Solar cell with composite perovskite structure and preparation method thereof

Abstract

The invention relates to the technical field of perovskite cells, and particularly discloses a solar cell with a composite perovskite structure and a preparation method thereof, and the cell comprises front glass, a transparent conductive layer, a hole transport layer, a perovskite functional layer, an electron transport layer, a back electrode and back glass which are sequentially stacked. The perovskite functional layer is of an interlayer structure and comprises a three-dimensional perovskite main body layer, a first two-dimensional layer and a second two-dimensional layer, the first two-dimensional layer and the second two-dimensional layer are stacked on the two opposite sides of the three-dimensional perovskite main body layer respectively, the first two-dimensional layer is stacked on the hole transport layer, and the second two-dimensional layer and the electron transport layer are stacked; the first two-dimensional layer and the second two-dimensional layer are respectively formed by two-dimensional materials containing large-volume organic cations, and the organic cations are ammonium salt cations formed by phenylethylamine, butylamine, octylamine or substituted derivatives thereof.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of perovskite battery, in particular to a solar cell with a composite perovskite structure and a preparation method thereof. BACKGROUND

[0002] The existing three-dimensional (3D) organic-inorganic hybrid perovskite material has excellent light absorption and charge transport characteristics, but its stability is insufficient in the environment of humidity, heat and light, which becomes a bottleneck restricting its commercialization. Two-dimensional (2D) material has stronger environmental stability due to the introduction of bulky organic cations, but its layered structure will limit the charge transmission in the vertical direction, thereby reducing the device efficiency. At present, the research of perovskite solar cells is mostly focused on 2D / 3D heterostructure, which introduces 2D layers on the surface or grain boundary of 3D perovskite to improve the stability of the battery device. However, in this structure, one side of the 3D layer is still exposed to the interface or electrode, and there is still a risk of ion migration, interface reaction and degradation during long-term operation.

[0003] Therefore, how to further optimize the structure design to greatly improve the long-term stability of the device while maintaining high efficiency is a technical problem to be solved. SUMMARY

[0004] The purpose of the present application is to provide a solar cell with a composite perovskite structure, aiming to improve the environmental stability and service life of perovskite battery devices.

[0005] To achieve the above purpose, the present application is realized by the following technical scheme: The present application provides a solar cell with a composite perovskite structure, which comprises a front glass, a transparent conductive layer, a hole transport layer, a perovskite functional layer, an electron transport layer, a back electrode and a back glass which are sequentially stacked; wherein the perovskite functional layer is a sandwich structure comprising a three-dimensional perovskite main body layer and a first two-dimensional layer and a second two-dimensional layer which are respectively stacked on the opposite sides of the three-dimensional perovskite main body layer, the first two-dimensional layer is stacked on the hole transport layer, and the second two-dimensional layer is stacked with the electron transport layer; the first two-dimensional layer and the second two-dimensional layer are respectively formed by a two-dimensional material containing bulky organic cations, and the organic cations are ammonium salt cations formed by phenethylamine, butylamine, octylamine or their substituted derivatives.

[0006] Specifically, the solar cell with the composite perovskite structure is constructed by introducing two-dimensional layers on opposite sides (upper and lower sides) of a three-dimensional perovskite main layer, thereby forming a 2D / 3D / 2D sandwich structure (perovskite functional layer) in an upper-lower symmetric or asymmetric structure, and through the synergistic effect of the upper and lower two-dimensional layers (first and second two-dimensional layers) of the three-dimensional perovskite main layer, the environmental stability and service life of the battery device are greatly improved.

[0007] The organic cations in the first and second two-dimensional layers are combined with uncoordinated PbI2 in the three-dimensional perovskite main layer, reducing interface defects.

[0008] Further, a solar cell with a composite perovskite structure: the thickness of the first two-dimensional layer is set to 1.0-20.0 nm.

[0009] Further, a solar cell with a composite perovskite structure: the thickness of the second two-dimensional layer is set to 1.0-20.0 nm.

[0010] The application also provides a preparation method of a solar cell with a composite perovskite structure, which comprises the following steps: S1. Sputtering to prepare a transparent conductive layer on a cleaned front glass; S2. Preparing a hole transport layer on the transparent conductive layer by sputtering, spin coating, evaporation, blade coating or slot coating; S3. Coating a first solution on the hole transport layer, and then annealing to prepare a first two-dimensional layer; wherein the first solution is obtained by dissolving phenethylamine, butylamine, octylamine or substituted derivatives thereof in a solvent; the annealing temperature is 80-100 DEG C, and the annealing time is 3-6 minutes; S4. Preparing a three-dimensional perovskite main layer on the first two-dimensional layer, and simultaneously annealing at 80-180 DEG C for 20-40 minutes; S5. Coating a second solution on the three-dimensional perovskite main layer, and then annealing to form a second two-dimensional layer, and then performing high-temperature recrystallization to promote the reaction between the two-dimensional materials in the first and second two-dimensional layers and uncoordinated PbI2 in the perovskite; wherein the second solution is obtained by dissolving phenethylamine, butylamine, octylamine or substituted derivatives thereof in a solvent; wherein the annealing temperature is 80-100 DEG C, and the annealing time is 3-6 minutes; S6. Preparing an electron transport layer on the second two-dimensional layer by sputtering, spin coating, evaporation, blade coating or slot coating; S7. Preparing a back electrode on the electron transport layer by evaporation or magnetron sputtering; S8. Laminating a back glass on the back electrode to prepare a solar cell with a composite perovskite structure.

[0011] Further, a preparation method of a solar cell with a composite perovskite structure: the thickness of the transparent conductive layer is set to 150-200 nm.

[0012] Further, a preparation method of a solar cell with a composite perovskite structure: the thickness of the hole transport layer is set to 50-100 nm.

[0013] Further, a preparation method of a solar cell with a composite perovskite structure: the thickness of the three-dimensional perovskite bulk layer is set to 350-600 nm.

[0014] Further, a preparation method of a solar cell with a composite perovskite structure: the concentration of the first solution is 1.0-2.0 mg / ml, and the concentration of the second solution is 0.5-1.0 mg / ml.

[0015] Further, a preparation method of a solar cell with a composite perovskite structure: the thickness of the electron transport layer is set to 20-100 nm.

[0016] Further, a preparation method of a solar cell with a composite perovskite structure: the thickness of the back electrode is set to 60-120 nm.

[0017] The beneficial effects of the present application are: The solar cell with a composite perovskite structure provided by the present application, wherein the perovskite functional layer has a 2D / 3D / 2D composite perovskite structure, the structure introduces oriented first and second two-dimensional layers (2D) on the upper and lower sides of a three-dimensional perovskite bulk layer (3D), respectively, thereby forming a stable structure similar to a "sandwich", wherein the first two-dimensional layer can act as a protective barrier to prevent water and oxygen penetration and electrode reaction, the three-dimensional perovskite bulk layer in the middle provides excellent light absorption and charge transport performance, and the second two-dimensional layer has the function of passivating interface defects, which can enhance the binding stability with the electron transport layer. Unlike the traditional 2D / 3D heterostructure, the present application first introduces two-dimensional layers on the upper and lower sides of the three-dimensional perovskite bulk layer, and constructs a 2D / 3D / 2D sandwich structure which is symmetric or asymmetric on the upper and lower sides, and through the 2D / 3D / 2D sandwich structure, the high efficiency and high stability of the perovskite battery device are realized.

[0018] The solar cell with the composite perovskite structure has the advantages that the perovskite functional layer with the sandwich structure can provide double protection in the vertical direction, ion migration and reaction at the interface of the transparent electrode can be avoided, and defect state recombination at the interface of the bottom electron transport layer can be reduced, the first two-dimensional layer plays the role of band regulation and surface packaging, and can effectively prevent moisture and oxygen from invading, and the service life is improved, the second two-dimensional layer can passivate interface defect states by directly contacting the electron transport layer, the non-radiative recombination rate is reduced, the open circuit voltage is improved, and the chemical reaction between the metal back electrode and the perovskite is inhibited. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0020] Figure 1 The structure diagram of the solar cell with the composite perovskite structure provided in the embodiment 1 of the present application.

[0021] The drawings are marked as follows: 1-front glass, 2-transparent conductive layer, 3-hole transport layer, 4-perovskite functional layer, 5-electron transport layer, 6-back electrode, 7-back glass, 41-first two-dimensional layer, 42-three-dimensional perovskite main body layer, 43-second two-dimensional layer. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. The description of the at least one exemplary embodiment is actually only illustrative, and is by no means any limitation on the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0023] Embodiment 1

[0024] As Figure 1As shown, the present embodiment 1 provides a solar cell with a composite perovskite structure, which includes a front glass 1, a transparent conductive layer 2, a hole transport layer 3, a perovskite functional layer 4, an electron transport layer 5, a back electrode 6 and a back glass 7 which are sequentially stacked, the perovskite functional layer 4 is a 2D / 3D / 2D sandwich structure, which includes a three-dimensional perovskite bulk layer 42 and a first two-dimensional layer 41 and a second two-dimensional layer 43 which are respectively stacked on the opposite sides of the three-dimensional perovskite bulk layer 42, the thickness of the first two-dimensional layer 41 is set to 8.0 nm, which is stacked on the hole transport layer 3, the thickness of the second two-dimensional layer 43 is set to 6.0 nm, which is stacked with the electron transport layer 5; the first two-dimensional layer 41 and the second two-dimensional layer 43 are respectively formed by a two-dimensional material containing a bulky organic cation, the organic cation is an ammonium salt cation formed by phenethylamine, butylamine, octylamine or a substituted derivative thereof.

[0025] The preparation method of the above-mentioned solar cell with a composite perovskite structure of embodiment 1, comprising the following steps: S1, clean the front glass 1 and then place it in an oven at 65°C for drying, and then sputter a TCO transparent conductive layer 2 with a thickness of 180.0 nm on the front glass 1; S2, spin-coat a NiOx solution on the transparent conductive layer 2, and then anneal at 150°C for 30 minutes to prepare a hole transport layer 3 with a thickness of 60.0 nm; S3, spin-coat a first solution on the hole transport layer 3, and then anneal at 100°C for 5 minutes to prepare a first two-dimensional layer 41 with a thickness of 8.0 nm; Wherein, the first solution is obtained by dissolving butylamine in isopropyl alcohol (IPA), the concentration of butylamine is 1.0 mg / ml, and the ammonium salt cation (BA + ) is formed; S4, use an evaporation machine to co-evaporate Pb : 0.5-1.0 Å / s, FAI: 0.25-0.5 Å / s, and CsI: 0.012-0.025 Å / s on the first two-dimensional layer 41 and anneal at 120°C for 30 minutes to promote perovskite crystallization to form a three-dimensional perovskite bulk layer 42; S5, coat a second solution on the three-dimensional perovskite bulk layer 42, and then anneal at 100°C for 5 minutes to prepare a second two-dimensional layer 43, and then perform high-humidity recrystallization (100°C annealing for 2 minutes) in a DMF atmosphere on the prepared thin film, and then perform 100°C annealing for 25 minutes in a nitrogen atmosphere to promote the reaction between the two-dimensional material in the first and second two-dimensional layers and the uncoordinated Pb in the perovskite; The second solution is obtained by dissolving phenylethylamine (PEA) in isopropyl alcohol (IPA), and the concentration of the phenylethylamine is 0.5 mg / ml, and ammonium salt cations (PEA + ) are formed; S6, using an evaporation machine to evaporate 30.0 nm of C60 on the second two-dimensional layer 43 as an electron transport layer 5, and then evaporating 8.0 nm of BCP as a hole blocking layer; S7, using an evaporation machine to evaporate a back electrode 6 (Ag electrode) with a thickness of 80.0 nm on the electron transport layer 5; S8, laminating a back glass 7 on the back electrode 6, and performing lamination to obtain a composite perovskite structure solar cell.

[0026] The perovskite functional layer 4 in the solar cell of Example 1 has a 2D / 3D / 2D composite sandwich structure, and the effective area of the solar cell is 100 mm 2 , and the area is accurately controlled by a mask during evaporation.

[0027] The above-mentioned Example 1 designs a perovskite solar cell with a two-dimensional / three-dimensional / two-dimensional (2D / 3D / 2D) composite structure. The solar cell with a composite perovskite structure in Example 1 introduces a two-dimensional layer with different functions on the upper and lower sides of the three-dimensional perovskite main body layer 42, respectively, forms a perovskite functional layer 4 with a sandwich structure similar to a “sandwich”, and the first two-dimensional layer 41 can be used as a protective barrier to effectively block water and oxygen penetration. The second two-dimensional layer 43 is mainly used for interface defect passivation and carrier selective transmission, and inhibits ion migration and electrode reaction, so that the high efficiency and high stability of the battery device are realized.

[0028] In addition, the preparation method of the three-dimensional perovskite main body layer 42 is preferably prepared by evaporation, rather than by solution method, and the perovskite solution is easy to cause the first two-dimensional layer 41 to dissolve.

[0029] Comparative Example 1

[0030] A preparation method of a perovskite solar cell is provided, which comprises the following steps: S1, cleaning the front glass 1 and placing it in an oven at 65°C for drying, and then sputtering a TCO transparent conductive layer 2 with a thickness of 180.0 nm on the front glass 1; S2, spin coating a NiOx solution on the transparent conductive layer 2, and then annealing at 150°C for 30 minutes to prepare a hole transport layer 3 with a thickness of 60.0 nm; S3, using an evaporation machine to evaporate Pb : 0.5~1.0 Å / s, FAI: 0.25~0.5 Å / s, and CsI: 0.012~0.025 Å / s at the same time and annealing at 120°C for 30 min to promote perovskite crystallization to form a three-dimensional perovskite bulk layer 42; S4, using an evaporation machine to evaporate 30.0 nm of C60 on the three-dimensional perovskite bulk layer 42 as an electron transport layer 5, and then evaporating 8.0 nm of BCP as a hole blocking layer; S5, using an evaporation machine to evaporate a back electrode 6 (Ag electrode) with a thickness of 80.0 nm on the electron transport layer 5; S6, laminating a back glass 7 on the back electrode 6 to obtain a composite perovskite structure solar cell.

[0031] The difference between Comparative Example 1 and Example 1 is that Comparative Example 1 does not prepare a first two-dimensional layer 41 and a second two-dimensional layer 43 on both sides of the three-dimensional perovskite bulk layer 42, and the rest of the conditions are the same.

[0032] Comparative Example 2

[0033] Comparative Example 2 provides a preparation method of a perovskite solar cell, comprising the following steps: S1, cleaning the front glass 1 and placing it in an oven at 65°C for drying, and then sputtering a TCO transparent conductive layer 2 with a thickness of 180.0 nm on the front glass 1; S2, spin coating a NiOx solution on the transparent conductive layer 2, and then annealing at 150°C for 30 min to prepare a hole transport layer 3 with a thickness of 60.0 nm; S3, using an evaporation machine to evaporate Pb : 0.5~1.0 Å / s, FAI: 0.25~0.5 Å / s, and CsI: 0.012~0.025 Å / s at the same time and annealing at 120°C for 30 min to promote perovskite crystallization to form a three-dimensional perovskite bulk layer 42; S4, coating a second solution on the three-dimensional perovskite bulk layer 42, and then annealing at 100°C for 5 min to prepare a second two-dimensional layer 43, and then performing high-humidity recrystallization (100°C annealing for 2 min) of the prepared film in a DMF atmosphere, and then performing 100°C annealing for 25 min in a nitrogen atmosphere; The second solution is obtained by dissolving phenethylamine (PEA) in isopropyl alcohol (IPA), and the concentration of the phenethylamine is 0.5 mg / ml to form ammonium salt cations (PEA + ); S5, using an evaporation machine to evaporate 30.0 nm of C60 on the second two-dimensional layer 43 as an electron transport layer 5, and then evaporating 8.0 nm of BCP as a hole blocking layer; S6, evaporating a back electrode 6 (Ag electrode) with a thickness of 80.0 nm on the electron transport layer 5 using an evaporation machine; S7, laminating a back glass 7 on the back electrode 6, and performing lamination to obtain a solar cell with a composite perovskite structure.

[0034] The difference between Comparative Example 2 and Example 1 is that the first two-dimensional layer 41 is not prepared on the three-dimensional perovskite bulk layer 42 in Comparative Example 2, and the rest of the conditions are the same as in Example 1.

[0035] Comparative Example 3

[0036] Comparative Example 3 provides a preparation method of a perovskite solar cell, comprising the following steps: S1, cleaning a front glass 1 and placing it in an oven at 65°C for drying, and then sputtering a TCO transparent conductive layer 2 with a thickness of 180.0 nm on the front glass 1; S2, spin-coating a NiOx solution on the transparent conductive layer 2, and then annealing at 150°C for 30 minutes to prepare a hole transport layer 3 with a thickness of 60.0 nm; S3, spin-coating a first solution on the hole transport layer 3, and then annealing at 100°C for 5 minutes to prepare a first two-dimensional layer 41 with a thickness of 8.0 nm; The first solution is obtained by dissolving butylamine in isopropyl alcohol (IPA), and the concentration of butylamine is 1.0 mg / ml, forming ammonium salt cations (BA + ); S4, using an evaporation machine to co-evaporate Pb : 0.5-1.0 Å / s, FAI: 0.25-0.5 Å / s, and CsI: 0.012-0.025 Å / s on the first two-dimensional layer 41, and annealing at 120°C for 30 minutes to promote perovskite crystallization, to form a three-dimensional perovskite bulk layer 42; S5, using an evaporation machine to evaporate 30.0 nm of C60 as an electron transport layer 5 on the three-dimensional perovskite bulk layer 42, and then evaporating 8.0 nm of BCP as a hole blocking layer; S6, evaporating a back electrode 6 (Ag electrode) with a thickness of 80.0 nm on the electron transport layer 5 using an evaporation machine; S7, laminating a back glass 7 on the back electrode 6, and performing lamination to obtain a solar cell with a composite perovskite structure.

[0037] The difference between Comparative Example 3 and Example 1 is that the second two-dimensional layer 43 is not prepared on the three-dimensional perovskite bulk layer 42 in Comparative Example 3, and the rest of the conditions are the same as in Example 1.

[0038] Test: The performance of the solar cells of the above-mentioned Example 1 and Comparative Examples 1-3 was tested, and the results are as follows:

[0039] As can be seen from the above test results, by designing the 2D / 3D / 2D composite sandwich structure perovskite functional layer 4, the perovskite solar cell can achieve high efficiency and high stability. Among them, the operating life can reflect the stability of the perovskite solar cell, and the test condition is 85℃ / 85%RH.

[0040] The above-mentioned preferred embodiments of the present application are only used to explain the present application, and are not used to limit the present application. Any obvious changes or variations derived from the technical solutions of the present application are still within the protection scope of the present application.

Claims

1. A solar cell with a composite perovskite structure, characterized in that, The solar cell includes a front glass (1), a transparent conductive layer (2), a hole transport layer (3), a perovskite functional layer (4), an electron transport layer (5), a back electrode (6), and a back glass (7) stacked in sequence. The perovskite functional layer (4) is a sandwich structure, which includes a three-dimensional perovskite main layer (42) and a first two-dimensional layer (41) and a second two-dimensional layer (43) respectively stacked on opposite sides of the three-dimensional perovskite main layer (42). The first two-dimensional layer (41) is stacked on the hole transport layer (3), and the second two-dimensional layer (43) is stacked with the electron transport layer (5). The first two-dimensional layer (41) and the second two-dimensional layer (43) are respectively formed by two-dimensional materials containing large-volume organic cations, and the organic cations are ammonium salt cations formed by phenylethylamine, butylamine, octylamine or their substituted derivatives.

2. A solar cell with a composite perovskite structure according to claim 1, characterized in that, The thickness of the first two-dimensional layer (41) is set to 1.0~20.0 nm.

3. A solar cell with a composite perovskite structure according to claim 1, characterized in that, The thickness of the second two-dimensional layer (43) is set to 1.0 to 20.0 nm.

4. A method for preparing a solar cell with a composite perovskite structure according to any one of claims 1 to 3, characterized in that, The method includes the following steps: S1. A transparent conductive layer (2) is sputtered onto the cleaned front glass (1). S2. A hole transport layer (3) is prepared on the transparent conductive layer (2) by sputtering, spin coating, vapor deposition, scraping or slot coating. S3. Coat the hole transport layer (3) with the first solution and then anneal it to prepare the first two-dimensional layer (41). The first solution is obtained by dissolving phenethylamine, butylamine, octylamine or their substituted derivatives in a solvent; S4. A three-dimensional perovskite host layer (42) is prepared on the first two-dimensional layer (41). S5. A second solution is coated on the three-dimensional perovskite host layer (42), and then annealed to prepare a second two-dimensional layer (43), and then high-temperature recrystallization is performed. The second solution is obtained by dissolving phenethylamine, butylamine, octylamine or their substituted derivatives in a solvent; S6. An electron transport layer (5) is prepared on the second two-dimensional layer (43) by sputtering, spin coating, vapor deposition, scraping or slot coating. S7. The back electrode (6) is prepared on the electron transport layer (5) by vapor deposition or magnetron sputtering. S8. A back glass (7) is laminated on the back electrode (6) to obtain a solar cell with a composite perovskite structure.

5. The method for fabricating a solar cell with a composite perovskite structure according to claim 4, characterized in that, The thickness of the transparent conductive layer (2) is set to 150-200 nm.

6. The method for preparing a solar cell with a composite perovskite structure according to claim 4, characterized in that, The thickness of the hole transport layer (3) is set to 50-100 nm.

7. The method for fabricating a solar cell with a composite perovskite structure according to claim 4, characterized in that, The thickness of the three-dimensional perovskite host layer (42) is set to 350-600 nm.

8. The method for preparing a solar cell with a composite perovskite structure according to claim 4, characterized in that, The concentration of the first solution is 1.0–2.0 mg / ml, and the concentration of the second solution is 0.5–1.0 mg / ml.

9. The method for fabricating a solar cell with a composite perovskite structure according to claim 4, characterized in that, The thickness of the electron transport layer (5) is set to 20-100 nm.

10. The method for preparing a solar cell with a composite perovskite structure according to claim 4, characterized in that, The thickness of the back electrode (6) is set to 60-120 nm.

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