KR101717430B1 - Perovskite-based solar cell - Google Patents

Abstract

A perovskite solar cell having a structure in which a first electrode, a hole transporting layer, a perovskite photoactive layer, an electron transporting layer, and a second electrode are sequentially laminated on a substrate, the perovskite solar cell comprising a first electrode There is provided a perovskite-based solar cell formed with a metal oxide layer.
According to the present invention, problems of low open-circuit voltage, photocurrent and short lifetime appearing in a conventional substrate / first electrode / hole transport layer / perovskite photoactive layer / electron transport layer / second electrode structure perovskite solar cell And a perovskite solar cell that can be manufactured through a solution process can be provided.

Description

[0001] PEROVSKITE-BASED SOLAR CELL [0002]

The present invention relates to a perovskite-based solar cell. More particularly, the present invention relates to a perovskite-based solar cell that incorporates an organic / inorganic oxide layer as an intermediate layer of the device to improve device performance and increase lifetime.

Perovskite solar cells are currently regarded as one of the most promising next generation energy sources because of their capability of solution processing of optically active layers and fabrication of high efficiency devices. A PiN perovskite solar cell having a structure including a first electrode, a hole transport layer, a photoactive layer, an electron transport layer, and a second electrode sequentially stacked on a substrate among various structures of various perovskite solar cells Transparent electrodes and a conductive charge transfer layer can be realized at a low temperature, so that it can be used as a flexible solar cell element. Despite the potential of such a perovskite solar cell, problems arise in terms of ensuring the stability of the device due to the low efficiency and instability of the material of the perovskite photoactive layer.

The problems of the perovskite solar cell having the above-described structure will be described in detail as follows. (I) exhibits a low open-circuit voltage compared to a TiO ₂ or ZnO based perovskite solar cell structure, (ii) there is instability in the junction between the upper cathode (cathode) and the PCBM layer, and (iii) (Iv) physical stability problems arise in the devices fabricated on a flexible substrate, (v) the lifetime of the perovskite photoactive layer is shortened due to moisture absorption and internal ion diffusion, there is a problem.

One aspect of the present invention is to propose a perovskite-based solar cell which can be produced through a solution process while increasing the open-circuit voltage, photocurrent and lifetime.

However, the problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

In order to accomplish the above object, one aspect of the present invention is to provide a perovskite solar cell having a structure in which a first electrode, a hole transport layer, a perovskite photoactive layer, an electron transport layer and a second electrode are sequentially laminated on a substrate In a battery, a perovskite-based solar cell is provided, in which a first metal oxide layer is formed between the electron transporting layer and the second electrode.

According to the present invention, problems of low open-circuit voltage, photocurrent and short lifetime appearing in conventional perovskite solar cells of the substrate / first electrode / hole transporting layer / perovskite photoactive layer / electron transporting layer / And a perovskite solar cell that can be manufactured through a solution process can be provided.

FIG. 1 is a structural diagram (a) of a perovskite-based solar cell having a metal oxide layer between a cathode and an electron transport layer according to an embodiment of the present invention, a current-voltage curve (b) (C), current-voltage curve comparison (d) for various metal electrodes, and ion-binding energy (e) at the device surface.
FIG. 2 is a structural view (a), a current-voltage curve (b), and an external view of a perovskite-based solar cell having an oxide layer between a perovskite photoactive and hole transporting layer according to an embodiment of the present invention. (C), photoelectric conversion efficiency (d) over time, energy band diagram (e), and work function change (f).
FIG. 3 is a structural diagram (a) and a current-voltage curve (b) of a perovskite-based solar cell having a metal oxide layer between an anode and a hole transporting layer according to an embodiment of the present invention.
FIG. 4 is a cross-sectional view of a perovskite-based solar cell having a metal oxide layer between a cathode and an electron transport layer according to an embodiment of the present invention and an oxide layer between the perovskite photoactive layer and the hole transport layer (A), a current-voltage curve (b), and a photoelectric conversion efficiency (c) with time.
5 illustrates a structure of a perovskite-based solar cell having a metal oxide layer between the anode and the hole transporting layer and an oxide layer between the perovskite photoactive layer and the hole transporting layer according to an embodiment of the present invention. (A) and the current-voltage curve (b).
6 is a structural view (a) of a perovskite-based solar cell having a metal oxide layer between an anode and a hole transporting layer and a metal oxide layer between a cathode and an electron transporting layer according to an embodiment of the present invention. to be.
FIG. 7 is a cross-sectional view of a light emitting device according to an embodiment of the present invention, which includes a metal oxide layer between the cathode and the electron transport layer, a metal oxide layer between the anode and the hole transport layer, and an oxide layer between the perovskite photoactive layer and the hole transport layer (A) of the perovskite-based solar cell.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. It should be understood, however, that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, the same reference numbers are used throughout the specification to refer to the same or like parts.

Throughout this specification, when a part is referred to as being "connected" to another part, it is not limited to a case where it is "directly connected" but also includes the case where it is "electrically connected" do.

Throughout this specification, when a member is "on " another member, it includes not only when the member is in contact with the other member, but also when there is another member between the two members.

Throughout this specification, when an element is referred to as "including " an element, it is understood that the element may include other elements as well, without departing from the other elements unless specifically stated otherwise. The terms "about "," substantially ", etc. used to the extent that they are used throughout the specification are intended to be taken to mean the approximation of the manufacturing and material tolerances inherent in the stated sense, Accurate or absolute numbers are used to help prevent unauthorized exploitation by unauthorized intruders of the referenced disclosure. The word " step (or step) "or" step "used to the extent that it is used throughout the specification does not mean" step for.

Throughout this specification, the term "combination thereof" included in the expression of the machine form means one or more combinations or combinations selected from the group consisting of the constituents described in the expression of the machine form, And the like.

The use of terms such as " comprising "or" comprising "in this specification should not be construed as necessarily including the various elements or steps described in the specification, including some or all of the steps Or may further include additional components or steps.

Furthermore, terms including ordinals such as first, second, etc. used in this specification can be used to describe various elements, but the elements should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

As used herein, "organic / inorganic oxide" may mean an organic oxide or an inorganic oxide.

In a perovskite solar cell having a substrate / first electrode / hole transporting layer / perovskite photoactive layer / electron transporting layer / second electrode structure, a metal oxide layer capable of solution process is introduced into the intermediate layer, Voltage, photocurrent and short life span.

For this purpose, in the present invention, a method of introducing a metal oxide layer between the first electrode and the hole transporting layer, a method of introducing the hole transporting layer and the perovskite photoactive layer organic / inorganic oxide layer, A method of introducing a metal oxide layer is used independently or a combination of two or more methods selected from the above methods is combined to manufacture a structure of a perovskite-based solar cell.

Accordingly, the present invention is applied to a perovskite solar cell having a structure in which a first electrode, a hole transport layer, a perovskite photoactive layer, an electron transport layer, and a second electrode are sequentially laminated on a substrate.

As the substrate, an inorganic substrate or an organic substrate can be used.

As the inorganic substrate with Si, SiO _2, Ge, GaN, AlN, GaP, InP, GaAs, SiC, Al ₂ O _3, LiAlO _3, MgO, glass, quartz, sapphire, graphite, graphene, and combinations thereof But are not limited to, those selected from the group consisting of

Examples of the organic material substrate include polyimide (PI), polyethersulfone (PES), polyacrylate (PAR), polyetherimide (PEI), polyethylene naphthalate PEN), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyarylate, polycarbonate (PC), cellulose triacetate (CTA) But is not limited to, cellulose acetate propionate (CAP). Since the electrode of the present invention seeks for excellent light transmittance, it is more preferable that the inorganic substrate and the organic substrate are made of a transparent material.

When the organic material substrate is introduced, the flexibility of the electrode can be enhanced.

The first electrode is located on the substrate and is preferably a conductive electrode, particularly a transparent conductive electrode for improving the transmission of light. The first electrode may correspond to a front electrode that is an electrode provided on a side where light is received by the solar cell, and may be a front electrode material commonly used in the solar cell field. As a specific example, the first electrode may include at least one of fluorine doped tin oxide (FTO), indium doped tin oxide (ITO), aluminum-doped zinc oxide (AZO) Indium doped zinc oxide (IZO), or a mixture thereof. However, the present invention is not limited thereto. In addition, a carbon-based metal such as a conductive polymer or graphene may be used.

The first electrode may be formed on the substrate by thermal evaporation, e-beam evaporation, radio frequency (RF) sputtering, magnetron sputtering, vacuum deposition or chemical vapor deposition Chemical vapor deposition, or the like.

The second electrode may be a rear electrode conventionally used in the field of solar cells. Specifically, the second electrode may be at least one material selected from gold, silver, platinum, palladium, copper, aluminum, carbon, cobalt sulfide, copper sulfide, nickel oxide, magnesium, calcium and combinations thereof, It is not. Since the second electrode may also be formed in the manner described in the first electrode, a duplicate description will be omitted.

A photoactive layer may be interposed between the first electrode and the second electrode.

The photoactive layer serves as a photoelectric conversion layer that separates electrons and holes to produce an electric current. When the perovskite structure is introduced into the photoactive layer, the HOMO (Highest Occupied Molecular Orbital) level of the hole transport layer (for example, PEDOT: PSS) and the Lowest Unoccupied Molecular Orbital (LUMO) of the electron transport layer ) Levels are well matched to the valence band and the conduction band of the perovskite (for example, CH ₃ NH ₃ PbI ₃ ) so that the electrons are transported to the electron transport layer (for example, PCBM) To the hole transport layer (for example, PEDOT: PSS).

In the present invention, a perovskite compound is adopted as a photoactive material that absorbs sunlight to generate photo-electron-hole pairs. The perovskite has a direct bandgap and has a light absorption coefficient as high as 550 × 1.5 × 10 ⁴ cm ^-1 , excellent charge transfer characteristics, and excellent resistance to defects.

In addition, the perovskite compound has an advantage of being able to form an optical absorber constituting the photoactive layer through an extremely simple and easy process of applying and drying a solution and performing a simple and inexpensive process. The perovskite compound is spontaneously crystallized Is formed. Thus, it is possible to form a light absorber of coarse crystal grain, and particularly, excellent conductivity for both electrons and holes.

The perovskite compound is ABX _{3 wherein} A is a C1-C20 alkyl group, a monovalent metal (such as Li, Na, Cs, Rb), a monovalent organic ammonium ion or a formamidinium having a resonance structure, B Is a divalent metal ion, and X is a halogen ion.

The photoactive layer may be formed by applying a coating composition on the hole transport layer and drying the coating composition.

However, the perovskite formed by the combination of the organic ions and the metal ions can easily react with surrounding non-covalent electron pairs, pie electrons, metals, etc., resulting in a problem that the performance of the device is easily deteriorated. Particularly, since the ionic bond of the perovskite structure is easily decomposed by polar molecules such as water and alcohol, the performance of the device due to moisture in the air is obvious. In addition, when a perovskite solar cell formed using a solution process is formed, an ion component remaining in the photoactive layer spreads toward the electrode over time to form a bond with the electrode, thereby deteriorating the performance of the device do. As will be described later, in the present invention, by coating an n-type inorganic oxide with a metal oxide between a cathode and an electron transporting layer, water contained in the cathode and the diffusion of ions from the inside are blocked, And the like.

A hole transport layer (HTL) may be disposed between the first electrode and the photoactive layer. The hole transport layer is a layer that allows holes generated in the photoactive layer to be easily transferred to the first electrode. As the hole transport layer, PEDOT: PSS, which is a polymer that ensures transparency and conductivity of visible light, may be used. Spin coating may be performed at a speed of 3000 to 5000 rpm for 40 to 50 seconds to form a hole transporting layer.

In detail, the material used for the hole transport layer is PEDOT: PSS, poly (9-vinylcarbazole), poly (9,9-dioctylfluorenyl-2,7-diyl) (4-secbutylphenyl) diphenylamine), CuPc (Copper Phthalocyanine) or N, N'-diphenyl-N, N'- bis (1-naphthyl) -1,1'biphenyl- diamine and TPD (N, N'-bis- (3-methylphenyl) -N, N'-bis-phenyl (1,1'-biphenyl) -4,4'-diamine) A solution process such as a printing process is applicable.

An electron transport layer (ETL) may be disposed between the photoactive layer and the second electrode. The electron transport layer may be formed of a material such as fullerene (C60), fullerene derivative, perylene, PBI (polybenzimidazole), and PTCBI (6,6) -phenyl-C61-butyric acid-methylester) or PCBCR ((6,6) -phenyl- (6,6) -phenyl-C61-butyric acid cholesteryl ester). However, it is not limited to these materials. Examples of the solvent include Cyclohexane, Dichloromethane, Alkanethiol, Alkanedithiol, Chlorobenzene, Dichlorobenzene, Toluene, Chloroform, Alcohols or mixtures thereof may be used as the solvent. The electron transport layer can be formed by spin coating at a speed of 1000 to 5000 rpm for 20 to 50 seconds.

Hereinafter, a perovskite-based solar cell manufactured as an embodiment of the present invention will be divided into structures.

As a substrate unless otherwise noted, the glass, the first electrode is ITO, the hole transport layer include PEDOT: PSS, a perovskite photoactive layer as the perovskite (specifically, _{CH 3 NH 3 PbI 3-x} Br _x ), fullerene (specifically PCBM) as the electron transporting layer, and Al as the second electrode.

<Structure 1: Glass / ITO / PEDOT: PSS / Perovskite / PCBM / TiOx / Al>

1A shows a structure of a perovskite-based solar cell according to a first embodiment of the present invention, and shows a structure in which a first metal oxide layer is formed between the electron transport layer and the second electrode.

The first metal oxide layer may include at least one of Ti, Zn, Sr, In, Ba, K, Nb, Fe, Ta, W, Sa, Bi, Ni, Cu, Mo, Ce, Pt, Ag, But the present invention is not limited thereto. The first metal oxide layer not only facilitates electron transfer, but also includes a metal ion generated in the perovskite photoactive layer Or to prevent the halogen ions from diffusing into the second electrode (cathode), and to block the moisture from the outside, thereby securing the stability of the high-voltage device. As a result, the lifetime of the device can be increased.

Further, although the fullerene-based inorganic layer used for the purpose of the electron acceptor can receive the electrons generated in the perovskite well, since the electrical connection with the second electrode (cathode) on the upper part is in question, a solution process is possible , And the performance of the device can be enhanced by introducing a first metal oxide layer having excellent electron transfer performance. In addition, a perovskite solar cell can be realized regardless of the work function of the upper electrode metal.

The metal oxide forming the first metal oxide layer is as described above. For example, TiO _x , NbO _x , ZnO, InO _x , and SnO _x can be used. In this embodiment, TiO _x was used.

A method of forming the first metal oxide layer is as follows.

A solution phase is prepared by dissolving a metal alkoxide or metal salt in a polar solvent (alcohol) or a nonpolar solvent (benzene) through a sol-gel method. At this time, additives can be added to control the hydrolysis and condensation of the solution and to increase the homogeneity and homogeneity, so that the acidity of the solution can be adjusted in the range of pH 1-11. Examples of the additive include acid / base materials (sulfuric acid (acid), amine / ammonium (base) and the like in the organic system and halogenated hydrocarbons (acid) and Lewis base in the inorganic system.

In addition to the process of adjusting the acidity of the solution, it is possible to improve the electrical characteristics of the metal oxide by doping with an atomic (nitrogen, phosphorus, sulfur, etc.) dopant. Thus, amines capable of chelation with the metal alkoxide -NHx), a phosphine-based compound, and a mercapto (R-SH) group.

A metal oxide precursor in solution form is applied to form a thin film. The coating method may be a solvent process such as a spin coating method, a roll coating method, a spray coating method, a flow coating method, an inkjet printing method, a nozzle printing method, a dip coating method, A screen printing method, a pad printing method, a doctor blade coating method, a gravure printing method, a thermal transfer method, or a gravure offset printing method.

Adjust the heat treatment temperature to suit the application after thin film formation. For example, although it may vary depending on the perovskite material, it is usually subjected to heat treatment at 100 DEG C or less.

In FIG. 1B, the current-voltage curves of a solar cell having TiO _x as a first metal oxide layer and a solar cell having no TiO _x as a first metal oxide layer are compared. FIG. 1C shows the photoelectric conversion efficiency with time, The results of the performance evaluation are shown in Table 1 below.

rescue Voc
(V) Jsc
(mA / cm 2) FF PCE (%) ITO / PEDOT: PSS / perovskite / PCBM / Al 0.90 17.14 0.79 12.16 ITO / PEDOT: PSS / perovskite / PCBM / TiOx / Al 0.86 20.22 0.71 12.47

As a result, the performance of the solar cell having TiO _x as the first metal oxide layer was improved in the open-circuit voltage (Voc), short-circuit current density (Jsc) and photoelectric conversion efficiency (PCE) The increase in lifetime can be confirmed. Further, in Fig. 1d, even if, unlike the various second electrode as Al, Ag, Au for a solar cell having a performance evaluation a result, TiO _x in the first metal oxide layer is almost but affect performance, provided with a TiO _x In the case of the solar cell which is not used, the variation of the performance is observed due to the influence of the metal constituting the electrode.

In addition, the perovskite solar cell manufactured using Ag as the second electrode was stored for 4 days under an N ₂ atmosphere. The XPS spectrum was observed. As a result, it was found that the introduction of TiO _x into the perovskite ion component I ) And the metal electrode is suppressed. That is, Referring to Figure 1e, the solar cells are not provided with a TiO _x there is observed, the first peak corresponding at 619.22 eV to AgI, the solar cell I _n at 618.48 eV provided with a TiO _x ^- first for the A peak is observed.

<Structure 2: Glass / ITO / PEDOT: PSS / VOx / Perovskite / PCBM / Al>

2A shows a structure of a perovskite-based solar cell according to a second embodiment of the present invention and shows a structure in which an organic / inorganic oxide layer is formed between the perovskite photoactive layer and the hole transport layer have.

The organic / inorganic oxide may be selected from the group consisting of polyethylene oxide, V oxide, W oxide, Ni oxide, Cu oxide, Mo oxide, Fe oxide, and combinations thereof, but is not limited thereto.

The organic / inorganic oxide layer may be introduced between the perovskite photoactive layer and the PEDOT: PSS having various work functions to enhance the internal electric field formed in the heterojunction structure or to adjust the quasi Fermi level of the photoactive layer, The function of increasing the open-circuit voltage can be performed.

The material forming the organic / inorganic oxide layer is as described above. For example, VOx, WOx, NiOx, CuOx, MoOx, or the like may be used. In this embodiment, VOx is used.

Since the method of forming the organic / inorganic oxide layer is the same as the method of forming the first metal oxide layer, detailed description is omitted. However, the heat treatment temperature may be 150 ° C or less, but it can also be suitably adjusted to suit the application.

In Fig. 2b perovskite and PEDOT: current is not provided with solar cells having a VO _x as an oxide layer between the PSS solar cell was shown as compared to the voltage curve, Fig. 2c was showing the external quantum efficiency, and Fig. 2d The photoelectric conversion efficiency with time was shown. The performance evaluation results for each solar cell are shown in Table 2 below.

rescue Voc
(V) Jsc
(mA / cm 2) FF PCE (%) ITO / PEDOT: PSS / perovskite / PCBM / Al 0.87 17.78 0.83 12.98 ITO / PEDOT: PSS / VOx / perovskite / PCBM / Al 1.03 17.88 0.82 15.10

Thus, a solar cell having an oxide layer between perovskite and PEDOT: PSS showed a significant improvement in the open-circuit voltage (Voc) and the photoelectric conversion efficiency (PCE). In Fig. 2d, Can be confirmed.

As shown in FIGS. 2E and 2F, the energy level of PEDOT: PSS is about 5.2 eV, and an oxide having a lower energy level is introduced between the perovskite photoactive layer and the PEDOT: PSS to increase the open- Can be increased. For reference, the notation "PD" in the drawings is an abbreviation for PEDOT: PSS.

<Structure 3: Glass / ITO / VOx / PEDOT: PSS / Perovskite / PCBM / Al>

FIG. 3A shows a structure of a perovskite-based solar cell according to a third embodiment of the present invention, in which a second metal oxide layer is formed between the hole transport layer and the first electrode.

The second metal oxide layer may include at least one of Ti, Zn, Sr, In, Ba, K, Nb, Fe, Ta, W, Sa, Bi, Ni, Cu, Mo, Ce, Pt, Ag, But not limited to, oxides, including those selected from the group consisting of oxides, nitrides, and mixtures thereof. By introducing the second metal oxide layer between the transparent electrode (ITO) and the PEDOT: PSS layer, the electric field distribution inside the device is changed to increase the light absorption amount of the photoactive layer and to prevent electron movement from the photoactive layer, It is possible to increase the lifetime of the device by preventing the decomposition of the transparent electrode (ITO) by the PEDOT: PSS layer and the diffusion of the decomposed metal ions into the device.

For example, VOx, WOx, NiOx, CuOx, MoOx, FeOx, or the like may be used as the metal oxide forming the second metal oxide layer. In this embodiment, VOx is used.

Since the method of forming the first metal oxide layer is the same as the method of forming the first metal oxide layer, detailed description is omitted. However, the heat treatment temperature may be 150 ° C or less, but it can also be suitably adjusted to suit the application.

In FIG. 3B, current-voltage curves of a solar cell having VO _x as an oxide layer and a solar cell having no oxide layer between ITO and PEDOT: PSS are shown in comparison. When VOx was used as an oxide layer, the performance evaluation results for each solar cell are shown in Table 3 below.

rescue Voc
(V) Jsc
(mA / cm 2) FF PCE (%) ITO / PEDOT: PSS / perovskite / PCBM / Al 0.86 16.82 0.72 10.38 ITO / VOx / PEDOT: PSS / perovskite / PCBM / Al 0.88 17.23 0.73 10.86

As a result, an increase in the short circuit current density (Jsc) can be confirmed in the case of a solar cell having an oxide layer between ITO and PEDOT: PSS.

<Structure 4: Glass / ITO / PEDOT: PSS / VOx / Perovskite / PCBM / TiOx / Al>

FIG. 4A shows a structure of a perovskite-based solar cell according to a fourth embodiment of the present invention, and it can be seen that the structure 1 and the structure 2 are combined. That is, a structure is shown in which a first metal oxide layer is formed between the electron transport layer and the second electrode, and an organic / inorganic oxide layer is further disposed between the perovskite photoactive layer and the hole transport layer .

As the first metal oxide layer with TiOx, the organic / inorganic oxide layer was used as the VO _x.

In FIG. 4B, the current-voltage curves of the solar cell having no first metal oxide layer, the first metal oxide layer, and the organic / inorganic oxide layer are shown in comparison. In FIG. 4C, The photoelectric conversion efficiency (PCE) with time was shown when the solar cell was placed in the box. The performance evaluation results for each solar cell are shown in Table 4 below.

rescue Voc
(V) Jsc
(mA / cm 2) FF PCE (%) ITO / PEDOT: PSS / VOx / perovskite / PCBM / Al 1.03 17.88 0.82 15.10 ITO / PEDOT: PSS / VOx / perovskite / PCBM / TiOx / Al 1.07 18.34 0.82 16.09

As a result, the open-circuit voltage (Voc) and the short-circuit current density (Jsc) of the solar cell having VO _x and TiO _x were increased and the lifetime of the solar cell was increased. No deterioration of characteristics was observed even after 1000 hours passed. This is considered to be a result of a combination of the effect of the structure 1 and the effect of the structure 2.

<Structure 5: Glass / ITO / VOx / PEDOT: PSS / VOx / Perovskite / PCBM / Al>

FIG. 5A shows a structure of a perovskite-based solar cell according to a fifth embodiment of the present invention, and it can be seen that the structure 2 and the structure 3 are combined. That is, a structure is shown in which an organic / inorganic oxide layer is formed between the perovskite photoactive layer and the hole transport layer, and a second metal oxide layer is further disposed between the hole transport layer and the first electrode have.

Is the VO _x as the second metal oxide layer, in the organic / inorganic oxide layer was used as the VO _x.

In FIG. 5B, the current-voltage curves of the solar cell having no second metal oxide layer, the second metal oxide layer, and the organic / inorganic oxide layer together are shown. The performance evaluation results for each solar cell are shown in Table 5 below.

rescue Voc
(V) Jsc
(mA / cm 2) FF PCE (%) ITO / PEDOT: PSS / VOx / perovskite / PCBM / Al 1.06 16.06 0.79 13.43 ITO / VOx / PEDOT: PSS / VOx / perovskite / PCBM / Al 1.06 17.46 0.75 13.85

As a result, in the case of the solar cell having the second metal oxide layer and the organic / inorganic oxide layer together, the short circuit current density (Jsc) was increased and the lifetime was increased as compared with the solar cell having no second metal oxide layer and the organic / inorganic oxide layer. It is estimated that the effect of the structure 2 and the effect of the structure 3 are a composite result.

<Structure 6: Glass / ITO / VOx / PEDOT: PSS / Perovskite / PCBM / TiOx / Al>

FIG. 6 shows a structure of a perovskite-based solar cell according to a sixth embodiment of the present invention, and it can be seen that the structure 1 and the structure 3 are combined. That is, a structure is shown in which a first metal oxide layer is formed between the electron transport layer and the second electrode, and an organic / inorganic oxide layer is additionally provided between the perovskite photoactive layer and the hole transport layer have.

In this case, it is expected that the effect of Structure 1 and the effect of Structure 3 will be complex.

<Structure 7: Glass / ITO / VOx / PEDOT: PSS / VOx / Perovskite / PCBM / TiOx / Al>

FIG. 7 shows a structure of a perovskite-based solar cell according to a seventh embodiment of the present invention, and it can be seen that the structure 1, structure 2, and structure 3 are combined. That is, a first metal oxide layer is formed between the electron transporting layer and the second electrode, an organic / inorganic oxide layer is formed between the perovskite photoactive layer and the hole transporting layer, And further includes a first metal oxide layer between the second electrodes.

In this case, it is expected that the effect of Structure 1, the effect of Structure 2, and the effect of Structure 3 will appear in a complex manner.

The perovskite-based solar cell according to the embodiment of the present invention, when manufactured by forming a transparent electrode such as ITO on a flexible substrate such as PET, is excellent in adhesion between the substrate and the functional layer by a precursor-based solution process, It is possible to realize a flexible transparent sealing system integrated with Therefore, the deterioration of electrical characteristics is not significant even through the bending repeat test. In addition, it is optically transparent, but it absorbs the ultraviolet region to protect the material of the device, and prevents penetration of moisture and oxygen to protect the material inside the device.

Claims (6)

A first electrode formed on a substrate;
A hole transport layer formed on the first electrode so that the generated holes are easily transferred to the first electrode;
An inorganic oxide layer formed on the hole transport layer and including a V oxide, a W oxide, or an Mo oxide for increasing an open-circuit voltage;
A photoactive layer having a perovskite compound formed on the inorganic oxide layer and generating electron-hole pairs;
An electron transport layer formed on the photoactive layer and facilitating movement of electrons generated in the photoactive layer; And
And a second electrode formed on the electron transporting layer. The method of claim 1, wherein the photoactive layer is _{CH 3 NH 3 PbI 3-x} Br x a perovskite-based solar cell characterized in that it comprises a. The perovskite-based solar cell according to claim 1, further comprising a first metal oxide layer containing Ti oxide for interrupting ion diffusion between the electron transporting layer and the second electrode. The perovskite-based solar cell according to claim 1, further comprising a second metal oxide layer including V oxide, W oxide, or Mo oxide between the first electrode and the hole transport layer. delete delete

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