Preparation method of amorphous oxide interface modification layer and perovskite solar cell device

Abstract

The application belongs to the technical field of perovskite solar cell devices, and particularly relates to a preparation method of an amorphous oxide interface modification layer and a perovskite solar cell device. Ethanol niobium is dispersed in an alcohol solvent according to a volume ratio of 1-4:10000 to obtain an ethanol niobium alcohol solution. After the ethanol niobium alcohol solution is coated on the surface of a SnO2 electron transport layer and then heated and treated by ultraviolet ozone, an amorphous oxide interface modification layer which can further form a perovskite absorption layer on the surface thereof is formed. The perovskite solar cell device is further prepared on the basis of the amorphous oxide interface modification layer.

Description

Technical Field

[0001] This invention belongs to the field of perovskite solar cell device technology, and specifically relates to a method for preparing an amorphous oxide interface modification layer and a perovskite solar cell device. Background Technology

[0002] Perovskite solar cells (PSCs) have attracted widespread attention worldwide due to their low cost, simple fabrication, and excellent photoelectric conversion performance.

[0003] SnO2 is widely used as an electron transport layer (ETL) in high-efficiency planar solar cells due to its excellent electron transport properties, light transmittance, stability, and low-temperature preparation. However, the interface problem between the perovskite film and the SnO2 layer seriously affects the power conversion efficiency of solar cells.

[0004] In nip-structured PSCs, the electron transport layer serves as the substrate for the growth of perovskite polycrystalline thin films, and its surface properties are crucial for the nucleation and grain growth of the perovskite films. Secondly, the conduction and valence band energy levels of perovskite materials do not perfectly match the band structure of SnO2, leading to band shift and band bending phenomena, which to some extent hinder electron transport. Furthermore, the multilayer films of PSCs often exhibit significant differences in mechanical properties; therefore, excellent interfaces contribute to improving the overall flexibility and stability of the thin-film battery. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a method for preparing an amorphous oxide interface modification layer:

[0006] (1) Disperse niobium ethanol in an alcohol solvent at a volume ratio of 1 to 4:10000 to obtain an alcohol solution of niobium ethanol.

[0007] (2) After coating the niobium ethanol solution obtained in step (1) onto the surface of the SnO2 electron transport layer, heat and ultraviolet ozone treatment are performed to form an amorphous oxide interface modification layer on its surface, which can be further used to prepare a perovskite absorption layer.

[0008] As a preferred option: in step (1), the alcohol solvent is ethanol or methanol. After adding niobium ethanol to the alcohol solvent, it is magnetically stirred to disperse it fully.

[0009] The present invention also provides an amorphous oxide interface modification layer prepared by the above method.

[0010] The present invention also provides a perovskite solar cell device, the layer structure of which is as follows: a conductive substrate, a SnO2 electron transport layer, an amorphous oxide interface modification layer prepared by the above method, a perovskite absorption layer, a hole transport layer, and a metal electrode.

[0011] Preferably, the SnO2 electron transport layer has a thickness of 10–40 nm; the perovskite absorber layer has a thickness of 500–1000 nm, preferably 500–800 nm; the hole transport layer has a thickness of 50–100 nm, preferably 60–80 nm; and the metal electrode has a thickness of 60–120 nm, preferably 80 nm.

[0012] The present invention also provides a method for fabricating the above-mentioned perovskite solar cell device as follows:

[0013] Step 1: Cleaning the conductive substrate

[0014] The conductive substrate was sequentially ultrasonically cleaned with conductive glass cleaner, deionized water, isopropanol, acetone, and ethanol for 15 minutes each. After cleaning, it was placed in an oven to dry.

[0015] The conductive substrate is FTO, ITO conductive glass, or PEN / ITO flexible conductive substrate;

[0016] Step 2: Form a SnO2 electron transport layer on the surface of a conductive substrate.

[0017] After preparing a SnO2 film on the conductive substrate surface treated in step 1 using a solution method, the substrate is annealed at 100–170°C for 30–60 minutes to form a SnO2 electron transport layer.

[0018] Solution methods include spin coating and chemical bath deposition.

[0019] When the conductive substrate is FTO conductive glass, the solution method is spin coating or chemical bath deposition; when the conductive substrate is ITO conductive glass or PEN / ITO flexible conductive substrate, the solution method is spin coating.

[0020] Step 3: Form an amorphous oxide interface modification layer on the surface of the SnO2 electron transport layer.

[0021] The aforementioned niobium ethanol solution was spin-coated onto the surface of the SnO2 electron transport layer obtained in step 2 at a speed of 3000-4000 rpm for 20-40 s. After spin-coating, the layer was placed on a heating stage and heated at 100-120°C for 10-30 min, followed by ultraviolet ozone treatment for 30-60 min to form an amorphous oxide interface modification layer.

[0022] Step 4: Form a perovskite absorber layer on the surface of the amorphous oxide interface modification layer.

[0023] The perovskite precursor solution is spin-coated onto the surface of the amorphous oxide interface modification layer obtained in step 3 at a speed of 3000–6000 rpm for 20–40 s. An antisolvent is added dropwise at the 7th–12th s mark during spin-coating. After spin-coating, the layer is placed on a heating stage and heated at 80–150 °C for 30–90 min to form the perovskite absorber layer.

[0024] The perovskite precursor solution was formed by dissolving PbI2, FAI, MACl, and MAPbBr3 in a mixed solvent of DMF and DMSO at concentrations of 1.53 M, 1.4 M, 0.5 M, and 0.0122 M, respectively, with a DMF:DMSO ratio of 8:1 (v / v).

[0025] The antisolvent is anisole or chlorobenzene;

[0026] Step 5: Form a hole transport layer on the surface of the perovskite absorber layer.

[0027] The hole transport layer precursor solution was spin-coated onto the surface of the perovskite absorber layer obtained in step 4 at a speed of 3000–5000 rpm for 20–40 s. After drying, the hole transport layer was formed.

[0028] The hole transport layer is Spiro-OMeTAD.

[0029] The hole transport layer precursor solution is a mixture of chlorobenzene solution of 2,2',7,7'-tetrabromo-9,9'-spirodi,tri(4-iodophenyl)amine (spiro-OMeTAD), tert-butylpyridine, lithium bis(trifluoromethanesulfonyl)imide, and acetonitrile solution of tri[4-tert-butyl-2-(1H-pyrazol-1-yl)pyridine]cobalt tri(1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide salt);

[0030] Step 6: Form a metal electrode on the surface of the hole transport layer.

[0031] In a thermal evaporation coating apparatus, a metal electrode is deposited on the surface of the hole transport layer obtained in step 5, thereby completing the fabrication of a perovskite solar cell device with amorphous oxide interface modification.

[0032] The metal electrode is a gold or silver electrode.

[0033] The beneficial effects of this invention are as follows: In this solution, the amorphous oxide interface modification layer on the surface of the SnO2 electron transport layer is composed of NbO x Composition: Amorphous NbO xIt exhibits excellent wettability, allowing it to uniformly cover the perovskite film and the SnO2 electron transport layer of the substrate, forming a tight interfacial contact. This excellent wettability reduces the nucleation barrier of perovskite crystals, which is beneficial for optimizing the crystallization process of perovskite films, promoting the orderly growth of perovskite crystals, and improving the crystallinity and film quality of perovskite. Amorphous NbO x It can also adjust the energy level arrangement between the perovskite thin film and the SnO2 electron transport layer on the substrate, promote electron transport, reduce recombination, and improve the collection efficiency of photogenerated carriers, thereby improving the photoelectric conversion efficiency of photovoltaic devices. In addition, the interface enhancement effect of the amorphous oxide interface modification layer can improve the flexibility of the device, which helps to improve the mechanical stability and durability of the device, and has broad application prospects in the fields of flexible electronic devices and wearable devices. Attached Figure Description

[0034] Figure 1 This is a cross-sectional view of the layer structure of the perovskite solar cell device modified with amorphous oxide interfaces according to this scheme.

[0035] Wherein, 1—conductive substrate, 2—SnO2 electron transport layer, 3—amorphous oxide interface modification layer, 4—perovskite absorption layer, 5—hole transport layer, 6—metal electrode;

[0036] Figure 2 A comparison chart showing the ultraviolet transmittance of the unmodified SnO2 electron transport layer formed in step 2 of Example 1 and the SnO2 electron transport layer modified with an amorphous oxide interface formed in step 3 of Example 1.

[0037] Figure 3 A comparison diagram of the water contact angle between the unmodified SnO2 electron transport layer formed in step 2 of Example 1 and the SnO2 electron transport layer modified with an amorphous oxide interface formed in step 3 of Example 1.

[0038] Figure 4 XRD comparison images are shown between the perovskite layer deposited in step 3 of Comparative Example 1 on the surface of the unmodified SnO2 electron transport layer and the perovskite layer deposited in step 3 of Comparative Example 2 and step 4 of Example 1 on the surface of the SnO2 electron transport layer modified with an amorphous oxide interface.

[0039] Figure 5 The JV curves are shown in the comparison diagram between the perovskite solar cell device prepared in Example 1 and the perovskite solar cell device with amorphous oxide interface modification prepared in Example 1. Detailed Implementation

[0040] The technical solutions in the embodiments of the present invention will be further described in detail below. The described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] A method for fabricating a perovskite solar cell device:

[0042] Step 1: Cleaning the conductive substrate

[0043] The conductive substrate was sequentially ultrasonically cleaned with conductive glass cleaner, deionized water, isopropanol, acetone, and ethanol for 15 minutes each. After cleaning, it was placed in an oven to dry.

[0044] The conductive substrate is FTO, ITO conductive glass, or PEN / ITO flexible conductive substrate;

[0045] Step 2: Form a SnO2 electron transport layer on the surface of a conductive substrate.

[0046] After preparing a SnO2 film on the conductive substrate surface treated in step 1 using a solution method, the substrate is annealed at 100–170°C for 30–60 minutes to form a SnO2 electron transport layer.

[0047] Solution methods include spin coating and chemical bath deposition.

[0048] When the conductive substrate is FTO conductive glass, the solution method is spin coating or chemical bath deposition; when the conductive substrate is ITO conductive glass or PEN / ITO flexible conductive substrate, the solution method is spin coating.

[0049] Step 3: Form an amorphous oxide interface modification layer on the surface of the SnO2 electron transport layer.

[0050] Niobium ethanol was dispersed in an alcohol solvent at a volume ratio of 1–4:10000 to obtain an alcoholic solution of niobium ethanol. The obtained alcoholic solution of niobium ethanol was spin-coated onto the surface of the SnO2 electron transport layer obtained in step 2 at a speed of 3000–4000 rpm for 20–40 s. After spin-coating, the layer was placed on a heating stage and heated at 100–120 °C for 10–30 min, followed by ultraviolet ozone treatment for 30–60 min to form an amorphous oxide interface modification layer.

[0051] Step 4: Form a perovskite absorber layer on the surface of the amorphous oxide interface modification layer.

[0052] The perovskite precursor solution is spin-coated onto the surface of the amorphous oxide interface modification layer obtained in step 3 at a speed of 3000–6000 rpm for 20–40 s. An antisolvent is added dropwise at the 7th–12th s mark during spin-coating. After spin-coating, the layer is placed on a heating stage and heated at 80–150 °C for 30–90 min to form the perovskite absorber layer.

[0053] The perovskite precursor solution was formed by dissolving PbI2, FAI, MACl, and MAPbBr3 in a mixed solvent of DMF and DMSO at concentrations of 1.53 M, 1.4 M, 0.5 M, and 0.0122 M, respectively, with a DMF:DMSO ratio of 8:1 (v / v).

[0054] The antisolvent is anisole or chlorobenzene;

[0055] Step 5: Form a hole transport layer on the surface of the perovskite absorber layer.

[0056] The hole transport layer precursor solution was spin-coated onto the surface of the perovskite absorber layer obtained in step 4 at a speed of 3000–5000 rpm for 20–40 s. After drying, the hole transport layer was formed.

[0057] The hole transport layer is Spiro-OMeTAD.

[0058] The hole transport layer precursor solution is a mixture of chlorobenzene solution of 2,2',7,7'-tetrabromo-9,9'-spirodi,tri(4-iodophenyl)amine (spiro-OMeTAD), tert-butylpyridine, lithium bis(trifluoromethanesulfonyl)imide, and acetonitrile solution of tri[4-tert-butyl-2-(1H-pyrazol-1-yl)pyridine]cobalt tri(1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide salt);

[0059] Step 6: Form a metal electrode on the surface of the hole transport layer.

[0060] In a thermal evaporation coating apparatus, a metal electrode is deposited on the surface of the hole transport layer obtained in step 5, thereby completing the fabrication of a perovskite solar cell device with amorphous oxide interface modification.

[0061] The metal electrode is a gold or silver electrode.

[0062] Example 1

[0063] Step 1: Cleaning the conductive substrate

[0064] The ITO conductive substrate was placed in a washing tank and ultrasonically cleaned for 15 minutes each with conductive glass cleaner, deionized water, isopropanol, acetone and ethanol. After cleaning, it was placed in an oven to dry.

[0065] Step 2: Form a SnO2 electron transport layer on the surface of a conductive substrate.

[0066] Deionized water was added to dilute a 15% (w / w) SnO2 nanocrystalline colloidal aqueous dispersion, with a volume ratio of 1:4 between the nanocrystalline colloidal aqueous dispersion and deionized water. The mixture was then magnetically stirred to obtain a SnO2 particle dispersion.

[0067] After treating the ITO conductive substrate in step 1 with an ultraviolet ozone generator for 20 minutes, the SnO2 particle dispersion in this step is spin-coated on the surface of the conductive substrate at a speed of 3000 rpm for 30 seconds. After spin-coating, the substrate is placed on a heating stage and heated at 150°C for 30 minutes to form a SnO2 electron transport layer with a thickness of 20 nm.

[0068] Step 3: Form an amorphous oxide interface modification layer on the surface of the SnO2 electron transport layer.

[0069] Niobium ethanol was dispersed in an alcohol solvent at a volume ratio of 3:10000 to obtain an alcoholic solution of niobium ethanol. In a glove box filled with N2, the obtained alcoholic solution of niobium ethanol was spin-coated onto the surface of the SnO2 electron transport layer obtained in step 2 at a speed of 3000 rpm for 30 s. After spin-coating, the layer was placed on a heating stage and heated at 100°C for 30 min, followed by ultraviolet ozone treatment for 60 min to form an amorphous oxide interface modification layer.

[0070] Step 4: Form a perovskite absorber layer on the surface of the amorphous oxide interface modification layer.

[0071] The surface of the amorphous oxide interface modification layer obtained in step 3 was spin-coated with a perovskite precursor solution. The perovskite precursor solution was formed by dissolving PbI2, FAI, MACl, and MAPbBr3 in a mixed solvent of DMF and DMSO at concentrations of 1.53M, 1.4M, 0.5M, and 0.0122M, respectively, with a DMF:DMSO ratio of 8:1 (v / v). The spin-coating speed was 5000 rpm and the spin-coating time was 30 s. When the spin-coating reached the 10th s mark, the anti-solvent chlorobenzene was added dropwise. After the spin-coating was completed, the layer was placed on a heating stage and heated at 100°C for 60 min to form a perovskite absorption layer with a thickness of approximately 600 nm.

[0072] Step 5: Form a hole transport layer on the surface of the perovskite absorber layer.

[0073] Weigh 0.1019 g of 2,2',7,7'-tetrabromo-9,9'-spirodi,tri(4-iodophenyl)amine (spiro-OMeTAD) and dissolve it in 1 mL of chlorobenzene. Then add 45.36 μL of tert-butylpyridine, 24.36 μL of acetonitrile solution of lithium bis(trifluoromethanesulfonyl)imide at 520 mg / mL, and 49.6 μL of acetonitrile solution of tris[4-tert-butyl-2-(1H-pyrazol-1-yl)pyridine]cobalttrium(1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide salt] and stir thoroughly to dissolve to obtain the hole transport layer precursor solution.

[0074] The hole transport layer precursor liquid was spin-coated onto the surface of the perovskite absorber layer obtained in step 4 at a speed of 4000 rpm for 30 s. After drying, a Spiro-OMeTAD hole transport layer with a thickness of about 150 nm was formed.

[0075] Step 6: Form a metal electrode on the surface of the hole transport layer.

[0076] The hole transport layer obtained in step 5 is placed in a thermal evaporation coating apparatus, and a silver electrode with a thickness of about 80 nm is deposited on the surface of the hole transport layer, thereby completing the fabrication of a perovskite solar cell device with amorphous oxide interface modification.

[0077] Example 2

[0078] Step 1: Cleaning the conductive substrate

[0079] The ITO conductive substrate was placed in a washing tank and ultrasonically cleaned for 15 minutes each with conductive glass cleaner, deionized water, isopropanol, acetone and ethanol. After cleaning, it was placed in an oven to dry.

[0080] Step 2: Form a SnO2 electron transport layer on the surface of a conductive substrate.

[0081] Deionized water was added to dilute a 15% (w / w) SnO2 nanocrystalline colloidal aqueous dispersion, with a volume ratio of 1:4 between the nanocrystalline colloidal aqueous dispersion and deionized water. The mixture was then magnetically stirred to obtain a SnO2 particle dispersion.

[0082] After treating the ITO conductive substrate in step 1 with an ultraviolet ozone generator for 20 minutes, the SnO2 particle dispersion in this step is spin-coated on the surface of the conductive substrate at a speed of 3000 rpm for 30 seconds. After spin-coating, the substrate is placed on a heating stage and heated at 150°C for 30 minutes to form a SnO2 electron transport layer with a thickness of 20 nm.

[0083] Step 3: Form an amorphous oxide interface modification layer on the surface of the SnO2 electron transport layer.

[0084] Niobium ethanol was dispersed in an alcohol solvent at a volume ratio of 2:10000 to obtain an alcoholic solution of niobium ethanol. In a glove box filled with N2, the obtained alcoholic solution of niobium ethanol was spin-coated onto the surface of the SnO2 electron transport layer obtained in step 2 at a speed of 3000 rpm for 30 s. After spin-coating, the layer was placed on a heating stage and heated at 100°C for 30 min, followed by ultraviolet ozone treatment for 60 min to form an amorphous oxide interface modification layer.

[0085] Step 4: Form a perovskite absorber layer on the surface of the amorphous oxide interface modification layer.

[0086] The surface of the amorphous oxide interface modification layer obtained in step 3 was spin-coated with a perovskite precursor solution. The perovskite precursor solution was formed by dissolving PbI2, FAI, MACl, and MAPbBr3 in a mixed solvent of DMF and DMSO at concentrations of 1.53M, 1.4M, 0.5M, and 0.0122M, respectively, with a DMF:DMSO ratio of 8:1 (v / v). The spin-coating speed was 5000 rpm and the spin-coating time was 30 s. When the spin-coating reached the 10th s mark, the anti-solvent chlorobenzene was added dropwise. After the spin-coating was completed, the layer was placed on a heating stage and heated at 100°C for 60 min to form a perovskite absorption layer with a thickness of approximately 600 nm.

[0087] Step 5: Form a hole transport layer on the surface of the perovskite absorber layer.

[0088] Weigh 0.1019 g of 2,2',7,7'-tetrabromo-9,9'-spirodi,tri(4-iodophenyl)amine (spiro-OMeTAD) and dissolve it in 1 mL of chlorobenzene. Then add 45.36 μL of tert-butylpyridine, 24.36 μL of acetonitrile solution of lithium bis(trifluoromethanesulfonyl)imide at 520 mg / mL, and 49.6 μL of acetonitrile solution of tris[4-tert-butyl-2-(1H-pyrazol-1-yl)pyridine]cobalttrium(1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide salt] and stir thoroughly to dissolve to obtain the hole transport layer precursor solution.

[0089] The hole transport layer precursor liquid was spin-coated onto the surface of the perovskite absorber layer obtained in step 4 at a speed of 4000 rpm for 30 s. After drying, a Spiro-OMeTAD hole transport layer with a thickness of about 150 nm was formed.

[0090] Step 6: Form a metal electrode on the surface of the hole transport layer.

[0091] The hole transport layer obtained in step 5 is placed in a thermal evaporation coating apparatus, and a silver electrode with a thickness of about 80 nm is deposited on the surface of the hole transport layer, thereby completing the fabrication of a perovskite solar cell device with amorphous oxide interface modification.

[0092] Example 3

[0093] Step 1: Cleaning the conductive substrate

[0094] The ITO conductive substrate was placed in a washing tank and ultrasonically cleaned for 15 minutes each with conductive glass cleaner, deionized water, isopropanol, acetone and ethanol. After cleaning, it was placed in an oven to dry.

[0095] Step 2: Form a SnO2 electron transport layer on the surface of a conductive substrate.

[0096] Deionized water was added to dilute a 15% (w / w) SnO2 nanocrystalline colloidal aqueous dispersion, with a volume ratio of 1:4 between the nanocrystalline colloidal aqueous dispersion and deionized water. The mixture was then magnetically stirred to obtain a SnO2 particle dispersion.

[0097] After treating the ITO conductive substrate in step 1 with an ultraviolet ozone generator for 20 minutes, the SnO2 particle dispersion in this step is spin-coated on the surface of the conductive substrate at a speed of 3000 rpm for 30 seconds. After spin-coating, the substrate is placed on a heating stage and heated at 150°C for 30 minutes to form a SnO2 electron transport layer with a thickness of 20 nm.

[0098] Step 3: Form an amorphous oxide interface modification layer on the surface of the SnO2 electron transport layer.

[0099] Niobium ethanol was dispersed in an alcohol solvent at a volume ratio of 4:10000 to obtain an alcoholic solution of niobium ethanol. In a glove box filled with N2, the obtained alcoholic solution of niobium ethanol was spin-coated onto the surface of the SnO2 electron transport layer obtained in step 2 at a speed of 3000 rpm for 30 s. After spin-coating, the layer was placed on a heating stage and heated at 100°C for 30 min, followed by ultraviolet ozone treatment for 60 min to form an amorphous oxide interface modification layer.

[0100] Step 4: Form a perovskite absorber layer on the surface of the amorphous oxide interface modification layer.

[0101] The surface of the amorphous oxide interface modification layer obtained in step 3 was spin-coated with a perovskite precursor solution. The perovskite precursor solution was formed by dissolving PbI2, FAI, MACl, and MAPbBr3 in a mixed solvent of DMF and DMSO at concentrations of 1.53M, 1.4M, 0.5M, and 0.0122M, respectively, with a DMF:DMSO ratio of 8:1 (v / v). The spin-coating speed was 5000 rpm and the spin-coating time was 30 s. When the spin-coating reached the 10th s mark, the anti-solvent chlorobenzene was added dropwise. After the spin-coating was completed, the layer was placed on a heating stage and heated at 100°C for 60 min to form a perovskite absorption layer with a thickness of approximately 600 nm.

[0102] Step 5: Form a hole transport layer on the surface of the perovskite absorber layer.

[0103] Weigh 0.1019 g of 2,2',7,7'-tetrabromo-9,9'-spirodi,tri(4-iodophenyl)amine (spiro-OMeTAD) and dissolve it in 1 mL of chlorobenzene. Then add 45.36 μL of tert-butylpyridine, 24.36 μL of acetonitrile solution of lithium bis(trifluoromethanesulfonyl)imide at 520 mg / mL, and 49.6 μL of acetonitrile solution of tris[4-tert-butyl-2-(1H-pyrazol-1-yl)pyridine]cobalttrium(1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide salt] and stir thoroughly to dissolve to obtain the hole transport layer precursor solution.

[0104] The hole transport layer precursor liquid was spin-coated onto the surface of the perovskite absorber layer obtained in step 4 at a speed of 4000 rpm for 30 s. After drying, a Spiro-OMeTAD hole transport layer with a thickness of about 150 nm was formed.

[0105] Step 6: Form a metal electrode on the surface of the hole transport layer.

[0106] The hole transport layer obtained in step 5 is placed in a thermal evaporation coating apparatus, and a silver electrode with a thickness of about 80 nm is deposited on the surface of the hole transport layer, thereby completing the fabrication of a perovskite solar cell device with amorphous oxide interface modification.

[0107] Comparative Example 1

[0108] A modification layer was applied between the SnO2 electron transport layer and the perovskite absorber layer before an amorphous oxide interface was formed; all other operations were the same as in Example 1.

[0109] Step 1: Cleaning the conductive substrate

[0110] The ITO conductive substrate was placed in a washing tank and ultrasonically cleaned for 15 minutes each with conductive glass cleaner, deionized water, isopropanol, acetone and ethanol. After cleaning, it was placed in an oven to dry.

[0111] Step 2: Form a SnO2 electron transport layer on the surface of a conductive substrate.

[0112] Deionized water was added to dilute a 15% (w / w) SnO2 nanocrystalline colloidal aqueous dispersion, with a volume ratio of 1:4 between the nanocrystalline colloidal aqueous dispersion and deionized water. The mixture was then magnetically stirred to obtain a SnO2 particle dispersion.

[0113] After treating the ITO conductive substrate in step 1 with an ultraviolet ozone generator for 20 minutes, the SnO2 particle dispersion in this step is spin-coated on the surface of the conductive substrate at a speed of 3000 rpm for 30 seconds. After spin-coating, the substrate is placed on a heating stage and heated at 150°C for 30 minutes to form a SnO2 electron transport layer with a thickness of 20 nm.

[0114] Step 3: Form a perovskite absorber layer on the surface of the SnO2 electron transport layer.

[0115] The SnO2 electron transport layer obtained in step 2 was spin-coated with a perovskite precursor solution. The perovskite precursor solution was formed by dissolving PbI2, FAI, MACl, and MAPbBr3 in a mixed solvent of DMF and DMSO at concentrations of 1.53M, 1.4M, 0.5M, and 0.0122M, respectively, with a DMF:DMSO ratio of 8:1 (v / v). The spin-coating speed was 5000 rpm and the spin-coating time was 30 s. At the 10th second of spin-coating, the anti-solvent chlorobenzene was added dropwise. After spin-coating, the layer was placed on a heating stage and heated at 100°C for 60 min to form a perovskite absorption layer with a thickness of approximately 600 nm.

[0116] Step 4: Form a hole transport layer on the surface of the perovskite absorber layer.

[0117] Weigh 0.1019 g of 2,2',7,7'-tetrabromo-9,9'-spirodi,tri(4-iodophenyl)amine (spiro-OMeTAD) and dissolve it in 1 mL of chlorobenzene. Then add 45.36 μL of tert-butylpyridine, 24.36 μL of acetonitrile solution of lithium bis(trifluoromethanesulfonyl)imide at 520 mg / mL, and 49.6 μL of acetonitrile solution of tris[4-tert-butyl-2-(1H-pyrazol-1-yl)pyridine]cobalttrium(1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide salt] and stir thoroughly to dissolve to obtain the hole transport layer precursor solution.

[0118] The hole transport layer precursor liquid was spin-coated onto the surface of the perovskite absorber layer obtained in step 3 at a speed of 4000 rpm for 30 s. After drying, a Spiro-OMeTAD hole transport layer with a thickness of about 150 nm was formed.

[0119] Step 5: Form a metal electrode on the surface of the hole transport layer.

[0120] The hole transport layer obtained in step 4 is placed in a thermal evaporation coating apparatus, and a silver electrode with a thickness of about 80 nm is deposited on the surface of the hole transport layer, thereby completing the fabrication of the perovskite solar cell device.

[0121] Figure 2To compare the ultraviolet transmittance of the unmodified SnO2 electron transport layer formed in step 2 of Example 1 and the SnO2 electron transport layer modified with an amorphous oxide interface formed in step 3 of Example 1, the following graphs are used.

[0122] from Figure 2 It can be seen that after the SnO2 electron transport layer is modified at the interface by the niobium amorphous oxide layer, the light transmittance does not decrease, and even increases slightly in the visible light range.

[0123] Figure 3 To compare the water contact angle of the unmodified SnO2 electron transport layer formed in step 2 of Example 1 and the SnO2 electron transport layer modified with an amorphous oxide interface formed in step 3 of Example 1, the diagram is shown.

[0124] from Figure 3 It can be seen that after the SnO2 electron transport layer is modified by the amorphous oxide layer of niobium, the contact angle of the SnO2 electron transport layer surface is significantly reduced, indicating that the surface hydrophilicity is enhanced. Therefore, the surface wettability is significantly improved and it is easier to be wetted by polar solvents.

[0125] Comparative Example 2

[0126] The niobium oxide material used for the amorphous oxide interface modification layer is used to coat tin oxide particles, and then an electron transport layer is formed based on the coated particles. All other operations are the same as in Example 1.

[0127] Step 1: Cleaning the conductive substrate

[0128] The FTO conductive substrate was placed in a washing tank and ultrasonically cleaned for 15 minutes each with conductive glass cleaner, deionized water, isopropanol, acetone and ethanol. After cleaning, it was placed in an oven to dry.

[0129] Step 2: Form an electron transport layer on the surface of a conductive substrate.

[0130] Deionized water was added to dilute the 15% SnO2 nanocrystal colloidal aqueous dispersion to 20 mL, with a volume ratio of nanocrystal colloidal aqueous dispersion to deionized water of 1:4. The mixture was then magnetically stirred to obtain a SnO2 particle dispersion.

[0131] In the glove box, use a pipette to measure 30 μL of niobium ethanol and add it to 1 mL of ethanol, then stir magnetically until fully dissolved to obtain an ethanol solution of niobium ethanol.

[0132] In a glove box under nitrogen atmosphere, the ethanol solution of niobium ethoxide was added dropwise to the SnO2 particle dispersion under continuous stirring until all the ethanol solution of niobium ethoxide was added. The mixture was then stirred for 12 hours until it gradually changed from milky white to clear and transparent. The mixture was then stirred at 100°C for 30 minutes to obtain the electron transport layer precursor slurry.

[0133] After treating the ITO conductive substrate in step 1 with an ultraviolet ozone generator for 20 minutes, the electron transport layer precursor paste from this step is spin-coated onto the surface of the conductive substrate at a speed of 3000 rpm for 30 seconds. After spin-coating, the substrate is placed on a heating stage and heated at 150°C for 30 minutes, followed by ultraviolet ozone treatment for 60 minutes to form an electron transport layer with a thickness of approximately 20 nm.

[0134] Step 3: Form a perovskite absorption layer on the surface of the electron transport layer.

[0135] The perovskite precursor solution obtained in step 2 was spin-coated onto the surface of the electron transport layer. The perovskite precursor solution was formed by dissolving PbI2, FAI, MACl, and MAPbBr3 in a mixed solvent of DMF and DMSO at concentrations of 1.53M, 1.4M, 0.5M, and 0.0122M, respectively, with a DMF:DMSO ratio of 8:1 (v / v). The spin-coating speed was 5000 rpm and the spin-coating time was 30 s. Chlorobenzene, the anti-solvent, was added dropwise at the 10th second of spin-coating. After spin-coating, the layer was placed on a heating stage and heated at 100°C for 60 min to form a perovskite absorption layer with a thickness of approximately 600 nm.

[0136] Step 4: Form a hole transport layer on the surface of the perovskite absorber layer.

[0137] Weigh 0.1019 g of 2,2',7,7'-tetrabromo-9,9'-spirodi,tri(4-iodophenyl)amine (spiro-OMeTAD) and dissolve it in 1 mL of chlorobenzene. Then add 45.36 μL of tert-butylpyridine, 24.36 μL of acetonitrile solution of lithium bis(trifluoromethanesulfonyl)imide at 520 mg / mL, and 49.6 μL of acetonitrile solution of tris[4-tert-butyl-2-(1H-pyrazol-1-yl)pyridine]cobalttrium(1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide salt] and stir thoroughly to dissolve to obtain the hole transport layer precursor solution.

[0138] The hole transport layer precursor liquid was spin-coated onto the surface of the perovskite absorber layer obtained in step 3 at a speed of 4000 rpm for 30 s. After drying, a Spiro-OMeTAD hole transport layer with a thickness of about 150 nm was formed.

[0139] Step 5: Form a metal electrode on the surface of the hole transport layer.

[0140] The hole transport layer obtained in step 4 is placed in a thermal evaporation coating apparatus, and a silver electrode with a thickness of about 80 nm is deposited on the surface of the hole transport layer, thereby completing the fabrication of the perovskite solar cell device.

[0141] Figure 4 XRD patterns are shown between the perovskite layer formed in step 3 of Comparative Example 1 on the surface of the unmodified SnO2 electron transport layer, and the perovskite layers formed in steps 3 of Comparative Example 2 and step 4 of Example 1 on the surface of the SnO2 electron transport layer modified with an amorphous oxide interface.

[0142] based on Figure 4 Calculations show that the full width at half maximum (FWHM) of the diffraction peak, i.e., the FWHM value of the peak at 2θ = 14.2° (110), decreased from 0.135° in the unmodified Comparative Example 1 to 0.121° in the modified Example 1. This indicates that, through this scheme, a high-quality perovskite film with improved crystallinity was formed on the SnO2 substrate modified with amorphous oxide. In Comparative Example 2, niobium oxide nanocrystals were first coated with niobium oxide and then spin-coated to form a film as a composite electron transport layer. In this way, the contact method of Example 1 and Comparative Example 2 is theoretically the same, with niobium oxide material directly contacting the perovskite film. However, compared with this scheme, only the microstructure of niobium oxide forming an integral film on the surface of the tin oxide electron transport layer effectively improves the crystallinity and crystal quality of the perovskite.

[0143] For the perovskite solar cell devices prepared in the above embodiments and comparative embodiments, a Keithley 2400 source meter and a standard AM1.5G (model Newport Oriel 94043A, 100mW / cm²) were used. 2 Current-voltage curves of perovskite solar cells were tested using an AM1.5G solar simulator. The test results are shown in Table 1.

[0144] Table 1

[0145] Example 1 1.10 22.67 80.93 25.59 Example 2 1.09 22.12 79.94 25.41 Example 3 1.11 21.61 76.86 25.23 Comparative Example 1 1.06 20.63 77.67 24.94 Comparative Example 2 1.09 21.51 79.29 24.96

[0146] The JV curves of the perovskite solar cells assembled in Example 1 and Comparative Example 1 are compared, as follows: Figure 5 As shown.

[0147] As can be seen from Table 1, when the surface of the electron transport layer of tin oxide was modified by spin-coating amorphous niobium oxide in Example 1, its conductivity did not decrease compared with the pure tin oxide in Comparative Example 1. This is because the interface between niobium oxide and tin oxide is good, and the niobium oxide layer is very thin, so its influence on the conductivity of tin oxide is very small. It can effectively transport electrons to the electrode and reduce the energy loss and voltage drop of electrons during the transmission process.

[0148] On the other hand, as can be seen from Table 1, in Comparative Example 1, the fill factor (FF) is low due to the low contact compatibility between the tin oxide electron transport layer and the perovskite material; in contrast, in this embodiment, due to the improved wettability, the amorphous niobium oxide can form an interfacial contact with the perovskite film, thus improving the fill factor.

[0149] In addition, the niobium oxide modification layer can also adjust the energy level arrangement between the perovskite film and the SnO2 electron transport layer, reduce recombination, improve the collection efficiency of photogenerated carriers, and thus improve the photoelectric conversion efficiency.

[0150] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method of preparing an amorphous oxide interface modification layer, characterized by: The preparation method is as follows: (1) Disperse niobium ethanol in an alcohol solvent at a volume ratio of 1 to 4:10000 to obtain an alcoholic solution of niobium ethanol; (2) After coating the niobium ethanol solution obtained in step (1) onto the surface of the pre-prepared and annealed SnO2 electron transport layer, heat and ultraviolet ozone treatment are performed to prepare an amorphous oxide interface modification layer of the perovskite absorption layer on its surface. The specific steps of step (2) are as follows: spin-coating the niobium ethanol solution obtained in step (1) onto the surface of the pre-prepared and annealed SnO2 electron transport layer to form a film at a rotation speed of 3000~4000 rpm and a spin-coating time of 20~40s. After spin-coating, the film is placed on a heating stage and heated at 100~120℃ for 10~30min, and then treated with ultraviolet ozone for 30~60min to prepare an amorphous oxide interface modification layer of perovskite absorption layer on its surface.

2. The method for preparing the amorphous oxide interface modification layer as described in claim 1, characterized in that: In step (1), the alcohol solvent is ethanol or methanol. After adding the niobium ethanol to the alcohol solvent, it is magnetically stirred and dispersed thoroughly.

3. An amorphous oxide interface modified layer prepared by the method described in claim 1 or 2.

4. A perovskite solar cell device, characterized in that: The perovskite solar cell device has the following layer structure in sequence: a conductive substrate, a SnO2 electron transport layer, an amorphous oxide interface modification layer as described in claim 3, a perovskite absorption layer, a hole transport layer, and a metal electrode.

5. The perovskite solar cell device as described in claim 4, characterized in that: The SnO2 electron transport layer has a thickness of 10–40 nm; the perovskite absorber layer has a thickness of 500–1000 nm; the hole transport layer has a thickness of 50–100 nm; and the metal electrode has a thickness of 60–120 nm.

6. A method for fabricating a perovskite solar cell device, characterized in that: The preparation method is as follows: Step 1: Cleaning the conductive substrate The conductive substrate was ultrasonically cleaned sequentially with conductive glass cleaner, deionized water, isopropanol, acetone, and ethanol. After cleaning, it was placed in an oven to dry. Step 2: Form a SnO2 electron transport layer on the surface of the conductive substrate. After preparing a SnO2 film layer on the surface of the conductive substrate treated in step 1 using a solution method, the SnO2 electron transport layer is formed by annealing at 100-170°C for 30-60 minutes. Step 3: Form an amorphous oxide interface modification layer on the surface of the SnO2 electron transport layer. Niobium ethanol was dispersed in an alcohol solvent at a volume ratio of 1 to 4:10000 to obtain an alcoholic solution of niobium ethanol. This solution was then spin-coated onto the surface of the SnO2 electron transport layer obtained in step 2 at a speed of 3000 to 4000 rpm for 20 to 40 seconds. After spin-coating, the solution was placed on a heating stage and heated at 100 to 120°C for 10 to 30 minutes, followed by ultraviolet ozone treatment for 30 to 60 minutes to form the amorphous oxide interface modification layer. Step 4: Form a perovskite absorber layer on the surface of the amorphous oxide interface modification layer. The perovskite precursor solution is spin-coated onto the surface of the amorphous oxide interface modification layer obtained in step 3 at a speed of 3000-6000 rpm for 20-40 s. When the spin coating reaches 7-12 s, the anti-solvent is added dropwise. After the spin coating is completed, the layer is placed on a heating stage and heated at 80-150°C for 30-90 min to form the perovskite absorption layer. Step 5: Form a hole transport layer on the surface of the perovskite absorber layer. The hole transport layer precursor solution is spin-coated onto the surface of the perovskite absorber layer obtained in step 4 at a speed of 3000–5000 rpm for 20–40 s. After drying, the hole transport layer is formed. Step 6: Form a metal electrode on the surface of the hole transport layer. In a thermal evaporation coating apparatus, the metal electrode is formed by vapor deposition on the surface of the hole transport layer obtained in step 5.

7. The method for fabricating a perovskite solar cell device as described in claim 6, characterized in that: The conductive substrate mentioned in step 1 is FTO, ITO conductive glass, or PEN / ITO flexible conductive substrate.

8. The method for fabricating a perovskite solar cell device as described in claim 7, characterized in that: When the conductive substrate is FTO conductive glass, the solution method in step 2 includes spin coating and chemical bath deposition; when the conductive substrate is ITO conductive glass or PEN / ITO flexible conductive substrate, the solution method in step 2 is spin coating.

9. The method for fabricating a perovskite solar cell device as described in claim 6, characterized in that: The perovskite precursor solution in step 4 is formed by dissolving PbI2, FAI, MACl, and MAPbBr3 in a mixed solvent of DMF and DMSO at concentrations of 1.53M, 1.4M, 0.5M, and 0.0122M respectively in a volume ratio of 8:1; the antisolvent is anisole or chlorobenzene.

10. The method for fabricating a perovskite solar cell device as described in claim 6, characterized in that: The hole transport layer precursor solution mentioned in step 5 is a mixture of a chlorobenzene solution of 2,2',7,7'-tetrabromo-9,9'-spirodi,tri(4-iodophenyl)amine (spiro-OMeTAD), a tert-butylpyridine solution, an acetonitrile solution of lithium bis(trifluoromethanesulfonylimide), and an acetonitrile solution of tri[4-tert-butyl-2-(1H-pyrazol-1-yl)pyridine]cobalt tris(1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide salt).

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