KR20190037463A - Assembled Structure for Perovskite Solar Cell, Perovskite Solar Cell Having Improved Photo-stability and the Fabrication Method thereof - Google Patents

Abstract

The present invention relates to a perovskite photovoltaic cell and a manufacturing method thereof. More specifically, according to the present invention, the manufacturing method of the perovskite photovoltaic cell includes the step of performing heat treatment on a structure for the perovskite photovoltaic cell including a metal oxide-based electron transporting body and an active layer located on the electron transporting body and including a chlorine source and a perovskite compound to pyrolyze the chlorine source.

Description

FIELD OF THE INVENTION The present invention relates to a perovskite solar cell, a perovskite solar cell structure, a perovskite solar cell exhibiting improved light stability, and a manufacturing method thereof,

The present invention relates to a structure for a perovskite solar cell having improved optical stability, a perovskite solar cell, and a method for manufacturing the same, and more particularly, to a perovskite solar cell having a perovskite solar cell having an improved photoelectric conversion efficiency, To a perovskite solar cell structure, a perovskite solar cell, and a method for manufacturing the same.

Organometallic halides of the perovskite structure, also referred to as organometallic halide perovskite compounds or organometallic halides, can be prepared by reacting organic cations (A), metal cations (M) and halide anions X) and is a substance represented by the formula of AMX ₃ .

Perovskite solar cells using organic or inorganic organometallic halides as light absorbers are the most commercialized among the next generation solar cells including dye sensitized and organic solar cells and have reported efficiency of up to 20% -0035284), and more and more attention is being paid to organic and inorganic metal halides.

These perovskite solar cells have efficiency comparable to that of silicon solar cells, but have a very low material cost, and are commercially available because they can be processed at low temperatures and at low cost. However, despite the excellent initial photoelectric conversion efficiency of the perovskite solar cell, the perovskite layer is decomposed by the photocatalytic action of the metal oxide mainly used as the material of the electron transport layer when exposed to the light for a long time, It has been reported that the photoelectric conversion efficiency is significantly lowered by about 43% compared to the initial photoelectric conversion efficiency when exposed to an LED having a wavelength of 1000 nm for 300 hours (J. Phys. Chem. C, 2016, 120 (49) pp 27840-27848). Therefore, in order to commercialize perovskite solar cells, it is required to develop a technique for improving the stability and life of the battery.

Korean Patent Publication No. 2014-0035284

J. Phys. Chem. C, 2016, 120 (49), pp 27840-27848

The present invention relates to a structure for a perovskite solar cell capable of producing a perovskite solar cell having an improved photoelectric conversion efficiency and maintaining an excellent photoelectric conversion efficiency even after exposure to light for a long period of time, A perovskite solar cell that maintains excellent photoelectric conversion efficiency even after being exposed, and a method of manufacturing the same.

The structure for a perovskite solar cell according to the present invention includes a metal oxide-based electron transporting material; And an active layer located on top of the electron transporting material and containing a chlorine source and a perovskite compound.

In the structure for a perovskite solar cell according to an embodiment of the present invention, the chlorine source contained in the active layer can supply chlorine to at least the electron transporting body by pyrolysis.

In the structure for a perovskite solar cell according to an embodiment of the present invention, the active layer may include 0.20 to 1.00 moles of chlorine source relative to 1.00 moles of the perovskite compound.

In the structure for a perovskite solar cell according to an embodiment of the present invention, the chlorine source may be an organic chloride having a pyrolysis temperature of 200 ° C or less.

In a structure for a perovskite solar cell according to an embodiment of the present invention, the chlorine source may be a C1 to C3 alkyl ammonium chloride.

The present invention includes a method of manufacturing a perovskite solar cell using the above-described solar cell structure.

The method for producing a perovskite solar cell according to the present invention includes a pyrolysis step of thermally decomposing a chlorine source by heat treatment.

In the method of manufacturing a perovskite solar cell according to an embodiment of the present invention, after the pyrolysis step, a step of forming a hole carrier on the upper part of the light absorbing layer, which is an active layer remaining after pyrolysis of a chlorine supply source have.

In the method for manufacturing a perovskite solar cell according to an embodiment of the present invention, the heat treatment temperature may satisfy the following relational expression (1).

(Relational expression 1)

T _dc ≤ T _heat ≤ 200 ℃

T _heat is the heat treatment temperature (캜), and T _dc is the pyrolysis temperature (캜) of the chlorine source.

The present invention includes a perovskite solar cell manufactured by the above-described manufacturing method.

A perovskite solar cell according to the present invention includes: an electron carrier containing a metal oxide and a chlorine; And a light absorbing layer comprising a perovskite compound located on the top of the electron transporting material and containing chlorine; And a hole carrier positioned above the light absorption layer.

A perovskite solar cell according to an embodiment of the present invention may have optical stability satisfying the following relational expression (2).

(Equation 1)

98? (? 1 /? 0) X 100

eta 0 is the initial photoelectric conversion efficiency (%) of photoelectric conversion efficiency (%) of the perovskite solar cell immediately after being exposed to light, and? 1 is the photoelectric conversion efficiency after the same perovskite solar cell is continuously exposed to light for 1000 hours (%), And the light exposure condition is a light source having a sunlight intensity of 1,000 W / m 2, a temperature of 30 ° C, a humidity of 25%, and a wavelength of 280 to 2500 nm.

The structure for a perovskite solar cell according to the present invention includes an active layer containing an perovskite compound and a chlorine source, which is located above an electron carrier and an electron transporting material. The chlorine source of the active layer is pyrolyzed, A perovskite solar cell including a light absorbing layer which is a perovskite compound layer containing chlorine and an electron transport layer containing chlorine can be produced. By the chlorine addition by the chlorine supply source, a perovskite solar cell having excellent photoelectric conversion efficiency can be manufactured, and furthermore, remarkably excellent photoelectric conversion efficiency can be obtained in which initial excellent photoelectric conversion efficiency is stably maintained even during an extremely long operation time. There is an advantage that a solar cell having stability can be manufactured.

The method for producing a perovskite solar cell according to the present invention is a commercial method in which a solution containing a perovskite compound and a chlorine source is applied to a metal oxide-based electron carrier and then heat-treated at a temperature above a temperature at which a chlorine source is pyrolyzed There is an advantage that a solar cell having excellent initial photoelectric conversion efficiency and remarkably excellent light stability can be produced by a simple process.

The perovskite solar cell according to the present invention has an advantage that chlorine supplied by thermal decomposition of an internal chlorine source is added to a light absorption layer and an electron transporting material, thereby having excellent initial photoelectric conversion efficiency and remarkably excellent light stability .

1 shows the results of X-ray diffraction analysis of the light absorbing layer prepared in Examples and Comparative Examples,
FIG. 2 is a diagram showing an elemental analysis result according to the depth of a solar cell manufactured in the embodiment,
Fig. 3 is a diagram showing the performance evaluation of the solar cell manufactured in Examples and Comparative Examples,
4 is a diagram showing measurement of the optical stability of the solar cell manufactured in Examples and Comparative Examples.

Hereinafter, a structure for a perovskite solar cell, a perovskite solar cell, and a method for manufacturing the same will be described in detail with reference to the accompanying drawings. Hereinafter, the technical and scientific terms used herein will be understood by those skilled in the art without departing from the scope of the present invention. Descriptions of known functions and configurations that may be unnecessarily blurred are omitted.

In the present invention, the perovskite solar cell means a solar cell containing a perovskite-type organometallic halide as a light absorber.

The structure for a perovskite solar cell according to the present invention is a structure for manufacturing a perovskite solar cell, which comprises a metal oxide-based electron carrier; And an active layer located on top of the electron transporting material and containing a chlorine source and a perovskite compound.

In detail, the structure for a perovskite solar cell according to the present invention includes a metal oxide-based electron transporting material; And an active layer which is located on the upper portion of the electron transporting material and is obtained by applying and drying an active solution containing a chlorine source and a perovskite compound (meaning that the solvent of the active layer solution is removed by volatilization).

The chlorine supply source contained in the active layer can function to supply chlorine to at least the electron transporting body by thermal decomposition. In detail, the chlorine supply source of the active layer can serve to supply chlorine to the electron transporting substance located in the lower part and the perovskite compound coexisting in the active layer.

Specifically, the chlorine supply source of the active layer is pyrolyzed to generate chlorine to supply chlorine to the electron transporting material and the perovskite compound, whereby the chlorine-containing electron transporting material and the chlorine supply source are pyrolyzed and removed, and the chlorine-containing perovskite Thereby making it possible to manufacture a light absorbing layer which is a compound layer.

The metal oxide of the electron transporting material and the perovskite compound of the light absorbing layer are chlorinated by the chlorine source that is pyrolyzed, whereby a perovskite solar cell having an excellent photoelectric conversion efficiency can be manufactured. Further, A perovskite solar cell having remarkably excellent light stability in which excellent photoelectric conversion efficiency can be stably maintained can be produced.

As described above, in the structure for a perovskite solar cell according to an embodiment of the present invention, the chlorine supply source is thermally decomposed in the structure in a state where both the electron carrier and the active layer that is converted to the light absorption layer are formed, Both the skate compound and the metal oxide of the electron transporting agent can be chlorinated.

After the metal oxide based electron transporting material is formed, the electron transporting material may be post-treated with a metal chloride or the like to leave chlorine (external supply), thereby independently chlorinating the electron transporting material. However, when an active layer containing an electron carrier, a chlorine source and a perovskite compound is formed, chlorine is supplied from the inside of the structure to chlorinate (both internally supply) the perovskite compound and the electron carrier, The light stability compared to the chlorination can be remarkably improved remarkably.

In order to stably and effectively supply chlorine while preventing the perovskite compound from being thermally damaged, it is advantageous that the chlorine source is an organic chloride having a pyrolysis temperature of 200 DEG C or lower. The organic chloride is advantageous because the organic material can be easily removed at the time of pyrolysis and residual impurities other than the desired chlorine can be prevented. It is also preferable that the organic chloride serving as the chlorine source has a pyrolysis temperature of 200 DEG C or less, specifically a pyrolysis temperature of 100 to 200 DEG C. The pyrolysis temperature of such organic chlorides is advantageous because it is possible to prevent the perovskite compound from being thermally damaged during thermal decomposition (heat treatment) for supplying chlorine, and the chlorine can be supplied by the intended heat treatment at the desired point It is advantageous to secure the thermal stability.

 More advantageously, the chlorine source is preferably a C1 to C3 alkylammonium chloride (C1-C3 alkylammonium chloride) and more advantageously the chlorine source is methylammonium chloride (methylammonium chloride). The low-carbon alkylammonium chloride of C1 to C3 is capable of ensuring the above-described thermal stability and is easily pyrolyzable and advantageous. In particular, methylammonium chloride is pyrolyzed stably at a low temperature at which the perovskite compound is not heat- It is more advantageous to not leave the residual impurities.

The active layer may contain 0.20 to 1.00 moles of chlorine source relative to 1.00 moles of the perovskite compound and specifically 0.25 to 0.50 moles of chlorine source relative to 1.00 moles of the perovskite compound.

When the active layer contains less than 0.20 moles of chlorine source relative to 1.00 moles of the perovskite compound, the chlorination of the perovskite compound may occur to some extent by the chlorine generated by pyrolysis, but the chlorination of the electron carrier does not occur There is a risk that the intended light stability effect is not exhibited or the effect is remarkably deteriorated. Further, when the active layer contains a chlorine source in excess of 1.00 moles per mole of the perovskite compound, a large amount of chlorine can be supplied, but there is also a risk that the amount of chlorine to be decomposed is increased and the film quality of the optical absorption layer is deteriorated.

 In view of the production method, an active solution containing a chlorine source and a perovskite compound and containing 0.20 to 1.00 mol, in particular 0.25 to 0.50 mol, of a chlorine source per 1.00 mol of the perovskite compound, , An active layer containing 0.20 to 1.00 mol, specifically 0.25 to 0.50 mol, of a chlorine source per 1.00 mol of the perovskite compound can be prepared.

The perovskite compound of the active layer may be an organometallic halide satisfying the formula (1), but is not limited thereto, and may be a perovskite structure known as a light absorber that absorbs light to generate photoelectrons and photo holes Of any organohalide metal halide.

(Formula 1)

AMX ₃

In formula 1, A is a first organic cation valence, M is a divalent metal ion, X is I ^-, Br ^-, F ^- and Cl ^- 1 alone or in combination of two or more substantially X is selected from is I ^-, Br ^-, and F ^- . Examples of M which is a divalent metal ion include Cu ²⁺ , Ni ²⁺ , Co ²⁺ , Fe ²⁺ , Mn ²⁺ , Cr ²⁺ , Pd ²⁺ , Cd ²⁺ , Ge ²⁺ , Sn ²⁺ , Pb ²⁺ and Yb ²⁺ , but is not limited thereto. A may be an amidinium group ion, an organic ammonium ion or an amidinium ion and an organic ammonium ion. Organic ammonium ions ^{_{(R 1 -NH 3 +) X}} (R 1 is an aryl-cycloalkyl or C6-C20 alkyl, C3-C20 of C1-C24, X is Cl ^-, Br ^-, F ^-, and I ^- (R ₂ -C ₃ H ₃ N ₂ ⁺ -R ₃ ) X wherein R ₂ is selected from the group consisting of C ₁ -C ₂₄ alkyl, C 3 -C 20 cycloalkyl or C 6 -C 20 aryl , R ₃ is hydrogen or C 1 -C ₂₄ alkyl, and X is one or more halogen ions selected from Cl ^- , Br ^- , F ^- and I ^- ). As a non-limiting and specific example, R ₁ may be a C ₁ -C ₂₄ alkyl, preferably a C ₁ -C 7 alkyl, more preferably a methyl. R ₂ can be C ₁ -C ₂₄ alkyl and R ₃ can be hydrogen or C 1 -C ₂₄ alkyl, preferably R ₂ can be C ₁ -C 7 alkyl and R ₃ can be hydrogen or C 1 -C 7 alkyl, More preferably R < ₂ > may be methyl and R < ₃ > may be hydrogen.

The amidinium ion may satisfy the following formula (2).

(2)

Wherein R ₄ to R ₈ are independently of each other hydrogen, C 1 -C ₂₄ alkyl, C 3 -C 20 cycloalkyl or C 6 -C 20 aryl. R ₄ to R ₈ independently of one another are hydrogen, amino or C 1 -C ₂₄ alkyl, specifically hydrogen, amino or C 1 -C 7 alkyl, more particularly hydrogen, Amino or methyl. More may be more specifically R ₄ is hydrogen, amino or methyl and R ₅ to R ₈ are hydrogen. Specific and non-limiting one example, an amidinyl you umgye ions formamidinium nium _{(formamidinium, NH 2 CH = NH} 2 +) ions, acetic amidinyl nium _{(acetamidinium, NH 2 C (CH} 3) = NH 2 +) Or guanidinium (NH ₂ C (NH ₂ ) = NH ₂ ⁺ ).

As described above, the monovalent organic ion (A) of the organic halide is a monovalent organic ammonium ion represented by the above-mentioned R ₁ -NH ₃ ⁺ or R ₂ -C ₃ H ₃ N ₂ ⁺ -R ₃ , An amidinium ion, or an organic ammonium ion and an amidinium ion.

When the monovalent organic ion includes both an organic ammonium ion and an amidinium ion, the organic halide is A ^' _1-x A _x X wherein A is a monovalent organic ammonium ion as described above, and A ^' And X is one or two or more halogen ions selected from I ^- , Br ^- , F ^- and Cl ^- , one or more selected from the group consisting of I ^- , Br ^- and F ^- , x is A real number of 0 < x < 1, preferably a real number of 0.3 of 0.05? X?). 1 contains an amidinium ion of 0.7 to 0.95 and an organic ammonium ion of 0.3 to 0.05 with the total molar amount of the organic cation being 1, it is possible to absorb light of a very wide wavelength band, ), And it is possible to move the photoelectrons and the optical holes faster, which is advantageous.

The active layer may be in the form of a layer covering the electron carrier. Specifically, when the electron carrier is in the form of a layer of a dense film, it may be in the form of a layer covering the upper surface of the dense film. When the electron transporting material is a porous structure including a porous film or the like, it may be in the form of a layer which fills the open pores of the electron transporting material and covers the electron transporting material.

The electron transporting material may be a metal oxide structure, and the metal oxide of the metal oxide structure may be used in a conventional quantum dot-based solar cell, a dye-sensitized solar cell, or a perovskite solar cell, Lt; / RTI &gt; As a specific example, the metal oxide may be an n-type metal oxide semiconductor. Non-limiting examples of the n-type metal oxide semiconductor include titanium oxide, zinc oxide, indium oxide, tin oxide, tungsten oxide, niobium oxide, molybdenum oxide, magnesium oxide, barium oxide, zirconium oxide, strontium oxide, , A vanadium oxide, an aluminum oxide, a yttrium oxide, a scandium oxide, a samarium oxide, a gallium oxide and a strontium-titanium oxide, or a mixture thereof (including a solid solution) . However, advantageously, according to the present invention, even when a metal oxide having an excellent electron transferring property and photodecomposing a perovskite compound and adversely affecting the lifetime of a solar cell is used, it can have extremely excellent light stability characteristics Accordingly, in order to effectively obtain the effect of the present invention and to maximize the efficiency of the solar cell, the metal oxide may be a metal oxide having photocatalytic activity. The metal oxide having photocatalytic activity to those skilled in the art is well-known materials. Specific examples thereof include titanium oxide, zinc oxide, zirconium oxide, tungsten oxide, a mixture thereof, and a complex (including solid solution thereof) But is not limited thereto.

 In the structure, the metal oxide structure may be a porous layer (porous membrane), or a laminate in which a dense layer (dense film) or a dense layer and a porous layer are laminated. That is, the metal oxide structure may be a laminate of a metal oxide dense film, a metal oxide porous film, or a metal oxide dense film metal oxide porous film. The porous film may be a porous film having a porous structure due to the intergranular space of the particles of the electron conductive metal oxide. However, the porous film is not limited thereto and may be a metal oxide film having open pores. The metal oxide of the porous film and the metal oxide of the dense film may be the same or different materials.

The thickness of the metal oxide porous film or the dense film may be 50 nm to 10 μm, specifically 50 nm to 1000 nm. In the case of a porous film, the specific surface area may be 10 to 100 m ² / g, and the average particle diameter of the metal oxide particles of the porous film may be 5 to 500 nm. The porosity (apparent porosity) of the porous membrane may be 30% to 65%, specifically 40% to 60%.

The structure may further include a first electrode located under the electron transporting body together with an electron transporting material and an active layer, and further may include a first substrate positioned under the first electrode, but the present invention is limited thereto It is not.

The present invention includes a method for manufacturing the above-described structure for a perovskite solar cell.

In detail, a method for fabricating a structure for a perovskite solar cell according to the present invention comprises: preparing an active layer by applying and drying an active solution containing a chlorine source and a perovskite compound on an upper portion of a metal oxide-based electron carrier; .

The structure and composition of the chlorine source, the metal oxide of the electron transporting material, the material of the perovskite compound, and the active layer are the same as or similar to those described above in the structure for the perovskite solar cell.

As mentioned above, the active solution may contain 0.20 to 1.00 moles of chlorine source relative to 1.00 moles of the perovskite compound, specifically 0.25 to 0.50 moles of chlorine source relative to 1.00 moles of the perovskite compound &Lt; / RTI &gt; The molar concentration of the perovskite compound and the chlorine source in the active solution may be within the dissolution limit of the solvent. As a practical, non-limiting example, the molar concentration of perovskite compound in the active solution may be from 0.1M to 0.8M.

The solvent of the active solution dissolves the chlorine source and the perovskite compound, and can be used as long as it is a solvent capable of easily removing volatiles. As a specific example in which the chlorine source is an organic chloride, the solvent of the active solution may be a non-aqueous polar organic solvent, and in one embodiment, the non-aqueous polar organic solvent may include gamma-butyrolactone, formamide, Methyl formamide, diformamide, acetonitrile, tetrahydrofuran, dimethyl sulfoxide, diethylene glycol, 1-methyl-2-pyrrolidone, N, N-dimethylacetamide, acetone, Any one selected from the group consisting of o-terpineol, dihydroterpineol, 2-methoxyethanol, acetylacetone, methanol, ethanol, propanol, isopropanol, butanol, pentanol, hexanol, ketone, methylisobutyl ketone Or two or more, but is not limited thereto.

The application of the active solution may be carried out by a method usually used for coating liquid or dispersed phase. For example, the coating may be dip coating, spin coating or casting, and the printing may be performed by screen printing, inkjet printing, electrostatic hydraulics printing, microcontact printing, imprinting, gravure printing, reverse offset printing or gravure offset printing However, it goes without saying that the present invention can not be limited by the specific application method.

Drying may be performed to volatilize the solvent of the applied active solution after the application, but this drying step may be selectively performed as the volatility of the solvent may be naturally dried in the application process. If drying is further carried out, the drying temperature may be a temperature below the pyrolysis temperature of the chlorine source so that the solvent of the active solution is readily volatilized and the chlorine source is not pyrolyzed. As a specific example, the temperature may be from room temperature to 50 ° C, but is not limited thereto.

Specifically, a method for fabricating a structure for a perovskite solar cell according to an embodiment of the present invention includes: forming a first electrode-based metal oxide based electron transporting material; And applying an active solution containing a chlorine source and a perovskite compound to an upper portion of the electron transporting material and drying the resultant to produce an active layer.

The electron transporting step may include a step of fabricating a metal oxide structure as a laminate in which a metal oxide porous film, a metal oxide porous film, or a metal oxide compacted metal oxide porous film is laminated on the first electrode.

Specifically, the metal oxide dense film may be manufactured by forming a dense film of a metal oxide through a deposition process such as physical vapor deposition or chemical vapor deposition, and the metal oxide porous film may be formed by applying a slurry containing metal oxide particles, And then drying and heat-treating the applied slurry layer. The application of the slurry may be performed by screen printing, spin coating, bar coating, gravure coating, blade coating and roll coating. But the present invention is not limited thereto. The average particle size of the metal oxide particles may be 5 to 500 nm, and the heat treatment may be performed at 200 to 600 ° C in air, but is not limited thereto. In forming the metal oxide porous film, the thickness of the metal oxide porous film produced by drying the applied slurry after heat treatment is, for example, 50 nm to 10 탆, preferably 50 nm to 5 탆, more preferably 50 nm To 1 mu m, but is not limited thereto.

The stacked body of the metal oxide compacted metal oxide porous film can be manufactured by forming a metal oxide dense film and then forming a metal oxide porous film on the metal oxide compacted film. The method of manufacturing the metal oxide compacted film and the method of manufacturing the metal oxide porous film The manufacturing method is the same as or similar to the above.

The active layer may be formed so as to directly contact the electron transporting body and directly contact the electron transporting body after the step of manufacturing the electron transporting body. The direct bonding between the electron transporting body and the active layer, The source is decomposed and the produced chlorine can be easily supplied to the electron carrier.

The present invention includes a structure for a perovskite solar cell manufactured by the above-described method for manufacturing a structure for a perovskite solar cell.

The present invention includes a method of manufacturing a perovskite solar cell using the above-described structure for a perovskite solar cell.

The method of manufacturing a perovskite solar cell according to the present invention comprises thermally decomposing a chlorine source by thermally treating a solar cell structure.

The heat treatment temperature for thermal decomposition of the chlorine source, advantageously the organic chloride, more advantageously the C1-C3 alkylammonium chloride, can satisfy the following relational expression (1).

(Relational expression 1)

T _dc ≤ T _heat ≤ 200 ℃

T _heat is the heat treatment temperature (캜), and T _dc is the pyrolysis temperature (캜) of the chlorine source.

On the basis of the more advantageous C 1 -C 3 alkylammonium chloride, T _dc can be 100-200 ° C, more specifically 100-150 ° C. Specifically, T _heat may be 100 to 200 캜, and more specifically 130 to 180 캜. At this time, the heat treatment atmosphere for pyrolysis may be air, and the pyrolysis time may be 5 to 15 minutes, but it is not limited thereto.

The chlorine source is pyrolyzed by the heat treatment of the structure and chlorine is generated and the chlorine generated by the pyrolysis is supplied to the perovskite compound and the electron transporting material so that the light absorbing layer containing the perovskite compound to which chlorine is added and the chlorine- An electron donor can be prepared. That is, the pyrolysis step may be a step of thermally decomposing the solar cell structure by thermally decomposing the solar cell structure to produce a light absorption layer, which is an active layer remaining after pyrolysis of the chlorine source, and the pyrolysis step is a step of thermally decomposing the chlorine source , A step of producing an electron transporting material containing a light absorption layer containing a chlorine and a perovskite compound and a metal oxide and a chlorine.

The method for manufacturing a perovskite solar cell according to an embodiment of the present invention may further include forming a metal oxide based electron transport material on the first electrode before the thermal decomposition step, And forming a hole transporting material on the upper part of the light absorbing layer, which is an active layer remaining after pyrolysis of the chlorine supply source. In addition, it is needless to say that the step of forming the second electrode, which is the charging electrode of the first electrode, on the hole carrier may be performed after the step of forming the hole carrier.

The electron carrier formation step is similar to or similar to that described above in the method of manufacturing the structure for a perovskite solar cell.

 The hole transporting material may be an organic hole transporting material, an inorganic hole transporting material, or a laminate thereof, but may be an organic hole transporting material which can be prepared by a solution process and has excellent hole transporting properties.

The organic hole transporting material may include an organic hole transporting material, specifically, a monomolecular or polymer organic hole transporting material (hole transporting organic material). The organic hole transport material can be used as an organic hole-transporting material used in conventional inorganic semiconductor-based solar cells or perovskite solar cells using inorganic semiconductor quantum dots as dyes.

Non-limiting examples of organic hole transport materials include pentacene, coumarin 6, 3- (2-benzothiazolyl) -7- (diethylamino) coumarin, ZnPC (zinc phthalocyanine), CuPC (copper phthalocyanine) , Titanium oxide phthalocyanine (TiOPC), Spiro-MeOTAD (2,2,2 ', 7,7,7'-tetrakis (N, N-di-p- methoxyphenyl amine) , F16CuPC (copper (II) 1,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25-hexadecafluoro-29H, 31H-phthalocyanine), SubPc boron subphthalocyanine chloride, N3 (cis-di (thiocyanato) -bis (2,2'-bipyridyl-4,4'-dicarboxylic acid) -ruthenium (II)), P3HT PPV (poly [2-methoxy-5- (3 ', 7'-dimethyloctyloxyl)] - 1,4-phenylene vinylene), MEH-PPV 3-octyl thiophene), POT (poly (octyl thiophene)), P3DT (poly-3-decyl thiophene), P3DDT (poly (3-dodecyl thiophene) (p-phenylene vinylene), poly (9,9'-dioctylfluorene-co-N- (4-butylphenyl) diphenyl amine), Polyaniline, Spiro- , 7,77'-tetrkis (N, N-di-p-methoxyphenyl amine) -9,9,9'-spirobi fluorine]), PCPDTBT (Poly [2,1,3-benzothiadiazole- 4,4-bis (2-ethylhexyl-4H-cyclopenta [2,1-b: 3,4-b '] dithiophene-2,6-diyl]], Si-PCPDTBT (poly [ (2-ethylhexyl) dithieno [3,2-b: 2 ', 3'-d] silole) -2,6-diyl-6- (2,1,3-benzothiadiazole) -4,7- PBDTTPD (poly ((4,8-diethylhexyloxyl) benzo [1,2-b: 4,5-b '] dithiophene) -2,6-diyl) ] pyrrole-4,6-dione) -1,3-diyl), PFDTBT (poly [2,7- (9- (2-ethylhexyl) -9- 2 ', 1', 3'-benzothiadiazole)], PFO-DBT (poly [2,7-9,9- (dioctyl-fluorene) (2,7-dioctylsilofluorene) -2,7-diyl-lower-2 ', 1', 3'-benzothiadiazole)]), PSiFDTBT (poly [ (4,7-bis (2-thienyl) -2,1,3-benzothiadiazole) -5,5'-diyl], PSBTBT (poly [(4,4'- bis (2-ethylhexyl) dithieno [ 2-b: 2 ', 3'-d] silole) -2,6-diyl-6- (2,1,3-benzothiadiazole) -4,7-diyl], PCDTBT (Poly [ -acetylonyl) -9H-carbazole-2,7-diyl] -2,5-thiophenediyl-2,1,3-benzothiadiazole zole-4,7-diyl-2,5-thiophenediyl], PFB (poly (9,9'-dioctylfluorene-co-bis (N, N '- Poly-3,4-ethylenedioxythiophene (PEDOT), PEDOT (poly (3,4-ethylenedioxythiophene) but are not limited to, one or more selected from poly (styrenesulfonate), PTAA (poly (triarylamine)), poly (4-butylphenyl-diphenyl-amine) and copolymers thereof.

Organic-based hole transport materials include tertiary butyl pyridine (TBP), lithium bis (trifluoromethanesulfonyl) imide (LiTFSI) and tris (2- (1H-pyrazol-1-yl) pyridine) which are commonly used for improving properties such as conductivity improvement. ) cobalt (III), and the like.

The hole carrier forming step may be performed by applying a solution containing an organic hole transporting material (hereinafter referred to as an organic hole transporting solution) and drying the organic hole transporting material so as to cover the upper part of the light absorption layer. The solvent used for forming the hole transporting material may be a solvent in which the organic hole transporting material is dissolved and the perovskite compound and the electron transporting material are not chemically reacted. For example, the solvent used to form the hole transporting material can be a nonpolar solvent and can be, for example, toluene, chloroform, chlorobenzene, dichlorobenzene, anisole, ), Xylene, and a hydrocarbon-based solvent having 6 to 14 carbon atoms, and the like.

The hole transporting material prepared by applying the organic hole transporting solution may be a thin film of an organic hole transporting material, and the thickness of the thin film may be 10 nm to 500 nm, but is not limited thereto.

The electrode (the first electrode or the second electrode) may be a conductive electrode that is ohmic-bonded to an adjacent charge carrier (an electron carrier or a hole carrier), and may be a material commonly used as an electrode material of a front electrode or a rear electrode in a solar cell Available. In a non-limiting example, when the electrode is an electrode material of the back electrode, the electrode is a material selected from one or more of gold, silver, platinum, palladium, copper, aluminum, carbon, cobalt sulphide, copper sulphide, nickel oxide, . In a non-limiting example, when the second electrode is a transparent electrode, the electrode may include a fluorine-containing tin oxide (FTO), indium doped tin oxide (ITO), ZnO, CNT ), Graphene, and may be an organic conductive electrode such as PEDOT: PSS.

The electrode (first electrode or second electrode) may be formed through a conventional metal deposition method used in a semiconductor process. As an example, the electrode (first electrode or second electrode) may be formed through a deposition process such as physical vapor deposition or chemical vapor deposition, and may be formed by thermal vapor deposition in particular.

The present invention includes a perovskite solar cell manufactured by the above-described solar cell manufacturing method.

A perovskite solar cell according to the present invention includes: an electron carrier containing a metal oxide and a chlorine; And a light absorbing layer comprising a perovskite compound located on the top of the electron transporting material and containing chlorine; And a hole carrier positioned above the light absorption layer.

The electron transporting material may contain a relatively large amount of chlorine relative to the light absorbing layer and the interface between the electron transporting material and the light absorbing layer may also contain a relatively large amount of chlorine relative to the light absorbing layer. With a light absorbing layer chlorinated by the chlorine generated from the inside of the solar cell and an electron carrier containing an electron carrier, especially a relatively large amount of chlorine, the solar cell exhibits surprisingly excellent light stability with excellent initial photoelectric conversion efficiency .

In terms of the production method, the perovskite solar cell according to one embodiment of the present invention is a solar cell in which an electron containing chlorine (added) metal oxide by chlorine generated by pyrolysis of a chlorine source mixed with a perovskite compound Carrier; A light absorbing layer comprising a perovskite compound located on top of the electron carrier and chlorinated (added) with chlorine generated by pyrolysis of the same chlorine source; And a hole carrier positioned above the light absorption layer.

The chlorine content in the light absorbing layer and the electron transporting material is preferably such that the active layer containing 0.20 to 1.00 moles of chlorine source relative to 1.00 moles of the perovskite compound is thermally treated at a temperature of 100 to 200 캜, specifically 130 to 180 캜, The chlorine source of the active layer is pyrolyzed, the active layer is chlorinated by the pyrolysis and the perovskite compound of the light absorbing layer is chlorinated, and at the same time, the electron transporting material is chlorinated by the chlorine provided by pyrolysis.

The light absorption layer may be in the form of a layer covering the electron transporting material. Specifically, the light absorption layer may be a perovskite compound layer located on the metal oxide densified film when the electron transporting material is a layer of a dense film. When the electron carrier is a porous structure including a porous film or the like, it may be a perovskite compound layer that fills open pores of the electron carrier and covers the electron carrier. The thickness of the light absorbing layer may be 100 nm to 1000 nm, but is not limited thereto.

The perovskite solar cell according to an embodiment of the present invention may further include a first electrode positioned below the electron transporting body and a second electrode located above the hole transporting body.

The materials of the electron transporting material, the hole transporting material, the perovskite compound, the chlorine source, the first electrode, and the second electrode of the perovskite solar cell are previously described in the production method of the solar cell, the structure for the perovskite solar cell, Are the same as or similar to those described above in the production method.

Hereinafter, the technical superiority of the present invention is experimentally demonstrated by preparing a solar cell using a methylammonium chloride salt as an advantageous chlorine supply source and testing its photoelectric conversion characteristics and light stability.

(Example 1)

After cutting a glass substrate (FTO: F-doped SnO ₂ , 8 ohms / cm 2, Pilkington, hereinafter referred to as FTO substrate) coated with fluorine-containing tin oxide to a size of 25 x 25 mm, the end portion was etched to partially remove the FTO Respectively.

A 50 ㎚ thick TiO ₂ dense film as a metal oxide thin film was prepared by spray pyrolysis on the cut and partially etched FTO substrate. Spray pyrolysis was carried out using a solution of titanium acetylacetonate (TAA): ethanol (1: 9 v / v%), spraying for 3 seconds on the FTO substrate placed on a hot plate kept at 450 ° C and stopping for 10 seconds The thickness was adjusted by the method.

TiO ₂ powder having an average particle size (diameter) of 50 nm (prepared by hydrothermally treating titanium peroxocomplex aqueous solution of 1 wt% based on TiO ₂ dissolved therein at 250 ° C for 12 hours) was mixed with 10% by weight of ethyl cellulose the ethyl cellulose solution in ethanol, and mixed with 5 ㎖ added per TiO ₂ powder 1g, adding the hotel pinol (terpinol) 5 g per 1 g TiO ₂ powder, a TiO ₂ paste by removing the ethanol by vacuum distillation .

Ethanol was added to the TiO ₂ powder paste so that the weight ratio was 1 (powder paste): 5 (ethanol) to prepare a TiO ₂ slurry for spin coating. On the TiO ₂ thin films of FTO substrate, spin-coated TiO coating (2500rpm) spin a _second slurry and heat treated at 500 ℃ for 60 minutes to prepare a porous TiO ₂ thin film thickness of 1000nm. The prepared porous TiO ₂ thin film had a specific surface area of 33 m 2 / g and a porosity (apparent porosity) of 50%.

To prepare the active solution, FAPbI ₃ (FA = formamidinium) and MAPbBr ₃ (MA = methylammonium) were dissolved in 0.8 ml of N, N-dimethylformamide and 0.1 ml of dimethylsulfoxide at a molar ratio of 0.85: A solution in which a perovskite compound was dissolved was prepared. A methylammonium chloride salt was added to the solution so that the molar ratio of perovskite compound: methylammonium chloride (CH ₃ NH ₃ Cl, hereinafter referred to as MACl) was 1: 0.25 To prepare an active solution.

The prepared active solution was coated on the porous TiO ₂ thin film and spin-coated at 5000 rpm to produce an active layer, followed by heat treatment at 150 ° C. for 10 minutes to thermally decompose the chlorine source and chlorinate the electron transporting material and the perovskite compound A light absorbing layer containing a chlorinated electron donor and a chlorinated perovskite compound was prepared. At the time of manufacturing the light absorbing layer, the surrounding environment was maintained at a temperature of 25 ° C and a relative humidity of 25%.

Thereafter, a solution (10 mg (PTAA) / 1 ml (toluene)) in which PTAA (poly (triarylamine)) was dissolved on the perovskite compound layer was spin-coated at 3000 rpm for 60 seconds to form a hole transport layer .

Thereafter, an Au electrode (second electrode) having a thickness of 70 nm was formed on the hole transporting layer by vacuum evaporation of Au with a thermal evaporator of a high vacuum (5 × 10 ^-6 torr or less) to produce a solar cell .

(Comparative Example 1)

In place of the active solution, FAPbI ₃ (FA = formamidinium) and MAPbBr ₃ (MA = methylammonium) were dissolved in 0.8 ml of N, N-dimethylformamide and 0.1 ml of dimethylsulfoxide at a molar ratio of 0.85: 0.15, A solar cell was prepared in the same manner as in Example 1 except that a solution in which a lobbing compound was dissolved was applied to an electron transporting material to prepare a light absorbing layer as a perovskite compound layer.

Fig. 1 is a graph showing the results of Cu K? X-ray diffraction analysis of the light absorbing layer prepared in Example 1 and Comparative Example 1. Fig. As can be seen from FIG. 1, when the inner chlorine source is used for the heat treatment, characteristic peaks of perovskite are observed at 14 ° (= 2θ) and 28 °, and other secondary phases are almost absent. However, in the case of the comparative example heat-treated without an internal chlorine source, the perovskite peak intensity is also very small and a large amount of other secondary phases are present. It can be seen from Fig. 1 that by the chlorine supply source, a light absorption layer which is an extremely highly oriented perovskite compound layer reaching pseudo single crystals is formed.

FIG. 2 is a graph showing a result of composition analysis according to depth by analyzing the solar cell manufactured in Example 1 by TOF-SIMS. FIG. It should be noted that the halogen element of the perovskite compound is I and Br in Example 1, and that the chlorine provided by the chlorine source (i.e., the chlorine caused by the chlorine source) It can be confirmed that it is added to the light absorbing layer and the electron transporting material. Further, as can be seen from Fig. 2, when the internal chlorine source is pyrolyzed, Cl component was present in a relatively large amount in the porous TiO ₂ thin film, and it was found that the light absorption layer also contained a small amount of Cl component.

(Performance evaluation)

The performance of the solar cell was evaluated by the following method using the perovskite solar cell manufactured through Example 1 and Comparative Example 1, and the results are shown in Table 1 and FIG. 3, (Y-axis η1 / η0, the time for which the solar cell was exposed to a light source at a wavelength of 280 to 2500 nm under the constant temperature and humidity conditions of a temperature of 30 ° C. and a humidity of 25% at a sunshine strength of 1,000 W / Respectively.

1) current-voltage characteristic: the artificial sun device (ORIEL class A solar simulator, Newport , model 91195A) and the source - by using m (source-meter, Kethley, model 2420), the open-circuit voltage (V _OC), short circuit current density (J _SC ) and fill factor (FF) were measured.

2) Power conversion efficiency (PCE): 1000 W / m &lt; 2 &gt;, a perovskite solar cell manufactured through Example 1 and Comparative Example 1 at a temperature of 30 DEG C and a humidity of 25% Was exposed to a light source having a wavelength of 280 to 2500 nm to measure the PCE value.

3) Optical Stability: The optical stability was evaluated by substituting the measured PCE value according to the photoelectric conversion efficiency into the following equation.

Calculation formula = (? 1 /? 0) X 100

In the calculation formula, eta 0 is the initial photoelectric conversion efficiency, which is the photoelectric conversion efficiency (%) of the perovskite solar cell immediately after exposure to light, and η1 is the photoelectric conversion efficiency after the exposure of the same perovskite solar cell to light for a certain period of time %)to be. The light exposure condition in the measurement of eta 1 is the same as the photoelectric conversion efficiency measurement condition.

(Table 1)

As can be seen from Table 1, it can be confirmed that the solar cell in which the perovskite compound and the electron carrier are chlorinated by the internal chlorine source according to the present invention has better performance than the conventional perovskite solar cell . Also, as can be seen from FIG. 4, it can be seen that the photovoltaic cell according to the present invention does not substantially lower the photoelectric conversion efficiency even with continuous light irradiation for 1000 hours at a sunlight intensity of 1,000 W / m 2.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Those skilled in the art will recognize that many modifications and variations are possible in light of the above teachings.

Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

Claims (11)

A metal oxide-based electron transporting material; And
An active layer located on the electron transporting body and including a chlorine source and a perovskite compound;
Wherein the solar cell is a solar cell. The method according to claim 1,
Wherein the chlorine supply source contained in the active layer supplies chlorine to at least the electron carrier by thermal decomposition. The method according to claim 1,
Wherein the active layer comprises 0.20 to 1.00 moles of chlorine source relative to 1.00 moles of the perovskite compound. The method according to claim 1,
Wherein the chlorine source is an organic chloride having a pyrolysis temperature of 200 DEG C or less. The method according to claim 1,
Wherein the chlorine source is a C1 to C3 alkyl ammonium chloride. A method of manufacturing a perovskite solar cell, comprising: heat treating a solar cell structure according to any one of claims 1 to 5 to pyrolyze a chlorine source. The method according to claim 6,
After the pyrolysis step,
And forming a hole transporting material on top of the light absorbing layer, which is an active layer remaining after the chlorine source is pyrolyzed. The method according to claim 6,
Wherein the heat treatment temperature satisfies the following relational expression (1): &quot; (1) &quot;
(Relational expression 1)
T _dc ≤ T _heat ≤ 200 ℃
(T _heat is the heat treatment temperature (占 폚), and T _dc is the thermal decomposition temperature (占 폚) of the chlorine source) A perovskite solar cell produced by the manufacturing method according to claim 6. An electron carrier containing a metal oxide and a chlorine; And
A light absorbing layer disposed on the electron transporting body and containing a perovskite compound containing chlorine; And
A hole transporting layer located above the light absorbing layer;
A perovskite solar cell. 11. The method of claim 10,
A perovskite solar cell having light stability satisfying the following relational expression (2).
(Equation 1)
98? (? 1 /? 0) X 100
(eta 0 is the initial photoelectric conversion efficiency, which is the photoelectric conversion efficiency (%) of the perovskite solar cell immediately after exposure to light, and eta 1 is the photoelectric conversion efficiency after the same perovskite solar cell is continuously exposed to light for 1000 hours (%), And the light exposure condition is a light source of a sunshine intensity of 1,000 W / m 2, a temperature of 25 캜, a humidity of 25% and a wavelength of 280 to 2500 nm)

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