KR20200034637A - Organic-inorganic complex solar cell - Google Patents

Abstract

The present specification provides an organic-inorganic complex solar cell. The organic-inorganic complex solar cell comprises: a first electrode; a light absorbing layer including a compound of perovskite structure disposed on the first electrode; an insertion layer disposed on the light absorption layer; a hole transport layer disposed on the insertion layer; and a second electrode disposed on the hole transport layer, wherein the light absorbing layer further includes a fluorine-based additive, and the insertion layer includes at least one of CuSCN, CuI, CuBr, CuCl, CuPc, and Cu-doped NiO.

Description

Organic-Inorganic Composite Solar Cell {ORGANIC-INORGANIC COMPLEX SOLAR CELL}

This application claims the benefit of the filing date of Korean Patent Application No. 10-2018-0113932 filed with the Korean Intellectual Property Office on September 21, 2018, all of which is incorporated herein.

This specification relates to an organic-inorganic composite solar cell.

In order to solve the global environmental problems caused by the depletion of fossil energy and its use, research on renewable and clean alternative energy sources such as solar energy, wind power, and hydropower has been actively conducted. Among them, interest in solar cells that directly change electrical energy from solar light is increasing. Here, a solar cell means a battery that absorbs light energy from sunlight and generates current-voltage using a photovoltaic effect that generates electrons and holes.

The organic-inorganic composite perovskite material has recently been spotlighted as an organic-inorganic composite solar cell light absorbing material because of its high absorption coefficient and its ability to be easily synthesized through a solution process.

However, in the case of the organic-inorganic composite solar cell using the existing perovskite material, despite the high efficiency, due to the thermal stability of the p-type dopant applied to the hole transport layer and the deterioration of the light absorbing layer by the p-type dopant There is a problem that long-term driving stability is lowered. In particular, there is a problem that the p-type dopant diffuses into the perovskite layer and reacts, thereby deteriorating the perovskite layer. When the temperature of the device increases, this reaction is further exacerbated, causing serious problems in the high temperature stability of the device.

Therefore, in order to solve this improvement in durability and fairness, it is necessary to introduce a functional layer that prevents diffusion of the p-type dopant.

Adv. Mater. 2014, 26, 4991-499

The present specification provides an organic-inorganic composite solar cell.

An exemplary embodiment of the present specification is a first electrode;

A light absorbing layer comprising a perovskite compound provided on the first electrode;

An insertion layer provided on the light absorption layer;

A hole transport layer provided on the insertion layer; And

It includes a second electrode provided on the hole transport layer,

The light absorbing layer further includes a fluorine-based additive,

The insertion layer provides an organic-inorganic composite solar cell comprising one or more of CuSCN, CuI, CuBr, CuCl, CuPc, and Cu-doped NiO.

The organic-inorganic composite solar cell according to an exemplary embodiment of the present specification is excellent in long-term stability at room temperature and high temperature.

The organic-inorganic composite solar cell according to the exemplary embodiment of the present specification can absorb a wide spectrum of light, thereby reducing light energy loss and increasing energy conversion efficiency.

The organic-inorganic composite solar cell according to an exemplary embodiment of the present specification has an effect of improving hysteresis.

1 and 2 are diagrams illustrating the structure of an organic-inorganic composite solar cell according to an exemplary embodiment of the present specification.
3 is a view showing the results of the reverse scan and forward scan measurement of the organic-inorganic composite solar cell prepared in Example 1.
4 is a view showing the results of the reverse scan and forward scan measurement of the organic-inorganic composite solar cells prepared in Examples 2 and 3.
5 is a view showing the results of the reverse scan and forward scan measurement of the organic-inorganic composite solar cell prepared in Comparative Example 1.
6 is a view showing the reverse scan and forward scan measurement results of the organic-inorganic composite solar cell prepared in Comparative Example 2.
7 is a view showing the results of the stability evaluation at 85 ℃ of the organic-inorganic composite solar cell prepared in Example 1 and Comparative Example 1.

Hereinafter, the present specification will be described in detail.

In this specification, when it is said that a part "includes" a certain component, this means that other components may be further included instead of excluding other components unless otherwise specified.

In the present specification, when it is said that a member is positioned “on” another member, this includes not only the case where one member abuts another member, but also the case where another member is present between two members.

An exemplary embodiment of the present specification is a first electrode;

A light absorbing layer comprising a perovskite compound provided on the first electrode;

An insertion layer provided on the light absorption layer;

A hole transport layer provided on the insertion layer; And

It includes a second electrode provided on the hole transport layer,

The light absorbing layer further includes a fluorine-based additive,

The insertion layer provides an organic-inorganic composite solar cell comprising one or more of CuSCN, CuI, CuBr, CuCl, CuPc, and Cu-doped NiO.

The insert layer material is a p-type inorganic compound having excellent hole transport properties, has a suitable valence band energy size with a perovskite interface, and has no conflict with the valence band energy size with a hole transport layer going up there, so there is a problem in hole transport properties. none. In addition, the large band gap has a small visible light absorption and has an effective electron blocking property, thereby enabling efficient hole transport without recombination in the hole transport layer. In addition, since the conductivity is high, charge accumulation at the interface between the light absorbing layer and the insertion layer is small, and thus the device hysteresis characteristics can be reduced.

In one embodiment of the present specification, the insertion layer includes a Cu composite or an oxide doped with Cu. The Cu composite is at least one of CuSCN, CuI, CuBr, CuCl and CuPc.

In the present specification, the Cu-doped NiO means NiO doped with Cu.

In one embodiment of the present specification, the insertion layer includes 1 to 3 of CuSCN, CuI, CuBr, CuCl, CuPc, and Cu-doped NiO.

1 shows an organic-inorganic composite solar cell according to an exemplary embodiment of the present specification. Specifically, FIG. 1 shows an organic-inorganic composite solar cell in which the first electrode 10, the light absorbing layer 20, the insertion layer 30, the hole transport layer 40, and the second electrode 50 are sequentially stacked. Did.

In one embodiment of the present specification, valence band energy of the insertion layer has an energy level between the HOMO level of the compound of the perovskite structure and the HOMO level of the hole transport layer.

That is, the valence band energy difference between the insertion layer and the photoactive layer is smaller than the valence band energy difference between the hole transport layer and the photoactive layer. Accordingly, the charge injection barrier between the light absorbing layer and the hole transport layer can be reduced to improve hysteresis due to charge accumulation at the interface.

In one embodiment of the present specification, the valence band energy is measured using an UPS (ultra violet photoelectron spectroscopy) analysis equipment. Specifically, the valence band energy is measured by irradiating ultraviolet rays having energy of several tens of eV to excite the electrons at the outermost valence band of the sample and measuring the emission.

In one embodiment of the present specification, the valence band energy of the insertion layer is 4.8 eV to 5.6 eV. Specifically, the valence band energy of the insertion layer is 5.0 eV to 5.4 eV.

Generally, the hole transport layer includes a hole transport material (eg, spiro-OMETAD) and a p-type dopant (eg, Li (TFSi)). Since the conventional organic-inorganic composite solar cell is provided in contact with the hole transport layer and the light absorbing layer, the p-type dopant is in contact with the light absorbing layer. Accordingly, a void is formed through a chemical reaction in the light absorbing layer, thereby causing a problem of deterioration of the device and a decrease in long-term stability. In addition, since the difference between the valence band of the hole transport material and the valence band of the light absorbing layer is large, charge accumulation and hysteresis due to a barrier occurs during hole transport, and thus the performance of the device is deteriorated.

On the other hand, in one embodiment of the present specification, by introducing an insertion layer between the light absorbing layer and the hole transporting layer, the ions in the light absorbing layer are prevented from diffusing into the hole transporting layer, and the valence band energy between each layer is controlled to solve the aforementioned problems. It shows the effect of improving (deterioration, poor long-term stability, poor performance).

In the present specification, the “hysteresis phenomenon” may be compared by obtaining a hysteresis diagram through Equation 1 below.

Equation (1):

는 reverse scan에서, 개방전압(V_oc)의 80%에 해당하는 전압 인가 시 측정된 전류밀도이다. In the formula (1),

Is the current density measured when a voltage corresponding to 80% of the open voltage (V _oc ) is applied in a reverse scan.

는 forward scan에서, 개방전압(V_oc)의 80%에 해당하는 전압 인가 시 측정된 전류밀도이다.In the formula (1),

Is the current density measured when a voltage corresponding to 80% of the open voltage (V _oc ) is applied in the forward scan.

The reverse scan is an IV scan in the direction of the short-circuit current from the open voltage, and the forward scan is an IV scan in the direction of the open voltage from the short-circuit current.

The hysteresis is an index indicating the degree of hysteresis of the device, and has a value of 0 to 1, which means that there is no history as it approaches 0.

In the present specification, "valence value vs. energy" means the amount of energy. Therefore, even when the valence band energy is displayed in the negative (-) direction of the conduction band, the valence band energy is interpreted to mean the absolute value of the corresponding energy value. For example, the highest occupied molecular orbital (HOMO) energy level means the distance from the conduction band to the highest occupied molecular orbital. In addition, the LUMO (lowest unoccupied molecular orbital) energy level means the distance from the conduction band to the lowest unoccupied molecular orbital.

In one embodiment of the present specification, the thickness of the insertion layer is 1 nm to 500 nm. Specifically, the thickness of the insertion layer is 10nm to 100nm.

When the thickness of the insertion layer satisfies the above range, the surface roughness of the light absorbing layer is flattened to reduce phenomena such as charge accumulation occurring at the interface, and the generation of micropores in the insertion layer is suppressed to prevent the dopant diffused from the upper hole transport layer. It can be effectively prevented.

In one embodiment of the present specification, the light absorbing layer includes a compound having a perovskite structure.

In one embodiment of the present specification, the compound of the perovskite structure is represented by any one of the following Chemical Formulas 1 to 3.

[Formula 1]

R1M1X1 ₃

[Formula 2]

R2 _a R3 _(1-a) M2X2 _z X3 _(3-z)

[Formula 3]

R4 _b R5 _c R6 _d M3X4 _{z '} X5 _(3-z')

In Chemical Formulas 1 to 3,

R2 and R3 are different from each other,

R4, R5 and R6 are different from each other,

R1 to R6 are each independently C _n H _{2n + 1} NH ₃ ⁺ , NH ₄ ⁺ , HC (NH ₂ ) ₂ ⁺ , Cs ⁺ , Rb ⁺ , NF ₄ ⁺ , NCl ₄ ⁺ , PF ₄ ⁺ , PCl ₄ ⁺ , CH ₃ PH ₃ ⁺ , CH ₃ AsH ₃ ⁺ , CH ₃ SbH ₃ ⁺ , PH ₄ ⁺ , AsH ₄ ⁺ and SbH ₄ ⁺ is a monovalent cation selected from,

M1 to M3 are the same as or different from each other, and each independently Cu ^{2 +} , Ni ^{2 +} , Co ^{2 +} , Fe ^{2 +} , Mn ²⁺ , Cr ^{2 +} , Pd ^{2 +} , Cd ^{2 +} , Ge ^{2 +} , Sn ^{2 +} , Bi ^{2 +} , Pb ^{2 +} and a divalent metal ion selected from Yb ^{2 +} ,

X1 to X5 are the same as or different from each other, and each independently a halogen ion,

n is an integer from 1 to 9,

a is a real number of 0 <a <1,

b is a real number of 0 <b <1,

c is a real number in 0 <c <1,

d is a real number of 0 <d <1,

b + c + d is 1,

z is a real number of 0 <z <3,

z 'is a real number of 0 <z' <3.

In one embodiment of the present specification, the compound of the perovskite structure of the light absorbing layer may include a single cation. In the present specification, a single cation means that one type of monovalent cation is used. That is, in Formula 1, R1 means that only one type of monovalent cation was selected. For example, R1 in Chemical Formula 1 is C _n H _{2n + 1} NH ₃ ⁺ , and n may be an integer from 1 to 9.

In one embodiment of the present specification, the compound of the perovskite structure of the light absorbing layer may include a complex cation. In the present specification, the complex cation means that two or more kinds of monovalent cations are used. That is, in Formula 2, it is meant that a monovalent cation in which R2 and R3 are different from each other is selected, and in Formula 3, a monovalent cation in which R4 to R6 are different from each other is selected. For example, R2 in Chemical Formula 2 may be C _n H _{2n + 1} NH ₃ ⁺ , and R3 may be HC (NH ₂ ) ₂ ⁺ . In addition, R4 in Chemical Formula 3 may be C _n H _{2n + 1} NH ₃ ⁺ , R5 may be HC (NH ₂ ) ₂ ⁺ , and R6 may be Cs ⁺ .

In one embodiment of the present specification, the compound of the perovskite structure is represented by Chemical Formula 1.

 In one embodiment of the present specification, the compound of the perovskite structure is represented by Chemical Formula 2.

In one embodiment of the present specification, the compound of the perovskite structure is represented by Chemical Formula 3.

In one embodiment of the present specification, R1 to R6 are each C _n H _{2n + 1} NH ₃ ⁺ , HC (NH ₂ ) ₂ ⁺ or Cs ⁺ . At this time, R2 and R3 are different from each other, and R4 to R6 are different from each other.

In one embodiment of the present specification, R1 is CH ₃ NH ₃ ⁺ , HC (NH ₂ ) ₂ ⁺ or Cs ⁺ .

In one embodiment of the present specification, R2 and R4 are each CH ₃ NH ₃ ⁺ .

In one embodiment of the present specification, R3 and R5 are each HC (NH ₂ ) ₂ ⁺ .

In one embodiment of the present specification, R6 is Cs ⁺ .

In one embodiment of the present disclosure, the M1 to M3 are each a Pb ^{+ 2.}

In one embodiment of the present specification, X2 and X3 are different from each other.

In one embodiment of the present specification, X4 and X5 are different from each other.

In one embodiment of the present disclosure, the X1 to X5 each is F ^- is ^- or Br.

In an exemplary embodiment of the present specification, in order that the sum of R2 and R3 becomes 1, a is a real number of 0 <a <1. Also, in order that the sum of X2 and X3 becomes 3, z is a real number of 0 <z <3.

In one embodiment of the present specification, in order for the sum of R4, R5, and R6 to become 1, b is a real number of 0 <b <1, c is a real number of 0 <c <1, and d is 0 <d <1 is a real number, and b + c + d is 1. In addition, in order that the sum of X4 and X5 becomes 3, z 'is a real number of 0 <z' <3.

In one embodiment of the present specification, the compound of the perovskite structure is CH ₃ NH ₃ PbI ₃ , HC (NH ₂ ) ₂ PbI _{3 ,} CH ₃ NH ₃ PbBr ₃ , HC (NH ₂ ) ₂ PbBr ₃ , (CH ₃ NH ₃ ) _a (HC (NH ₂ ) ₂ ) _(1-a) PbI _z Br _(3-z) or (HC (NH ₂ ) ₂ ) _b (CH ₃ NH ₃ ) _c Cs _d PbI _{z '} Br _(3-z') , a is a real number of 0 <a <1, b is a real number of 0 <b <1, c is a real number of 0 <c <1, d is a real number of 0 <d <1, b + c + d is 1, z is a real number of 0 <z <3, z 'is a real number of 0 <z'<3 .

In one embodiment of the present specification, the light absorbing layer further includes a fluorine-based additive.

In the present specification, the fluorine-based additive means a compound containing fluorine in the main chain of the compound.

In one embodiment of the present specification, the fluorine-based additive contains at least one member from the group consisting of a fluorine group and a fluoroalkyl group in the main chain of the compound.

In one embodiment of the present specification, the fluoroalkyl group means that the alkyl group is substituted with at least one fluorine group (F). For example, the fluoroalkyl group may be a perfluoroalkyl group.

In one embodiment of the present specification, the fluorine-based additive serves as a surfactant in the exciton generating layer. For example, the fluorine-based additive includes a fluorine-based surfactant.

In the present specification, the fluorine-based surfactant means a surfactant containing fluorine in the main chain of the surfactant.

In one embodiment of the present specification, the fluorine-based additive may be used without limitation as long as it is a material used in the art. Specifically, a compound whose main chain contains a hydrophilic group, a lipophilic group, and a fluorine group; A compound whose main chain contains a hydrophilic group, a lipophilic group, and a fluoroalkyl group; A compound whose main chain contains a hydrophilic group, a lipophilic group, and a perfluoroalkyl group; Alternatively, the main chain may be a compound including a hydrophilic group, a lipophilic group, a fluorine group, and a perfluoroalkyl group, but is not limited thereto.

In one embodiment of the present specification, the fluorine-based additive may be represented by Formula A below.

[Formula A]

In the formula (A), x and y are each an integer of 1 to 10.

Specifically, as the fluorine-based additive, Dupont FS-31, Zonyl FS-300, DIC RS-72-K or 3M FC-4430 may be used.

In one embodiment of the present specification, the light absorbing layer contains 0.005 wt% to 0.5 wt% based on 100 wt% of the light absorbing layer of the fluorine-based additive. Specifically, the light absorbing layer contains the fluorine-based additive in an amount of 0.01wt% to 0.2wt% based on 100wt% of the light absorbing layer.

In one embodiment of the present specification, the light absorbing layer includes a compound of perovskite structure; And fluorine-based additives.

In one embodiment of the present specification, the thickness of the light absorbing layer is 100 nm to 1 μm.

In one embodiment of the present specification, the light absorbing layer may be introduced through spin coating, dip coating, inkjet printing, gravure printing, spray coating, doctor blade, bar coating, brush painting, thermal deposition, or the like.

In one embodiment of the present specification, an electron transport layer is further included between the first electrode and the light absorbing layer.

In one embodiment of the present specification, the organic-inorganic composite solar cell has an n-i-p structure.

 In the present specification, the nip structure is a structure in which a first electrode, a light absorbing layer, an insertion layer, a hole transport layer and a second electrode are sequentially stacked, or a first electrode, an electron transport layer, a light absorption layer, an insertion layer, a hole transport layer and a second electrode This refers to a structure sequentially stacked.

2 shows an organic-inorganic composite solar cell according to an exemplary embodiment of the present specification. Specifically, Figure 1 is the first electrode 10, the electron transport layer 60, the light absorbing layer 20, the insertion layer 30, the hole transport layer 40 and the second electrode 50 are sequentially stacked U- An inorganic composite solar cell is shown.

In one embodiment of the present specification, the organic-inorganic composite solar cell may further include a substrate under the first electrode.

In one embodiment of the present specification, the substrate may be a substrate having excellent transparency, surface smoothness, ease of handling, and waterproofness. Specifically, a glass substrate, a thin glass substrate, or a plastic substrate can be used. The plastic substrate has a flexible film such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyether ether ketone and polyimide in the form of a single layer or multiple layers. Can be included. However, the substrate is not limited thereto, and a substrate commonly used in organic-inorganic composite solar cells may be used.

In the present specification, the first electrode may be an anode, and the second electrode may be a cathode. Further, the first electrode may be a cathode, and the second electrode may be an anode.

In one embodiment of the present specification, the first electrode is a transparent electrode, and the solar cell may absorb light through the first electrode.

In one embodiment of the present specification, when the first electrode is a transparent electrode, the first electrode is polyethylene terephthalate (PET), polyethylene naphthelate (PEN), poly, in addition to glass and quartz plates Propylene (polyperopylene, PP), polyimide (PI), polycarbonate (polycarbornate, PC), polystyrene (PS), polyoxyethlene (POM), AS resin (acrylonitrile styrene copolymer), ABS resin ( The conductive material may be doped with a flexible and transparent material such as acrylonitrile butadiene styrene copolymer, triacetyl cellulose (TAC), and polyarylate (PAR). Specifically, the first electrode is indium tin oxide (ITO), fluorine doped tin oxide (FTO), aluminum doped zinc oxide (aluminium doped zink oxide, AZO), IZO (indium tin) zinc oxide), ZnO-Ga ₂ O ₃ , ZnOAl ₂ O ₃ and antimony tin oxide (ATO), and more specifically, the first electrode may be ITO.

In one embodiment of the present specification, the first electrode may be a translucent electrode. When the first electrode is a semi-transparent electrode, it may be made of a metal such as silver (Ag), gold (Au), magnesium (Mg) or alloys thereof.

In the present specification, the electron transport layer may include a metal oxide. Metal oxide is specifically, Ti oxide, Zn oxide, In oxide, Sn oxide, W oxide, Nb oxide, Mo oxide, Mg oxide, Zr oxide, Sr oxide, Yr oxide, La oxide, V oxide, Al oxide, Y oxide , Sc oxide, Sm oxide, Ga oxide, SrTi oxide and one or more selected from these composites may be used, but is not limited thereto.

In one embodiment of the present specification, the hole transport layer is tertiary butyl pyridine (tBP), lithium bis (trifluoromethanesulfonyl) imide (Lithium Bis (Trifluoro methanesulfonyl) Imide, Li (TFSi) ), Poly (3,4-ethylenedioxythiophene): poly (4-styrenesulfonate) (PEDOT: PSS), 2,2 ', 7,7'-tetrakis (N, N-di-p-meth) Thoxyphenylamine) -9,9'-spirobifluorene (2,2 ', 7,7'-tetrakis (N, N-di-p-methoxyphenylamine) -9,9'-spirobifluorene, Spiro-OMeTAD), etc. Can be used, but is not limited to this.

In the exemplary embodiment of the present specification, the hole transport layer may be a Li-based dopant, a Co-based dopant, Li (TFSi), V ₂ O ₄ , WO _x , MoO _X, and FK209 as a p-type dopant, but only It is not limited.

In one embodiment of the present specification, the hole transport layer has a thickness of 10 nm to 1 μm.

When the thickness of the hole transport layer satisfies the above range, a uniform film can be formed on the lower layer without defects such as pinholes, and the contact between the upper electrode and the lower insertion layer can be prevented to obtain a device structure that can be effectively driven. .

In one embodiment of the present specification, the hole transport layer may be introduced through spin coating, dip coating, inkjet printing, gravure printing, spray coating, doctor blade, bar coating, brush painting, thermal evaporation, or the like.

In one embodiment of the present specification, the insertion layer may be introduced through spin coating, dip coating, inkjet printing, gravure printing, spray coating, doctor blade, bar coating, brush painting, thermal deposition, or the like.

Hereinafter, examples will be described in detail to specifically describe the present specification. However, the embodiments according to the present specification may be modified in various other forms, and the scope of the present specification is not interpreted to be limited to the embodiments described below. The embodiments of the present specification are provided to more fully describe the present specification to those skilled in the art.

Example 1.

A glass substrate (40 Ω / sq) coated with indium tin oxide (ITO) was washed with isopropyl alcohol for 20 minutes using ultrasonic waves. On the ITO substrate, 250 μl of a precursor solution containing SnCl precursor (0.1 M) was spin-coated at a rate of 2,000 rpm, and heat-treated at 200 ° C. for 1 hour to form an electron transport layer.

Perovskite precursor ((HC (NH ₂ ) ₂ ) _x (CH ₃ NH ₃ ) yCs _{1 -xy} PbI _z Br _3-z (0 <x <1, 0 <y <1, 0.8) on the electron transport layer <x + y <1, 0 <z <3)) and a solution of 0.05 wt% of a fluorine-based surfactant (3M, FC-4430) compared to a perovskite precursor in dimethylformamide at 5,000 rpm. After spin coating, heat treatment was performed at 150 ° C for 30 minutes to form a light absorbing layer.

After dissolving CuSCN in diethylsulfide at a concentration of 35 mg / ml, the solution stirred for 1 hour was spin-coated on the light absorbing layer at a rate of 3000 rpm to form an intercalation layer.

After dissolving Spiro-OMeTAD in chlorobenzene (concentration: 80 mg / mL), 17.5 μL of Li (TFSi) acetonitrile solution (concentration: 520 mg / ml) and 28.5 μL of tBP were added and 100 μL of the mixed solution was placed on the insert layer. Spin coating at a rate of 5,000 rpm to form a hole transport layer.

An organic-inorganic composite solar cell was completed by depositing gold (Au) on the hole transport layer to a thickness of 70 nm at a pressure of 10 ^{to 8} torr or less to form a second electrode.

Example 2.

A glass substrate (40 Ω / sq) coated with indium tin oxide (ITO) was washed with isopropyl alcohol for 20 minutes using ultrasonic waves. On the ITO substrate, 250 μl of a precursor solution containing SnCl precursor (0.1 M) was spin-coated at a rate of 2,000 rpm, and heat-treated at 200 ° C. for 1 hour to form an electron transport layer.

Perovskite precursor ((HC (NH ₂ ) ₂ ) _x (CH ₃ NH ₃ ) yCs _{1 -xy} PbI _z Br _3-z (0 <x <1, 0 <y <1, 0.8) on the electron transport layer <x + y <1, 0 <z <3)) and a solution of 0.05 wt% fluorine-based surfactant (3M, FC-4430) in comparison with perovskite precursor in dimethylformamide at 5,000 rpm. After spin coating, heat treatment was performed at 150 ° C for 30 minutes to form a light absorption layer.

After dissolving CuPc (Copper (II) phthalocyanine) in chlorobenzene at a concentration of 5 mg / ml, a solution stirred for 3 hours was spin coated on the light absorbing layer at a rate of 5,000 rpm to form an intercalation layer.

After dissolving Spiro-OMeTAD in chlorobenzene (concentration: 80 mg / mL), 17.5 μL of Li (TFSi) acetonitrile solution (concentration: 520 mg / ml) and 28.5 μL of tBP were added and 100 μL of the mixed solution was placed on the light absorbing layer. A hole transport layer was formed by spin coating at a speed of 5,000 rpm.

An organic-inorganic composite solar cell was completed by depositing gold (Au) on the hole transport layer to a thickness of 70 nm at a pressure of 10 ^{to 8} torr or less to form a second electrode.

Example 3.

A glass substrate (40 Ω / sq) coated with indium tin oxide (ITO) was washed with isopropyl alcohol for 20 minutes using ultrasonic waves. On the ITO substrate, 250 μl of a precursor solution containing SnCl precursor (0.1 M) was spin-coated at a rate of 2,000 rpm, and heat-treated at 200 ° C. for 1 hour to form an electron transport layer.

Perovskite precursor ((HC (NH ₂ ) ₂ ) _x (CH ₃ NH ₃ ) yCs _{1 -xy} PbI _z Br _3-z (0 <x <1, 0 <y <1, 0.8) on the electron transport layer <x + y <1, 0 <z <3)) and a solution of 0.05 wt% fluorine-based surfactant (3M, FC-4430) in comparison with perovskite precursor in dimethylformamide at 5,000 rpm. After spin coating, heat treatment was performed at 150 ° C for 30 minutes to form a light absorbing layer.

After dissolving CuI in acetonitrile at a concentration of 10 mg / ml, the solution stirred for 1 hour was spin coated on the light absorbing layer at a rate of 5,000 rpm to form an intercalation layer.

After dissolving Spiro-OMeTAD in chlorobenzene (concentration: 80 mg / mL), 17.5 μL of Li (TFSi) acetonitrile solution (concentration: 520 mg / ml) and 28.5 μL of tBP were added and 100 μL of the mixed solution was put on the light absorbing layer. Spin coating at a rate of 5,000 rpm to form a hole transport layer.

An organic-inorganic composite solar cell was completed by depositing gold (Au) on the hole transport layer to a thickness of 70 nm at a pressure of 10 ^{to 8} torr or less to form a second electrode.

Comparative Example 1.

A glass substrate (40 Ω / sq) coated with indium tin oxide (ITO) was washed with isopropyl alcohol for 20 minutes using ultrasonic waves. On the ITO substrate, 250 μl of a precursor solution containing SnCl precursor (0.1 M) was spin-coated at a rate of 2,000 rpm, and heat-treated at 200 ° C. for 1 hour to form an electron transport layer.

Perovskite precursor ((HC (NH ₂ ) ₂ ) _x (CH ₃ NH ₃ ) yCs _{1 -xy} PbI _z Br _3-z (0 <x <1, 0 <y <1, 0.8) on the electron transport layer <x + y <1, 0 <z <3)) and a solution of 0.05 wt% fluorine-based surfactant (3M, FC-4430) in comparison with perovskite precursor in dimethylformamide at 5,000 rpm. After spin coating, heat treatment was performed at 150 ° C for 30 minutes to form a light absorbing layer.

After dissolving Spiro-OMeTAD in chlorobenzene (concentration: 80 mg / mL), 17.5 μL of Li (TFSi) acetonitrile solution (concentration: 520 mg / ml) and 28.5 μL of tBP were added and 100 μL of the mixed solution was put on the light absorbing layer. Spin coating at a rate of 5,000 rpm to form a hole transport layer.

The organic-inorganic composite solar cell was completed by depositing gold (Au) on the hole transport layer to a thickness of 70 nm at a pressure of 10 ^-8 torr or less to form a second electrode.

Comparative Example 2.

A glass substrate (40 Ω / sq) coated with indium tin oxide (ITO) was washed with isopropyl alcohol for 20 minutes using ultrasonic waves. On the ITO substrate, 250 μl of a precursor solution containing SnCl precursor (0.1 M) was spin-coated at a rate of 2,000 rpm, and heat-treated at 200 ° C. for 1 hour to form an electron transport layer.

Perovskite precursor ((HC (NH ₂ ) ₂ ) _x (CH ₃ NH ₃ ) yCs _{1 -xy} PbI _z Br _3-z (0 <x <1, 0 <y <1, 0.8) on the electron transport layer <x + y <1, 0 <z <3)) and a solution of 0.05 wt% fluorine-based surfactant (3M, FC-4430) in comparison with perovskite precursor in dimethylformamide at 5,000 rpm. After spin coating, heat treatment was performed at 150 ° C for 30 minutes to form a light absorbing layer.

After coating 150 μL of NiO nanoparticle dispersion (particle size ~ 15 nm, dispersion medium: toluene, solid content 1.5 wt%) on the perovskite light absorbing layer, spin coating at a rate of 5000 rpm, followed by heat treatment at 60 ° C. for 10 minutes Was carried out for a while.

Then, after dissolving Spiro-OMeTAD in chlorobenzene (concentration: 80 mg / mL), 17.5 μL of Li (TFSi) acetonitrile solution (concentration: 520 mg / ml) and 28.5 μL of tBP were added, and 100 μL of the mixed solution was described above. A hole transport layer was formed by spin coating on NiO at a rate of 5,000 rpm.

The organic-inorganic composite solar cell was completed by depositing gold (Au) on the hole transport layer to a thickness of 70 nm at a pressure of 10 ^-8 torr or less to form a second electrode.

Comparative Example 3.

A glass substrate (40 Ω / sq) coated with indium tin oxide (ITO) was washed with isopropyl alcohol for 20 minutes using ultrasonic waves. On the ITO substrate, 250 μl of a precursor solution containing SnCl precursor (0.1 M) was spin-coated at a rate of 2,000 rpm, and heat-treated at 200 ° C. for 1 hour to form an electron transport layer.

Perovskite precursor ((HC (NH ₂ ) ₂ ) _x (CH ₃ NH ₃ ) yCs _{1 -xy} PbI _z Br _3-z (0 <x <1, 0 <y <1, 0.8) on the electron transport layer The solution of <x + y <1, 0 <z <3)) dissolved in dimethylformamide was spin-coated at 5,000 rpm, and then heat-treated at 150 ° C for 30 minutes to form a light absorbing layer.

After dissolving CuPc (Copper (II) phthalocyanine) in chlorobenzene at a concentration of 5 mg / ml, a solution stirred for 3 hours was spin coated on the light absorbing layer at a rate of 5,000 rpm to form an intercalation layer.

After dissolving Spiro-OMeTAD in chlorobenzene (concentration: 80 mg / mL), 17.5 μL of Li (TFSi) acetonitrile solution (concentration: 520 mg / ml) and 28.5 μL of tBP were added, and 100 μL of the mixed solution was added onto the light absorption layer. A hole transport layer was formed by spin coating at a speed of 5,000 rpm.

An organic-inorganic composite solar cell was completed by depositing gold (Au) on the hole transport layer to a thickness of 70 nm at a pressure of 10 ^{to 8} torr or less to form a second electrode.

In order to measure the performance of the prepared organic-inorganic composite solar cell, the following method was used. First, install a Solar Simulator and calibrate to an intensity of 1 Sun (100 mW / cm ² ) using a standard silicon cell. Thereafter, the performance of the organic-inorganic composite solar cells prepared in Examples 1 to 3 and Comparative Examples 1 to 3 was measured by connecting the current-voltage measuring equipment (Keithley 2420 and driving computer, software) with the organic-inorganic composite solar cell. Did.

Table 1 shows the performance measurement results of the organic-inorganic composite solar cells prepared in Examples 1 to 3 and Comparative Examples 1 to 3.

Jsc (mA / cm ² ) Voc
(V) FF η
(%) History Example
One Reverse scan 19.9 1.00 72.0 14.3 0.067 Forward scan 19.6 0.99 69.2 13.4 Example
2 Reverse scan 19.7 0.972 68.6 13.2 0.091 Forward scan 19.8 1.015 73.5 14.8 Example
3 Reverse scan 16.7 1.081 65.3 11.8 0.025 Forward scan 16.7 1.079 69.0 12.5 Comparative example
One Reverse scan 20.6 1.01 72.6 15.2 0.375 Forward scan 20.6 0.97 54.2 10.9 Comparative example
2 Reverse scan 17.5 0.68 46.3 5.5 0.509 Forward scan 18.4 0.80 32.3 4.8 Comparative example
3 Reverse scan 18.5 0.964 62.4 11.1 -

In Table 1, V _OC is an open voltage, J _SC is a short-circuit current density, FF is a fill factor, and η is energy conversion efficiency. The open-voltage and short-circuit current densities are the X-axis and Y-axis intercepts in the quadrant of the voltage-current density curve, respectively, and the higher these two values, the higher the efficiency of the solar cell is. In addition, the fill factor is a value obtained by dividing the area of the rectangle that can be drawn inside the curve by the product of the short-circuit current density and the open voltage. The energy conversion efficiency (η) can be obtained by dividing the product of the open voltage (Voc), short-circuit current density (Jsc), and charging rate (FF) by the intensity of the incident light (P _in ) (see Equation 2 below). The higher this is, the more preferable.

Equation (2):

In Table 1, the hysteresis was calculated through the following equation (1).

Equation (1):

는 reverse scan에서, 개방전압(V_oc)의 80%에 해당하는 전압 인가 시 측정된 전류밀도이다. In the formula (1),

Is the current density measured when a voltage corresponding to 80% of the open voltage (V _oc ) is applied in a reverse scan.

는 forward scan에서, 개방전압(V_oc)의 80%에 해당하는 전압 인가 시 측정된 전류밀도이다.In the formula (1),

Is the current density measured when a voltage corresponding to 80% of the open voltage (V _oc ) is applied in the forward scan.

The reverse scan is an IV scan in the direction of the short-circuit current from the open voltage (approximately 1.2V to 0V), and the forward scan is an IV scan in the direction of the open-voltage in the short-circuit current (from 0V to 1.2V) will be.

3 shows the results of the reverse scan and forward scan measurements of the organic-inorganic composite solar cell prepared in Example 1, and FIG. 4 shows the results of the reverse scan and forward scan measurements of the organic-inorganic composite solar cell manufactured in Examples 2 and 3 5, the reverse scan and forward scan measurement results of the organic-inorganic composite solar cell prepared in Comparative Example 1, and FIG. 6 shows the reverse scan and forward scan measurement results of the organic-inorganic composite solar cell prepared in Comparative Example 2. It was shown.

It can be seen from Table 1 and FIGS. 3 to 6 that the current-voltage characteristics of the reverse scans and the forward scans of Examples 1 to 3 have little difference. This is because CuSCN, CuPC, and CuI used in the examples do not conflict in valence band energy between the light absorbing layer and the hole transporting layer, so the effect of effectively moving without accumulation of charge at the interface is excellent. On the other hand, in Comparative Examples 1 and 2, it can be seen that the difference between the current-voltage characteristics of the reverse scan and the forward scan is large.

In addition, it can be seen from Table 1 that the light absorbing layer does not contain a fluorine-based surfactant (Comparative Example 3), and deteriorates in performance compared to a case where a fluorine-based surfactant is included (Example 2).

In order to evaluate the stability of the organic-inorganic composite solar cell according to an exemplary embodiment of the present specification at high temperature, the organic-inorganic composite solar cell prepared in Example 1 and Comparative Example 1 was 85 ° C without humidity control (humidity After storing at 50%), it was taken out every hour and evaluated by measuring the efficiency. 7 shows stability evaluation results at 85 ° C. of the organic-inorganic composite solar cell prepared in Example 1 and Comparative Example 1.

From FIG. 7, in the case of Example 1, the efficiency of the solar cell was maintained at 70% or more even after 400 hours at 85 ° C., whereas in Comparative Example 1, the efficiency rapidly decreased at 85 ° C. over time. Can be confirmed. From this, it can be seen that the high temperature stability of the organic-inorganic composite solar cell according to one embodiment of the present specification is excellent.

10: first electrode
20: light absorbing layer
30: insertion layer
40: hole transport layer
50: second electrode
60: electron transport layer

Claims (6)

A first electrode;
A light absorbing layer comprising a perovskite compound provided on the first electrode;
An insertion layer provided on the light absorption layer;
A hole transport layer provided on the insertion layer; And
It includes a second electrode provided on the hole transport layer,
The light absorbing layer further includes a fluorine-based additive,
The insert layer is an organic-inorganic composite solar cell comprising one or more of CuSCN, CuI, CuBr, CuCl, CuPc and Cu-doped NiO. The method according to claim 1,
The valence band energy of the insertion layer is an organic-inorganic composite solar cell having an energy level between the HOMO level of the compound of the perovskite structure and the HOMO level of the hole transport layer. The method according to claim 1,
The organic-inorganic composite solar cell having valence band energy of 4.8 eV to 5.6 eV in the insertion layer. The method according to claim 1,
The thickness of the insertion layer is 1nm to 500nm organic-inorganic composite solar cell. The method according to claim 1,
An organic-inorganic composite solar cell further comprising an electron transport layer between the first electrode and the light absorbing layer. The method according to claim 1,
The compound of the perovskite structure is an organic-inorganic composite solar cell represented by any one of the following Chemical Formulas 1 to 3:
[Formula 1]
R1M1X1 ₃
[Formula 2]
R2 _a R3 _(1-a) M2X2 _z X3 _(3-z)
[Formula 3]
R4 _b R5 _c R6 _d M3X4 _{z '} X5 _(3-z')
In Chemical Formulas 1 to 3,
R2 and R3 are different from each other,
R4, R5 and R6 are different from each other,
R1 to R6 are each independently C _n H _{2n + 1} NH ₃ ⁺ , NH ₄ ⁺ , HC (NH ₂ ) ₂ ⁺ , Cs ⁺ , Rb ⁺ , NF ₄ ⁺ , NCl ₄ ⁺ , PF ₄ ⁺ , PCl ₄ ⁺ , CH ₃ PH ₃ ⁺ , CH ₃ AsH ₃ ⁺ , CH ₃ SbH ₃ ⁺ , PH ₄ ⁺ , AsH ₄ ⁺ and SbH ₄ ⁺ is a monovalent cation selected from,
M1 to M3 are the same as or different from each other, and each independently Cu ^{2 +} , Ni ^{2 +} , Co ^{2 +} , Fe ^{2 +} , Mn ²⁺ , Cr ^{2 +} , Pd ^{2 +} , Cd ^{2 +} , Ge ^{2 +} , Sn ^{2 +} , Bi ^{2 +} , Pb ^{2 +} and a divalent metal ion selected from Yb ^{2 +} ,
X1 to X5 are the same as or different from each other, and each independently a halogen ion,
n is an integer from 1 to 9,
a is a real number of 0 <a <1,
b is a real number of 0 <b <1,
c is a real number in 0 <c <1,
d is a real number of 0 <d <1,
b + c + d is 1,
z is a real number of 0 <z <3,
z 'is a real number of 0 <z'<3.

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