A perovskite photovoltaic device and its annealing method, preparation method and application

Abstract

The present invention belongs to the field of semiconductor manufacturing technology, and relates to a perovskite photovoltaic device and an annealing method, a preparation method and an application thereof, wherein the annealing method comprises: placing the perovskite photovoltaic device on a hot stage, and locally heating the area to be annealed of the perovskite photovoltaic device using a laser, so that the perovskite crystal is transformed from a non-optically active phase to an optically active phase; wherein the radiation flux density of the laser is determined according to the Stefan-Boltzmann law. The annealing method provided by the present invention is particularly suitable for the annealing treatment of the perovskite photovoltaic device, improves the annealing efficiency and temperature accuracy, and realizes selective annealing, thereby avoiding the degradation of the perovskite film caused by annealing in the air for a long time.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor manufacturing, and relates to a perovskite photovoltaic device, and in particular to a perovskite photovoltaic device and an annealing method, a preparation method and an application thereof. Background Art

[0002] In the manufacturing process of perovskite photovoltaic devices, an annealing process is usually required to assist the crystal growth of perovskite. The traditional annealing process often uses an annealing furnace for thermal annealing, that is, the material is placed in the annealing furnace and heated to a specific temperature and maintained for a period of time. However, this process requires a long annealing time, low temperature accuracy, and heating of the entire workpiece, making it difficult to achieve selective annealing.

[0003] In addition, with the development of semiconductor manufacturing technology, especially the fact that perovskite photovoltaic devices are easily degraded by the environment, the traditional annealing process cannot meet the needs of modern semiconductor manufacturing.

[0004] It can be seen that how to develop an annealing process that is particularly suitable for the annealing treatment of perovskite photovoltaic devices, improve the annealing efficiency and temperature accuracy, and achieve selective annealing while avoiding the degradation of the perovskite film caused by long-term annealing in the air has become an urgent problem that technical personnel in this field need to solve. Summary of the invention

[0005] In view of the deficiencies in the prior art, the object of the present invention is to provide a perovskite photovoltaic device and an annealing method, a preparation method and an application thereof. The annealing method is particularly suitable for annealing treatment of perovskite photovoltaic devices, improves annealing efficiency and temperature accuracy, and realizes selective annealing, thereby avoiding degradation of the perovskite film caused by long-term annealing in air.

[0006] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides an annealing method for a perovskite photovoltaic device, the annealing method comprising: placing the perovskite photovoltaic device on a hot stage, and using a laser to locally heat the area to be annealed of the perovskite photovoltaic device, thereby transforming the perovskite crystal from a non-optically active phase to an optically active phase.

[0008] The radiation flux density of the laser is determined according to the Stefan-Boltzmann law.

[0009] The present invention adopts a laser annealing process to replace the traditional thermal annealing process, which can provide a higher radiation flux injection rate in a shorter time, thereby significantly shortening the annealing time, improving the annealing efficiency and temperature accuracy. In addition, laser annealing can locally heat the annealing area to be annealed, realizing selective annealing, effectively avoiding the degradation of the perovskite film caused by long-term annealing in the air, and is conducive to the preparation of perovskite photovoltaic devices with complex structures.

[0010] In addition, the laser annealing process can determine the radiation flux density of the laser according to the Stefan-Boltzmann law, and then determine the energy required for optimal thin film growth. Post-processing through laser annealing can fully protect the flexible substrate and the transmission layer that is not suitable for long-term annealing, ultimately ensuring the stability and reliability of the photovoltaic device.

[0011] Preferably, the annealing method is carried out in air, and the humidity of the air is 10-50% and the temperature is 20-30°C.

[0012] Preferably, the calculation formula of the Stefan-Boltzmann law is:

[0013] Q = k·σ·T 4 (1)

[0014] In the above formula, Q is the radiation flux density, that is, the radiation flux per unit area, W / cm²; σ is the Stefan-Boltzmann constant, which is equal to 5.67×10 −8 W / (m²·K 4 ), T is the absolute temperature of the object, K, and k is the emissivity of the object, that is, the radiation ability of the object relative to a black body, which here refers to the emissivity of the hot plate.

[0015] Preferably, the laser comprises blue light with a wavelength of 455 nm.

[0016] Preferably, the radiation flux density of the laser is 1-160 W / cm².

[0017] Preferably, the radiation energy received by the perovskite photovoltaic device is calculated using the following formula:

[0018] E = Q t S (2)

[0019] In the above formula, E is the radiation energy, J; t is the annealing time, s; S is the annealing area, cm².

[0020] Preferably, the perovskite photovoltaic device includes any one of a mixed-cation system perovskite photovoltaic device, a FAPbI3 system perovskite photovoltaic device, a MAPbI3 system perovskite photovoltaic device or a CsPbI3 system perovskite photovoltaic device.

[0021] Preferably, during the annealing process of the mixed-cation system perovskite photovoltaic device, the laser radiation flux density Q is 20W / cm², and the annealing time t is 15-25s.

[0022] Preferably, during the annealing process of the FAPbI3 system perovskite photovoltaic device, the laser radiation flux density Q is 20W / cm², and the annealing time t is 20-30s.

[0023] Preferably, during the annealing process of the MAPbI3 system perovskite photovoltaic device, the laser radiation flux density Q is 20W / cm², and the annealing time t is 5-15s.

[0024] Preferably, during the annealing process of the CsPbI3 system perovskite photovoltaic device, the laser radiation flux density Q is 20W / cm², and the annealing time t is 25-35s.

[0025] In a second aspect, the present invention provides a method for preparing a perovskite photovoltaic device, the preparation method comprising the annealing method of the perovskite photovoltaic device as described in the first aspect.

[0026] In a third aspect, the present invention provides a perovskite photovoltaic device, wherein the perovskite photovoltaic device is prepared by the preparation method described in the second aspect, or the perovskite photovoltaic device is annealed by the annealing method described in the first aspect.

[0027] In a fourth aspect, the present invention provides an application of a perovskite photovoltaic device, wherein the perovskite photovoltaic device is used in the fields of construction, electronics, aviation or military.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) The present invention adopts a laser annealing process to replace the traditional thermal annealing process, which can provide a higher radiation flux injection rate in a shorter time, thereby significantly shortening the annealing time, improving the annealing efficiency and temperature accuracy. In addition, laser annealing can locally heat the annealing area to be annealed, realizing selective annealing, effectively avoiding the degradation of the perovskite film caused by long-term annealing in the air, and is conducive to the preparation of perovskite photovoltaic devices with complex structures.

[0030] (2) The laser annealing process can determine the radiation flux density of the laser according to the Stefan-Boltzmann law, and then determine the energy required for optimal thin film growth. Post-processing through laser annealing can fully protect the flexible substrate and the transmission layer that is not suitable for long-term annealing, ultimately ensuring the stability and reliability of the photovoltaic device. DETAILED DESCRIPTION

[0031] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0032] A certain embodiment of the present invention provides an annealing method for a perovskite photovoltaic device, the annealing method comprising: placing the perovskite photovoltaic device on a hot stage, and using a laser to locally heat the area to be annealed of the perovskite photovoltaic device, thereby transforming the perovskite crystal from a non-optically active phase to an optically active phase.

[0033] The radiation flux density of the laser is determined according to the Stefan-Boltzmann law.

[0034] The present invention adopts a laser annealing process to replace the traditional thermal annealing process, which can provide a higher radiation flux injection rate in a shorter time, thereby significantly shortening the annealing time, improving the annealing efficiency and temperature accuracy. In addition, laser annealing can locally heat the annealing area to be annealed, realizing selective annealing, effectively avoiding the degradation of the perovskite film caused by long-term annealing in the air, and is conducive to the preparation of perovskite photovoltaic devices with complex structures.

[0035] In addition, the laser annealing process can determine the radiation flux density of the laser according to the Stefan-Boltzmann law, and then determine the energy required for optimal thin film growth. Post-processing through laser annealing can fully protect the flexible substrate and the transmission layer that is not suitable for long-term annealing, ultimately ensuring the stability and reliability of the photovoltaic device.

[0036] In some embodiments, the annealing method is carried out in air, and the humidity of the air is 10-50%, for example, it can be 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45% or 50%, and the temperature is 20-30°C, for example, it can be 20°C, 21°C, 22°C, 23°C, 24°C, 25°C, 26°C, 27°C, 28°C, 29°C or 30°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0037] The present invention performs annealing in an air atmosphere, and the conditions are relatively loose, which is conducive to commercial application.

[0038] In some embodiments, the calculation formula of the Stefan-Boltzmann law is:

[0039] Q = k·σ·T 4 (1)

[0040] In the above formula, Q is the radiation flux density, that is, the radiation flux per unit area, W / cm²; σ is the Stefan-Boltzmann constant, which is equal to 5.67×10 −8 W / (m²·K4 ), T is the absolute temperature of the object, K, and k is the emissivity of the object, that is, the radiation ability of the object relative to a black body, which here refers to the emissivity of the hot plate.

[0041] In some embodiments, the emissivity k of the heat stage is specifically 0.98.

[0042] In some embodiments, the laser light includes blue light having a wavelength of 455 nm.

[0043] The present invention specifically selects blue light with a wavelength of 455nm as the laser for annealing treatment. This is because blue light has a shorter wavelength, a smaller beam diffraction limit, and a stronger focusing ability, so that the laser can be more accurately focused on the area to be annealed, achieving local heating of a specific area, that is, achieving selective annealing.

[0044] In addition, compared with other types of lasers, perovskite films have better absorption effects on blue light, which can promote the growth of perovskite crystals with better quality.

[0045] In some embodiments, the radiation flux density of the laser is 1-160W / cm², for example, it can be 1W / cm², 10W / cm², 20W / cm², 30W / cm², 40W / cm², 50W / cm², 60W / cm², 70W / cm², 80W / cm², 90W / cm², 100W / cm², 110W / cm², 120W / cm², 130W / cm², 140W / cm², 150W / cm² or 160W / cm², but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0046] In the present invention, the radiation flux density of the laser is set by a computer, and the specific value can be accurately adjusted according to actual conditions.

[0047] In some embodiments, the radiation energy received by the perovskite photovoltaic device is calculated using the following formula:

[0048] E = Q t S (2)

[0049] In the above formula, E is the radiation energy, J; t is the annealing time, s; S is the annealing area, cm².

[0050] In some embodiments, the perovskite photovoltaic device includes any one of a mixed-cation system perovskite photovoltaic device, a FAPbI3 system perovskite photovoltaic device, a MAPbI3 system perovskite photovoltaic device, or a CsPbI3 system perovskite photovoltaic device.

[0051] In some embodiments, during the annealing process of the mixed-cation system perovskite photovoltaic device, the radiation flux density Q of the laser is 20 W / cm², and the annealing time t is 15-25 s, for example, it can be 15 s, 16 s, 17 s, 18 s, 19 s, 20 s, 21 s, 22 s, 23 s, 24 s or 25 s, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0052] In some embodiments, during the annealing process of the FAPbI3 system perovskite photovoltaic device, the laser radiation flux density Q is 20 W / cm², and the annealing time t is 20-30 s, for example, it can be 20 s, 21 s, 22 s, 23 s, 24 s, 25 s, 26 s, 27 s, 28 s, 29 s or 30 s, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0053] In some embodiments, during the annealing process of the MAPbI3 system perovskite photovoltaic device, the laser radiation flux density Q is 20W / cm², and the annealing time t is 5-15s, for example, it can be 5s, 6s, 7s, 8s, 9s, 10s, 11s, 12s, 13s, 14s or 15s, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0054] In some embodiments, during the annealing process of the CsPbI3 system perovskite photovoltaic device, the laser radiation flux density Q is 20W / cm², and the annealing time t is 25-35s, for example, it can be 25s, 26s, 27s, 28s, 29s, 30s, 31s, 32s, 33s, 34s ​​or 35s, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0055] The present invention defines different annealing times for different systems of perovskite photovoltaic devices, thereby determining the energy required for optimal film growth, so that the crystallinity of the perovskite film reaches the optimal state. If the annealing time is too long, since perovskite is a lead-iodine soft lattice structure, excessive annealing will cause the perovskite structure to collapse, and then cause the components to precipitate; if the annealing time is too short, it will lead to incomplete crystallization of the film, residual solvents and impurities, affecting the stability and photoelectric conversion efficiency of the photovoltaic device.

[0056] A certain embodiment of the present invention provides a method for preparing a perovskite photovoltaic device, wherein the preparation method includes the annealing method of the perovskite photovoltaic device described in any of the above embodiments.

[0057] A certain embodiment of the present invention provides a perovskite photovoltaic device, wherein the perovskite photovoltaic device is prepared by the preparation method described in any of the above embodiments, or the perovskite photovoltaic device is annealed by the annealing method described in any of the above embodiments.

[0058] A certain embodiment of the present invention provides an application of a perovskite photovoltaic device, wherein the perovskite photovoltaic device is used in the fields of construction, electronics, aviation or military.

[0059] The numerical range described in the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0060] Example 1

[0061] This embodiment provides a mixed-cation system perovskite photovoltaic device and a preparation method thereof, the preparation method comprising the following steps:

[0062] (1) Dissolve 7.8 mg MABr, 16.2 mg MACl, 13.2 mg CsI, 222.5 mg FAI, 20 mg PbBr2 and 632 mg PbI2 in a mixed solution of 800 μL DMF and 200 μL DMSO to obtain a mixed cation system perovskite precursor solution;

[0063] (2) The ITO glass substrate with laser pattern was ultrasonically cleaned in deionized water, acetone and isopropanol for 20 minutes, and then dried with nitrogen gas flow. The ITO glass substrate was then treated with ozone for 10 minutes. A SnO2 precursor solution (SnO2 colloid / deionized water, volume ratio of 1:3) was used for meniscus printing deposition at room temperature. The blade speed was controlled to be 10 mm / s, the distance between the scraper and the substrate was 50 μm, and the substrate heating temperature was 40°C. The substrate with SnO2 coating was then annealed in air at 150°C for 30 minutes.

[0064] (3) Using the mixed-cation system perovskite precursor solution to perform meniscus printing deposition on the surface of the substrate with SnO2 coating, the blade speed is controlled to be 10 mm / s, and the distance between the scraper and the substrate is 150 μm; the printed perovskite wet film is placed in a vacuum box, the vacuum degree is controlled to be 310 Pa, and the perovskite semi-dry film is taken out after vacuum flash evaporation for 8 seconds;

[0065] (4) Place the semi-dry perovskite film on a hot stage, and use laser (blue light with a wavelength of 455 nm) to locally heat the annealing area of ​​the semi-dry perovskite film in air (humidity 30%, temperature 25°C). Set the laser radiation flux density Q to 20 W / cm², the annealing time t to 20 s, start the laser annealing program, anneal the semi-dry perovskite film, and obtain a perovskite film.

[0066] (5) Mix 28.8 μL of 4-tert-butylpyridine and 520 mg / mL of Li-TFSI / acetonitrile to obtain a 72.3 mg / mL spiro-OMeTAD / CB solution, which was printed on the surface of the perovskite film at a printing speed of 5 mm / s.

[0067] (6) After the perovskite film is dried, the −4 Pa under high vacuum conditions to evaporate silver contact electrodes (0.04 cm 2 The device is 100nm), and the preparation of the photovoltaic device is completed.

[0068] Example 2

[0069] This embodiment provides a FAPbI3 system perovskite photovoltaic device and a preparation method thereof, wherein the preparation method comprises the following steps:

[0070] (1) Dissolve 258 mg FAI and 715 mg PbI2 in a mixed solution of 800 μL DMF and 200 μL DMSO to obtain a FAPbI3 system perovskite precursor solution;

[0071] (2) The ITO glass substrate with laser pattern was ultrasonically cleaned in deionized water, acetone and isopropanol for 20 minutes, and then dried with nitrogen gas flow. The ITO glass substrate was then treated with ozone for 10 minutes. A SnO2 precursor solution (SnO2 colloid / deionized water, volume ratio of 1:3) was used for meniscus printing deposition at room temperature. The blade speed was controlled to be 10 mm / s, the distance between the scraper and the substrate was 50 μm, and the substrate heating temperature was 40°C. The substrate with SnO2 coating was then annealed in air at 150°C for 30 minutes.

[0072] (3) Using the FAPbI3 system perovskite precursor solution to perform meniscus printing deposition on the surface of the substrate with SnO2 coating, the blade speed was controlled to be 10 mm / s, and the distance between the scraper and the substrate was 150 μm; the printed perovskite wet film was placed in a vacuum box, the vacuum degree was controlled to be 310 Pa, and the perovskite semi-dry film was taken out after vacuum flash evaporation for 8 seconds;

[0073] (4) Place the semi-dry perovskite film on a hot stage, and use laser (blue light with a wavelength of 455 nm) to locally heat the annealing area of ​​the semi-dry perovskite film in air (humidity 30%, temperature 25°C). Set the laser radiation flux density Q to 20 W / cm², the annealing time t to 25 s, start the laser annealing program, anneal the semi-dry perovskite film, and obtain a perovskite film.

[0074] (5) Mix 28.8 μL of 4-tert-butylpyridine and 520 mg / mL of Li-TFSI / acetonitrile to obtain a 72.3 mg / mL spiro-OMeTAD / CB solution, which was printed on the surface of the perovskite film at a printing speed of 5 mm / s.

[0075] (6) After the perovskite film is dried, the −4 Pa under high vacuum conditions to evaporate silver contact electrodes (0.04 cm 2 The device is 100nm), and the preparation of the photovoltaic device is completed.

[0076] Example 3

[0077] This embodiment provides a MAPbI3 system perovskite photovoltaic device and a preparation method thereof, wherein the preparation method comprises the following steps:

[0078] (1) Dissolve 238 mg MAI and 700 mg PbI2 in a mixed solution of 800 μL DMF and 200 μL DMSO to obtain a MAPbI3 system perovskite precursor solution;

[0079] (2) The ITO glass substrate with laser pattern was ultrasonically cleaned in deionized water, acetone and isopropanol for 20 minutes, and then dried with nitrogen gas flow. The ITO glass substrate was then treated with ozone for 10 minutes. A SnO2 precursor solution (SnO2 colloid / deionized water, volume ratio of 1:3) was used for meniscus printing deposition at room temperature. The blade speed was controlled to be 10 mm / s, the distance between the scraper and the substrate was 50 μm, and the substrate heating temperature was 40°C. The substrate with SnO2 coating was then annealed in air at 150°C for 30 minutes.

[0080] (3) Using the MAPbI3 system perovskite precursor solution to perform meniscus printing deposition on the surface of a substrate with a SnO2 coating, the blade speed was controlled to be 10 mm / s, and the distance between the scraper and the substrate was 150 μm; the printed perovskite wet film was placed in a vacuum box, the vacuum degree was controlled to be 310 Pa, and the perovskite semi-dry film was taken out after vacuum flash evaporation for 8 seconds;

[0081] (4) Place the semi-dry perovskite film on a hot stage, and use laser (blue light with a wavelength of 455 nm) to locally heat the annealing area of ​​the semi-dry perovskite film in air (humidity 30%, temperature 25°C). Set the laser radiation flux density Q to 20 W / cm², the annealing time t to 10 s, start the laser annealing program, anneal the semi-dry perovskite film, and obtain a perovskite film.

[0082] (5) Mix 28.8 μL of 4-tert-butylpyridine and 520 mg / mL of Li-TFSI / acetonitrile to obtain a 72.3 mg / mL spiro-OMeTAD / CB solution, which was printed on the surface of the perovskite film at a printing speed of 5 mm / s.

[0083] (6) After the perovskite film is dried, the −4 Pa under high vacuum conditions to evaporate silver contact electrodes (0.04 cm 2 The device is 100nm), and the preparation of the photovoltaic device is completed.

[0084] Example 4

[0085] This embodiment provides a CsPbI3 system perovskite photovoltaic device and a preparation method thereof, the preparation method comprising the following steps:

[0086] (1) Dissolve 338 mg CsI and 710 mg PbI2 in a mixed solution of 800 μL DMF and 200 μL DMSO to obtain a CsPbI3 system perovskite precursor solution;

[0087] (2) The ITO glass substrate with laser pattern was ultrasonically cleaned in deionized water, acetone and isopropanol for 20 minutes, and then dried with nitrogen gas flow. The ITO glass substrate was then treated with ozone for 10 minutes. A SnO2 precursor solution (SnO2 colloid / deionized water, volume ratio of 1:3) was used for meniscus printing deposition at room temperature. The blade speed was controlled to be 10 mm / s, the distance between the scraper and the substrate was 50 μm, and the substrate heating temperature was 40°C. The substrate with SnO2 coating was then annealed in air at 150°C for 30 minutes.

[0088] (3) Using CsPbI3 system perovskite precursor solution to perform meniscus printing deposition on the surface of a substrate with a SnO2 coating, the blade speed is controlled to be 10 mm / s, and the distance between the scraper and the substrate is 150 μm; the printed perovskite wet film is placed in a vacuum box, the vacuum degree is controlled to be 310 Pa, and the perovskite semi-dry film is taken out after vacuum flash evaporation for 8 seconds;

[0089] (4) Place the semi-dry perovskite film on a hot stage, and use laser (blue light with a wavelength of 455 nm) to locally heat the annealing area of ​​the semi-dry perovskite film in air (humidity 30%, temperature 25°C). Set the laser radiation flux density Q to 20 W / cm², the annealing time t to 30 s, start the laser annealing program, anneal the semi-dry perovskite film, and obtain a perovskite film.

[0090] (5) Mix 28.8 μL of 4-tert-butylpyridine and 520 mg / mL of Li-TFSI / acetonitrile to obtain a 72.3 mg / mL spiro-OMeTAD / CB solution, which was printed on the surface of the perovskite film at a printing speed of 5 mm / s.

[0091] (6) After the perovskite film is dried, the −4 Pa under high vacuum conditions to evaporate silver contact electrodes (0.04 cm 2 The device is 100nm), and the preparation of the photovoltaic device is completed.

[0092] Comparative Example 1

[0093] This comparative example provides a mixed-cation system perovskite photovoltaic device and a preparation method thereof, except that step (4) is changed to: placing the perovskite semi-dry film on a hot stage, heating it to 100° C. in an air atmosphere and annealing it for 50 minutes to obtain a perovskite film; the remaining steps and conditions are the same as those in Example 1, and thus are not described in detail here.

[0094] After calculation, the radiation flux density Q of thermal annealing of Example 1 is Q = k·σ·T 4 =0.98×5.67×10 -8 ×373.15 4 =1077W / m 2 ≈0.10W / cm 2 .

[0095] The annealing area is 100cm 2 Taking the perovskite film as an example, the radiation energy received by the perovskite film obtained in Example 1 is E=Q·t·S=20×20×100=40000J, while the radiation energy received by the perovskite film obtained in Comparative Example 1 is E=Q·t·S=0.10×3000×100=30000J.

[0096] It can be seen that compared with the thermal annealing of Comparative Example 1, the laser annealing of Example 1 can provide a higher radiation flux injection rate and an energy level comparable to thermal annealing in a shorter time, thereby ensuring the processing of high-quality crystals within a specified time frame.

[0097] Comparative Example 2

[0098] This comparative example provides a FAPbI3 system perovskite photovoltaic device and a preparation method thereof, except that step (4) is changed to: placing the perovskite semi-dry film on a hot stage, heating it to 150°C in an air atmosphere and annealing it for 30 minutes to obtain a perovskite film; the remaining steps and conditions are the same as those in Example 2, and therefore are not described in detail here.

[0099] After calculation, the radiation flux density Q of thermal annealing in Example 2 is Q = k·σ·T 4 =0.98×5.67×10 -8 ×423.15 4 =1782W / m 2 ≈0.18W / cm 2 .

[0100] The annealing area is 100cm 2 Taking the perovskite film as an example, the radiation energy received by the perovskite film obtained in Example 2 is E=Q·t·S=20×25×100=50000J, while the radiation energy received by the perovskite film obtained in Comparative Example 2 is E=Q·t·S=0.18×1800×100=32400J.

[0101] It can be seen that compared with the thermal annealing of Comparative Example 2, the laser annealing of Example 2 can provide a higher radiation flux injection rate and an energy level comparable to thermal annealing in a shorter time, thereby ensuring the processing of high-quality crystals within a specified time frame.

[0102] Comparative Example 3

[0103] This comparative example provides a MAPbI3 system perovskite photovoltaic device and a preparation method thereof, except that step (4) is changed to: placing the perovskite semi-dry film on a hot stage, heating it to 100°C in an air atmosphere and annealing it for 10 minutes to obtain a perovskite film; the remaining steps and conditions are the same as those in Example 3, and therefore are not described in detail here.

[0104] After calculation, the radiation flux density Q of thermal annealing in Example 3 is Q = k·σ·T 4 =0.98×5.67×10 -8 ×373.15 4 =1077W / m 2 ≈0.10W / cm 2 .

[0105] The annealing area is 100cm 2Taking the perovskite film as an example, the radiation energy received by the perovskite film obtained in Example 3 is E=Q·t·S=20×10×100=20000J, while the radiation energy received by the perovskite film obtained in Comparative Example 3 is E=Q·t·S=0.10×600×100=6000J.

[0106] It can be seen that compared with the thermal annealing of Comparative Example 3, the laser annealing of Example 3 can provide a higher radiation flux injection rate and an energy level comparable to thermal annealing in a shorter time, thereby ensuring the processing of high-quality crystals within a specified time frame.

[0107] Comparative Example 4

[0108] This comparative example provides a CsPbI3 system perovskite photovoltaic device and a preparation method thereof, except that step (4) is changed to: placing the perovskite semi-dry film on a hot stage, heating it to 200°C in an air atmosphere and annealing it for 20 minutes to obtain a perovskite film; the remaining steps and conditions are the same as those in Example 4, and therefore are not described in detail here.

[0109] After calculation, the radiation flux density Q of thermal annealing in Example 4 is Q = k·σ·T 4 =0.98×5.67×10 -8 ×473.15 4 =2785W / m 2 ≈0.28W / cm 2 .

[0110] The annealing area is 100cm 2 Taking the perovskite film as an example, the radiation energy received by the perovskite film obtained in Example 4 is E=Q·t·S=20×30×100=60000J, while the radiation energy received by the perovskite film obtained in Comparative Example 4 is E=Q·t·S=0.28×1200×100=33600J.

[0111] It can be seen that compared with the thermal annealing of Comparative Example 4, the laser annealing of Example 4 can provide a higher radiation flux injection rate and an energy level equivalent to thermal annealing in a shorter time, thereby ensuring the processing of high-quality crystals within a specified time frame.

[0112] Performance Testing

[0113] The perovskite photovoltaic devices obtained in Examples 1-4 and Comparative Examples 1-4 were tested for open circuit voltage (Voltage), short circuit current (Jsc), fill factor (Fill Factor) and photoelectric conversion efficiency (PCE), respectively. The relevant test results are shown in Table 1 below.

[0114] Table 1

[0115]

[0116] It can be seen from Table 1 that for perovskite photovoltaic devices of different systems, compared with the traditional thermal annealing process, the photovoltaic devices obtained by the laser annealing process provided by the present invention are improved to varying degrees in terms of open circuit voltage, short circuit current, fill factor and photoelectric conversion efficiency.

[0117] It can be seen that the present invention adopts laser annealing process to replace the traditional thermal annealing process, which can provide a higher radiation flux injection rate in a shorter time, thereby significantly shortening the annealing time, improving the annealing efficiency and temperature accuracy, and laser annealing can locally heat the annealing area to be annealed, realizing selective annealing, effectively avoiding the degradation of the perovskite film caused by long-term annealing in the air, and is conducive to the preparation of perovskite photovoltaic devices with complex structures.

[0118] In addition, the laser annealing process can determine the radiation flux density of the laser according to the Stefan-Boltzmann law, and then determine the energy required for optimal thin film growth. Post-processing through laser annealing can fully protect the flexible substrate and the transmission layer that is not suitable for long-term annealing, ultimately ensuring the stability and reliability of the photovoltaic device.

[0119] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention are within the protection scope and disclosure scope of the present invention.

Claims

1. A method for annealing a perovskite photovoltaic device, characterized in that: The annealing method comprises: placing the perovskite photovoltaic device on a hot stage, locally heating the area to be annealed of the perovskite photovoltaic device using a laser, thereby transforming the perovskite crystal from a non-optically active phase to an optically active phase; Wherein, the radiation flux density of the laser is determined according to the Stefan-Boltzmann law; The perovskite photovoltaic device includes any one of a mixed-cation system perovskite photovoltaic device, a FAPbI3 system perovskite photovoltaic device, a MAPbI3 system perovskite photovoltaic device or a CsPbI3 system perovskite photovoltaic device; During the annealing process of the mixed-cation system perovskite photovoltaic device, the laser radiation flux density 20W / cm², annealing time 15-25s; During the annealing process of the FAPbI3 system perovskite photovoltaic device, the radiation flux density of the laser 20W / cm², annealing time 20-30s; During the annealing process of the MAPbI3 system perovskite photovoltaic device, the radiation flux density of the laser 20W / cm², annealing time 5-15s; During the annealing process of the CsPbI3 system perovskite photovoltaic device, the radiation flux density of the laser 20W / cm², annealing time 25-35s.

2. The annealing method of the perovskite photovoltaic device according to claim 1, characterized in that: The annealing method is carried out in air, and the humidity of the air is 10-50% and the temperature is 20-30°C.

3. The annealing method of the perovskite photovoltaic device according to claim 1 or 2, characterized in that: The calculation formula of the Stefan-Boltzmann law is: （1） In the above formula, is the radiation flux density, that is, the radiation flux per unit area, W / cm²; is the Stefan-Boltzmann constant, equal to 5.67×10 −8 W / (m²·K 4 ); is the absolute temperature of the object, K; is the emissivity of the object, that is, the radiation ability of the object relative to a black body. Here it refers to the emissivity of the hot stage.

4. The annealing method of the perovskite photovoltaic device according to claim 3, characterized in that: The laser includes blue light with a wavelength of 455nm; And / or, the radiation flux density of the laser is 1-160W / cm².

5. The annealing method of the perovskite photovoltaic device according to claim 3, characterized in that: The radiation energy received by the perovskite photovoltaic device is calculated using the following formula: （2） In the above formula, is the radiation energy, J; is the annealing time, s; is the annealing area, cm².

6. A method for preparing a perovskite photovoltaic device, characterized in that: The preparation method comprises the annealing method of the perovskite photovoltaic device according to any one of claims 1 to 5.

7. A perovskite photovoltaic device, characterized in that: The perovskite photovoltaic device is prepared by the preparation method as claimed in claim 6, or the perovskite photovoltaic device is annealed by the annealing method as claimed in any one of claims 1 to 5.

8. An application of the perovskite photovoltaic device as claimed in claim 7, characterized in that: The perovskite photovoltaic device is used in the fields of construction, electronics, aviation or military.

Images