Perovskite solar cell with oriented interface modification layer

Abstract

The utility model relates to a perovskite solar cell with a directional interface modification layer, and the perovskite solar cell sequentially comprises a substrate, a conductive substrate, a hole transmission layer, a three-dimensional perovskite active layer, a two-dimensional perovskite interface modification layer, an electron transmission layer, a hole blocking layer, and a back electrode from the bottom to the top. A solvent with a high Gartmann donor number is added into a two-dimensional perovskite precursor solution, and the two-dimensional perovskite precursor solution is composed of one or more than two of isopropanol, DMF, DMSO, DMPO and DMPU. The solvents not only have high solubility and permeability, can effectively introduce a two-dimensional ligand into the three-dimensional perovskite thin film, but also can maintain the perovskite structure not to be decomposed through strong interaction with a lead-iodine octahedron, and the volatilization speed of the solvents can be regulated and controlled by regulating and controlling the proportion of the solvents. Therefore, directional secondary growth of perovskite crystal grains is realized in annealing of preparation of the modification layer, and a two-dimensional perovskite phase with a high lead iodine octahedron layer number, namely a high n value, is mainly used.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of photovoltaic cells, in particular to a perovskite solar cell with a directional interface modification layer. BACKGROUND

[0002] Perovskite solar cells (PSCs) have attracted much attention due to their tunable band gap, simple preparation and high photoelectric conversion efficiency, and are suitable for various spectral conditions. However, the performance stability of traditional PSCs under weak light is still a challenge, especially in wide band gap materials. Two-dimensional perovskite modification layers have attracted widespread attention due to their special structural advantages.

[0003] Currently, two-dimensional perovskite modification layers are mainly prepared by solution method and evaporation method, wherein the solution method includes preparing a two-dimensional perovskite precursor solution, and forming a thin film on a substrate by solution spin coating, drop coating or spraying, and then performing heat treatment or solvent treatment, and the evaporation method uses a thermal evaporation technology to co-evaporate perovskite source materials onto a substrate to form a thin film. However, the two-dimensional perovskite modification layers prepared by the two methods are not stable in quality. CONTENT OF THE UTILITY MODEL

[0004] Therefore, the present application provides a perovskite solar cell with a directional interface modification layer, which can control the thickness of the two-dimensional perovskite interface modification layer and the directional precise regulation of the two-dimensional phase, thereby improving the performance of the cell.

[0005] According to an aspect of the present application, a perovskite solar cell with a directional interface modification layer is provided, comprising: a substrate; a conductive substrate disposed on the top of the substrate; a hole transport layer disposed on the top of the conductive substrate; a three-dimensional perovskite active layer disposed on the top of the hole transport layer; a two-dimensional perovskite interface modification layer disposed on the top of the three-dimensional perovskite active layer; an electron transport layer disposed on the top of the two-dimensional perovskite interface modification layer; a hole blocking layer disposed on the top of the electron transport layer; and a back electrode disposed on the top of the hole blocking layer.

[0006] In an implementable manner, the two-dimensional perovskite interface modification layer comprises IPA and DMF, and further comprises one or more of DMSO, DMPO and DMPU.

[0007] In an implementable manner, the substrate is a glass substrate.

[0008] In an implementable manner, the conductive substrate is ITO or FTO.

[0009] In an implementable manner, the hole transport layer is a PTAA layer or a NiO x layer.

[0010] In an implementable manner, the three-dimensional perovskite active layer comprises DMF and DMSO.

[0011] In an implementable manner, the electron transport layer is a C60 layer or a PCBM layer.

[0012] In an implementable manner, the hole blocking layer is a bathocuproine layer.

[0013] In an implementable manner, the material of the back electrode is silver or copper.

[0014] Advantages of the present application: The perovskite solar cell of the present application is sequentially from bottom to top: a substrate, a conductive substrate, a hole transport layer, a three-dimensional perovskite active layer, a two-dimensional perovskite interface modification layer, an electron transport layer, a hole blocking layer, and a back electrode. A high-Goodyear donor number solvent is added to the two-dimensional perovskite precursor solution, which is composed of one or more than two of isopropyl alcohol, DMF, DMSO, DMPO, and DMPU. These solvents not only have high solubility and permeability, but also can effectively introduce two-dimensional ligands into the three-dimensional perovskite thin film. In addition, the strong interaction between these solvents and lead iodine octahedron can maintain the perovskite structure without decomposition. By adjusting the proportion of these solvents, the evaporation speed can be controlled, thereby realizing the directional secondary growth of perovskite grains in the preparation of the modification layer annealing, and the two-dimensional perovskite phase with high lead iodine octahedron layer, i.e., high n value, is mainly obtained.

[0015] Other features and aspects of the present application will become apparent from the following detailed description of exemplary embodiments with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0016] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the present application and serve to explain the principles of the present application.

[0017] Figure 1 A structural schematic diagram of a perovskite solar cell with a directional interface modification layer according to an embodiment of the present application is shown;

[0018] Figure 2 A molecular structure schematic diagram of DMSO according to an embodiment of the present application is shown;

[0019] Figure 3 A molecular structure schematic diagram of DPSO according to an embodiment of the present application is shown;

[0020] Figure 4 A molecular structure schematic diagram of DMPU according to an embodiment of the present application is shown;

[0021] Figure 5 A voltage-current curve schematic diagram of a perovskite solar cell in Example 1 and Comparative Example 1 is shown;

[0022] Figure 6 Voltage-current curve of the perovskite solar cell in Example 2 and Comparative Example 2 is shown schematically;

[0023] Figure 7 Voltage-current curve of the perovskite solar cell in Example 3 and Comparative Example 3 is shown schematically;

[0024] Figure 8 Optical absorption curve of the perovskite solar cell in Example 2 is shown in comparison with the spectrum of the indoor fluorescent lamp;

[0025] Figure 9 Voltage-current curve of the perovskite solar cell in Example 2 and Comparative Example 2 under indoor fluorescent lamp (1000 lux) is shown schematically. DETAILED DESCRIPTION

[0026] Various exemplary embodiments, features, and aspects of the present application will be described herein below with reference to the accompanying drawings. The same reference numbers in different drawings indicate the same or similar elements. Although various aspects of embodiments are illustrated in the drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

[0027] It should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application or simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0028] In addition, the terms "first", "second", are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0029] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations.

[0030] In addition, for a better illustration of the present application, numerous specific details are set forth in the following detailed description. One skilled in the art will understand, however, that the present application can be practiced without certain of the specific details set forth in the detailed description. In some instances, methods, apparatuses, elements and circuits that would be familiar to those skilled in the art are not described in detail in order to avoid obscuring the present application.

[0031] A perovskite solar cell with a directional interface modification layer, comprising: a substrate; a conductive substrate ① disposed on top of the substrate; a hole transport layer ② disposed on top of the conductive substrate ①; a three-dimensional perovskite active layer ③ disposed on top of the hole transport layer ②; a two-dimensional perovskite interface modification layer ④ disposed on top of the three-dimensional perovskite active layer ③; an electron transport layer ⑤ disposed on top of the two-dimensional perovskite interface modification layer ④; a hole blocking layer ⑥ disposed on top of the electron transport layer ⑤; a back electrode ⑦ disposed on top of the hole blocking layer ⑥.

[0032] In an implementable manner, the precursor solvent of the two-dimensional perovskite interface modification layer ④ comprises IPA and DMF, and further comprises one or more of DMSO, DMPO and DMPU.

[0033] In an implementable manner, the substrate is a glass substrate.

[0034] In an implementable manner, the conductive substrate ① is ITO or FTO.

[0035] In an implementable manner, the hole transport layer ② is PTAA or NiO x .

[0036] In an implementable manner, the three-dimensional perovskite active layer ③ comprises a solution of AX and BX2; A is any one of cesium, rubidium, potassium, amine group, amidine group or any one of the cations in the alkali group, B is any one of the divalent metal cations in lead, tin, tungsten, copper, zinc, gallium, germanium, arsenic, selenium, rhodium, palladium, silver, cadmium, indium, antimony, osmium, iridium, platinum, gold, mercury, thallium, bismuth, polonium, C is any one of the anions in chloride, bromide, iodide, thiocyanate, cyanide, oxycyanide, acetate, azide, borohydride, Co(CO) 4 - , C(NO2) 3 - , C(CN) 3 - .

[0037] In an implementable manner, the precursor solvent of the three-dimensional perovskite active layer ③ comprises DMF and DMSO.

[0038] In an implementable manner, the electron transport layer ⑤ is a C60 layer or a PCBM layer.

[0039] In one feasible approach, the hole-blocking layer ⑥ is a copper bath layer.

[0040] In one feasible approach, the back electrode ⑦ is made of silver or copper.

[0041] like Figure 1 As shown, the substrate serves as the supporting structure for the solar cell, and a transparent conductive substrate ① is deposited on it as the electrode material to facilitate subsequent charge collection and transport. A hole transport layer ② is prepared on the transparent conductive substrate ① to help holes be efficiently transported from the perovskite layer to the electrode. Then, the perovskite material is prepared and processed, including the preparation of a three-dimensional perovskite precursor solution and a two-dimensional perovskite precursor solution. The solvent added to the two-dimensional perovskite precursor solution ensures a high Goodman donor number. The prepared perovskite material is then deposited on the hole transport layer ②. First, the three-dimensional perovskite precursor material is coated to form a perovskite light-absorbing layer ③, and then the two-dimensional perovskite precursor solution is coated and deposited to form a modification layer ④. An electron transport material is deposited on the modification layer ④ to form an electron transport layer ⑤, which helps electrons transport from the perovskite layer to the electrode layer. Then, a hole blocking layer ⑥ is prepared on the electron transport layer ⑤ to protect the perovskite layer and the electron transport layer ⑤ and to promote charge collection efficiency. Finally, a back electrode ⑦ is deposited, serving as the top electrode throughout the entire solar cell process. The fabricated perovskite photovoltaic cell is then encapsulated and tested. Encapsulation prevents the impact of environmental conditions on device performance, such as changes in light and humidity. Performance tests are also performed on the encapsulated perovskite solar cell, including photoelectric conversion efficiency (PCE), short-circuit current density (Jsc), open-circuit voltage (Voc), and fill factor (FF), to evaluate the photoelectric conversion efficiency and stability during the process.

[0042] In one feasible manner, the solvent of the two-dimensional perovskite precursor solution is composed of one or more of isopropanol, DMF, DMSO, DMPO, and DMPU.

[0043] like Figures 2-4 As shown, in addition to the conventional IPA (isopropanol) and DMF (dimethylamide) used in the precursor solution of the modified layer ④, one or more of DMSO (dimethyl sulfoxide), DMPO (diphenyl sulfoxide), and DMPU (N,N-dimethylprop-2-acetylacetylamine) were additionally introduced. These all have high Gutmann donor number (D N The solvent of ), where D NThe value refers to the strength of the electron-donating part in a molecule or ion, which represents the ability of the compound to donate electrons. These solvents not only have high solubility and permeability, but also can effectively introduce two-dimensional ligands into the three-dimensional perovskite film, and can maintain the perovskite structure by strong interaction with lead iodine octahedron. By adjusting the proportion of these solvents, the evaporation speed can be controlled, so as to realize the directional secondary growth and optimization of perovskite grains in the annealing after the preparation of the modified layer (IV), so as to mainly form a two-dimensional perovskite phase with high lead iodine octahedron layer, that is, high n value, which significantly improves the crystallization quality and electron transport performance of the perovskite film, and realizes the improvement of indoor photovoltaic performance through spectral matching.

[0044] In an implementable manner, the preparation of the three-dimensional perovskite precursor solution further comprises: preparing a solution containing three-dimensional perovskite precursor substances AX and BX2, and the solvent of the three-dimensional perovskite precursor solution is DMF and DMSO; and the preparation of the two-dimensional perovskite precursor solution further comprises: preparing a solution containing two-dimensional perovskite precursor substances RX.

[0045] In an implementable manner, A is any one of cesium, rubidium, potassium, amine group, amidine group or any one of the cations in the alkali group, B is any one of the divalent metal cations in lead, tin, tungsten, copper, zinc, gallium, germanium, arsenic, selenium, rhodium, palladium, silver, cadmium, indium, antimony, osmium, iridium, platinum, gold, mercury, thallium, bismuth, polonium, R is any one of phenethylamine, 1,4-butanediamine, guanidine group, X is any one of chloride, bromide, iodide, thiocyanate, cyanide, oxycyanide, acetate, azide, borohydride, Co(CO) 4 - , C(NO2) 3 - , C(CN) 3- , and the solvent is DMF (dimethylformamide) and DMSO (dimethyl sulfoxide).

[0046] In addition, the preparation of the two-dimensional perovskite precursor solution is to prepare a solution containing two-dimensional perovskite precursor substances PX, wherein R is one of phenethylamine, 1,4-butanediamine and guanidine group, and the solvent is one or more of IPA (isopropyl alcohol), DMF (dimethylformamide), DMSO (dimethyl sulfoxide), DMPO (diphenyl sulfoxide) and DMPU (N,N-dimethylprop-2-ynylamine).

[0047] In this embodiment, when preparing the three-dimensional perovskite precursor solution, AX and BX2 substances are contained in the three-dimensional perovskite precursor solution. The perovskite structure is ABX3, wherein A is any one of cation of cesium, rubidium, potassium, amine group, amidine group or any one of alkali group, B is any one of divalent metal cation of lead, tin, tungsten, copper, zinc, gallium, germanium, arsenic, selenium, rhodium, palladium, silver, cadmium, indium, antimony, osmium, iridium, platinum, gold, mercury, thallium, bismuth, polonium, and X is any one of anion of chloride, bromide, iodide, thiocyanate, cyanide, oxycyanide, acetate, azide, borohydride, Co(CO )4 - , C(NO2) 3 - , C(CN) 3 - .

[0048] In an implementable manner, the coating of the three-dimensional perovskite precursor solution on the hole transport layer ② further comprises: depositing the perovskite precursor solution on the NiO x layer by spin coating or slot coating, and annealing at 100°C for 10 minutes.

[0049] In an implementable manner, the coating of the two-dimensional perovskite precursor solution on the perovskite light absorption layer ③ further comprises: depositing the two-dimensional perovskite precursor solution on the perovskite absorption layer by spin coating or slot coating, and annealing at 70-100°C for 5-10 minutes.

[0050] In an implementable manner, the depositing of the conductive substrate ① on the substrate further comprises: the substrate is a glass substrate, and an ITO (indium tin oxide) or FTO (fluorine-doped tin oxide) film is deposited on the glass substrate to form a transparent conductive oxide (TCO) coating layer; the preparation of the hole transport layer ② on the TCO further comprises: depositing a PTAA (poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine) or NiO x (oxidized nickel) film on the conductive substrate ① by spin coating or magnetron sputtering.

[0051] In an implementable manner, the preparation of the electron transport layer ⑤ on the modification layer ④ further comprises: depositing a fullerene (C60 or PCBM) layer on the modification layer ④ by thermal evaporation or spin coating, which serves as an electron transport material and helps the electron transport from the perovskite layer to the electrode layer.

[0052] In an implementable manner, the preparation of the hole blocking layer ⑥ on the electron transport layer ⑤ further comprises: depositing a bathocuproin (BCP) layer on the electron transport layer ⑤ by thermal evaporation or spin coating, which is used to protect the perovskite layer and the electron transport layer ⑤ and promote the charge collection efficiency.

[0053] In an implementable manner, the back electrode ⑦ is prepared on the hole blocking layer ⑥, and the perovskite solar cell is packaged, which further comprises: depositing a metal electrode on the hole blocking layer ⑥, completing the preparation of the perovskite solar cell, packaging the prepared solar cell, and testing the performance of the packaged perovskite solar cell.

[0054] In this embodiment, a metal electrode is deposited on the BCP as the top electrode of the entire perovskite solar cell, wherein the metal electrode is silver or copper. The completed perovskite solar cell device is packaged to prevent environmental conditions from affecting the performance of the device, and the performance of the device is tested, including the photoelectric conversion efficiency (PCE), short-circuit current density (Jsc), open-circuit voltage (Voc), and fill factor (FF) to test the photoelectric conversion efficiency and stability of the device.

[0055] Comparative Examples 1, 2 and 3 are prepared by the same process as the technical solution of the present application, preferably, the TCO anode here uses ITO, the perovskite A site uses CsFAMA (cesium (Cs), formamidinium (FA, i.e. HC(NH2) 2+ ), methylamine (MA, i.e. CH3NH 3+ ) and A-site cations), B-site is Pb, X-site is I, Br mixed component, two-dimensional perovskite interface modification layer ④ precursor solution is BDAI (1,4-butanediamine) dissolved in IPA (isopropyl alcohol), concentration is adjustable from 0.5 mg / ml to 4 mg / ml, electron transport layer ⑤ uses PCBM (fullerene derivative), back electrode ⑦ uses Ag.

[0056] The two-dimensional perovskite cation interface modifier (BDAI (1,4-butanediamine), PEACI (chlorobenzeneamine) or GAI (methylamine iodine) and the like) is dissolved in a solvent to prepare an interface modification solution with a concentration of 0.5 mg / ml to 4 mg / ml, and the concentration of the interface modification solution is preferably 0.5 mg / ml to 1.5 mg / ml, and the solvent is one or more of IPA, DMSO, DMPO and DMPU;

[0057] The interface modification solution is deposited on the prepared three-dimensional perovskite surface by spin coating or slot coating, wherein the spin coating method uses static spin coating with a rotation speed of 2000 rpm to 6000 rpm, preferably 4000 rpm; the slot coating method has a coating speed of 8 mm / s to 30 mm / s, preferably 20 mm / s.

[0058] Heat annealing treatment is performed, and the treatment temperature is preferably 70°C to 100°C, and the treatment time is 5 min to 10 min.

[0059] To illustrate the superiority of the surface modification method of the present application, the following examples are now carried out:

[0060] Example 1: Compared with the comparative example, the solvent of the two-dimensional perovskite interface modification layer IV precursor solution in Example 1 is changed to IPA mixed with DMSO at a ratio of 99:1, and the rest of the preparation process is not modified.

[0061] Example 2: Compared with the comparative example, the solvent of the two-dimensional perovskite interface modification layer IV precursor solution in Example 2 is changed to IPA mixed with DMPO at a ratio of 99:1, and the rest of the preparation process is not modified.

[0062] Example 3: Compared with the comparative example, the solvent of the two-dimensional perovskite interface modification layer IV precursor solution in Example 3 is changed to IPA mixed with DMPU at a ratio of 99:1, and the rest of the preparation process is not modified.

[0063] According to Figures 5-7 , it can be seen from the voltage-current curve diagram of the perovskite solar cell in the examples and the comparative example that the typical photoelectric conversion efficiency of the comparative example is 21.53%, the open circuit voltage and short circuit current of Example 1, Example 2 and Example 3 are all higher than that of the comparative example, and the photoelectric conversion efficiencies thereof are 23.40%, 24.03% and 21.83% respectively, which are significantly improved. The test conditions are AM1.5G, 100mW / cm 2 .

[0064] Figure 8 Example 2 is the highest efficiency example in the present application, and the optical absorption curve and short circuit current integral are compared with the spectrum of the indoor fluorescent lamp. It can be seen that the modified perovskite film in Example 2 forms a two-dimensional perovskite phase with n = 2 and n = 3 as the main component (the chemical formula is BDA(A)n-1BnX3n+1, and the value of n is the number of lead iodine octahedron layers), which forms a good match with the spectrum of the indoor fluorescent lamp light source, and the current is obviously improved at the wavelength with the strongest light intensity of the fluorescent lamp. Therefore, this example should be beneficial to the performance improvement of perovskite indoor photovoltaic.

[0065] The above Example 2 and Comparative Example 2 are placed under a fluorescent lamp light source to test the J-V curve, as shown in Figure 9 , the open circuit voltage of Example 2 is 0.988V, the short circuit current density is 146μA / cm -2 , the fill factor is 83.09%, and the photoelectric conversion efficiency is 42.89%; while the open circuit voltage of Comparative Example 2 is 0.970V, the short circuit current density is 134μA / cm -2 , the fill factor is 81.94%, and the photoelectric conversion efficiency is 38.01%.

[0066] It should be noted that although the perovskite solar cell with directional interface modification layer is introduced as an example in the present application, those skilled in the art can understand that the present application should not be limited thereto. In fact, users can flexibly set various parameters according to personal preferences and / or actual application scenarios, as long as the design is reasonable.

[0067] In this way, the perovskite solar cell of the present application is sequentially arranged from bottom to top as substrate, conductive substrate, hole transport layer, three-dimensional perovskite active layer, two-dimensional perovskite interface modification layer, electron transport layer, hole blocking layer and back electrode, and a high Grotthuss donor number solvent is added to the two-dimensional perovskite precursor solution, which is composed of one or more than two of isopropanol, DMF, DMSO, DMPO and DMPU. These solvents not only have high solubility and permeability, but also can effectively introduce two-dimensional ligands into the three-dimensional perovskite thin film, and can maintain the perovskite structure from decomposition through strong interaction with lead iodine octahedron. By adjusting the proportion of these solvents, the evaporation speed can be controlled, so as to realize directional secondary growth of perovskite grains in the preparation of the modification layer annealing, so as to mainly form two-dimensional perovskite phase with high lead iodine octahedron layer, i.e. high n value.

[0068] The above has described various embodiments of the present application, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles, practical applications or improvements to the technology in the market of the embodiments, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein.

Claims

1. A perovskite solar cell with a directional interface modification layer, characterized in that, Comprising: a substrate; a conductive substrate disposed on top of the substrate; a hole transport layer disposed on top of the conductive substrate; a three-dimensional perovskite active layer disposed on top of the hole transport layer; a two-dimensional perovskite interface modification layer disposed on top of the three-dimensional perovskite active layer; an electron transport layer disposed on top of the two-dimensional perovskite interface modification layer; a hole blocking layer disposed on top of the electron transport layer; a back electrode disposed on top of the hole blocking layer.

2. The perovskite solar cell having a directional interface modification layer according to claim 1, characterized in that, The substrate is a glass substrate.

3. The perovskite solar cell having a directional interface modification layer according to claim 1, characterized in that, The hole transport layer is a PTAA layer or a NiO x layer.

4. The perovskite solar cell having a directional interface modification layer according to claim 1, characterized in that, The electron transport layer is a C60 layer or a PCBM layer.

5. The perovskite solar cell having a directional interface modification layer according to claim 1, characterized in that, The hole blocking layer is a bathocuproine layer.

6. The perovskite solar cell having a directional interfacial modification layer according to claim 1, characterized in that, The back electrode is made of silver or copper.

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