Perovskite solar cell and preparation method of electron transport layer

Abstract

The application provides a perovskite solar cell and a preparation method of an electron transport layer, and belongs to the technical field of solar cells.The perovskite solar cell comprises an electron transport layer, and the material of the electron transport layer comprises PCBM and 9,9-di(4-amino-3-methylphenyl)fluorene.In the electron transport layer, 9,9-di(4-amino-3-methylphenyl)fluorene is introduced to dope and modify PCBM, 9,9-di(4-amino-3-methylphenyl)fluorene interacts with PCBM, the aggregation phenomenon of PCBM is reduced, the conductivity of PCBM is improved, the charge transport performance is enhanced, the efficiency of the perovskite solar cell assembly is effectively improved, and the structure of 9,9-di(4-amino-3-methylphenyl)fluorene is simple and easy to synthesize, so that the cost can be reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of solar cells and relates to a perovskite solar cell and a method for preparing an electron transport layer. Background Art

[0002] The electron transport layer material of conventional trans-perovskite components is PCBM (fullerene derivative [6,6]-phenyl C 61 -methyl butyrate), its molecular structure is shown below: .

[0003] However, using PCBM as an electron transport layer material has the following problems: (1) The PCBM deposited on the perovskite layer has poor fluidity and will aggregate, thus affecting the performance of the component; (2) In order to solve the aggregation phenomenon of PCBM, such as thickening the PCBM layer, it will affect the conductivity of the PCBM itself.

[0004] There are literature reports in the prior art that DMAPF is added to PCBM as an electron transport layer to improve the performance of the component. The molecular structure of DMAPF is shown below: However, if DMAPF is used as the doping material for the electron transport layer, the performance of the component needs to be further improved.

[0005] Therefore, in this field, it is expected to develop a perovskite solar cell with PCBM as the main material of the electron transport layer, in which the doping material can not only suppress the aggregation phenomenon of PCBM, but also improve the conductivity of the component, and the cost is low. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the present invention aims to provide a method for preparing a perovskite solar cell and an electron transport layer.

[0007] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a perovskite solar cell, comprising an electron transport layer, wherein the material of the electron transport layer comprises PCBM and 9,9-bis(4-amino-3-tolyl)fluorene, and the molecular structure of 9,9-bis(4-amino-3-tolyl)fluorene is as follows:

[0009] .

[0010] The present invention introduces 9,9-bis(4-amino-3-methylphenyl)fluorene into the electron transport layer to perform doping modification on PCBM. 9,9-bis(4-amino-3-methylphenyl)fluorene interacts with PCBM, reduces the aggregation of PCBM, improves the electrical conductivity of PCBM, enhances the charge transport performance, and effectively improves the efficiency of the perovskite solar cell module. Furthermore, 9,9-bis(4-amino-3-methylphenyl)fluorene has a simple structure and is easy to synthesize, thereby reducing costs.

[0011] Compared to DMAPF, 9,9-bis(4-amino-3-methylphenyl)fluorene has an additional benzene ring structure. The conjugated structure of the benzene ring can form a continuous electron transport channel through π-π stacking, reducing interfacial resistance, thereby promoting the efficient extraction of photogenerated electrons and improving the conductivity of PCBM. In addition, the amino group in 9,9-bis(4-amino-3-methylphenyl)fluorene forms hydrogen bonds or polar interactions with the carbonyl (C=O) oxygen atom of PCBM through the lone pair of electrons of the nitrogen atom. This interaction disperses the PCBM molecules, thereby inhibiting their aggregation during the solution drying process.

[0012] Preferably, based on the total molar amount of PCBM and 9,9-bis(4-amino-3-tolyl)fluorene as 100%, the molar amount of 9,9-bis(4-amino-3-tolyl)fluorene is 0.6% to 3%, for example, 0.6%, 0.8%, 1%, 1.2%, 1.4%, 1.6%, 1.8%, 2%, 2.2%, 2.4%, 2.6%, 2.8%, 3%, etc.

[0013] Preferably, when preparing the electron transport layer, the solvent for dissolving PCBM and 9,9-bis(4-amino-3-methylphenyl)fluorene includes chlorobenzene and / or anisole, preferably a mixture of chlorobenzene and anisole in a volume ratio of (2 to 4):1 (e.g., 2:1, 2.5:1, 3:1, 3.5:1, 4:1, etc.).

[0014] The present invention does not specifically limit other layers included in the perovskite solar cell. Exemplarily, the perovskite solar cell further includes a substrate, a hole transport layer, a perovskite layer, a hole blocking layer and an electrode layer.

[0015] Preferably, the electron transport layer is arranged on a side of the perovskite layer away from the hole transport layer.

[0016] Preferably, the perovskite solar cell comprises a substrate, a hole transport layer, a perovskite layer, an electron transport layer, a hole blocking layer and an electrode layer stacked in sequence.

[0017] Preferably, the perovskite solar cell may further include a passivation layer, a waterproof layer, etc.

[0018] Preferably, the substrate is FTO conductive glass or ITO conductive glass.

[0019] Preferably, the material of the hole transport layer includes but is not limited to nickel oxide (NiO) and / or molybdenum trioxide (MoO 3 ).

[0020] Preferably, the thickness of the perovskite layer is 300 nm to 800 nm, for example, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, 550 nm, 600 nm, 650 nm, 700 nm, 750 nm, 800 nm, etc.

[0021] Preferably, the material of the hole blocking layer includes but is not limited to SnO2.

[0022] Preferably, the material of the electrode layer includes but is not limited to any one of gold, silver, copper, titanium, chromium, nickel and aluminum.

[0023] In a second aspect, the present invention provides a method for preparing an electron transport layer, the preparation method comprising the following steps:

[0024] Mixing PCBM and solvent to obtain a PCBM solution;

[0025] adding 9,9-bis(4-amino-3-methylphenyl)fluorene to the PCBM solution, and mixing the 9,9-bis(4-amino-3-methylphenyl)fluorene and the PCBM solution to obtain a mixed solution;

[0026] The mixed solution is applied to obtain a coating layer, and the coating layer is annealed to obtain the electron transport layer.

[0027] The flow chart of the method for preparing the electron transport layer provided by the present invention is as follows Figure 1 shown.

[0028] Preferably, the solvent comprises chlorobenzene and / or anisole, preferably a mixture of chlorobenzene and anisole in a volume ratio of (2-4):1 (e.g., 2:1, 2.5:1, 3:1, 3.5:1, 4:1, etc.).

[0029] Preferably, the mixing of the 9,9-bis(4-amino-3-methylphenyl)fluorene and the PCBM solution comprises:

[0030] The 9,9-bis(4-amino-3-methylphenyl)fluorene and the PCBM solution are ultrasonically mixed.

[0031] Preferably, after mixing the 9,9-bis(4-amino-3-methylphenyl)fluorene and the PCBM solution, the method further comprises: filtering the mixed solution.

[0032] Preferably, applying the mixed liquid comprises:

[0033] The mixed liquid is applied by scraping with a wire rod at a speed of 5 mm / s to 15 mm / s (e.g., 5 mm / s, 6 mm / s, 8 mm / s, 10 mm / s, 12 mm / s, 13 mm / s, 15 mm / s, etc.).

[0034] Preferably, annealing the coating comprises:

[0035] The coating is annealed at 90° C. to 110° C. (e.g., 90° C., 95° C., 100° C., 105° C., 110° C., etc.) for 2.5 min to 5 min (e.g., 2.5 min, 3 min, 3.5 min, 4 min, 4.5 min, 5 min, etc.).

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] The present invention introduces 9,9-bis(4-amino-3-methylphenyl)fluorene into the electron transport layer to perform doping modification on PCBM. 9,9-bis(4-amino-3-methylphenyl)fluorene interacts with PCBM, reduces the aggregation of PCBM, improves the electrical conductivity of PCBM, enhances the charge transport performance, and effectively improves the efficiency of the perovskite solar cell module. Furthermore, 9,9-bis(4-amino-3-methylphenyl)fluorene has a simple structure and is easy to synthesize, thereby reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The present invention provides a flow chart of the method for preparing the electron transport layer.

[0039] Figure 2 A schematic structural diagram of a perovskite solar cell provided in Example 1 of the present invention;

[0040] Among them, 1-FTO conductive glass, 2-hole transport layer, 3-perovskite layer, 4-electron transport layer, 5-hole blocking layer, 6-electrode layer.

[0041] Figure 3 Photoluminescence spectra of the perovskite solar cell modules provided in Examples 1-3 of the present invention and Comparative Example 1.

[0042] Figure 4 Graph showing the conductivity test results of the perovskite solar cell modules provided in Examples 1-3 of the present invention and Comparative Example 1. DETAILED DESCRIPTION

[0043] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0044] Unless otherwise specified, the specific composition of the perovskite precursor solution used in the examples and comparative examples of the present invention is as follows: 1.2M FA 0.9 Cs 0.1 PbI3 (it should be noted that the material of the perovskite layer of the present invention is not limited to that prepared by the above formula, which is only an example).

[0045] Example 1

[0046] This embodiment provides a perovskite solar cell, the structural diagram of which is shown in FIG. Figure 2 As shown, the preparation method comprises the following steps:

[0047] A 15×15 cm FTO conductive glass 1 is provided, P1 lines are performed on the glass, the glass is cleaned, dried, and then UV treated to improve the wettability of subsequent film layers.

[0048] Nickel oxide is sputtered on the FTO conductive glass 1 by using a magnetron sputtering process as the hole transport layer 2.

[0049] A perovskite precursor solution was coated on the nickel oxide layer by blade coating, followed by annealing to obtain a perovskite layer 3 with a thickness of 500 nm.

[0050] 0.011 mmol of PCBM, 0.75 mL of chlorobenzene, and 0.25 mL of anisole were mixed to obtain a PCBM solution, and then 0.000066 mmol of 9,9-bis(4-amino-3-methylphenyl)fluorene was added (i.e., based on the total molar amount of PCBM and 9,9-bis(4-amino-3-methylphenyl)fluorene being 100%, the molar amount of 9,9-bis(4-amino-3-methylphenyl)fluorene was 0.6%). The mixture was then ultrasonically mixed in an ultrasonic cleaner and filtered to obtain a mixed solution. The mixed solution was then scraped onto the perovskite layer 3 using a wire rod at a scraping speed of 10 mm / s, and then annealed on a hot plate at 100° C. for 2.5 min to obtain a PCBM thin film, i.e., an electron transport layer 4.

[0051] The substrate with the PCBM film deposited thereon is placed in an evaporation chamber and SnO2 is deposited by atomic layer deposition (ALD) to obtain a hole blocking layer 5, followed by P2 scribing.

[0052] The oxide IWO (indium tungsten oxide) and metal Cu are evaporated on the surface of the hole blocking layer 5 by a vacuum evaporation process to obtain the electrode layer 6, and finally P3 scribing is performed to obtain the perovskite solar cell.

[0053] Example 2

[0054] This embodiment provides a perovskite solar cell, the preparation method of which includes the following steps:

[0055] Provide 15×15cm FTO conductive glass, perform P1 marking on it, clean it, dry it and then perform UV treatment to improve the wettability of subsequent film layers.

[0056] Nickel oxide was sputtered on FTO conductive glass using magnetron sputtering process as a hole transport layer.

[0057] The perovskite precursor solution was scraped onto the nickel oxide layer, followed by annealing to obtain a perovskite layer with a thickness of 500 nm.

[0058] 0.011 mmol of PCBM, 0.75 mL of chlorobenzene, and 0.25 mL of anisole were mixed to obtain a PCBM solution, and then 0.000088 mmol of 9,9-bis(4-amino-3-methylphenyl)fluorene was added (i.e., based on the total molar amount of PCBM and 9,9-bis(4-amino-3-methylphenyl)fluorene being 100%, the molar amount of 9,9-bis(4-amino-3-methylphenyl)fluorene was 0.8%). The mixture was then ultrasonically mixed in an ultrasonic cleaner and filtered to obtain a mixed solution. The mixed solution was then applied to the perovskite layer using a wire rod at a coating speed of 10 mm / s, and then annealed on a hot plate at 100°C for 2.5 minutes to obtain a PCBM thin film, i.e., an electron transport layer.

[0059] The substrate with the PCBM film deposited is placed in an evaporation chamber and SnO2 is deposited using ALD to obtain a hole blocking layer, followed by P2 scribing.

[0060] The oxide IWO and metal Cu are evaporated on the surface of the hole blocking layer by a vacuum evaporation process to obtain an electrode layer, and finally P3 scribing is performed to obtain the perovskite solar cell.

[0061] Example 3

[0062] This embodiment provides a perovskite solar cell, the preparation method of which includes the following steps:

[0063] Provide 15×15cm FTO conductive glass, perform P1 marking on it, clean it, dry it and then perform UV treatment to improve the wettability of subsequent film layers.

[0064] Nickel oxide was sputtered on FTO conductive glass using magnetron sputtering process as a hole transport layer.

[0065] The perovskite precursor solution was scraped onto the nickel oxide layer, followed by annealing to obtain a perovskite layer with a thickness of 500 nm.

[0066] 0.011 mmol of PCBM, 0.75 mL of chlorobenzene, and 0.25 mL of anisole were mixed to obtain a PCBM solution, and then 0.00011 mmol of 9,9-bis(4-amino-3-methylphenyl)fluorene was added (i.e., based on the total molar amount of PCBM and 9,9-bis(4-amino-3-methylphenyl)fluorene being 100%, the molar amount of 9,9-bis(4-amino-3-methylphenyl)fluorene was 1%). The mixture was then ultrasonically mixed in an ultrasonic cleaner and filtered to obtain a mixed solution. The mixed solution was then scraped onto the perovskite layer using a wire rod at a scraping speed of 10 mm / s, and then annealed on a hot plate at 100°C for 2.5 min to obtain a PCBM thin film, i.e., an electron transport layer.

[0067] The substrate with the PCBM film deposited is placed in an evaporation chamber and SnO2 is deposited using ALD to obtain a hole blocking layer, followed by P2 scribing.

[0068] The oxide IWO and metal Cu are evaporated on the surface of the hole blocking layer by a vacuum evaporation process to obtain an electrode layer, and finally P3 scribing is performed to obtain the perovskite solar cell.

[0069] Example 4

[0070] This embodiment provides a perovskite solar cell, the preparation method of which includes the following steps:

[0071] Provide 15×15cm FTO conductive glass, perform P1 marking on it, clean it, dry it and then perform UV treatment to improve the wettability of subsequent film layers.

[0072] Nickel oxide was sputtered on FTO conductive glass using magnetron sputtering process as a hole transport layer.

[0073] The perovskite precursor solution was scraped onto the nickel oxide layer, followed by annealing to obtain a perovskite layer with a thickness of 500 nm.

[0074] 0.011 mmol of PCBM, 0.75 mL of chlorobenzene, and 0.25 mL of anisole were mixed to obtain a PCBM solution, and then 0.000066 mmol of 9,9-bis(4-amino-3-methylphenyl)fluorene was added (i.e., based on the total molar amount of PCBM and 9,9-bis(4-amino-3-methylphenyl)fluorene being 100%, the molar amount of 9,9-bis(4-amino-3-methylphenyl)fluorene was 0.6%). The mixture was then ultrasonically mixed in an ultrasonic cleaner and filtered to obtain a mixed solution. The mixed solution was then applied to the perovskite layer using a wire rod at a coating speed of 10 mm / s, and then annealed on a hot plate at 100°C for 5 minutes to obtain a PCBM thin film, i.e., an electron transport layer.

[0075] The substrate with the PCBM film deposited is placed in an evaporation chamber and SnO2 is deposited using ALD to obtain a hole blocking layer, followed by P2 scribing.

[0076] The oxide IWO and metal Cu are evaporated on the surface of the hole blocking layer by using a vacuum evaporation process, and finally P3 scribing is performed to obtain the perovskite solar cell.

[0077] Example 5

[0078] This embodiment provides a perovskite solar cell, the preparation method of which includes the following steps:

[0079] Provide 15×15cm FTO conductive glass, perform P1 marking on it, clean it, dry it and then perform UV treatment to improve the wettability of subsequent film layers.

[0080] Nickel oxide was sputtered on FTO conductive glass using magnetron sputtering process as a hole transport layer.

[0081] The perovskite precursor solution was scraped onto the nickel oxide layer, followed by annealing to obtain a perovskite layer with a thickness of 500 nm.

[0082] 0.011 mmol of PCBM, 0.75 mL of chlorobenzene, and 0.25 mL of anisole were mixed to obtain a PCBM solution, and then 0.000088 mmol of 9,9-bis(4-amino-3-methylphenyl)fluorene was added (i.e., based on the total molar amount of PCBM and 9,9-bis(4-amino-3-methylphenyl)fluorene being 100%, the molar amount of 9,9-bis(4-amino-3-methylphenyl)fluorene was 0.8%). The mixture was then ultrasonically mixed in an ultrasonic cleaner and filtered to obtain a mixed solution. The mixed solution was then applied to the perovskite layer using a wire rod at a coating speed of 10 mm / s, and then annealed on a hot plate at 100°C for 5 minutes to obtain a PCBM thin film, i.e., an electron transport layer.

[0083] The substrate with the PCBM film deposited is placed in an evaporation chamber and SnO2 is deposited using ALD to obtain a hole blocking layer, followed by P2 scribing.

[0084] The oxide IWO and metal Cu are evaporated on the surface of the hole blocking layer by using a vacuum evaporation process, and finally P3 scribing is performed to obtain the perovskite solar cell.

[0085] Example 6

[0086] This embodiment provides a perovskite solar cell, the preparation method of which includes the following steps:

[0087] Provide 15×15cm FTO conductive glass, perform P1 marking on it, clean it, dry it and then perform UV treatment to improve the wettability of subsequent film layers.

[0088] Nickel oxide was sputtered on FTO conductive glass using magnetron sputtering process as a hole transport layer.

[0089] The perovskite precursor solution was scraped onto the nickel oxide layer, followed by annealing to obtain a perovskite layer with a thickness of 500 nm.

[0090] 0.011 mmol of PCBM, 0.75 mL of chlorobenzene, and 0.25 mL of anisole were mixed to obtain a PCBM solution, and then 0.00011 mmol of 9,9-bis(4-amino-3-methylphenyl)fluorene was added (i.e., based on the total molar amount of PCBM and 9,9-bis(4-amino-3-methylphenyl)fluorene being 100%, the molar amount of 9,9-bis(4-amino-3-methylphenyl)fluorene was 1%). The mixture was then ultrasonically mixed in an ultrasonic cleaner and filtered to obtain a mixed solution. The mixed solution was then applied to the perovskite layer using a wire rod at a coating speed of 10 mm / s, and then annealed on a hot plate at 100°C for 5 minutes to obtain a PCBM thin film, i.e., an electron transport layer.

[0091] The substrate with the PCBM film deposited is placed in an evaporation chamber and SnO2 is deposited using ALD to obtain a hole blocking layer, followed by P2 scribing.

[0092] The oxide IWO and metal Cu are evaporated on the surface of the hole blocking layer by using a vacuum evaporation process, and finally P3 scribing is performed to obtain the perovskite solar cell.

[0093] Comparative Example 1

[0094] The only difference between this comparative example and Example 1 is that the electron transport layer is not doped with 9,9-bis(4-amino-3-methylphenyl)fluorene.

[0095] The perovskite solar cell modules provided in the embodiments of the present invention and the comparative examples were subjected to photoluminescence spectrum testing and conductivity testing, wherein the conductivity testing method is as follows:

[0096] Conductivity test: Measure the current-voltage curve of a pure electron transport layer device in the dark state.

[0097] The photoluminescence spectra of the perovskite solar cell modules provided in Examples 1-3 of the present invention and Comparative Example 1 are shown in FIG. Figure 3 As shown, it can be seen that compared with Comparative Example 1, the doped PCBM provided by the embodiment of the present invention has a better fluorescence quenching effect on photogenerated carriers, and thus has better charge extraction performance.

[0098] The conductivity test results of the perovskite solar cell modules provided in Examples 1-3 of the present invention and Comparative Example 1 are shown in FIG. Figure 4 As shown, it can be seen that compared with Comparative Example 1, the doped PCBM provided by the embodiment of the present invention has relatively excellent electrical conductivity, and its conductive performance is improved.

[0099] The present invention uses the above-mentioned embodiments to illustrate the preparation methods of the perovskite solar cell and the electron transport layer of the present invention. However, the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent replacement of the raw materials selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the scope of protection and disclosure of the present invention.

Claims

1. A perovskite solar cell, characterized in that The perovskite solar cell includes an electron transport layer, wherein the materials of the electron transport layer include PCBM and 9,9-bis(4-amino-3-methylphenyl)fluorene, and the molecular structure of 9,9-bis(4-amino-3-methylphenyl)fluorene is as follows: ； Based on the total molar amount of PCBM and 9,9-bis(4-amino-3-methylphenyl)fluorene being 100%, the molar amount of the 9,9-bis(4-amino-3-methylphenyl)fluorene is 0.6% to 3%.

2. The perovskite solar cell according to claim 1, wherein When preparing the electron transport layer, the solvent for dissolving PCBM and 9,9-bis(4-amino-3-methylphenyl)fluorene includes chlorobenzene and / or anisole.

3. The perovskite solar cell according to claim 2, characterized in that The solvent comprises a mixture of chlorobenzene and anisole in a volume ratio of (2-4):

1.

4. A method for preparing an electron transport layer, characterized in that: The preparation method comprises the following steps: Mixing PCBM and solvent to obtain a PCBM solution; adding 9,9-bis(4-amino-3-methylphenyl)fluorene to the PCBM solution, and mixing the 9,9-bis(4-amino-3-methylphenyl)fluorene and the PCBM solution to obtain a mixed solution; applying the mixed solution to obtain a coating, and annealing the coating to obtain the electron transport layer; Based on the total molar amount of PCBM and 9,9-bis(4-amino-3-methylphenyl)fluorene being 100%, the molar amount of the 9,9-bis(4-amino-3-methylphenyl)fluorene is 0.6% to 3%.

5. The preparation method according to claim 4, characterized in that The solvent includes chlorobenzene and / or anisole.

6. The preparation method according to claim 5, characterized in that The solvent comprises a mixture of chlorobenzene and anisole in a volume ratio of (2-4):

1.

7. The preparation method according to claim 4, characterized in that The mixing of the 9,9-bis(4-amino-3-methylphenyl)fluorene and the PCBM solution comprises: Ultrasonic mixing of the 9,9-bis(4-amino-3-methylphenyl)fluorene and the PCBM solution; After the 9,9-bis(4-amino-3-methylphenyl)fluorene and the PCBM solution are mixed, the method further comprises: filtering the mixed solution.

8. The preparation method according to claim 4, characterized in that The step of applying the mixed liquid comprises: The mixed liquid is applied by scraping with a wire rod at a speed of 5 mm / s to 15 mm / s.

9. The preparation method according to claim 4, characterized in that The annealing of the coating comprises: The coating is annealed at 90° C. to 110° C. for 2.5 min to 5 min.

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