Preparation method, product and application of a strongly polar tin oxide nanomaterial

Abstract

The present invention belongs to the technical field of solar cells, and relates to a preparation method, product and application of a strongly polar tin oxide nanomaterial. In the present invention, ligand modification is carried out on the SnO2 nanomaterial modified by organic amine organic acid by using Meerwein reagent to obtain a nanomaterial modified with one or more ligands among BF4 ‑ , Me3O ‑ , Et3O ‑ , so that the nanomaterial can be dispersed in a strongly polar organic solvent, and then spin-coated or blade-coated on an ITO / FTO substrate or a perovskite layer. The obtained tin oxide thin film has good conductivity, leveling property, excellent film-forming property and good spreading property; at the same time, the strongly polar organic dispersion of tin oxide not only has long-term stability in terms of storage stability; but also has excellent light conversion efficiency in terms of device performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of solar cells, and relates to a preparation method, product and application of a strongly polar tin oxide nanomaterial. Background Art

[0002] In a perovskite solar cell, for the normal structure, the upper layer of the transparent electrode is the electron transport layer. After sunlight passes through the transparent electrode, it passes through the electron transport layer and then reaches the light-absorbing layer. The conversion efficiency of the normal (n-i-p) structure is higher than that of the inverted structure, and it has higher Voc and Jsc values, but the hysteresis effect is more obvious than that of the inverted structure.

[0003] Tin oxide is an important n-type semiconductor material with a band gap energy between 3.6 - 4.0 eV and an electron mobility of up to 240 cm 2 / V·s. As a commonly used electron transport layer material in normal perovskite solar cells, it has the advantages of being cheap, stable and easy to prepare. For normal perovskite devices, conventional tin oxide is spin-coated after being dispersed in water. The introduction of water will dissociate the upper perovskite, affecting the device performance and lifespan. For inverted devices, tin oxide needs to be spin-coated on the perovskite layer, and the conventional water dispersion of tin oxide cannot be used, which greatly affects the application of tin oxide in solar cells. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method, product and application of a strongly polar tin oxide nanomaterial to solve the problems existing in the above-mentioned prior art.

[0005] A preparation method of a strongly polar tin oxide nanomaterial includes the following steps:

[0006] S1. At an environment of 10 - 30 °C, mix an organic amine, an organic acid and an organic solvent to form a first reaction system;

[0007] S2. Mix tin oxide nanopowder and the first reaction system to obtain a second reaction system, and stir for 0.1 - 72 h. Then add methanol or ethanol for precipitation and centrifugation to obtain an organic amine and organic acid modified tin oxide nanomaterial;

[0008] S3. Add the tin oxide nanomaterial obtained in S2 to an organic solvent and a Meerwein reagent, stir for 1 - 7 days, then add a precipitating agent for precipitation and centrifugation, and collect the precipitate. The obtained precipitate is strongly polar tin oxide nanoparticles.

[0009] S4. Disperse the strongly polar tin oxide nanoparticles in a strongly polar organic solvent.

[0010] Further, the organic amine described in S1 is a straight-chain amine with 4 to 18 carbon atoms; the organic acid is a straight-chain acid with 4 to 18 carbon atoms.

[0011] Further, the organic solvent described in S1 is one of dichloromethane, chloroform, toluene, n-hexane, n-heptane, and n-octane.

[0012] Further, in the second reaction system of S2, when the mass of tin oxide is 1 g, the volume ratio of the organic amine, organic acid, and organic solvent is (1 - 10):(1 - 10):(10 - 50).

[0013] Further, the Meerwein reagent in S3 is trimethyloxonium tetrafluoroborate or triethyloxonium tetrafluoroborate.

[0014] Further, the precipitant in S3 is acetonitrile or acetone.

[0015] For the strongly polar tin oxide nanomaterial prepared by any of the above preparation methods, its tin oxide nanoparticles include tin oxide inorganic substances and inorganic ligands and organic ligands on the surface of the tin oxide inorganic substances. The inorganic ligand is tetrafluoroborate BF4 - , and the organic ligand is MeO - , EtO - .

[0016] Further, the ligand content accounts for 5% - 30% of the total weight of the entire nanomaterial, the particle size of the nanomaterial is 3 - 10 nm, and the band gap range is 3.6 eV - 4.0 eV.

[0017] Application of the strongly polar tin oxide nanomaterial as described above as an electron transport layer material for perovskite solar cells.

[0018] The beneficial effects of the present invention are as follows:

[0019] In the present invention, ligand modification is performed on the SnO2 nanomaterial modified with an organic amine and an organic acid by using a Meerwein reagent to obtain a nanomaterial modified with tetrafluoroborate BF4 - , MeO - , EtO - . The nanomaterial can be dispersed in a strongly polar organic solvent, and then spin-coated or blade-coated on an ITO / FTO substrate or a perovskite layer. The obtained tin oxide film has good conductivity, leveling property, excellent film-forming property, and good spreading property; at the same time, the strongly polar tin oxide organic dispersion not only has long-term stability in terms of storage stability; but also has excellent light conversion efficiency in terms of device performance.

[0020] The present invention introduces anhydrous water during the synthesis process, and secondly, the tetrafluoroborate on the surface of tin oxide makes tin oxide have a good dispersing and dissolving effect in a strong polar solvent, which is suitable for spin coating and more conducive to scraping, so that perovskite solar cells can be industrialized and mass-produced. The inorganic ligand (BF4 - ) has a short chain structure and has an inherent advantage in conductivity compared to organic ligands; the particle size of 3-10nm is conducive to the smoothness of the SnO2 film surface and reduces the interface barrier. The introduction of organic acids and organic amines makes it easy for SnO2 nanomaterials to be dispersed in organic solvents and react better with Me3OBF4. SnO2 and Me3OBF4 alone cannot react or cannot achieve the dispersion effect. The entire reaction is carried out at room temperature, which is green, environmentally friendly and pollution-free, avoiding the occurrence of danger. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is the TEM image of the highly polar SnO2 nanoparticles prepared in the present invention.

[0022] Figure 2 This is the XRD diagram of the highly polar SnO2 nanoparticles prepared in the present invention.

[0023] Figure 3 This is the UV-visible absorption diagram of the highly polar SnO2 nanoparticles prepared in the present invention.

[0024] Figure 4 This is the thermogravimetric analysis diagram of the highly polar SnO2 nanoparticles prepared in the present invention. DETAILED DESCRIPTION

[0025] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] The present invention provides a method for preparing highly polar SnO2 nanoparticles, comprising the following steps:

[0027] S1. Under a 10-30°C environment, organic amine, organic acid and organic solvent are mixed to form a first reaction system;

[0028] S2. The tin oxide nanopowder and the first reaction system are mixed to obtain a second reaction system, and stirred for 0.1-72h, after which methanol or ethanol is added for precipitation and centrifugation to obtain an organic amine or organic acid-modified tin oxide nanomaterial;

[0029] S3. Add the tin oxide nanomaterial obtained in S2 to an organic solvent, stir with Meerwein reagent for 1-7 days, then add a precipitant thereto, precipitate, centrifuge, and collect the precipitate. The precipitate obtained is the highly polar tin oxide nanomaterial.

[0030] S4. The highly polar tin oxide nanomaterial can be dispersed in a highly polar organic solvent.

[0031] The strongly polar tin oxide nanomaterials can be dissolved in strongly polar organic solvents such as DMF, DMSO, NMP, MeOH, EtOH, acetonitrile, etc.;

[0032] The organic amine described in S1 above is a straight-chain amine with C4-C18. For example: one of n-butylamine, n-hexylamine, n-dodecylamine, and oleylamine.

[0033] The organic acid described in S1 above is a straight-chain acid with C4-C18. For example: one of n-butyric acid, n-hexanoic acid, n-dodecanoic acid, and oleic acid.

[0034] The organic solvent described in S1 above is one of dichloromethane, chloroform, toluene, n-hexane, n-heptane, and n-octane.

[0035] The SnO2 nanopowder described in S2 above has a particle size of 3-10 nm;

[0036] The SnO2 nanopowder described in S2 above has a band gap of 3.6-4.0 eV;

[0037] The synthesis method of the SnO2 nanopowder described in S2 above is not limited to sol-gel, hydrothermal method, and pyrolysis method;

[0038] The synthesis process in the S2 system is not limited to stirring reaction, and can be one of microwave reaction, stirring reaction, ultrasonic reaction, and hydrothermal reaction.

[0039] Example 1

[0040] S1. At room temperature, 10 ml of n-butylamine, 1 ml of n-butyric acid and 100 ml of n-heptane are mixed to form a first reaction system;

[0041] S2. 0.5 g of 5 nm SnO2 nanopowder is mixed with the first reaction system to obtain a second reaction system, and stirred for 24 h. Then 200 ml of methanol is added for precipitation and centrifuged at 4000 rpm to obtain the SnO2 nanomaterials modified with butylamine and butyric acid;

[0042] S3. The SnO2 nanomaterials obtained in S2 are added with 50 ml of acetonitrile and 1 g of trimethyloxonium tetrafluoroborate and stirred for 5 days. Then 50 ml of acetone is added and centrifuged at 5000 rpm. The obtained precipitate is the strongly polar SnO2 nanomaterials;

[0043] S4. The above-mentioned strongly polar SnO2 nanomaterials are dispersed in 50 ml of DMF solution to prepare a 2.5 wt% SnO2 DMF dispersion.

[0044] Example 2

[0045] S1. At room temperature, mix 10 ml of n-octylamine, 1 ml of n-octanoic acid with 100 ml of n-octane to form a first reaction system;

[0046] S2. Mix 0.5 g of 5-nm SnO2 nano powder with the first reaction system to obtain a second reaction system, and perform ultrasonic treatment for 3 h. Then add 200 ml of ethanol for precipitation and centrifuge at 500 rpm to obtain SnO2 nano material modified with n-octylamine and n-octanoic acid;

[0047] S3. Add the SnO2 nano material obtained in S2 to 50 ml of acetonitrile and 1 g of triethyloxonium tetrafluoroborate, stir for 5 days, then add 50 ml of acetone and centrifuge at 5000 rpm. The obtained precipitate is the strongly polar SnO2 nano material;

[0048] S4. Disperse the above-mentioned strongly polar SnO2 nano material in 50 ml of DMSO solution to prepare a 3 wt% SnO2 DMSO dispersion.

[0049] Example 3

[0050] S1. At room temperature, mix 10 ml of oleylamine, 2 ml of oleic acid with 100 ml of n-hexane to form a first reaction system;

[0051] S2. Mix 0.6 g of 7-nm SnO2 nano powder with the first reaction system to obtain a second reaction system, and heat and react in a microwave oven for 1 h. Then add 300 ml of methanol for precipitation and centrifuge at 5000 rpm to obtain SnO2 nano material modified with oleylamine and oleic acid;

[0052] S3. Add the SnO2 nano material obtained in S2 to 60 ml of n-hexane, add 2.5 g of triethyloxonium tetrafluoroborate and stir for 6 days. Then add 50 ml of acetone for precipitation and centrifuge at 4000 rpm. The obtained precipitate is the strongly polar SnO2 nano material;

[0053] S4. Disperse the above-mentioned strongly polar SnO2 nano material in 50 ml of NMP solution to prepare a 3 wt% SnO2 2DMSO dispersion.

[0054] A solar perovskite battery device, and its manufacturing method includes the following steps: spin-coat the above-mentioned 2.5 wt% SnO2 nano material DMF dispersion on the ITO anode layer, and then anneal at 120 °C for 30 min to form an electron transport layer; spin-coat a perovskite solution on the hole transport layer as the carrier part to form an absorption layer; spin-coat an isopropanol solution of zinc oxide on the absorption layer, and form an electron transport layer after drying; finally, evaporate and deposit an Au cathode electrode layer and encapsulate to form a formal perovskite solar battery device.

[0055] A solar perovskite battery device, and its manufacturing method includes the following steps: spin-coating a NiOx aqueous dispersion on an ITO anode layer, and then annealing at 150 °C for 30 min to form a hole transport layer; forming an absorption layer by spin-coating a perovskite solution on the hole transport layer serving as a carrier part; spin-coating the 3 wt% SnO2 DMSO dispersion in Example 2 on the absorption layer, and drying to form an electron transport layer; finally, evaporating an Au cathode electrode layer and encapsulating to form a reverse perovskite solar battery device.

[0056] The device performance parameters of the SnO2 dispersion in the above examples are shown in Table 1

[0057]

[0058]

[0059] The above examples are merely illustrations given for clarity and are not limitations on the implementation. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to list all the implementations here. And the obvious changes or variations derived therefrom are still within the protection scope of this invention.

Claims

1. A preparation method of a strongly polar tin oxide nanomaterial, characterized in that, It includes the following steps: Under the environment of 10 - 30 °C, mix organic amine, organic acid and organic solvent to form a first reaction system; Mix tin oxide nano powder and the first reaction system to obtain a second reaction system, and stir for 0.1 - 72 h. Then add methanol or ethanol for precipitation and centrifugation to obtain tin oxide nano material modified by organic amine and organic acid; Add the tin oxide nano material obtained in S2 into organic solvent, stir with Meerwein reagent for 1 - 7 days, then add a precipitant for precipitation and centrifugation, and collect the precipitate. The obtained precipitate is strongly polar tin oxide nano particles; Disperse the strongly polar tin oxide nano particles into a strongly polar organic solvent; In the second reaction system in S2, when the mass of tin oxide is 1 g, the volume ratio of organic amine, organic acid and organic solvent is (1 - 10):(1 - 10):(10 - 50); The Meerwein reagent in S3 is trimethyloxonium tetrafluoroborate or triethyloxonium tetrafluoroborate.

2. The preparation method of the strongly polar tin oxide nanomaterial according to claim 1, characterized in that: The organic amine described in S1 is a straight-chain amine with C4 - C18; the organic acid is a straight-chain acid with C4 - C18.

3. The preparation method of the strongly polar tin oxide nanomaterial according to claim 1, wherein: The organic solvent described in S1 is one of dichloromethane, chloroform, toluene, n-hexane, n-heptane, n-octane.

4. The preparation method of the strongly polar tin oxide nanomaterial according to claim 1, wherein: The precipitant in S3 is acetonitrile or acetone.

5. The strongly polar tin oxide nanomaterial prepared by the preparation method according to any one of claims 1 to 4, wherein the tin oxide nanoparticles comprise tin oxide inorganic substances and inorganic and organic ligands on the surface of the tin oxide inorganic substances, and the inorganic ligand is tetrafluoroborate BF4 - , and the organic ligand is MeO - , EtO - .

6. The strongly polar tin oxide nanomaterial according to claim 5, wherein: The ligand content accounts for 5% - 30% of the total weight of the whole nano material, the particle size of the nano material is 3 - 10 nm, and the band gap range is 3.6 eV - 4.0 eV.

7. Application of the strongly polar tin oxide nano material as claimed in claim 5 as an electron transport layer material for perovskite solar cells.

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