Method for preparing perovskite unijunction and laminated cell by using perovskite single crystal

Abstract

The invention discloses a method for preparing a perovskite unijunction and a laminated cell by using a perovskite single crystal, in the preparation process, a halogenated perovskite single crystal prepared in advance is dissolved in a polar solvent to prepare a perovskite photoactive layer precursor solution, other additives are not needed in the precursor solution except the halogenated perovskite single crystal, and the perovskite photoactive layer is prepared. The film quality and the device performance are improved; wherein the perovskite optical active layer is made of a perovskite material matched with a monocrystalline silicon band gap; the photoelectric conversion efficiency of the perovskite sub-cell contained in the solar cell prepared by the method in a laboratory test exceeds 23%, the initial efficiency is kept above 97% after 408 hours under an open-circuit illumination condition, the photoelectric conversion efficiency of the perovskite / crystalline silicon two-end laminated cell in a laboratory test exceeds 33%, and the perovskite / crystalline silicon two-end laminated cell has excellent operation stability.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of solar cells, and particularly relates to a method for preparing a perovskite single-junction and laminated cell by using a perovskite single crystal. BACKGROUND

[0002] With the excellent photoelectric properties of the organic-inorganic hybrid metal halide perovskite material, the photoelectric conversion efficiency record of the perovskite solar cell has been continuously broken in the past ten years, but the average power cost is still higher than that of the crystalline silicon cell. The construction of the perovskite / crystalline silicon laminated cell can further improve the photoelectric conversion efficiency and reduce the average power cost. However, the light active layer of the wide-bandgap single-junction perovskite solar cell matched with the single-crystal silicon has a large number of point defects, resulting in more serious open-circuit voltage loss. At the same time, the halogen ion migration phenomenon is easy to occur in the wide-bandgap halide perovskite under the long-time light operation condition, and finally a serious halogen phase separation occurs, thereby causing a serious decrease in the efficiency of the perovskite sub-cell and the laminated cell.

[0003] It is found that improving the initial-state halogen distribution uniformity of the thin film can significantly improve the phase stability of the thin film and the operation stability of the laminated cell, but the methods for improving the phase stability reported at present often introduce an additive into the wide-bandgap halide perovskite, and the ion migration is inhibited by passivation defects or stress regulation, such as the introduction of trimethylphenyl tribromide. However, these methods have obvious limitations, and cannot improve the initial-state uniformity of the perovskite thin film, and are difficult to fundamentally improve the phase stability of the perovskite thin film under the operation condition.

[0004] Therefore, how to effectively improve the phase stability of the perovskite thin film under the operation condition is a key scientific problem to be solved in the field at present. SUMMARY

[0005] In order to solve the above problems existing in the prior art, the application aims to provide a method for preparing a perovskite single-junction and laminated cell by using a perovskite single crystal. The perovskite light active layer of the solar cell prepared by the method can be matched with the band gap of the single-crystal silicon, so that the solar cell has high photoelectric conversion performance and excellent stability.

[0006] In one aspect, the application provides a preparation method of a perovskite single-junction solar cell, which comprises the following steps:

[0007] S1, cleaning a transparent conductive substrate;

[0008] S2, preparing a first layer of transport layer material on the cleaned transparent conductive substrate;

[0009] S3, only dissolving halogenated perovskite single crystal in a polar solvent to prepare a perovskite photoactive layer precursor solution with a concentration of 0.5-2.0M, wherein the halogenated perovskite single crystal contains carbon, hydrogen, nitrogen, cesium, lead, iodine, bromine and chlorine elements;

[0010] S4, coating the perovskite photoactive layer precursor solution on the first layer of transport layer material to form a film, adding chlorobenzene during the coating process, and then preparing a perovskite photoactive layer after annealing heat treatment, wherein the perovskite photoactive layer can be matched with the band gap of single crystal silicon;

[0011] S5, preparing a second layer of transport layer material on the perovskite photoactive layer;

[0012] S6, after preparing a back electrode on the second layer of transport layer material, the perovskite single junction solar cell is obtained.

[0013] Preferably, in the above step S1, the transparent conductive substrate can be an indium tin oxide transparent conductive substrate or a fluorine-doped tin oxide transparent conductive substrate.

[0014] Preferably, in the above step S2, a chlorobenzene solution of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] can be used to coat and prepare the first layer of transport layer material.

[0015] Preferably, in the above step S3, the polar solvent is a mixed solvent of dimethylformamide and dimethyl sulfoxide, wherein the volume ratio of dimethylformamide to dimethyl sulfoxide is 4-9:1.

[0016] Preferably, in the above step S3, the halogenated perovskite single crystal is prepared by dissolving methylamine chloride, lead chloride, methylamine bromide, formamidine bromide, formamidine iodide and lead iodide in γ-butyrolactone to prepare a single crystal mother liquor, and the halogenated perovskite single crystal is precipitated using the single crystal mother liquor.

[0017] Preferably, in the above step S4, the perovskite photoactive layer can be prepared by a one-step method (simultaneous deposition of inorganic and organic species), which is a one-time film forming method.

[0018] Preferably, in the above step S4, the excess solution can be removed by negative pressure before annealing heat treatment.

[0019] Preferably, in the above step S5, the second layer of transport layer material can be prepared on the perovskite photoactive layer by existing spin coating, spraying, deposition and other processes.

[0020] Preferably, in the above step S6, the back electrode is a metal electrode or a carbon electrode, wherein the metal electrode is prepared by depositing copper on the second layer of transport layer material, or the carbon electrode is deposited.

[0021] Preferably, in the step S6, the metal electrode is deposited on the second layer of transport material by sputtering, evaporation or the like process under high vacuum conditions, or the carbon electrode is deposited by printing.

[0022] In another aspect, the present application further provides a perovskite single-junction solar cell prepared based on the preparation method.

[0023] Preferably, the thickness of the perovskite photoactive layer of the perovskite single-junction solar cell is 100-2000 nm.

[0024] In another aspect, the present application further provides a preparation method of a perovskite tandem solar cell, comprising the following steps:

[0025] S1, depositing indium tin oxide or fluorine-doped tin oxide on a single crystal silicon cell;

[0026] S2, preparing a hole transport layer on the deposited single crystal silicon cell;

[0027] S3, dissolving only a halogenated perovskite single crystal in a polar solvent to prepare a perovskite photoactive layer precursor solution with a concentration of 0.5-2.0 M, wherein the halogenated perovskite single crystal contains carbon, hydrogen, nitrogen, cesium, lead, iodine, bromine and chlorine elements;

[0028] S4, coating the perovskite photoactive layer precursor solution on the hole transport layer to form a film, and then preparing a perovskite photoactive layer after annealing heat treatment, wherein the perovskite photoactive layer can match the single crystal silicon band gap;

[0029] S5, sequentially evaporating fullerene C 60 an electron transport layer and depositing a tin oxide layer to prepare a second layer of transport material;

[0030] S6, sequentially sputtering an indium tin oxide layer, evaporating a metal electrode and a magnesium fluoride anti-reflection layer on the above-mentioned second layer of transport material to obtain a perovskite tandem solar cell.

[0031] Preferably, in the step S2, a chlorobenzene solution of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] is used to coat and prepare the above-mentioned hole transport layer.

[0032] Preferably, in the step S3, the polar solvent is a mixed solvent of dimethylformamide and dimethyl sulfoxide, and the volume ratio of dimethylformamide to dimethyl sulfoxide is 4-9:1.

[0033] Preferably, in the step S3, the halogenated perovskite single crystal is prepared by dissolving methylamine chloride, lead chloride, methylamine bromide, formamidinium bromide, formamidinium iodide and lead iodide in gamma-butyrolactone to form a single crystal mother liquor, and using the single crystal mother liquor to precipitate the halogenated perovskite single crystal.

[0034] Preferably, in the step S4, the excess solution can be removed by negative pressure before the annealing heat treatment.

[0035] Preferably, in the step S5, the tin oxide layer is deposited by atomic layer deposition.

[0036] Preferably, in the step S6, the indium tin oxide layer is sputtered by direct current sputtering, and / or the metal electrode and the magnesium fluoride anti-reflection layer are evaporated under high vacuum conditions.

[0037] Preferably, in the step S6, the metal electrode is made of gold, silver or copper.

[0038] Finally, the present application further provides a perovskite stacked solar cell prepared according to the above preparation method.

[0039] In the above preparation methods of the present application, the perovskite photoactive layer can be prepared by existing spin coating process, printing process or spraying process.

[0040] In the above preparation methods of the present application, the single crystal dissolved in the perovskite photoactive layer precursor is a halogenated perovskite single crystal, which contains elements carbon, hydrogen, nitrogen, cesium, lead, iodine, bromine and chlorine.

[0041] In the present application, the solar cell has two electrodes, and uses organic small molecules, polymers or inorganic materials as electron and hole transport materials; the light-receiving surface electrode of the solar cell is an indium tin oxide transparent electrode or a fluorine-doped tin oxide transparent electrode, and the back electrode of the solar cell is a metal electrode or a carbon electrode.

[0042] In the present application, by using a polar solution of halogenated perovskite single crystal as a precursor, a high-quality single-junction perovskite solar cell active layer matching the band gap of single crystal silicon is prepared, which plays a role in improving the uniformity of halogen distribution in the initial state of the perovskite thin film, the efficiency and stability of the solar cell. The solar cell has two electrodes, and uses organic small molecules, polymers or inorganic materials as electron and hole transport materials, and has very high photoelectric conversion performance and excellent stability.

[0043] The preparation method of the present application, in the preparation process, the prepared halide perovskite single crystal is dissolved in a polar solvent to prepare a perovskite photoactive layer precursor solution, no other additives are needed in the precursor solution except for the halide perovskite single crystal, which plays a role in improving the quality of the thin film and the performance of the device; wherein the perovskite photoactive layer is a perovskite material matched with the band gap of monocrystalline silicon.

[0044] Compared with the prior art, the perovskite photoactive layer prepared by the preparation method provided by the present application has excellent photoelectric properties, the efficiency of the perovskite single junction solar cell exceeds 23%, and the initial efficiency is maintained at more than 97% after 408 hours of open circuit illumination, the single junction perovskite sub-cell and the monocrystalline silicon cell are combined to form a laminated cell with very high photoelectric conversion efficiency, the laboratory test efficiency exceeds 33%, and the certified efficiency at Wuxi National Photovoltaic Quality Inspection Center exceeds 32%; the perovskite photoactive layer has excellent photo-illumination separation stability; at the same time, the preparation of the perovskite single crystal can reduce the demand for raw material purity, and reduce the preparation cost of the perovskite solar cell. BRIEF DESCRIPTION OF DRAWINGS

[0045] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings. In the drawings, like reference numerals refer to like elements throughout the several figures, unless otherwise indicated. The drawings are not necessarily to scale, the emphasis instead being placed upon illustrating the principles of the application. It should be understood that the drawings are merely for purposes of illustrating the embodiments in accordance with the present disclosure, and are not intended to limit the scope of the application. In the drawings:

[0046] Figure 1 is a photoelectric conversion efficiency test curve of a perovskite single junction solar cell prepared by using a perovskite single crystal solution as a precursor according to Embodiment One of the present application, which is matched with the band gap of monocrystalline silicon;

[0047] Figure 2 is a photoelectric conversion efficiency test curve of a perovskite laminated solar cell prepared by using a perovskite single crystal solution as a precursor according to Embodiment Two of the present application;

[0048] Figure 3 is a comparison chart of open circuit illumination stability of perovskite single junction solar cells in Embodiment One and Comparative Example One of the present application. DETAILED DESCRIPTION

[0049] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and should not be construed as limiting the present application.

[0050] Embodiment one

[0051] Firstly, the present application provides a preparation method of perovskite single-junction solar cell, in this embodiment, taking a solar cell with p-i-n structure as an example, the preparation method comprises the following steps:

[0052] S1, ultrasonic cleaning of indium tin oxide transparent conductive substrate;

[0053] S2, coating a 2mg / mL poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] chlorobenzene solution on the cleaned indium tin oxide transparent conductive substrate to form a film to prepare a first layer of transport layer material;

[0054] S3, respectively weighing 8.1mg of methylamine chloride, 33.4mg of lead chloride, 71.6mg of methylamine bromide, 160mg of methylformamidine bromide, 357.8mg of methylformamidine iodide and 1844mg of lead iodide, dissolving all of them in 2.5ml of gamma-butyrolactone to prepare a single crystal mother liquor, heating the single crystal mother liquor from 25℃ to 80℃ at a rate of 12℃ / min, and then heating to 110℃ at a rate of 1℃ / h, and then the halogenated perovskite single crystal is precipitated from the single crystal mother liquor, the halogenated perovskite single crystal contains carbon, hydrogen, nitrogen, cesium, lead, iodine, bromine and chlorine elements; then, only the halogenated perovskite single crystal is dissolved in a polar solvent prepared from dimethylformamide and dimethyl sulfoxide in a volume ratio of 4:1 to prepare a perovskite photoactive layer precursor solution with a concentration of 1.4M;

[0055] S4, spin coating the above-mentioned perovskite photoactive layer precursor solution on the above-mentioned first layer of transport layer material to form a film, adding 200μL of chlorobenzene dropwise during the spin coating process, or using 1.0*10 -1 tor negative pressure to remove excess solvent, and then annealing at 120℃ for 20 minutes to prepare a perovskite photoactive layer, wherein the perovskite photoactive layer can match the band gap of single crystal silicon;

[0056] S5, sequentially evaporating fullerene C 60 and depositing a tin oxide layer by atomic layer deposition on the above-mentioned perovskite photoactive layer to prepare a second layer of transport layer material;

[0057] S6, depositing a metal copper on the above-mentioned second layer of transport layer material to prepare a back electrode, thereby obtaining a perovskite single-junction solar cell.

[0058] wherein, Figure 1is a photoelectric conversion efficiency test curve of a perovskite single-junction solar cell with a bandgap matched to that of a single-crystal silicon prepared using a perovskite photoactive layer precursor solution as a precursor, which is obtained by scanning the voltage-current curve of the device under a standard sunlight, including forward scanning (from short-circuit current to open-circuit voltage) and reverse scanning (scanning direction from open-circuit voltage to short-circuit current), and is obtained by Figure 1 It can be seen that the photoelectric conversion efficiency of this type of solar cell exceeds 23%, and the difference between forward and reverse scanning is very small, showing excellent photoelectric conversion performance.

[0059] Example Two

[0060] In addition, the present application also provides a preparation method of a perovskite tandem solar cell, in this embodiment, taking a perovskite tandem cell with a p-i-n structure as an example, the preparation method comprises the following steps:

[0061] S1, sputtering deposition of indium tin oxide or fluorine-doped tin oxide on a single-crystal silicon cell;

[0062] S2, coating a 4 mg / mL chlorobenzene solution of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] on the sputtered single-crystal silicon cell to prepare a hole transport layer;

[0063] S3, respectively weighing 8.1 mg of methylamine chloride, 33.4 mg of lead chloride, 71.6 mg of methylamine bromide, 160 mg of formamidine bromide, 357.8 mg of formamidine iodide and 1844 mg of lead iodide, dissolving them all in 4 milliliters of gamma-butyrolactone to prepare a single-crystal mother liquor, heating the single-crystal mother liquor from 25°C to 80°C at a rate of 12°C / min, and then heating to 120°C at a rate of 3°C / h, and then the halogenated perovskite single crystal is precipitated from the single-crystal mother liquor, the halogenated perovskite single crystal contains carbon, hydrogen, nitrogen, cesium, lead, iodine, bromine and chlorine elements; then, only the halogenated perovskite single crystal is dissolved in a polar solvent prepared from dimethylformamide: dimethyl sulfoxide at a volume ratio of 9:1 to prepare a perovskite photoactive layer precursor solution with a concentration of 1.8M;

[0064] S4, spin coating the above-mentioned perovskite photoactive layer precursor solution on the above-mentioned hole transport layer to form a film, using a 1.0*10 -1 tor negative pressure to remove excess solvent, and then annealing at 120°C for 20 minutes to prepare a perovskite photoactive layer, wherein the perovskite photoactive layer can be matched to the bandgap of a single-crystal silicon;

[0065] S5, under high vacuum conditions, sequentially evaporating fullerene C 60 electron transport layer and a tin oxide layer deposited by atomic layer deposition method to prepare a second layer of transport layer material;

[0066] S6. After sequentially sputtering an indium tin oxide layer onto the second transport layer material using DC sputtering, depositing a copper electrode and a magnesium fluoride antireflection layer under high vacuum conditions, a perovskite tandem solar cell can be obtained.

[0067] in, Figure 2 This is a photoelectric conversion efficiency test curve for a perovskite tandem solar cell fabricated using a perovskite photoactive layer precursor solution as a precursor. It is obtained under standard sunlight by scanning the device's voltage-current profile, including forward scan (from short-circuit current to open-circuit voltage) and reverse scan (scanning direction from open-circuit voltage to short-circuit current). Figure 2 It can be seen that the photoelectric conversion efficiency of this type of solar cell exceeds 31.5%, and the difference between forward and reverse scanning is very small, showing excellent photoelectric conversion performance.

[0068] Comparative Examples

[0069] In this comparative embodiment, equal amounts of solid raw materials from Example 1 above, namely 8.1 mg methylamine chloride, 33.4 mg lead chloride, 71.6 mg methylamine bromide, 160 mg formamidinium bromide, 357.8 mg formamidinium iodide, and 1844 mg lead iodide, were directly dissolved in a polar solvent prepared from dimethylformamide and dimethyl sulfoxide in a volume ratio of 4:1 to prepare a precursor solution of the same concentration. Conventional perovskite single-junction solar cells with band gaps matching monocrystalline silicon were prepared according to the same steps.

[0070] in, Figure 3 The perovskite single-junction solar cell prepared in Example 1 above and the perovskite single-junction solar cell prepared in the comparative example above have a performance of 1000 W / m 2 A comparison chart of device efficiency under open-circuit illumination aging of white LEDs, by Figure 3 It can be seen that the perovskite photoactive layer prepared using the perovskite photoactive layer precursor solution as a precursor in Example 1 has its component phase separation phenomenon significantly suppressed after photoaging. Therefore, the corresponding single-junction cell has better open-circuit illumination stability and maintains more than 97% of its initial efficiency after 408 hours of aging.

[0071] It should be noted that, unless otherwise specified in the examples, the conditions shall be performed in accordance with conventional conditions or the conditions recommended by the manufacturer. If the manufacturers of the reagents or instruments used are not specified, they are all conventional products that can be purchased commercially.

[0072] 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 without departing from the principles and spirit of the present invention.

Claims

1. A method for fabricating a perovskite single-junction solar cell, characterized in that: The preparation method includes the following steps: S1. Clean the transparent conductive substrate; S2. Prepare a first transport layer material on the cleaned transparent conductive substrate; S3. Dissolve only halide perovskite single crystals in a polar solvent to prepare a perovskite photoactive layer precursor solution with a concentration of 0.5-2.0M, wherein the halide perovskite single crystals contain carbon, hydrogen, nitrogen, cesium, lead, iodine, bromine and chlorine elements; S4. The perovskite photoactive layer precursor solution is coated onto the first transport layer material to form a film. Chlorobenzene is added dropwise during the coating process. After annealing heat treatment, the perovskite photoactive layer is prepared. The perovskite photoactive layer can match the band gap of single crystal silicon. S5. Prepare a second transport layer material on the perovskite photoactive layer; S6. After fabricating the back electrode on the second transport layer material, the perovskite single-junction solar cell can be obtained.

2. The preparation method according to claim 1, characterized in that, In step S3, the polar solvent is a mixed solvent of dimethylformamide and dimethyl sulfoxide, wherein the volume ratio of dimethylformamide to dimethyl sulfoxide is 4-9:

1.

3. The preparation method according to claim 1, characterized in that, In step S3, the halide perovskite single crystal is prepared by dissolving methylamine chloride, lead chloride, methylamine bromide, formamidine bromide, formamidine iodide and lead iodide in γ-butyrolactone to prepare a single crystal mother liquor, and using the single crystal mother liquor to precipitate the halide perovskite single crystal.

4. The preparation method according to claim 1, characterized in that, In step S6, the back electrode is a metal electrode or a carbon electrode.

5. A perovskite single-junction solar cell, characterized in that: This perovskite single-junction solar cell was prepared according to the preparation method described in any one of claims 1-4.

6. The perovskite single-junction solar cell according to claim 5, characterized in that, The thickness of the perovskite photoactive layer in this perovskite single-junction solar cell is 100-2000 nm.

7. A method for fabricating a perovskite tandem solar cell, characterized in that: The preparation method includes the following steps: S1. Deposit indium tin oxide or fluorine-doped tin oxide on monocrystalline silicon solar cells; S2. Prepare a hole transport layer on the deposited monocrystalline silicon cell; S3. Dissolve only halide perovskite single crystals in a polar solvent to prepare a perovskite photoactive layer precursor solution with a concentration of 0.5-2.0M, wherein the halide perovskite single crystals contain carbon, hydrogen, nitrogen, cesium, lead, iodine, bromine and chlorine elements; S4. The perovskite photoactive layer precursor solution is coated onto the hole transport layer to form a film, and then the perovskite photoactive layer is prepared by annealing heat treatment, wherein the perovskite photoactive layer can match the band gap of single crystal silicon. S5. Fullerene C is sequentially deposited onto the perovskite photoactive layer. 60 An electron transport layer and a deposited tin oxide layer are used to prepare the second transport layer material; S6. After sequentially sputtering an indium tin oxide layer, evaporating a metal electrode, and depositing a magnesium fluoride antireflection layer on the second transport layer material, the perovskite tandem solar cell can be obtained.

8. The preparation method according to claim 7, characterized in that, In step S3, the polar solvent is a mixed solvent of dimethylformamide and dimethyl sulfoxide, wherein the volume ratio of dimethylformamide to dimethyl sulfoxide is 4-9:

1.

9. The preparation method according to claim 7 or 8, characterized in that, In step S3, the halide perovskite single crystal is prepared by dissolving methylamine chloride, lead chloride, methylamine bromide, formamidine bromide, formamidine iodide and lead iodide in γ-butyrolactone to prepare a single crystal mother liquor, and using the single crystal mother liquor to precipitate the halide perovskite single crystal.

10. A perovskite tandem solar cell, characterized in that: The perovskite tandem solar cell was prepared according to the preparation method described in any one of claims 7-9.

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