 140 is limited to 250 or less as the process temperature of the second electrode 130 in order to prevent hydrogen bond breakdown in the amorphous silicon, do. In this case, the first electrode 140 may be formed before the second electrode 130, or the first electrode 140 and the second electrode 130 may be formed simultaneously.

The first electrode 140 forms a transparent electrode layer 117 first after the first conductive type layer 115. When a transparent conductive oxide such as ITO (Indium Tin Oxide), ZITO (Zinc Indium Tin Oxide), ZIO (Zinc Indium Oxide) or ZTO (Zinc Tin Oxide)) is used as the transparent electrode layer material, the transparent electrode layer 117 is sputtered Can be deposited.

After the transparent electrode layer 117 is formed, a grid electrode 118 is formed. Of course, the grid electrode 118 may be directly formed on the rear front layer 115 without forming the transparent electrode layer 117. However, the amorphous silicon may have a relatively low carrier to collect carriers through the metal grid, ), The transparent electrode layer 117 is more preferably formed.

At this time, the grid electrode 118 is formed by a heat treatment printing a first electrode paste on the transparent electrode layer 117 by a screen printing method and having a first temperature (same as the second temperature).

The first electrode 140 can be manufactured by selectively applying a first electrode paste not containing glass frit and then low-temperature firing at a first temperature. Here, the first electrode paste may include metal particles and organic materials that are binders for low-temperature firing, and the first electrode paste does not include glass frit. In particular, the second temperature may be 250 ° C or less, more specifically 100 to 200 ° C.

Alternatively, the first electrode 140 and the second electrode 130 may not be formed at the same time, but the first electrode 140 may be formed by a high-temperature sintering process at 700 ° C or higher, The process of forming the second electrode 130 at a low temperature of 250 DEG C or less by using the second electrode paste not containing the frit can be performed in a dual manner.

After the lower crystalline silicon solar cell 110 is formed, an intermediate layer 116 is formed on the crystalline silicon solar cell (FIG. 9). Or a tandem solar cell, for example, a perovskite solar cell is made by itself, a transparent electrode is formed on the glass substrate.

In this case, the intermediate layer 116 may be formed of a transparent conductive oxide, a carbonaceous conductive material, or the like, so that light of a long wavelength transmitted through the upper perovskite solar cell 120 can be incident on the silicon solar cell 110 disposed below, , Or a metallic material. The intermediate layer 116 may be doped with an n-type or p-type material.

Examples of the transparent conductive oxide include ITO (Indium Tin Oxide), IWO (Indium Tungsten Oxide), ZITO (Zinc Indium Tin Oxide), ZIO (Zinc Indium Oxide), ZTO (Zinc Tin Oxide), GITO (Gallium Indium Tin Oxide) (Gallium Indium Oxide), GZO (Gallium Zinc Oxide), AZO (Aluminum Doped Zinc Oxide), FTO (Fluorine Tin Oxide) or ZnO.

As the carbonaceous conductive material, graphene or carbon nanotube may be used. As the metallic material, a metal thin film of a multi-layer structure such as a metal (Ag) nanowire or Au / Ag / Cu / Mg / have.

The intermediate layer 116 in the present invention is formed on the substrate using a generally known sputtering method, more specifically, RF magnetron sputtering.

In the present invention, AZO (Aluminum Doped Zinc Oxide) and FTO (Fluorine Tin Oxide) are used as the material of the intermediate layer 116 or the transparent electrode, respectively. In addition, various transparent conductive oxides, metallic materials, and conductive polymers may also be used.

The perovskite solar cell and the tandem solar cell including the same according to the present invention next form an electron transport layer 123 on the transparent conductive material (FIG. 10).

At this time, the electron transport layer 123 may be formed of a layer including an electron conductive organic layer, an electron conductive inorganic material layer, or silicon (Si).

The electron conductive organic material may be an organic material used as an n-type semiconductor in a conventional solar cell. In a specific and non-limiting example, the electron-conducting organics include fullerenes (C ₆₀ , C ₇₀ , C ₇₄ , C ₇₆ , C ₇₈ , C ₈₂ , C ₉₅ ), PCBM ([6,6] -phenyl- C 61 butyric acid methyl ester (Fulleren-derivative), PBI (polybenzimidazole), PTCBI (3, 4, 6) -phenyl C70-butyric acid methyl ester, 9,10-perylenetetracarboxylic bisbenzimidazole), F4-TCNQ (tetrauorotetracyanoquinodimethane), or mixtures thereof.

For C ₆₀ Of these, the fullerene derivative may be dissolved in a solvent comprising a C _60, using a spin coating method to form an electron transport layer.

Meanwhile, when the crystalline silicon substrate has a texture like the embodiment of the present invention, a deposition method such as evaporation may be more effective. In this case, the processing conditions of the evaporation method may be any ordinary conditions.

The electron conductive inorganic material may be a metal oxide conventionally used for electron transfer in a conventional quantum dot-based solar cell or a dye-sensitized solar cell. Specific examples of the metal oxide include Ti oxide, Zn oxide, In oxide, Sn oxide, W oxide, Nb oxide, Mo oxide, Mg oxide, Ba oxide, Zr oxide, Sr oxide, Yr oxide, La oxide, A material selected from one or more of V oxide, Al oxide, Y oxide, Sc oxide, Sm oxide, Ga oxide, In oxide and SrTi oxide, or a mixture thereof or a composite thereof .

On the other hand, the electron transport layer made of a layer containing silicon (Si) is more specifically composed of amorphous silicon (na-Si), amorphous silicon oxide (na-SiO), amorphous silicon nitride (na-SiN), amorphous silicon carbide amorphous silicon oxynitride (n-SiC), amorphous silicon oxynitride (na-SiON), amorphous silicon carbonitride (na-SiCN), amorphous silicon germanium (na-SiGe) (n-μc-SiCe), microcrystalline silicon germanium (n-μc-SiCe), n-μc- Material.

The electron transport layer 123 in the present invention may be formed by using a PECVD process such as SiH ₄ , Si ₂ H ₆ , SiHCl _3, and SiH ₂ Cl ₂ in the same manner as the first conductive type layer 114) H ₂ gas, and PH ₃ gas as a dopant gas are used as reactants. At this time, the temperature and pressure conditions of the PECVD process can be said to be the same as the PECVD conditions of the amorphous intrinsic silicon layer. Therefore, the electron-withdrawing layer of the present invention is deposited by n-type amorphous silicon (pa-Si) under such process conditions.

Alternatively, the electronic warp layer 123 in the present invention may be formed of one or a mixture of two or more of TiO ₂ , ZnO, SnO ₂ , CdS, PCBM, or C ₆₀ .

In the present invention, a buffer layer may be additionally formed on the electron transporting layer, if necessary. The buffer layer of the present invention is characterized by being one or more of TiO _x , ZnO, SnO ₂ , CdS, PCBM and C ₆₀ . In this case, when TiO _x , which is a metal oxide, is used as a buffer layer, deposition can be performed through a relatively low temperature process such as PECVD.

A perovskite absorption layer 124 is formed again on the electron transfer layer or the buffer layer (FIG. 11).

In the present invention, a precursor for a perovskite seed layer of a metal halide component is first formed on the electron transport layer 123 (124-1 in FIG. 11).

The solution for forming the precursor uses the method for producing the solution for the precursor in the present invention as illustrated in Figs. 4 and 5 above.

First, a metal halide and an organic halide are prepared in a polar solvent at room temperature.

In this case, the polar solvent is not particularly limited as long as it is a solvent capable of dissolving an ion-binding substance such as a metal halide and an organic halide. Typically, one or more of DMF, DMSO, NMP and GBL is preferred.

The metal halide in the present invention is a component existing in the form of BX ₂ in the composition of the perovskite absorption layer represented by ABX ₃ . In this case, B is ^{Pb 2 +, Sn 2 +,} Cu 2 +, Ca 2 +, Sr 2+, Cd 2 +, Ni 2 +, Mn 2 +, Fe 2 +, Co 2 +, Pd 2 +, Ge ^{2 +} , Yb ^{2 +} , Eu ^{2 +} , and X includes at least one of F ^- , Cl ^- , Br ^- , and I ^- .

On the other hand, the organic halide is a component existing in the form of AX in the composition of the perovskite absorption layer represented by ABX ₃ . In this case, A includes one or two or more of a +1 C _1-20 alkyl group, an amine group-substituted alkyl group, and an organic amidinium. However, it is preferable that A includes MA (methylamminium) component or FA (Formamidinium) component.

On the other hand, when preparing the solution for the precursor in the present invention, it is preferable to further include an alkali halide (A'X) (wherein A 'includes an alkaline group of +1 valence).

Particularly when A is formamidinium in the organoamidinium, it is more preferable that some of the A components include an alkali metal, especially Cs. This is because the FA-based perovskite absorbing layer is superior in high-temperature stability to the MA-based compound, and can inhibit the generation of undesired delta (δ) -based FA compounds due to addition of Cs.

As already illustrated in FIGS. 4 and 5, in the present invention, 1 M metal halide (PbI ₂ ) and 30 mol% organic halide (MAI) of the metal halide are added as a solute to DMF solvent as an embodiment, A fully dissolved precursor solution could be prepared.

The present invention is characterized by providing a method for producing a solar cell having a perovskite absorbing layer having an increased Br content and a solar cell using the same, in addition to obtaining the solution for the precursor completely dissolved at room temperature.

In a 2-junction tandem solar cell in which different types of solar cells are formed, the upper solar cell has a larger bandgap than the lower solar cell. In such a tandem solar cell, the photoconversion efficiency of the entire solar cell is greatly changed according to the band gap of the upper solar cell and the band gap of the lower solar cell.

If the lower solar cell is a silicon solar cell, the inherent bandgap of the silicon solar cell is well known to be about 1.1 eV. As a result, it can be seen from FIG. 14 that the upper solar cell capable of obtaining the maximum photoconversion efficiency has a band gap of about 1.7 to 1.8 eV in the tandem solar cell selected as the silicon solar cell as the lower solar cell.

This is because when the band gap energy in the upper solar cell is included in a high range, the high band gap perovskite layer absorbs the short wavelength light compared to the conventional silicon solar cell, and thereby the thermal loss caused by the difference between the photon energy and the band gap So that a high voltage can be generated. As a result, the efficiency of the solar cell is increased.

However, it is generally known that the band gap of the perovskite absorption layer typified by the composition of ABX ₃ varies depending on each constituent constituting the composition.

The bandgap of MAPbI ₃ used as a typical perovskite (absorption) layer is known to be about 1.55 to 1.6 eV. On the other hand, it is known that the band gap of the FA (Formamidinium) system used as another perovskite absorption layer is smaller than the band gap of the MA (methylamminium) system. For example, the band gap of FAPbI ₃ is about 1.45 eV.

However, when Br is added to the FA system, the Br is substituted for the I. The substitution of I for Br may make the bandgap of the FA-based perovskite absorption layer similar to or larger than the band gap of the existing MA-based perovskite absorption layer.

According to the present invention in more detail, FA _{0. 83} Cs _0. The change in the band gap of the perovskite absorption layer according to the content of Br was measured in the FA series perovskite absorption layer having the composition of ₁₇ Pb (I _1-x Br _x ) ₃ (FIG. 15). As shown in FIG. 15, when Br is added to the perovskite composition of the FA series, the band gap of the perovskite increases linearly with the addition amount of Br.

In particular, in connection with the calculation results shown in FIG. 14, in order to increase the light conversion efficiency in a tandem solar cell selected as a lower solar cell, a top solar cell having a band gap energy of 1.7 eV or more is required. Of the FA-based perovskite absorbing layer should have a band gap energy of 1.7 eV or more, and at least about 35% of the total I (Iodine) should be replaced with Br.

That is, when approximately 35% of all I of halogen substances constituting X in the perovskite absorbing layer represented by the composition of ABX ₃ is substituted with Br, the perovskite absorbing layer has a FA _{0. 83} Cs _{0 . 17} Pb (I _0.65 Br _0.35 ) ₃ , and the total addition amount of Br in the perovskite composition is 1.05.

However, as a conventional method for producing a solution for a precursor of the perovskite absorption layer, the addition amount of Br can not be increased as much as desired.

For example, in the conventional method shown in FIG. 2, a precursor solution is prepared by selectively adding an alkali halide such as PbI ₂ and optionally xCsI to a solvent such as DMF (di-methyl-formamide). Next, after the precursor solution is coated, an organic halide reaction material of (1-b) FAI + bFABr is applied on the precursor layer, and then a heat treatment is performed to form a perovskite crystal structure, and Cs _x FA _{1 - x} PbI _{3 - y (1-x)} Br _{y (1-x)} .

Therefore, the maximum possible Br content in the conventional method is a value of b in the organic halide reaction material. In this case, if Cs is added to the FA by 20% in the step of preparing the precursor solution, the final perovskite absorption layer has a composition of x = 0.2 and y = 1, and thus Cs _0.2 FA _0.8 PbI _2.2 Br _0.8 .

According to the experimental results shown in Fig. 15, the perovskite absorption layer having such a composition has a band gap of about 1.65 eV. As a result, as predicted by the simulation results in Fig. 14, even if the solution for the perovskite precursor was completely dissolved by the conventional method, the perovskite absorbing layer made of the solution was about 1.65 eV , And as a result, the final tandem solar cell is expected to have no maximum efficiency.

On the other hand, unlike the conventional example, the amount of Br added to the perovskite absorption layer by the precursor production method of the present invention can be further increased compared to the prior art. More specifically, the present invention can provide a perovskite absorbing layer having a Br content exceeding 0.8, which can not be produced by the prior art.

For example, the precursor solution in the present invention is prepared by first dissolving (aCsI + bPbI ₂ + (1-b) PbBr ₂ ) in a solvent such as MEI to prepare a precursor solution. Next, after the precursor solution is coated, an organic halide reaction material of (1-c) FAI + cFABr is applied on the precursor layer, and then an absorption layer having a perovskite crystal structure is formed through heat treatment. The perovskite absorption layer formed at this time has _{a composition} of Cs _a FA _{1 - a} PbI _{2b + c (a-1) + 1} Br _{2 (1-b) + c (1-a)} .

If the amount of FAI and FABr added is 50% (50%) for PbI ₂ and PbBr ₂ (b = 0.5), CsI is 20% 75% and 25%, respectively (c = 0.25), the final perovskite absorption layer has a composition of Cs _0.2 FA _0.8 PbI _1.8 Br _1.2 .

The perovskite absorption layer of this composition has a band gap of about 1.73 eV (Fig. 15), and the tandem solar cell having the perovskite absorption layer with such a band gap has a near- (Fig. 14).

The table below shows the results of simulating the composition and band gap of the perovskite absorption layer which can be produced by the method of producing the precursor solution of the present invention. As described in the following table, the perovskite absorbing layer in the present invention is prepared as a precursor solution completely dissolved even at room temperature, so that not only a uniform perovskite absorbing layer is formed but also the content of Br is controlled as desired As a result, the bandgap of the perovskite absorption layer can be adjusted as desired.

<Table> Perovskite composition and band gap according to addition amounts of components

The precursor of the metal halide component is coated on the electron transport layer 123. The coating method in the present invention is applicable to any method capable of conformal coating.

Considering that the precursor solution is a liquid phase, a solution process can be used first. At this time, the solution process is preferably a process using a liquid drop. Processes using droplets (for example, spray processes) are advantageous for conformal coatings that directly coat the substrate shape rather than other solution processes such as screen printing or spin coating. Therefore, the coating using the precursor solution in the present invention is preferably any one of a spray process, an electro-deposition process, an ink jet process, and an aerosol process.

However, since the droplet is essentially liquid, the droplets coated by gravity during coating may flow down the substrate. However, the present inventors have found that the vector sum of the friction force between the droplet and the substrate and the surface tension of the droplet itself is larger than the gravity. As a result, the coating method using the droplet in the present invention is considered to be conformal because the position where the droplet is initially coated is maintained relatively well.

On the other hand, before spray coating, the substrate may be modified as needed. More specifically, since the solvent of the precursor solution in the present invention is a polar solvent, it is more preferable that the surface has hydrophilicity on the surface modification. Hydrophilic surface modification is typically plasma treatment or the like, and the plasma treatment for surface modification is well known in the art to which the present invention pertains, so a detailed description thereof will be omitted.

In the droplet coating method of the precursor solution according to the present invention, it is preferable that the processing conditions include a substrate temperature of room temperature to 100 ° C and a droplet size of 0.05 to 1 μm.

Since the precursor solution of the present invention can be completely dissolved at room temperature, the lower limit of the temperature of the substrate need not be specified. However, when the temperature of the substrate is higher than 100 ° C, there is a possibility that the composition of the precursor solution is changed by evaporation or thermal decomposition of some solvent.

On the other hand, when the size of the droplet is smaller than 0.05 mu m, there is a problem that the process time for coating the precursor layer of the desired thickness is excessively long due to the small droplet size. On the other hand, when the size of the droplet is larger than 1 탆, the droplet size becomes larger than the texture when the texture is fine, so that the conformal coating may be difficult and the droplet may flow down due to the increase of the weight of the droplet. There is a drawback that it becomes difficult.

As described above, a step of coating the metal halide precursor layer on the substrate and drying at 100 ° C or less within 60 minutes can be added as needed. The drying process is a process for drying the solvent contained in the precursor solution.

In this case, when the process temperature is higher than 100 ° C in the drying process, the composition of the metal halide or alkali halide contained in the precursor layer may be changed. On the other hand, in case of drying time, the lower limit value need not be specially defined, and the upper limit value need not be specially defined as long as it does not act as a neck process in the entire process time because the process time is over 1 hour.

Next, on the precursor layer, a secondary reaction material containing an organic halide of {cAX + (1-c) AX '} is applied (124-2 in FIG. 11). The second reactant reacts with a precursor layer previously formed to form a perovskite absorption layer.

At this time, the secondary reaction material including the organic halide can be applied on the precursor layer through various methods.

Since the second reactive material includes an organic halide, the organic halide solution may be prepared by dissolving the organic halide using a solvent, and then the organic halide solution may be applied onto the precursor layer through a solution method. The solution method that can be used at this time is a spraying process, a slot die process, a dipping process, a drop cast process, a printing process, and the like.

In the present invention, the dipping step is used as one of the solution methods. Specifically, the organic halide to the _{0.01g / ㎖ (CH (NH 2} ) 2) Br solution and _{0.01g / ㎖ (CH (NH 2} ) 2) I a solution of 2-propanol (Sigma-Aldrich, 99.5%) as a solvent After the substrate having the precursor layer formed thereon was immersed in the secondary reaction material solution, the substrate was rotated at a maximum of 3,000 rpm for 30 seconds.

In addition to the solution method, the present invention can be applied to any one of the above-mentioned secondary reactions including an organic halide using any one of chemical vapor deposition, physical vapor deposition, thermal evaporation process, and vapor annealing process. The material can be applied on a substrate having a precursor layer formed thereon.

More specifically, in the present invention, the secondary reaction material can be applied using a LP (low pressure) -CVD process of less than 10 torr.

Generally, the LP-CVD process is a type of CVD performed at pressures below atmospheric pressure. LP-CVD, unlike atmospheric pressure CVD (AP-CVD), is advantageous in that the vapor phase precursor for vapor deposition is transported through a reduced pressure environment, so that the conformal coating . On the other hand, unlike AP (atmospheric pressure) CVD, deposition rate is low.

In the present invention, a perovskite precursor layer was conveyed toward a substrate already formed with a secondary reactant gas containing an organic halide of the component {cAX + (1-c) AX '}. At this time, the secondary reaction material powder containing the organic halide of the component {cax + (1-c) AX '} was loaded in a solid state into the evaporation unit such as a crucible. The CVD furnace was then evacuated and purged with nitrogen gas before the substrate was heated. Thereafter, the FAI + FABr mixed powder was heated to 180 DEG C, and then the CVD furnace was adjusted so that nitrogen gas was introduced. The total sublimation time of the FAI + FABr mixed organic halide was about 30 minutes, and the sublimation temperature (180 ° C) maintenance time except heating and cooling was about 10 minutes. While the substrate was being heated, the FAI + FABr mixed organic halide was absorbed into the substrate, and the thickness of the second reactive material layer made of the measured FAI + FABr mixed organic halide was measured to be approximately 200 nm.

The amount of the organic halide of the {cAX + (1-c) AX '} component applied on the substrate at this time depends on various factors such as the surface area of the evaporation unit containing the organic halide powder represented by AX, Time, location and orientation of the substrate, packing density of the substrate, and the like. Therefore, the thickness of the layer of the secondary reactive material to be coated can be controlled by adjusting the process parameters and the like.

After the secondary reaction material of the organic halide component is applied to the substrate having the metal halide precursor formed thereon, the post heat treatment process can be performed to convert it to the perovskite absorption layer.

The post-heat treatment process in the present invention preferably proceeds at room temperature to 200 DEG C for 120 minutes or less.

There is no particular limitation on the lower limit of the temperature in the post-heat treatment process, but if the upper limit of the temperature is higher than 200, the perovskite absorption layer may thermally degrade, which is not preferable. Also, when the perovskite absorption layer is formed through the deposition process, the precursor layers may be thermally decomposed before the perovskite layer is formed by reacting with each other, or the composition may be changed due to pyrolysis.

There is no particular limitation on the lower limit of the post-annealing process time, but the upper limit of the post-annealing time is long enough to affect the total process time (tact time) when the post-annealing unit lead time exceeds 120 minutes It is not desirable.

As a specific example, in the present invention, the substrate on which the second organic material layer is formed is subjected to post-heat treatment on a hot plate (100 ° C / 15 min) to complete crystallization into a perovskite layer.

In the post-heat treatment step, the solvent may be treated with one or more polar solvents such as DMF, DMSO, NMP, and GBL, followed by a heat treatment.

In this case, the solvent treatment can be carried out in a closed space like a chamber, in a flow manner in which the polar solvent is flown over the substrate at a temperature of 200 DEG C or less.

The domain size of the perovskite absorbing layer converted through the solvent treatment can be increased and the light conversion efficiency can be improved.

A hole transport layer 125 is formed on the perovskite layer (FIG. 12). The hole transport layer 125 is a layer that allows the holes generated in the perovskite layer to be easily transferred to the first electrode 130, and can ensure transparency of visible light and conductivity of holes.

In the embodiment of the present invention, an organic hole transport layer such as Spiro-MeOTAD was coated by a solution process. Specifically, the Spiro-MeOTAD coating solution was prepared by dissolving 4-tert-butyl pyridine and lithium bis (trifluoromethanesulfonyl) imide [lithium bis trifluoromethanesulfonyl) imide] solution. The solution was then immersed in a substrate having a perovskite layer formed thereon, and then rotated at 3,000 rpm for 30 seconds and then dried.

A second electrode 130 including a grid electrode 127 is formed on the hole transport layer (FIG. 13) after a front transparent electrode layer 126 is formed if necessary.

At this time, the transparent electrode layer 126 is formed on the entire upper surface of the perovskite solar cell 120, and collects the charge generated in the perovskite solar cell 120. The transparent electrode layer 126 may be embodied as various transparent conductive materials. That is, as the transparent conductive material, the same material as the transparent conductive material of the bonding layer 116 can be used.

At this time, the second electrode (specifically, the grid electrode 127) is disposed on the transparent electrode layer 126 and disposed in a part of the transparent electrode layer 126.

The second electrode (specifically, the grid electrode 127) can be manufactured by selectively applying a second electrode paste not containing glass frit, followed by low-temperature firing at a second temperature. Here, the second electrode paste may include metal particles and an organic material that is a binder for low-temperature firing, and the second electrode paste does not include glass frit. In particular, the second temperature may be 250 or less, more specifically 100 to 200.

As described above, the first electrode 140 and the second electrode 130 may be formed at the same time when the first electrode 140 is formed, or may be formed simultaneously with the first electrode 140 And the second electrode 130 may be formed after the perovskite solar cell is formed. In addition, in the case of a heterojunction silicon solar cell, the first electrode 140 and the second electrode 130 are both formed by a low-temperature firing process at 250 ° C or less.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the scope of the invention is not limited to the disclosed exemplary embodiments. It is obvious that a transformation can be made. Although the embodiments of the present invention have been described in detail above, the effects of the present invention are not explicitly described and described, but it is needless to say that the effects that can be predicted by the configurations should also be recognized.

Claims (29)

Adding (bBX ₂ + (1-b) BX ₂ '+ AX) to the solvent as a solute to prepare a dissolved precursor solution;
&Lt; / RTI &gt; wherein the perovskite composition comprises a perovskite compound.
(Wherein X and X 'each independently represent a halogen group, A includes one or more of a C _1-20 alkyl group, an amine group-substituted alkyl group, and an organic amidinium group, and B represents a +2 valent Pb ^{2 +, Sn 2+, Cu 2 +} , Ca 2 +, Sr 2 +, Cd 2 +, Ni 2 +, Mn 2 +, Fe 2 +, Co 2 +, Pd 2 +, Ge 2 +, Yb 2 +, Eu &lt; ^{2 +} &gt;).
The method according to claim 1,
Further comprising an alkali halide (aA'X) in the process of making said solution;
&Lt; / RTI &gt;
(Wherein A &lt; 1 &gt; includes an alkaline group of +1 valency)
3. The method according to claim 1 or 2,
The solution is completely dissolved at room temperature;
&Lt; / RTI &gt;
3. The method of claim 2,
A ': A = (0.05 to 0.3): (0.95 to 0.7);
&Lt; / RTI &gt;
The method according to claim 1,
Said solvent being one or more of DMF, DMSO, NMP and GBL;
&Lt; / RTI &gt;
Adding (bBX ₂ + (1-b) BX ₂ '+ AX) to the solvent as a solute to form a seed layer by coating the dissolved precursor solution on the substrate;
Applying cAX + (1-c) AX 'on the coated seed layer to convert it to a perovskite layer;
Wherein the first electrode and the second electrode are electrically connected to each other.
(Wherein X and X 'each independently represent a halogen group, A includes one or more of a C _1-20 alkyl group, an amine group-substituted alkyl group, and an organic amidinium group, and B represents a +2 valent Pb ^{2 +, Sn 2+, Cu 2 +} , Ca 2 +, Sr 2 +, Cd 2 +, Ni 2 +, Mn 2 +, Fe 2 +, Co 2 +, Pd 2 +, Ge 2 +, Yb 2 +, Eu &lt; ^{2 +} &gt;).
The method according to claim 6,
Further comprising an alkali halide (aA'X) in the process of making said solution;
Wherein the solar cell is a solar cell.
(Wherein A &lt; 1 &gt; includes an alkaline group of +1 valency)
8. The method according to claim 6 or 7,
Wherein the solution is completely dissolved at room temperature.
8. The method of claim 7,
A ': A = (0.05 to 0.3): (0.95 to 0.7);
Wherein the solar cell is a solar cell.
The method according to claim 6,
Said solvent being one or more of DMF, DMSO, NMP and GBL;
Wherein the solar cell is a solar cell.
The method according to claim 6,
Wherein the substrate is any one of glass, polymer, and crystalline silicon;
Wherein the solar cell is a solar cell.
12. The method of claim 11,
A first intrinsic amorphous silicon layer (ia-Si: H) is formed on a first surface of the crystalline silicon substrate, and a second intrinsic amorphous silicon (ia-Si: H) layer is formed on a second surface of the crystalline silicon substrate fair;
Forming a first conductive amorphous silicon layer on the first intrinsic amorphous silicon layer;
Forming a second conductive amorphous silicon layer on the second intrinsic amorphous silicon layer;
Wherein the first electrode and the second electrode are electrically connected to each other.
13. The method of claim 12,
Forming a texturing pattern by texturing at least one of the first surface and the second surface before the step of forming the intrinsic amorphous silicon (ia-Si: H);
Further comprising the steps of:
12. The method of claim 11,
Forming an emitter layer on a first surface of the crystalline silicon substrate;
Forming a whole layer formed on a second surface of the crystalline silicon substrate;
Wherein the first electrode and the second electrode are electrically connected to each other.
15. The method of claim 14,
Forming a texturing pattern by texturing at least one or more of a first surface and a second surface of the crystalline silicon substrate prior to forming the emitter layer and the whole layer of the crystalline silicon substrate;
Further comprising the steps of:
The method according to claim 6,
The perovskite absorber layer is a component of FA _{1 x} Cs _x PbBr _y I _{3 -y} ;
Wherein the solar cell is a solar cell.
(Where 0? X? 1, 0.8 <y? 2.8)
The method according to claim 6,
Forming an electron transporting layer or a hole transporting layer on the substrate before the coating step;
Wherein the first electrode and the second electrode are electrically connected to each other.
The method according to claim 6,
The coating process may be a conformal coating;
Wherein the solar cell is a solar cell.
The method according to claim 6,
The coating process may be any one of a spray process, an electro-deposition process, an ink jet process, and an aerosol process;
A method of manufacturing a solar cell
The method according to claim 6,
Further comprising the step of hydrophilizing the substrate before the coating step;
Wherein the solar cell is a solar cell.
The method according to claim 6,
And drying at a temperature of 100 DEG C or less within 60 minutes after the coating step.
The method according to claim 6,
The application process may be any one of a spray process, a slot die process, a dipping process, a drop cast process, and a printing process;
Wherein the solar cell is a solar cell.
The method according to claim 6,
The process may be one of chemical vapor deposition, physical vapor deposition, thermal evaporation process, and vapor annealing process;
Wherein the solar cell is a solar cell.
The method according to claim 6,
Further comprising the step of post-heat treatment at a temperature of 200 DEG C or less for 120 minutes or less after the switching step;
Wherein the solar cell is a solar cell.
25. The method of claim 24,
In the post-heat treatment step,
Including a solvent treatment process in which the solvent flows in the chamber;
Wherein the solar cell is a solar cell.
Board;
And a perovskite absorber layer on the substrate,
The perovskite absorber layer is a component of FA _{1 x} Cs _x PbBr _y I _{3 -y} ;
And a solar cell.
(Where 0? X? 1, 0.8 <y? 2.8)
27. The method of claim 26,
Wherein the substrate is any one of glass, polymer, and crystalline silicon;
And a solar cell.
28. The method of claim 27,
A first intrinsic amorphous silicon layer (ia-Si: H) located on a first side of the crystalline silicon substrate;
A second intrinsic amorphous silicon (ia-Si: H) layer located on the rear surface of the second surface of the crystalline silicon substrate;
A first conductive amorphous silicon layer located on the first intrinsic amorphous silicon layer;
A second conductive amorphous silicon layer located on the rear surface of the second intrinsic amorphous silicon layer;
And a second electrode.
28. The method of claim 27,
An emitter layer located on a first side of the crystalline silicon substrate;
A front layer positioned on the rear surface of the second surface of the crystalline silicon substrate;
And a second electrode.

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