阅读说明：本技术 一种钙钛矿太阳能电池及其制备方法 (Perovskite solar cell and preparation method thereof ) 是由 盛雯婷 陈传露 朱鹏臣 于 2021-08-24 设计创作，主要内容包括：本发明公开了一种钙钛矿太阳能电池,依次包括电极、空穴传输层、钙钛矿层、电子传输层和ITO玻璃衬底,钙钛矿层中含有氟化镉。本发明还公开了一种钙钛矿太阳能电池的制备方法,包括以下步骤：a、清洗ITO玻璃衬底,吹干后进行紫外臭氧处理；b、将钛酸四丁酯的乙醇溶液旋涂在ITO玻璃衬底上,退火形成c-TiO-(2)膜层,将二氧化钛胶状物的乙醇溶液旋涂在c-TiO-(2)膜层上,退火形成mp-TiO-(2)膜层,紫外臭氧处理,制得电子传输层；c、制备钙钛矿膜层；d、制备空穴传输层；e、制备电极。本发明能够有效提升钙钛矿薄膜的成膜性,有利于提升钙钛矿电池的稳定性,在钙钛矿模组的商业化等方面具有良好的指导意义。(The invention discloses a perovskite solar cell which sequentially comprises an electrode, a hole transport layer, a perovskite layer, an electron transport layer and an ITO glass substrate, wherein the perovskite layer contains cadmium fluoride. The invention also discloses a preparation method of the perovskite solar cell, which comprises the following steps: a. cleaning an ITO glass substrate, and carrying out ultraviolet ozone treatment after blow-drying; b. spin-coating ethanol solution of tetrabutyl titanate on an ITO glass substrate, and annealing to form c-TiO 2 Coating the ethanol solution of titanium dioxide jelly on the c-TiO layer 2 Annealing to form mp-TiO on the film layer 2 Carrying out ultraviolet ozone treatment on the film layer to obtain an electron transport layer; c. preparing a perovskite film layer; d. preparing a hole transport layer; e. and preparing an electrode. The invention can effectively improve the film forming property of the perovskite thin film, is beneficial to improving the stability of the perovskite battery, and has good guiding significance in the aspects of commercialization of perovskite modules and the like.)

1. A perovskite solar cell, characterized in that: the electrode sequentially comprises an electrode (1), a hole transport layer (2), a perovskite film layer (3), an electron transport layer (4) and an ITO glass substrate (5), wherein the perovskite film layer (3) contains cadmium fluoride.

2. A perovskite solar cell according to claim 1, characterized in that: the thickness of the electrode (1) is 30-300 nm, the thickness of the hole transport layer (2) is 100-170 nm, the thickness of the perovskite film layer (3) is 400-800 nm, and the thickness of the electron transport layer (4) is 330-400 nm.

3. A perovskite solar cell according to claim 1, characterized in that: the electron transport layer (4) comprises c-TiO₂Film layer and mp-TiO₂And (5) film layer.

4. The method for preparing a perovskite solar cell according to any one of claims 1 to 3, characterized by comprising the following steps:

(a) cleaning the ITO glass substrate (5), and carrying out ultraviolet ozone treatment after blow-drying;

(b) spin-coating ethanol solution of tetrabutyl titanate on an ITO glass substrate (5), and annealing at 350-550 ℃ to form c-TiO₂Coating the ethanol solution of titanium dioxide jelly on the c-TiO layer₂Annealing the film layer at 350-550 ℃ to form mp-TiO₂Carrying out ultraviolet ozone treatment on the film layer to obtain an electron transport layer (4);

(c) spin-coating a lead iodide solution containing cadmium fluoride on the electron transport layer (4), drying in a protective atmosphere, spin-coating an FAI/MABr/MACl solution on the surface of the electron transport layer, and annealing at 120-170 ℃ to obtain a perovskite film layer (3);

(d) 2,2',7,7' -tetra [ N, N-di (4-methoxyphenyl) amino ] -9,9' -spirobifluorene solution is coated on the perovskite film layer (3) in a spinning way to prepare a hole transport layer (2);

(e) a conductive metal is deposited on the surface of the hole transport layer (2) to form an electrode (1).

5. The method of manufacturing a perovskite solar cell as claimed in claim 4, wherein: in the step (a), the ITO glass substrate (5) is sequentially cleaned by deionized water, acetone and isopropanol.

6. The method of manufacturing a perovskite solar cell as claimed in claim 4, wherein: in the step (b), the concentration of the ethanol solution of tetrabutyl titanate is 0.25-0.5g/mL, the spin coating speed is 1500-6000 rpm, the time is 20-120 s, and the annealing time is 10-60 min.

7. The method of manufacturing a perovskite solar cell as claimed in claim 4, wherein: in the step (c), the concentration of the lead iodide solution of cadmium fluoride is 1.0-1.5M, the spin coating speed is 1000-5000 rpm, the time is 10-120 s, the annealing time is 3-50 min, and the protective atmosphere is nitrogen.

8. The method of manufacturing a perovskite solar cell as claimed in claim 4, wherein: in the step (d), the concentration of the 2,2',7,7' -tetra [ N, N-di (4-methoxyphenyl) amino ] -9,9' -spirobifluorene solution is 70-80 mg/mL.

9. The method of manufacturing a perovskite solar cell as claimed in claim 4, wherein: in the step (d), the spin coating speed is 2000-4000 rpm, and the time is 20-60 s.

10. The method of manufacturing a perovskite solar cell as claimed in claim 4, wherein: in the step (e), the conductive metal is any one of gold, silver, copper and aluminum.

Technical Field

The invention relates to a solar cell and a manufacturing method thereof, in particular to a perovskite solar cell and a manufacturing method thereof.

Background

As a clean energy source, solar energy can meet the increasing global energy demand. Among the numerous optoelectronic devices, perovskite solar cells are of interest due to their higher power conversion efficiency and lower manufacturing costs.

In the prior art, the commercial bottleneck of the perovskite battery is mainly that the stability of the battery is insufficient, and the requirement of commercial battery operation cannot be met. In the prior art, passivation of a film layer is often performed by using organic small molecules (ACS nano8, 9815-9821 (2014), nat. commun.6 and 7081 (2015)), but the small molecules are easy to volatilize and cannot stay in the film layer for a long time to play a passivation effect, so that other types of additives need to be developed to improve the stability of the perovskite battery.

Disclosure of Invention

The purpose of the invention is as follows: in order to overcome the defects in the prior art, the invention aims to provide a perovskite solar cell with good stability, and the invention also aims to provide a simple and convenient preparation method of the perovskite solar cell.

The technical scheme is as follows: the perovskite solar cell sequentially comprises an electrode, a hole transport layer, a perovskite film layer, an electron transport layer and an ITO glass substrate, wherein the perovskite film layer contains cadmium fluoride.

Furthermore, the thickness of the electrode is 30-300 nm, the thickness of the hole transport layer is 100-170 nm, the thickness of the perovskite film layer is 400-800 nm, and the thickness of the electron transport layer is 330-400 nm.

Further, the electron transport layer comprises c-TiO₂Film layer and mp-TiO₂And (5) film layer.

The preparation method of the perovskite solar cell comprises the following steps:

(a) preparing a precursor solution: the ITO glass substrate is cleaned, and ultraviolet ozone treatment is carried out after blow-drying, so that residual oil stains on the surface of the substrate can be removed, and the hydrophilicity is enhanced;

(b) pretreatment of the substrate: spin-coating ethanol solution of tetrabutyl titanate on an ITO glass substrate, and annealing at 350-550 ℃ to form c-TiO₂Coating the ethanol solution of titanium dioxide jelly on the c-TiO layer₂Annealing the film layer at 350-550 ℃ to form mp-TiO₂Film layer, ultraviolet ozone regionProcessing to obtain an electron transport layer;

(c) preparing a perovskite film layer: spin-coating a lead iodide solution containing cadmium fluoride on an electron transport layer, drying in a protective atmosphere, spin-coating an FAI/MABr/MACl solution on the surface of the electron transport layer, and annealing at 120-170 ℃ to obtain a perovskite film layer;

(d) preparation of hole transport layer: 2,2',7,7' -tetra [ N, N-di (4-methoxyphenyl) amino ] -9,9' -spirobifluorene solution is coated on the perovskite film layer in a rotating mode to obtain a hole transport layer;

(e) preparing an electrode: and evaporating conductive metal on the surface of the hole transport layer to be used as an electrode.

Further, in the step (a), the ITO glass substrate is sequentially washed with deionized water, acetone, and isopropyl alcohol (IPA).

Further, in the step (b), the concentration of the ethanol solution of tetrabutyl titanate is 0.25-0.5g/mL, the spin coating speed is 1500-6000 rpm, the time is 20-120 s, and the annealing time is 10-60 min. Annealing at a temperature lower than 350 ℃ can cause incomplete annealing and influence transmission; annealing above 550 ℃ can cause film cracking. The spin coating speed is lower than 1500rpm, so that the thickness of the film layer is large and the conductivity is hindered; spin coating rates above 6000rpm can result in thin film layers that do not completely cover.

Further, in the step (c), the concentration of the lead iodide solution of cadmium fluoride is 1.0-1.5M, the spin coating speed is 1000-4000 rpm, the time is 10-120 s, the annealing time of the perovskite thin film formed after the organic salt is spin coated is 3-50 min, and the protective atmosphere is nitrogen. The spin coating speed is lower than 1000rpm, so that the thickness of the film layer is large, and charges are difficult to derive; spin coating rates above 5000rpm result in poor quality film layers. The concentration of lead iodide solution of cadmium fluoride is lower than 0.5M, so that the film layer is very thin and cannot be completely covered, holes are generated, and the recombination rate of the film layer is increased; a lead iodide solution of cadmium fluoride having a concentration higher than 1.5M may make it difficult to form a flat film layer.

Further, in the step (d), the concentration of the 2,2',7,7' -tetra [ N, N-di (4-methoxyphenyl) amino ] -9,9' -spirobifluorene solution is 70-80 mg/mL. The spin coating speed is 2000-4000 rpm, and the time is 20-60 s. The concentration of the 2,2',7,7' -tetra [ N, N-di (4-methoxyphenyl) amino ] -9,9' -spirobifluorene solution is lower than 70mg/mL, and an uneven film with holes can be formed; the concentration of the 2,2',7,7' -tetra [ N, N-di (4-methoxyphenyl) amino ] -9,9' -spirobifluorene solution is higher than 80mg/mL, so that the film layer is too thick and the conductivity is reduced. The spin coating rate is lower than 2000rp or higher than 4000rpm, and the thickness of the formed film layer is not suitable.

Further, in the step (e), the conductive metal is any one of gold, silver, copper and aluminum.

The working principle is as follows: sources of perovskite cell instability are defect states and low decomposition energies in the perovskite film layer. By introducing efficient passivation groups, defect states are effectively passivated, so that the density of the defect states is reduced, the extraction and transmission capability of charges is improved, and the stability and the conversion efficiency of the battery are improved. Introduction of highly effective additive cadmium fluoride (CdF)₂) To reduce defect state density while enhancing intergranular interactions. CdF₂Has Cd in²⁺And F^-The radius of Cd ions is smaller than that of Pb ions in the perovskite, so that the stress of crystal lattices can be effectively released, the formation energy of defects is improved, and the defect density is reduced. Meanwhile, the F ions with high electronegativity can form strong hydrogen bonds with organic cations and strong ionic bonds with Pb ions, so that the vacancy defect of the ions is effectively eliminated, and the long-term stability of the battery is improved.

Has the advantages that: compared with the prior art, the invention has the following remarkable characteristics: the film forming property of the perovskite thin film can be effectively improved, the stability of the perovskite battery can be improved, and the perovskite battery has good guiding significance in the aspects of commercialization of perovskite modules and the like; the additive cadmium fluoride can reduce the defect state density, enhance the interaction among crystal lattices, effectively eliminate the vacancy defect of ions and improve the long-term stability of the battery; the invention has simple process and easy large-scale production, and the additive is an inorganic component, has weak volatility and strong stability, can be remained in the perovskite film layer for a long time, and has the effects of passivation and stability improvement.

Drawings

FIG. 1 is a structural diagram of a perovskite battery of the present invention;

FIG. 2 is an I-V curve for perovskite cells of example 1 of the present invention and comparative example 1;

FIG. 3 is a stability curve of example 1 of the present invention and comparative example 1.

Detailed Description

Example 1

(1) Preparing a precursor solution:

the precursor solution comprises ethanol solution of tetrabutyl titanate and lead iodide (PbI)₂) With cadmium fluoride (CdF)₂) Mixed solution, formamidine iodine/methylamine bromine/methylamine chloride (FAI/MABr/MACl) solution, 2,2',7,7' -tetrakis [ N, N-di (4-methoxyphenyl) amino]-9,9' -spirobifluorene (spiro-OMeTAD) solution and lithium bistrifluoromethanesulfonylimide (Li-TFSI) solution.

0.5g of tetrabutyltitanate is dissolved in 2.0mL of ethanol, stirred with shaking and filtered using a 0.45 μm filter element for further use.

1g of titanium dioxide (TiO)₂) The jelly was dissolved in 5.5g of absolute ethanol and sufficiently stirred for use.

553mg of PbI₂Dissolved in 0.95mL of N-Dimethylformamide (DMF) and 0.1mL of dimethyl sulfoxide (DMSO), to which CdF was added₂Is 0.05 percent, is heated to 100 ℃, is stirred for 30min until being completely dissolved, and is filtered by a filter element with the diameter of 0.45 mu M to prepare a lead iodide solution with the concentration of 1.2M and containing cadmium fluoride for standby.

1100mg of FAI, 105mg of MABr, and 100mg of MACl powder were dissolved in 15mL of isopropanol solution, stirred well until the solution was clear, and filtered using a 0.45 μm filter cartridge for use.

520mg of Li-TFSI was dissolved in 1mL of acetonitrile at a concentration of 520 mg/mL. 72.3mg of spiro-OMeTAD was dissolved in 1mL of chlorobenzene solution, and 17.5. mu.L of Li-TFSI solution and 28.8. mu.L of tetra-t-butylpyridine were added to 1mL of spiro solution, and filtered using a 0.45 μm filter core for use.

(2) Pretreatment of the substrate:

the ITO glass substrate 5 was first ultrasonically cleaned in deionized water for 30 minutes, then ultrasonically cleaned in acetone for 30 minutes, and finally ultrasonically cleaned in isopropyl alcohol for 30 minutes, then blow-dried with a nitrogen gun, and treated in an ultraviolet ozone processor for 30 minutes for standby.

(3) Preparation of the electron transport layer 4:

spin-coating the filtered ethanol solution of tetrabutyl titanate on an ITO glass substrate 5 at a spin-coating rate of 3000rpm for 30s, followed by annealing at 450 ℃ for 30min to form c-TiO₂And (5) film layer.

Followed by dissolving the TiO₂The colloidal ethanol solution is coated on the c-TiO by spinning₂Spin coating on the film at 3000rpm for 30s, and annealing at 450 deg.C for 30min to form mp-TiO₂And (5) cooling the film layer, and then treating the film layer in an ultraviolet ozone processor for 20 minutes for later use. c-TiO₂Film layer and mp-TiO₂The film layers together constitute an electron transport layer 4.

(4) Preparation of perovskite film layer 3:

spin coating the prepared lead iodide solution (containing cadmium fluoride) on mp-TiO₂On the film, the speed was 2200rpm and the time was 40 s. Subsequently, the mixture was dried naturally for 3 minutes under a nitrogen atmosphere. The formulated FAI/MABr/MACl solution was then spin coated onto PbI₂On the film, the speed is 1800rpm, the time is 30s, then annealing at 140 ℃ for 15min, cooling and standby.

(5) Preparation of hole transport layer 2:

the doped spiro solution was spin coated on the modified perovskite film layer 3 at a spin coating rate of 3000rpm for 30 s.

(6) Preparation of electrode 1:

a layer of 100nm gold was deposited on the surface of the spiro by thermal evaporation as electrode 1.

Referring to fig. 1, the prepared perovskite solar cell sequentially comprises a 100nm electrode 11, a 140nm hole transport layer 22, a 650nm perovskite film layer 33, a 370nm electron transport layer 44 and an ITO glass substrate 55 which are fixedly connected from top to bottom.

Comparative example

The remaining steps of this comparative example are the same as example 1, except that: CdF is not added into lead iodide solution₂。

Table 1 example 1 and comparative perovskite solar cell photovoltaic parameters

The perovskite solar cells prepared in example 1 and comparative example 1 were tested according to the parameters of table 1 above, as can be seen from table 1, fig. 2 and fig. 3: the perovskite solar cell prepared in example 1 has better overall performance than the comparative example. Introduction of highly effective additive CdF₂The defect state density is reduced, and the interaction between crystal lattices is enhanced. CdF₂Has Cd in^{2 +}And F^-The radius of Cd ions is smaller than that of Pb ions in the perovskite, so that the stress of crystal lattices can be effectively released, the formation energy of defects is improved, and the defect density is reduced. Meanwhile, the F ions with high electronegativity can form strong hydrogen bonds with organic cations and strong ionic bonds with Pb ions, so that the vacancy defect of the ions is effectively eliminated, and the long-term stability of the battery is improved.

By introducing efficient passivation groups, defect states are effectively passivated, so that the density of the defect states is reduced, the extraction and transmission capability of charges is improved, and the stability and the conversion efficiency of the battery are improved.

Example 2

(1) Preparing a precursor solution:

the precursor solution comprises ethanol solution of tetrabutyl titanate and lead iodide (PbI)₂) With cadmium fluoride (CdF)₂) Mixed solution, formamidine iodine/methylamine bromine/methylamine chloride (FAI/MABr/MACl) solution, 2,2',7,7' -tetrakis [ N, N-di (4-methoxyphenyl) amino]-9,9' -spirobifluorene (spiro-OMeTAD) solution and lithium bistrifluoromethanesulfonylimide (Li-TFSI) solution.

0.8g of tetrabutyltitanate is dissolved in 2.0mL of ethanol, stirred with shaking and filtered using a 0.45 μm filter element for further use.

1g of titanium dioxide (TiO)₂) The jelly was dissolved in 5.5g of absolute ethanol and sufficiently stirred for use.

691mg of PbI₂Dissolved in 0.95mL of N-N dimethylFormamide (DMF) and 0.1mL of dimethyl sulfoxide (DMSO), wherein CdF is added to the solution₂Is 0.05 percent, is heated to 100 ℃, is stirred for 30min until being completely dissolved, and is filtered by a filter element with the diameter of 0.45 mu M to prepare a lead iodide solution with the concentration of 1.5M and containing cadmium fluoride for standby. .

1100mg of FAI, 105mg of MABr, and 120mg of MACl powder were dissolved in 15mL of isopropanol solution, stirred well until the solution was clear, and filtered using a 0.45 μm filter cartridge for use.

520mg of Li-TFSI was dissolved in 1mL of acetonitrile at a concentration of 520 mg/mL. 75mg of spiro-OMeTAD was dissolved in 1mL of chlorobenzene solution, and 17.5. mu.L of Li-TFSI solution and 28.8. mu.L of tetra-tert-butylpyridine were added to 1mL of spiro solution, and filtered using a 0.45 μm filter core for use.

(2) Pretreatment of the substrate:

the ITO glass substrate 5 was first ultrasonically cleaned in deionized water for 30 minutes, then ultrasonically cleaned in acetone for 30 minutes, and finally ultrasonically cleaned in isopropyl alcohol for 30 minutes, then blow-dried with a nitrogen gun, and treated in an ultraviolet ozone processor for 30 minutes for standby.

(3) Preparation of the electron transport layer 4:

spin-coating the filtered ethanol solution of tetrabutyl titanate on an ITO glass substrate 5 at a spin-coating rate of 1500rpm for 120s, and then annealing at 350 deg.C for 60min to form c-TiO₂And (5) film layer.

Followed by dissolving the TiO₂The colloidal ethanol solution is coated on the c-TiO by spinning₂Spin coating on the film at 1500rpm for 120s, and annealing at 350 deg.C for 60min to form mp-TiO₂And (5) cooling the film layer, and then treating the film layer in an ultraviolet ozone processor for 20 minutes for later use. c-TiO₂Film layer and mp-TiO₂The film layers together constitute an electron transport layer 4.

(4) Preparation of perovskite film layer 3:

spin coating the prepared lead iodide solution (containing cadmium fluoride) on mp-TiO₂On the film, the speed was 1000rpm and the time was 120 s. Subsequently, the mixture was dried naturally for 3 minutes under a nitrogen atmosphere. The formulated FAI/MABr/MACl solution was then spin coated onto PbI₂On the film, the speed is 1000rpm, the time is 120s, then annealing at 120 ℃ for 50min, cooling and standby.

(5) Preparation of hole transport layer 2:

the doped spiro solution was spin coated on the modified perovskite film layer 3 at 2000rpm for 60 s.

(6) Preparation of electrode 1:

a layer of 30nm silver was deposited on the surface of the spiro by thermal evaporation as electrode 1.

The prepared perovskite solar cell sequentially comprises a 30nm electrode 1, a 200nm hole transmission layer 2, an 800nm perovskite film layer 3, a 400nm electron transmission layer 4 and an ITO glass substrate 5 which are fixedly connected from top to bottom.

Example 3

(1) Preparing a precursor solution:

the precursor solution comprises ethanol solution of tetrabutyl titanate and lead iodide (PbI)₂) With cadmium fluoride (CdF)₂) Mixed solution, formamidine iodine/methylamine bromine/methylamine chloride (FAI/MABr/MACl) solution, 2,2',7,7' -tetrakis [ N, N-di (4-methoxyphenyl) amino]-9,9' -spirobifluorene (spiro-OMeTAD) solution and lithium bistrifluoromethanesulfonylimide (Li-TFSI) solution.

0.75g of tetrabutyltitanate is dissolved in 2.0mL of ethanol, stirred with shaking and filtered using a 0.45 μm filter element for further use.

1g of titanium dioxide (TiO)₂) The jelly was dissolved in 5.5g of absolute ethanol and sufficiently stirred for use.

599mg of PbI₂Dissolved in 0.95mL of N-Dimethylformamide (DMF) and 0.1mL of dimethyl sulfoxide (DMSO), to which CdF was added₂Is 0.07%, is heated to 100 ℃, is stirred for 30min until being completely dissolved, and is filtered by a filter element with the diameter of 0.45 mu M to prepare a lead iodide solution with the concentration of 1.3M and containing cadmium fluoride for standby. .

1300mg of FAI, 110mg of MABr, and 110mg of MACl powder were dissolved in 15mL of isopropanol solution, stirred well until the solution was clear, and filtered using a 0.45 μm filter cartridge for use.

520mg of Li-TFSI was dissolved in 1mL of acetonitrile at a concentration of 520 mg/mL. 72.3mg of spiro-oMeTAD was dissolved in 1mL of chlorobenzene solution, and 17.5. mu.L of Li-TFSI solution and 28.8. mu.L of tetra-t-butylpyridine were added to 1mL of spiro solution and filtered using a 0.45 μm filter core for use.

(2) Pretreatment of the substrate:

the ITO glass substrate 5 was first ultrasonically cleaned in deionized water for 30 minutes, then ultrasonically cleaned in acetone for 30 minutes, and finally ultrasonically cleaned in isopropyl alcohol for 30 minutes, then blow-dried with a nitrogen gun, and treated in an ultraviolet ozone processor for 30 minutes for standby.

(3) Preparation of the electron transport layer 4:

spin-coating the filtered ethanol solution of tetrabutyl titanate on an ITO glass substrate 5 at 6000rpm for 20s, followed by annealing at 550 ℃ for 10min to form c-TiO₂And (5) film layer.

Followed by dissolving the TiO₂The colloidal ethanol solution is coated on the c-TiO by spinning₂Spin coating on the film at 6000rpm for 20s, and annealing at 550 deg.C for 10min to form mp-TiO₂And (5) cooling the film layer, and then treating the film layer in an ultraviolet ozone processor for 20 minutes for later use. c-TiO₂Film layer and mp-TiO₂The film layers together constitute an electron transport layer 4.

(4) Preparation of perovskite film layer 3:

spin coating the prepared lead iodide solution (containing cadmium fluoride) on mp-TiO₂On the film, the speed was 5000rpm and the time was 10 s. Subsequently, the mixture was dried naturally for 3 minutes under a nitrogen atmosphere. The formulated FAI/MABr/MACl solution was then spin coated onto PbI₂On the film, the speed is 4000rpm, the time is 10s, then annealing at 160 ℃ for 5min, cooling and standby.

(5) Preparation of hole transport layer 2:

the doped spiro solution was spin coated on the modified perovskite film layer 3 at 4000rpm for 20 s.

(6) Preparation of electrode 1:

a layer of 300nm copper was deposited by thermal evaporation on the surface of the spiro as electrode 1.

The prepared perovskite solar cell sequentially comprises a 300nm electrode 1, a 100nm hole transmission layer 2, a 400nm perovskite film layer 3, a 330nm electron transmission layer 4 and an ITO glass substrate 5 which are fixedly connected from top to bottom.

Example 4

(1) Preparing a precursor solution:

the precursor solution comprises ethanol solution of tetrabutyl titanate and lead iodide (PbI)₂) With cadmium fluoride (CdF)₂) Mixed solution, formamidine iodine/methylamine bromine/methylamine chloride (FAI/MABr/MACl) solution, 2,2',7,7' -tetrakis [ N, N-di (4-methoxyphenyl) amino]-9,9' -spirobifluorene (spiro-OMeTAD) solution and lithium bistrifluoromethanesulfonylimide (Li-TFSI) solution.

1.0g of tetrabutyltitanate is dissolved in 2.0mL of ethanol, stirred with shaking and filtered using a 0.45 μm filter element for further use.

1g of titanium dioxide (TiO)₂) The jelly was dissolved in 5.5g of absolute ethanol and sufficiently stirred for use.

461mg of PbI₂Dissolved in 0.95mL of N-Dimethylformamide (DMF) and 0.1mL of dimethyl sulfoxide (DMSO), to which CdF was added₂Is 0.065 percent, is heated to 100 ℃, is stirred for 30min until being completely dissolved, and is filtered by a filter element with the diameter of 0.45 mu M to prepare a lead iodide solution with the concentration of 1.0M and containing cadmium fluoride for standby. .

1200mg of FAI, 105mg of MABr, and 100mg of MACl powder were dissolved in 15mL of isopropanol solution, stirred well until the solution was clear, and filtered using a 0.45 μm filter cartridge for use.

520mg of Li-TFSI was dissolved in 1mL of acetonitrile at a concentration of 520 mg/mL. 80mg of spiro-OMeTAD was dissolved in 1mL of chlorobenzene solution, and 17.5. mu.L of Li-TFSI solution and 28.8. mu.L of tetra-tert-butylpyridine were added to 1mL of spiro solution and filtered using a 0.45 μm filter cartridge for use.

(2) Pretreatment of the substrate:

the ITO glass substrate 5 was first ultrasonically cleaned in deionized water for 30 minutes, then ultrasonically cleaned in acetone for 30 minutes, and finally ultrasonically cleaned in isopropyl alcohol for 30 minutes, then blow-dried with a nitrogen gun, and treated in an ultraviolet ozone processor for 30 minutes for standby.

(3) Preparation of the electron transport layer 4:

spin-coating the filtered ethanol solution of tetrabutyl titanate on an ITO glass substrate 5 at a spin-coating rate of 3800rpm for 70s, followed by annealing at 400 deg.C for 50min to form c-TiO₂And (5) film layer.

Followed by dissolving the TiO₂The colloidal ethanol solution is coated on the c-TiO by spinning₂Spin coating on the film at 3800rpm for 70s, and annealing at 400 deg.C for 50min to form mp-TiO₂And (5) cooling the film layer, and then treating the film layer in an ultraviolet ozone processor for 20 minutes for later use. c-TiO₂Film layer and mp-TiO₂The film layers together constitute an electron transport layer 4.

(4) Preparation of perovskite film layer 3:

spin coating the prepared lead iodide solution (containing cadmium fluoride) on mp-TiO₂On the film, the speed was 4000rpm and the time was 50 s. Subsequently, the mixture was dried naturally for 3 minutes under a nitrogen atmosphere. The formulated FAI/MABr/MACl solution was then spin coated onto PbI₂On the film, the speed is 3800rpm, the time is 50s, then annealing at 170 ℃ for 3min, cooling and standby.

(5) Preparation of hole transport layer 2:

the doped spiro solution was spin coated on the modified perovskite film layer 3 at 2500rpm for 50 s.

(6) Preparation of electrode 1:

a layer of 100nm aluminum was deposited on the surface of the spiro by thermal evaporation as electrode 1.

The prepared perovskite solar cell sequentially comprises a 100nm electrode 1, a 170nm hole transmission layer 2, a 500nm perovskite film layer 3, a 365nm electron transmission layer 4 and an ITO glass substrate 5 which are fixedly connected from top to bottom.

Example 5

(1) Preparing a precursor solution:

the precursor solution comprises ethanol solution of tetrabutyl titanate and lead iodide (PbI)₂) With cadmium fluoride (CdF)₂) Mixed solution, formamidine iodine/methylamine bromine/methylamine chloride (FAI/MABr/MACl) solution, 2,2',7,7' -tetra-methyl-amine[ N, N-bis (4-methoxyphenyl) amino group]-9,9' -spirobifluorene (spiro-OMeTAD) solution and lithium bistrifluoromethanesulfonylimide (Li-TFSI) solution.

0.5g of tetrabutyltitanate is dissolved in 2.0mL of ethanol, stirred with shaking and filtered using a 0.45 μm filter element for further use.

1g of titanium dioxide (TiO)₂) The jelly was dissolved in 5.5g of absolute ethanol and sufficiently stirred for use.

645mg of PbI₂Dissolved in 0.95mL of N-Dimethylformamide (DMF) and 0.1mL of dimethyl sulfoxide (DMSO), to which CdF was added₂Is 0.035%, heated to 100 ℃ and stirred for 30min until completely dissolved, and filtered by using a filter element of 0.45 μm for standby.

1200mg of FAI, 120mg of MABr, and 100mg of MACl powder were dissolved in 15mL of isopropanol solution, stirred well until the solution was clear, and filtered using a 0.45 μm filter cartridge for use.

520mg of Li-TFSI was dissolved in 1mL of acetonitrile at a concentration of 520 mg/mL. 70mg of spiro-oMeTAD was dissolved in 1mL of chlorobenzene solution, and 17.5. mu.L of Li-TFSI solution and 28.8. mu.L of tetra-tert-butylpyridine were added to 1mL of spiro solution and filtered using a 0.45 μm filter cartridge for use.

(2) Pretreatment of the substrate:

the ITO glass substrate 5 was first ultrasonically cleaned in deionized water for 30 minutes, then ultrasonically cleaned in acetone for 30 minutes, and finally ultrasonically cleaned in isopropyl alcohol for 30 minutes, then blow-dried with a nitrogen gun, and treated in an ultraviolet ozone processor for 30 minutes for standby.

(3) Preparation of the electron transport layer 4:

spin-coating the filtered ethanol solution of tetrabutyl titanate on an ITO glass substrate 5 at a spin-coating rate of 5000rpm for 100s, followed by annealing at 500 ℃ for 20min to form c-TiO₂And (5) film layer.

Followed by dissolving the TiO₂The colloidal ethanol solution is coated on the c-TiO by spinning₂Spin coating on the film at 5000rpm for 100s, and annealing at 500 deg.C for 20min to form mp-TiO₂Cooling, and ultraviolet deodorizingTreating in an oxygen treater for 20min for later use. c-TiO₂Film layer and mp-TiO₂The film layers together constitute an electron transport layer 4.

(4) Preparation of perovskite film layer 3:

spin coating the prepared lead iodide solution (containing cadmium fluoride) on mp-TiO₂On the film, the speed was 3000rpm and the time was 60 s. Subsequently, the mixture was dried naturally for 3 minutes under a nitrogen atmosphere. The formulated FAI/MABr/MACl solution was then spin coated onto PbI₂On the film, the speed was 2700rpm and the time was 40s, followed by annealing at 150 ℃ for 10min and cooling for use.

(5) Preparation of hole transport layer 2:

the doped spiro solution was spin coated on the modified perovskite film layer 3 at 3500rpm for 40 s.

(6) Preparation of electrode 1:

a layer of 200nm gold was deposited on the surface of the spiro by thermal evaporation as electrode 1.

The prepared perovskite solar cell sequentially comprises a 200nm electrode 1, a 135nm hole transmission layer 2, a 600nm perovskite film layer 3, a 360nm electron transmission layer 4 and an ITO glass substrate 5 which are fixedly connected from top to bottom.