Preparation process of perovskite layer and perovskite solar cell

Abstract

The invention discloses a preparation process of a perovskite layer and a perovskite solar cell, and the preparation process of the perovskite layer comprises the following steps: carrying out the blade coating of a perovskite layer precursor solution on a hole transport layer or an electron transport layer, and carrying out the annealing, thereby obtaining the perovskite layer; the hole transport layer or the electron transport layer is arranged on the conductive substrate layer at the temperature of 80-120 DEG C; the perovskite layer precursor solution comprises a raw material for forming the perovskite layer and valerolactone. The conductive substrate layer is heated, and when the temperature of the conductive substrate layer is 80-120 DEG C, a perovskite layer precursor solution prepared by using valerolactone as a green solvent is coated on the hole transport layer or the electron transport layer in a blade coating manner, so that a perovskite layer is obtained; verolactone is used as a green solvent, a perovskite layer can be prepared by blade coating, and then the positive and negative perovskite solar cell with high energy conversion efficiency is prepared.

Description

Technical Field

[0001] The present invention belongs to the technical field of perovskite solar cells, and in particular relates to a preparation process of a perovskite layer and a perovskite solar cell. Background Art

[0002] Energy, as one of the earliest natural resources used by humans, has promoted the progress of civilized society and the development of the economic field. In the face of the continuous consumption of non-renewable energy and the increasingly severe energy crisis, it is imperative to develop green renewable energy technology. Although traditional solar cells based on inorganic semiconductor materials such as silicon have been commercialized, their production process is complicated, the cost is too high, and there are defects such as inorganic materials are non-degradable and difficult to flexibly process, which limits their application scope. Solar energy, as a green renewable energy source that is inexhaustible, is one of the most promising photovoltaic technologies.

[0003] Perovskite cells are one of the many types of solar cells and are a promising green and renewable energy source. The perovskite layer is an important component of the perovskite cell. The prior art usually uses spin coating or scraping technology to prepare the perovskite layer. Compared with the spin coating process, the perovskite solar cell prepared by the scraping process has a higher energy conversion efficiency. At the same time, when preparing the perovskite layer, a solvent is usually required to dissolve the perovskite material, and valerolactone is a green solvent commonly used to dissolve perovskite materials to prepare the perovskite layer. However, during the experiment, the inventors found that using valerolactone as a green solvent to dissolve the perovskite material can only prepare the perovskite layer by spin coating on the hole transport layer or the electron transport layer, but cannot prepare the perovskite layer by scraping on the hole transport layer or the electron transport layer.

[0004] Therefore, developing a process suitable for preparing the perovskite layer of perovskite solar cells using blade coating and valerolactone has certain market value. Summary of the invention

[0005] In view of the deficiencies in the above-mentioned prior art, a preparation process of a perovskite layer is provided, wherein a conductive substrate layer is heated, and when the temperature of the conductive substrate layer is 80-120°C, a perovskite layer precursor liquid prepared using valerolactone as a green solvent is scraped on a hole transport layer or an electron transport layer to obtain a perovskite layer; the perovskite layer can also be prepared by scraping using valerolactone as a green solvent, thereby preparing a forward and reverse perovskite solar cell with high energy conversion efficiency.

[0006] The object of the present invention is to provide a process for preparing a perovskite layer, comprising the following steps:

[0007] The perovskite layer precursor solution is scraped onto the hole transport layer or the electron transport layer, and annealed to obtain the perovskite layer; the hole transport layer or the electron transport layer is arranged on a conductive substrate layer at 80 to 120° C.; the perovskite layer precursor solution includes raw materials for forming the perovskite layer and valerolactone.

[0008] In some embodiments of the present invention, the valerolactone is selected from at least one of δ-valerolactone and γ-valerolactone.

[0009] In some embodiments of the present invention, the usage ratio of the raw material for forming the perovskite layer to the valerolactone is (100-300) mg:1 ml, including but not limited to 100 mg:1 ml, 150 mg:1 ml, 200 mg:1 ml, 250 mg:1 ml, 300 mg:1 ml.

[0010] In some embodiments of the present invention, the raw materials for forming the perovskite layer include AX raw materials and BX2 raw materials.

[0011] In some embodiments of the present invention, the perovskite has an ABX3 structure.

[0012] In some embodiments of the present invention, the AX source is selected from at least one of CH3NH3X, CH3CH2NH3X, and NH2CH=NH2X.

[0013] In some embodiments of the present invention, the BX2 source is selected from at least one of PbX2 and SnX2.

[0014] In some embodiments of the present invention, the X is selected from at least one of Cl, Br and I.

[0015] In some embodiments of the present invention, the speed of the scraping is 2-10 mm / s, and the flow rate of the nitrogen knife during the scraping is 10-30 L / min.

[0016] In some embodiments of the present invention, the annealing temperature is 80-120° C. and the time is 5-15 min.

[0017] In some embodiments of the present invention, the thickness of the perovskite layer of the perovskite solar cell is 400-700 nm, including but not limited to 500 nm, 530 nm, 560 nm, 590 nm, 620 nm, 650 nm, 680 nm, 710 nm, 740 nm, 770 nm, and 800 nm.

[0018] In some embodiments of the present invention, the material of the hole transport layer is selected from at least one of polyvinyl carbazole, poly[[9-(1-octylnonyl)-9H-carbazole-2,7-diyl]-2,5-thiophenediyl-2,1,3-benzothiadiazole-4,7-diyl-2,5-thiophenediyl], poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], and poly[bis(4-phenyl)(4-butylphenyl)amine].

[0019] In some embodiments of the present invention, the thickness of the hole transport layer is 10 to 35 nm, including but not limited to 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, and 35 nm.

[0020] In some embodiments of the present invention, the material of the electron transport layer is selected from PC 61 At least one of BM and BCP.

[0021] In some embodiments of the present invention, the thickness of the electron transport layer is 100-200 nm, including but not limited to 100 nm, 105 nm, 110 nm, 115 nm, 120 nm, 125 nm, 130 nm, 135 nm, 140 nm, 145 nm, 150 nm, 155 nm, 160 nm, 165 nm, 170 nm, 175 nm, 180 nm, 185 nm, 190 nm, 195 nm, and 200 nm.

[0022] Another object of the present invention is to provide a green mixed solvent, which consists of diethyl methylphosphonoacetate and valerolactone.

[0023] In some embodiments of the present invention, the valerolactone is selected from at least one of δ-valerolactone and γ-valerolactone.

[0024] In some embodiments of the present invention, the mass ratio of diethyl methylphosphonoacetate to valerolactone is 1:10 to 1:10.

[0025] Another object of the present invention is to provide a perovskite layer precursor solution, comprising raw materials for forming a perovskite layer and the green mixed solvent.

[0026] In some embodiments of the present invention, the raw materials for forming the perovskite layer include AX raw materials and BX2 raw materials.

[0027] In some embodiments of the present invention, the perovskite has an ABX3 structure.

[0028] In some embodiments of the present invention, the AX source is selected from at least one of CH3NH3X, CH3CH2NH3X, and NH2CH=NH2X.

[0029] In some embodiments of the present invention, the BX2 source is selected from at least one of PbX2 and SnX2.

[0030] In some embodiments of the present invention, the X is selected from at least one of Cl, Br and I.

[0031] In some embodiments of the present invention, the mass ratio of the AX source to the BX2 source is (1-3):1.

[0032] In some embodiments of the present invention, the usage ratio of the raw material for forming the perovskite layer to the green mixed solvent is (100-300) mg: 1 ml.

[0033] Another object of the present invention is to provide a process for preparing a perovskite layer, comprising the following steps:

[0034] The perovskite layer precursor solution is scraped onto the hole transport layer or the electron transport layer, and annealed to obtain the perovskite layer; the hole transport layer or the electron transport layer is arranged on a conductive substrate layer at 80-120°C.

[0035] In some embodiments of the present invention, the speed of the scraping is 2-10 mm / s, and the flow rate of the nitrogen knife during the scraping is 10-30 L / min.

[0036] In some embodiments of the present invention, the annealing temperature is 50-70° C. and the time is 2-10 min.

[0037] In some embodiments of the present invention, the thickness of the perovskite layer of the perovskite solar cell is 400-700 nm, including but not limited to 500 nm, 530 nm, 560 nm, 590 nm, 620 nm, 650 nm, 680 nm, 710 nm, 740 nm, 770 nm, and 800 nm.

[0038] In some embodiments of the present invention, the material of the hole transport layer is selected from at least one of polyvinyl carbazole, poly[[9-(1-octylnonyl)-9H-carbazole-2,7-diyl]-2,5-thiophenediyl-2,1,3-benzothiadiazole-4,7-diyl-2,5-thiophenediyl], poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], and poly[bis(4-phenyl)(4-butylphenyl)amine].

[0039] In some embodiments of the present invention, the thickness of the hole transport layer is 10 to 35 nm, including but not limited to 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, and 35 nm.

[0040] In some embodiments of the present invention, the material of the electron transport layer is selected from PC 61 At least one of BM and BCP.

[0041] In some embodiments of the present invention, the thickness of the electron transport layer is 100-200 nm, including but not limited to 100 nm, 105 nm, 110 nm, 115 nm, 120 nm, 125 nm, 130 nm, 135 nm, 140 nm, 145 nm, 150 nm, 155 nm, 160 nm, 165 nm, 170 nm, 175 nm, 180 nm, 185 nm, 190 nm, 195 nm, and 200 nm.

[0042] In some embodiments of the present invention, the material of the transparent base layer includes but is not limited to transparent conductive glass ITO.

[0043] In some embodiments of the present invention, the sheet resistance of the transparent substrate layer is ≤80Ω.

[0044] Another object of the present invention is to provide a perovskite solar cell, comprising a perovskite layer prepared by the above-mentioned process for preparing a perovskite layer.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] (1) The present invention heats the conductive substrate layer, and when the temperature of the conductive substrate layer is 80 to 120° C., a perovskite layer precursor solution prepared by using valerolactone as a green solvent is scraped onto a hole transport layer or an electron transport layer to obtain a perovskite layer; thus, the perovskite layer can be prepared by scraping using valerolactone as a green solvent, thereby preparing a forward and reverse perovskite solar cell with a high energy conversion efficiency.

[0047] (2) The present invention can obtain a perovskite precursor solution with high stability by compounding valerolactone and diethyl methylphosphonoacetate as a green mixed solvent; when preparing the perovskite layer, annealing can be performed at a lower temperature and in a shorter time to prepare a forward and reverse perovskite solar cell with high energy conversion efficiency. DETAILED DESCRIPTION

[0048] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0049] All raw materials of the present invention have no particular limitation on their sources, and can be purchased from the market or prepared according to conventional methods known to those skilled in the art.

[0050] There is no particular limitation on the purity of all raw materials in the present invention. The present invention preferably uses analytically pure materials or materials of conventional purity used in the field of perovskite solar cells.

[0051] The brands and abbreviations of all raw materials of the present invention are conventional brands and abbreviations in the art. Each brand and abbreviation is clear and definite in the field of its related use. Those skilled in the art can purchase them from the market or prepare them by conventional methods according to the brands, abbreviations and corresponding uses.

[0052] The present invention provides a process for preparing a perovskite layer, comprising the following steps:

[0053] The perovskite layer precursor solution is scraped onto the hole transport layer or the electron transport layer, and annealed to obtain the perovskite layer; the hole transport layer or the electron transport layer is arranged on a conductive substrate layer at 80 to 120° C.; the perovskite layer precursor solution includes raw materials for forming the perovskite layer and valerolactone.

[0054] The valerolactone of the present invention is selected from at least one of δ-valerolactone and γ-valerolactone.

[0055] The present invention has no particular restriction on the ratio of the raw material for forming the perovskite layer and the solvent system valerolactone, and the conventional ratio familiar to those skilled in the art can be used. Those skilled in the art can select and adjust it according to the actual application, product requirements and quality requirements. The usage ratio of the raw material for forming the perovskite layer and the valerolactone in the present invention is (100-300) mg:1ml, including but not limited to 100mg:1ml, 150mg:1ml, 200mg:1ml, 250mg:1ml, 300mg:1ml.

[0056] Those skilled in the art can select and adjust according to actual application conditions, product requirements and quality requirements. Among the raw materials for forming the perovskite layer described in the present invention, the raw materials for forming the perovskite layer include AX raw material and BX2 raw material.

[0057] The present invention has no particular limitation on the structure and definition of the perovskite, and the structure and definition of the perovskite familiar to those skilled in the art may be used. Those skilled in the art may select and adjust according to actual application conditions, product requirements and quality requirements. The perovskite has an ABX3 structure.

[0058] The AX source of the present invention is selected from at least one of CH3NH3X, CH3CH2NH3X, and NH2CH=NH2X, the BX2 source is selected from at least one of PbX2 and SnX2, and the X is selected from at least one of Cl, Br and I.

[0059] The invention has no special restrictions on the specific steps of the scraping coating. The conventional steps of preparing the perovskite layer by the scraping coating method well known to those skilled in the art can be used. Those skilled in the art can select and adjust according to the actual production situation, product requirements and quality requirements. In order to further improve the performance of the perovskite layer, the scraping speed of the invention is 2-10 mm / s, and the nitrogen knife flow rate during the scraping coating process is 10-30 L / min. Preferably, the scraping speed is 4-7 mm / s, and the nitrogen knife flow rate during the scraping coating process is 15-25 L / min.

[0060] After the scraping of the present invention, an annealing step may be included, wherein the annealing temperature is 80-120° C. and the time is 5-15 minutes, preferably the annealing temperature is 90-110° C. and the time is 8-12 minutes.

[0061] The present invention has no particular limitation on the thickness of the perovskite layer, and the conventional perovskite layer thickness for forming a perovskite solar cell known to those skilled in the art can be used. Those skilled in the art can select and adjust it according to actual application conditions, product requirements and quality requirements. The thickness of the perovskite layer of the perovskite solar cell of the present invention is 400 to 700 nm, including but not limited to 500 nm, 530 nm, 560 nm, 590 nm, 620 nm, 650 nm, 680 nm, 710 nm, 740 nm, 770 nm, and 800 nm.

[0062] The present invention has no particular restriction on the selection of the hole transport layer, and a conventional hole transport layer for forming a perovskite solar cell known to those skilled in the art can be used. Those skilled in the art can select and adjust it according to actual application conditions, product requirements and quality requirements. The material of the hole transport layer of the present invention is selected from at least one of polyvinyl carbazole, poly [[9-(1-octylnonyl)-9H-carbazole-2,7-diyl]-2,5-thiophenediyl-2,1,3-benzothiadiazole-4,7-diyl-2,5-thiophenediyl], poly [bis (4-phenyl) (2,4,6-trimethylphenyl) amine], and poly [bis (4-phenyl) (4-butylphenyl) amine].

[0063] The present invention has no particular limitation on the thickness of the hole transport layer, and the conventional hole transport thickness for forming perovskite solar cells known to those skilled in the art can be used. Those skilled in the art can select and adjust according to actual application conditions, product requirements and quality requirements. The thickness of the hole transport layer of the present invention is 10 to 35 nm, including but not limited to 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, and 35 nm.

[0064] The present invention has no particular restriction on the selection of the electron transport layer. A conventional electron transport layer for forming a perovskite solar cell known to those skilled in the art can be used. Those skilled in the art can select and adjust the material according to the actual application, product requirements and quality requirements. The material of the electron transport layer of the present invention is selected from PC 61 At least one of BM and BCP.

[0065] The present invention has no particular limitation on the thickness of the electron transport layer, and the conventional electron transport layer thickness for forming perovskite solar cells known to those skilled in the art can be used. Those skilled in the art can select and adjust according to actual application conditions, product requirements and quality requirements. The thickness of the electron transport layer of the present invention is 100-200nm, including but not limited to 100nm, 105nm, 110nm, 115nm, 120nm, 125nm, 130nm, 135nm, 140nm, 145nm, 150nm, 155nm, 160nm, 165nm, 170nm, 175nm, 180nm, 185nm, 190nm, 195nm, and 200nm.

[0066] The invention provides a green mixed solvent, which consists of diethyl methylphosphonoacetate and valerolactone.

[0067] The valerolactone of the present invention is selected from at least one of δ-valerolactone and γ-valerolactone.

[0068] The conventional content of the mixed solvent well known to those skilled in the art can be used. Those skilled in the art can select and adjust it according to the actual application, product requirements and quality requirements. The mass ratio of diethyl methylphosphonoacetate and valerolactone in the present invention is 1:10 to 1:10, preferably 2:8 to 2:8, and more preferably 4 to 6:3 to 7.

[0069] The invention provides a perovskite layer precursor solution, comprising a raw material for forming a perovskite layer and the green mixed solvent.

[0070] The present invention has no particular limitation on the raw materials for forming the perovskite layer, and any conventional raw materials for forming the perovskite layer known to those skilled in the art may be used. The raw materials for forming the perovskite layer of the present invention include AX raw materials and BX2 raw materials.

[0071] The present invention has no particular limitation on the structure and definition of the perovskite, and the structure and definition of the perovskite familiar to those skilled in the art may be used. Those skilled in the art may select and adjust according to actual application conditions, product requirements and quality requirements. The perovskite of the present invention has an ABX3 structure.

[0072] Those skilled in the art can select and adjust according to actual application conditions, product requirements and quality requirements. Among the raw materials for forming the perovskite layer described in the present invention, the AX source is selected from at least one of CH3NH3X, CH3CH2NH3X, and NH2CH=NH2X, the BX2 source is selected from at least one of PbX2 and SnX2, and the X is selected from at least one of Cl, Br and I.

[0073] The present invention has no particular restriction on the ratio of the raw materials for forming the perovskite layer. The conventional ratio for forming the perovskite layer known to those skilled in the art can be used. Those skilled in the art can select and adjust according to the actual application conditions, product requirements and quality requirements. The mass ratio of the AX source to the BX2 source in the present invention is (1 to 3):1.

[0074] The present invention has no particular restriction on the ratio of the raw materials for forming the perovskite layer and the solvent system, and the conventional ratio familiar to those skilled in the art can be used. Those skilled in the art can select and adjust it according to the actual application, product requirements and quality requirements. The usage ratio of the raw materials for forming the perovskite layer and the green mixed solvent in the present invention is (100-300) mg: 1 ml.

[0075] The present invention provides a process for preparing a perovskite layer, comprising the following steps:

[0076] The perovskite layer precursor solution is scraped onto the hole transport layer or the electron transport layer, and annealed to obtain the perovskite layer; the hole transport layer or the electron transport layer is arranged on a conductive substrate layer at 80-120°C.

[0077] The invention has no special restrictions on the specific steps of the scraping coating. The conventional steps of preparing the perovskite layer by the scraping coating method familiar to those skilled in the art can be used. Those skilled in the art can select and adjust according to actual production conditions, product requirements and quality requirements. In order to further improve the performance of the perovskite layer, the scraping coating speed of the invention is 2 to 10 mm / s, and the nitrogen knife flow rate during the scraping coating process is 10 to 30 L / min.

[0078] In the present invention, due to the use of a specific solvent system, the present invention can anneal at a lower temperature and a shorter time to prepare a positive and negative perovskite solar cell with a higher energy conversion efficiency. In order to complete and optimize the preparation method, after the scraping of the present invention, an annealing step may be included, and a low-temperature annealing step is more preferably included. The annealing temperature of the present invention is 50 to 70°C and the time is 2 to 10 minutes.

[0079] The present invention has no particular limitation on the thickness of the perovskite layer, and the conventional perovskite layer thickness for forming a perovskite solar cell known to those skilled in the art can be used. Those skilled in the art can select and adjust it according to actual application conditions, product requirements and quality requirements. The thickness of the perovskite layer of the perovskite solar cell of the present invention is 400 to 700 nm, including but not limited to 500 nm, 530 nm, 560 nm, 590 nm, 620 nm, 650 nm, 680 nm, 710 nm, 740 nm, 770 nm, and 800 nm.

[0080] The present invention has no particular restriction on the selection of the hole transport layer, and a conventional hole transport layer for forming a perovskite solar cell known to those skilled in the art can be used. Those skilled in the art can select and adjust it according to actual application conditions, product requirements and quality requirements. The material of the hole transport layer of the present invention is selected from at least one of polyvinyl carbazole, poly [[9-(1-octylnonyl)-9H-carbazole-2,7-diyl]-2,5-thiophenediyl-2,1,3-benzothiadiazole-4,7-diyl-2,5-thiophenediyl], poly [bis (4-phenyl) (2,4,6-trimethylphenyl) amine], and poly [bis (4-phenyl) (4-butylphenyl) amine].

[0081] The present invention has no particular limitation on the thickness of the hole transport layer, and the conventional hole transport thickness for forming perovskite solar cells known to those skilled in the art can be used. Those skilled in the art can select and adjust according to actual application conditions, product requirements and quality requirements. The thickness of the hole transport layer of the present invention is 10 to 35 nm, including but not limited to 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, and 35 nm.

[0082] The present invention has no particular restriction on the selection of the electron transport layer. A conventional electron transport layer for forming a perovskite solar cell known to those skilled in the art can be used. Those skilled in the art can select and adjust the material according to the actual application, product requirements and quality requirements. The material of the electron transport layer of the present invention is selected from PC 61 At least one of BM and BCP.

[0083] The present invention has no particular limitation on the thickness of the electron transport layer, and the conventional electron transport layer thickness for forming perovskite solar cells known to those skilled in the art can be used. Those skilled in the art can select and adjust according to actual application conditions, product requirements and quality requirements. The thickness of the electron transport layer of the present invention is 100-200nm, including but not limited to 100nm, 105nm, 110nm, 115nm, 120nm, 125nm, 130nm, 135nm, 140nm, 145nm, 150nm, 155nm, 160nm, 165nm, 170nm, 175nm, 180nm, 185nm, 190nm, 195nm, and 200nm.

[0084] The present invention has no special limitation on the transparent substrate layer. It can be a conventional transparent substrate layer for forming perovskite solar cells that is well known to those skilled in the art. Those skilled in the art can select and adjust it according to actual application conditions, product requirements and quality requirements. The material of the transparent substrate layer of the present invention includes but is not limited to transparent conductive glass ITO.

[0085] The present invention has no particular limitation on the square resistance of the transparent substrate layer. The square resistance of a conventional transparent substrate layer for forming a perovskite solar cell known to those skilled in the art can be used. Those skilled in the art can select and adjust it according to actual application conditions, product requirements and quality requirements. The square resistance of the transparent substrate layer of the present invention is ≤80Ω.

[0086] Another object of the present invention is to provide a perovskite solar cell, comprising a perovskite layer prepared by the above-mentioned process for preparing a perovskite layer.

[0087] The present invention has no particular limitation on the definition and structure of the perovskite solar cell, and the definition and structure of conventional perovskite solar cells familiar to those skilled in the art may be used. Those skilled in the art may select and adjust according to actual application conditions, product requirements and quality requirements. The perovskite solar cell described in the present invention is preferably a perovskite solar cell with a flat heterojunction structure (planar structure), which may be a NIP structure or a PIN structure. The perovskite solar cell described in the present invention further includes a transparent substrate layer, a hole transport layer, an electron transport layer, a hole blocking layer and a metal electrode layer.

[0088] The present invention has no particular limitation on the hole blocking layer, and any conventional hole blocking layer for forming a perovskite solar cell known to those skilled in the art may be used. Those skilled in the art may select and adjust the hole blocking layer according to actual application conditions, product requirements and quality requirements. The material of the hole blocking layer of the present invention is selected from BCP.

[0089] The present invention has no special limitation on the metal electrode layer, and any conventional metal electrode layer for forming a perovskite solar cell known to those skilled in the art may be used. Those skilled in the art may select and adjust the metal electrode layer according to actual application conditions, product requirements and quality requirements. The material of the metal electrode layer of the present invention is selected from silver or gold.

[0090] The present invention has no particular limitation on the thickness of the hole blocking layer, and the conventional hole blocking layer thickness for forming perovskite solar cells known to those skilled in the art can be used. Those skilled in the art can select and adjust the thickness according to actual application conditions, product requirements and quality requirements. The thickness of the hole blocking layer of the present invention is 5 to 10 nm, preferably 6 to 9 nm, and preferably 7 to 8 nm.

[0091] The present invention has no particular limitation on the thickness of the metal electrode layer, and the conventional metal electrode layer thickness for forming perovskite solar cells known to those skilled in the art can be used. Those skilled in the art can select and adjust the thickness according to actual application conditions, product requirements and quality requirements. The thickness of the metal electrode layer of the present invention is 50 to 200 nm, preferably 80 to 160 nm, and preferably 100 to 120 nm.

[0092] The present invention provides a method for preparing the perovskite solar cell, comprising the following steps:

[0093] A hole transport layer, a perovskite layer, an electron transport layer, a hole blocking layer and a metal electrode layer are sequentially stacked on the transparent base layer.

[0094] The present invention provides a method for preparing the perovskite solar cell, comprising the following steps:

[0095] A hole blocking layer, an electron transport layer, a perovskite layer, a hole transport layer and a metal electrode layer are sequentially stacked on the transparent base layer.

[0096] Example 1

[0097] This embodiment provides a perovskite solar cell, the specific cell structure is ITO / PTAA / perovskite layer / PCBM / BCP / Ag, and the specific implementation steps are as follows:

[0098] S1. Cleaning of transparent substrate layer: first take out the ITO transparent conductive glass with a square resistance of ≤80Ω, tear off the plastic protective film on the surface, first gently wipe the surface oil with detergent, then ultrasonically clean it in a low concentration of detergent solution, deionized water, and isopropanol for 15 minutes respectively, finally blow dry the isopropanol on the ITO surface with nitrogen, and pack it in a box for later use;

[0099] S2. Preparation of hole transport layer (PTAA): PTAA was prepared into a 2.5 mg / mL precursor solution, the solvent was chlorobenzene, the cleaned ITO was first placed in an ultraviolet ozone cleaner for surface hydrophilic treatment, and then the PTAA precursor solution was sucked out with a pipette and evenly covered on the ITO surface, first spin-coated at 500 rpm / min for 3 seconds, then spin-coated at 3000 rpm / min for 20 seconds, and the solvent was dried to form a hole transport layer with a thickness of 10 to 35 nm;

[0100] S3. Preparation of a perovskite layer precursor solution: 2 g of lead iodide and methyl iodide in a mass ratio of 1:1 were dissolved in 10 mL of δ-valerolactone to prepare a mixed solution of lead iodide and methyl iodide, i.e., a perovskite layer precursor solution;

[0101] S4. Preparation of perovskite layer: using a scraper coater, the hole transport layer prepared in S2 is placed under the scraper, the perovskite layer precursor solution prepared in S3 is injected into the scraper gap, and the conductive substrate layer is heated to 80-120°C, and the perovskite layer precursor solution is scraped on the hole transport layer at a scraping speed of 2-10 mm / s. The nitrogen knife flow rate during the scraping process is 10-30 L / min to form a perovskite layer, and then annealed at 100°C on a hot stage for 10 minutes to form a perovskite layer with a thickness of 400-700 nm;

[0102] S5. Preparation of electron transport layer: weigh 20 mg PC 61 BM was added with 1 mL of chlorobenzene to prepare a precursor solution of the electron transport layer, and the precursor solution of the electron transport layer was deposited on the surface of the perovskite layer by spin coating (first at 500 rpm / min for 3 s, then at 2500 rpm / min for 20 s) to form an electron transport layer with a thickness of 100 to 200 nm;

[0103] S6. Preparation of hole blocking layer: 8 mg BCP was weighed, 16 mL isopropanol was added to prepare a precursor solution, and then the prepared precursor solution was sucked out with a pipette and evenly covered on the surface of the electron transport layer, first spin-coated at 100 rpm / min for 3 s, then spin-coated at 5000 rpm / min for 20 s, and the solvent was dried to form a hole blocking layer with a thickness of 5 to 10 nm;

[0104] S7. Deposition of metal electrode layer: 100 nm thick Ag film was evaporated under high vacuum at an evaporation rate of: 20nm was deposited under the conditions, and then Under the conditions, it is deposited on the surface of the hole blocking layer, with a deposition thickness of 50 to 200 nm and a deposition area of ​​about 0.07 cm 2 .

[0105] Example 2

[0106] This embodiment provides a perovskite solar cell, and the specific cell structure is ITO / polyvinyl carbazole / perovskite layer / PCBM / BCP / Ag. The difference from the embodiment 1 is only that steps S2, S3 and S4 are different. The PTAA in step S2 is replaced by polyvinyl carbazole. The specific implementation steps of steps S3 and S4 are as follows:

[0107] S3. Preparation of a perovskite layer precursor solution: 3 g of lead iodide and methyl iodide in a mass ratio of 3:1 were dissolved in 10 ml of γ-valerolactone to prepare a mixed solution of lead iodide and methyl iodide, i.e., a perovskite layer precursor solution;

[0108] S4. Preparation of perovskite layer: Use a scraper coater to place the hole transport layer prepared in S2 under the scraper, take the perovskite layer precursor prepared in S3 and inject it into the scraper gap, and heat the conductive base layer to 80-120°C, scrape the perovskite layer precursor on the hole transport layer at a scraping speed of 2-10 mm / s. The nitrogen knife flow rate during the scraping process is 10-30 L / min to form a perovskite layer, and then anneal on a hot stage at 80°C for 15 minutes to form a perovskite layer with a thickness of 400-700 nm.

[0109] Example 3

[0110] This embodiment provides a perovskite solar cell, the specific cell structure is ITO / PTAA / perovskite layer / PCBM / BCP / Ag, and the difference from the embodiment 1 is only that steps S3 and S4 are different. The specific implementation steps of steps S3 and S4 are as follows:

[0111] S3. Preparation of a perovskite layer precursor solution: 1 g of lead iodide and methyl iodide in a mass ratio of 1:1 was dissolved in 10 ml of δ-valerolactone to prepare a mixed solution of lead iodide and methyl iodide, i.e., a perovskite layer precursor solution;

[0112] S4. Preparation of perovskite layer: Use a scraper coater to place the hole transport layer prepared in S2 under the scraper, take the perovskite layer precursor prepared in S3 and inject it into the scraper gap, and heat the conductive base layer to 80-120°C, and scrape the perovskite layer precursor on the hole transport layer at a scraping speed of 2-10 mm / s. The nitrogen knife flow rate during the scraping process is 10-30 L / min to form a perovskite layer, and then anneal on a hot stage at 120°C for 5 minutes to form a perovskite layer with a thickness of 400-700 nm.

[0113] Example 4

[0114] This embodiment provides a perovskite solar cell, the specific cell structure is ITO / PTAA / perovskite layer / PCBM / BCP / Ag, and the difference from the embodiment 1 is only that steps S3 and S4 are different. The specific implementation steps of steps S3 and S4 are as follows:

[0115] S3. Preparation of perovskite layer precursor solution: 2 g of lead iodide and methyl iodide in a mass ratio of 1:1 was dissolved in 10 ml of diethyl methylphosphoryl acetate and valerolactone in a mass ratio of 1:10 to prepare a mixed solution of lead iodide and methyl iodide, i.e., a perovskite layer precursor solution;

[0116] S4. Preparation of perovskite layer: Use a scraper coater to place the hole transport layer prepared in S2 under the scraper, take the perovskite layer precursor prepared in S3 and inject it into the scraper gap, and heat the conductive base layer to 80-120°C, and scrape the perovskite layer precursor on the hole transport layer at a scraping speed of 2-10 mm / s. The nitrogen knife flow rate during the scraping process is 10-30 L / min to form a perovskite layer, and then anneal on a hot stage at 70°C for 2 minutes to form a perovskite layer with a thickness of 400-700 nm.

[0117] Example 5

[0118] This embodiment provides a perovskite solar cell, the specific cell structure is ITO / PTAA / perovskite layer / PCBM / BCP / Ag, and the difference from the embodiment 2 is only that steps S3 and S4 are different. The specific implementation steps of steps S3 and S4 are as follows:

[0119] S3. Preparation of perovskite layer precursor solution: 3 g of lead iodide and methyl iodide in a mass ratio of 1:1 was dissolved in 10 ml of diethyl methylphosphoryl acetate and valerolactone in a mass ratio of 10:1 to prepare a mixed solution of lead iodide and methyl iodide, i.e., a perovskite layer precursor solution;

[0120] S4. Preparation of perovskite layer: Use a scraper coater to place the hole transport layer prepared in S2 under the scraper, take the perovskite layer precursor prepared in S3 and inject it into the scraper gap, and heat the conductive base layer to 80-120°C, scrape the perovskite layer precursor on the hole transport layer at a scraping speed of 2-10 mm / s. The nitrogen knife flow rate during the scraping process is 10-30 L / min to form a perovskite layer, and then anneal on a hot stage at 50°C for 10 minutes to form a perovskite layer with a thickness of 400-700 nm.

[0121] Example 6

[0122] This embodiment provides a perovskite solar cell, the specific cell structure is ITO / PTAA / perovskite layer / PCBM / BCP / Ag, and the difference from the embodiment 3 is only that steps S3 and S4 are different. The specific implementation steps of steps S3 and S4 are as follows:

[0123] S3. Preparation of a perovskite layer precursor solution: 1 g of lead iodide and methyl iodide in a mass ratio of 1:1 was dissolved in 10 ml of diethyl methylphosphoryl acetate and valerolactone in a mass ratio of 1:1 to obtain a mixed solution of lead iodide and methyl iodide, i.e., a perovskite layer precursor solution;

[0124] S4. Preparation of perovskite layer: Use a scraper coater to place the hole transport layer prepared in S2 under the scraper, take the perovskite layer precursor prepared in S3 and inject it into the scraper gap, and heat the conductive base layer to 80-120°C, and scrape the perovskite layer precursor on the hole transport layer at a scraping speed of 2-10 mm / s. The nitrogen knife flow rate during the scraping process is 10-30 L / min to form a perovskite layer, and then anneal on a hot stage at 60°C for 5 minutes to form a perovskite layer with a thickness of 400-700 nm.

[0125] Example 7

[0126] This embodiment provides a perovskite solar cell, and the specific cell structure is ITO / PTAA / perovskite layer / PCBM / BCP / Ag. The difference from the embodiment 1 is only that step S4 is different. The specific implementation steps of step S4 are as follows:

[0127] S4. Preparation of perovskite layer: Use a scraper coater to place the hole transport layer prepared in S2 under the scraper, take the perovskite layer precursor prepared in S3 and inject it into the scraper gap, and heat the conductive base layer to 80-120°C, and scrape the perovskite layer precursor on the hole transport layer at a scraping speed of 2-10 mm / s. The nitrogen knife flow rate during the scraping process is 10-30 L / min to form a perovskite layer, and then anneal on a hot stage at 70°C for 2 minutes to form a perovskite layer with a thickness of 400-700 nm.

[0128] Comparative Example 1

[0129] This comparative example provides a perovskite solar cell, the specific cell structure is ITO / PTAA / perovskite layer / PCBM / BCP / Ag, and the difference from Example 1 is only that step S4 is different. This comparative example does not heat the conductive substrate layer, and the specific implementation steps of step S4 are as follows:

[0130] S4. Preparation of perovskite layer: Use a scraper coater to place the hole transport layer prepared in S2 under the scraper, take the perovskite layer precursor prepared in S3 and inject it into the scraper gap, scrape the perovskite layer precursor on the hole transport layer at a scraping speed of 2 to 10 mm / s, and the nitrogen knife flow rate during the scraping process is 10 to 30 L / min to form a perovskite layer, and then anneal on a hot stage at 100°C for 10 minutes to form a perovskite layer with a thickness of 400 to 700 nm.

[0131] Performance test: The perovskite solar cells of Examples 1 to 7 and Comparative Example 1 were tested for performance. The JV characteristic curves of the devices were measured using a Keithley 2440 light source under a simulated AM1.5G spectrum. A solar simulator (Newport, 91160) was used to calibrate the light intensity using a standard silicon solar cell device from NREL. The effective measurement area was 0.07 cm 2 , under reverse and forward bias scans, the scan rate was 100mV / s and the bias range was from -0.2V to 1.2V.

[0132] Table 1. Performance tests of perovskite solar cells of Examples 1 to 7 and Comparative Example 1.

[0133]

[0134]

[0135] As can be seen from Table 1, the energy conversion efficiency of the perovskite solar cells prepared in Examples 1 to 7 of the present invention is high. Compared with Examples 1 to 3, due to the use of valerolactone and diethyl methylphosphoryl acetate as green mixed solvents, Examples 4 to 6 can obtain a perovskite precursor solution with higher stability; when preparing the perovskite layer, annealing can be performed at a lower temperature and a shorter time to prepare a positive and negative perovskite solar cell with higher energy conversion efficiency, while the green mixed solvent in Example 7 does not contain diethyl methylphosphoryl acetate, and annealing at a lower temperature and a shorter time reduces the energy conversion efficiency of the perovskite solar cell. The perovskite solar cell that cannot be prepared in Comparative Example 1.

[0136] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that after reading the specification of this application, the technicians can still modify or replace the specific implementation mode of the present invention with equivalents, but these modifications or changes do not deviate from the scope of protection of the pending claims of the present application.

Claims

1. A process for preparing a perovskite layer, characterized in that: The steps include: The perovskite layer precursor solution is scraped onto the hole transport layer or the electron transport layer, and annealed to obtain the perovskite layer; the hole transport layer or the electron transport layer is arranged on a conductive substrate layer at 80-120° C.; the perovskite layer precursor solution includes raw materials for forming the perovskite layer and valerolactone.

2. The process for preparing the perovskite layer according to claim 1, characterized in that: The valerolactone is selected from at least one of δ-valerolactone and γ-valerolactone; The usage ratio of the raw material for forming the perovskite layer to the valerolactone is (100-300) mg:1 ml.

3. The process for preparing the perovskite layer according to claim 2, characterized in that: The raw materials for forming the perovskite layer include AX raw materials and BX2 raw materials; The perovskite has an ABX3 structure; The AX source is selected from at least one of CH3NH3X, CH3CH2NH3X, and NH2CH=NH2X; The BX2 source is selected from at least one of PbX2 and SnX2; The X is selected from at least one of Cl, Br and I.

4. The process for preparing the perovskite layer according to claim 1, characterized in that: The speed of the scraping is 2-10 mm / s, and the flow rate of the nitrogen knife during the scraping is 10-30 L / min; The annealing temperature is 80-120°C and the time is 5-15min; The thickness of the perovskite layer of the perovskite solar cell is 400-700 nm.

5. A green mixed solvent, characterized in that: The green mixed solvent consists of diethyl methylphosphonoacetate and valerolactone.

6. The green mixed solvent as claimed in claim 5, characterized in that: The valerolactone is selected from at least one of δ-valerolactone and γ-valerolactone; The mass ratio of diethyl methylphosphonoacetate to valerolactone is 1:10 to 1:

10.

7. A perovskite layer precursor solution, characterized in that: Comprising a raw material for forming a perovskite layer and the green mixed solvent according to any one of claims 5 to 6; The raw materials for forming the perovskite layer include AX raw materials and BX2 raw materials; The perovskite has an ABX3 structure; The AX source is selected from at least one of CH3NH3X, CH3CH2NH3X, and NH2CH=NH2X; The BX2 source is selected from at least one of PbX2 and SnX2; The X is selected from at least one of Cl, Br and I.

8. The perovskite layer precursor solution according to claim 4, characterized in that: The mass ratio of the AX source to the BX2 source is (1-3):1; The usage ratio of the raw material for forming the perovskite layer to the green mixed solvent according to any one of claims 5 to 6 is (100 to 300) mg: 1 ml.

9. A process for preparing a perovskite layer, characterized in that: The steps include: The perovskite layer precursor solution according to any one of claims 7 to 8 is scraped onto a hole transport layer or an electron transport layer, and annealed to obtain a perovskite layer; the hole transport layer or the electron transport layer is disposed on a conductive substrate layer at 80 to 120°C.

10. A perovskite solar cell, characterized in that: A perovskite layer prepared by the preparation process of the perovskite layer according to any one of claims 1 to 4 or the preparation process according to claim 9.

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