A laser-sintered perovskite solar cell and its preparation method

Abstract

The present invention provides a laser-sintered perovskite solar cell and a preparation method thereof. The preparation method of the laser-sintered perovskite solar cell comprises the following steps: preparing a hole-blocking layer on a conductive substrate; preparing a mesoporous nanocrystal layer on the hole-blocking layer and sintering the mesoporous nanocrystal layer by laser; preparing an insulating spacer layer on the mesoporous nanocrystal layer; preparing a counter electrode layer on the insulating spacer layer and sintering the insulating spacer layer and the counter electrode layer; and coating a perovskite precursor solution on the counter electrode layer to obtain the laser-sintered perovskite solar cell. The preparation method of the laser-sintered perovskite solar cell of the present invention utilizes the instantaneous high temperature generated by the laser to realize the preparation of a large-area mesoporous film in a very short time, greatly reducing the energy consumption, shortening the processing time, improving the preparation efficiency, improving the product preparation repeatability, and reducing the requirements for the processing environment.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cell preparation, and in particular to a laser sintered perovskite solar cell and a preparation method thereof. Background Art

[0002] A mesoscopic perovskite solar cell is a solar cell that uses a perovskite-type organometallic halide semiconductor as a light-absorbing material. Its working principle is generally as follows: First, sunlight passes through the glass and the conductive substrate film and enters the interior of the cell. Then, the perovskite active light-absorbing material absorbs photons and forms excitons. Since the dissociation of excitons requires a certain exciton dissociation energy, some excitons are excited to generate electron-hole pairs and become free carriers. The electrons are transported through the perovskite layer to the mesoporous nanocrystal layer and are finally collected at the conductive substrate, while the holes are introduced into the counter electrode layer through the perovskite material and are collected. Finally, the transport and transfer of carriers form a voltage at both ends of the cell and generate a current in the external circuit.

[0003] Currently, the preparation process of mesoscopic perovskite solar cells is mainly as follows: First, a hole blocking layer is sprayed on the conductive glass, and then a mesoporous nanocrystal layer, an insulating spacer layer, and a counter electrode layer are printed on the hole blocking layer in sequence. After printing, the required mesoporous structure needs to be obtained in each layer of the film through high-temperature sintering in sequence. Finally, a perovskite precursor solution is drop-coated on the surface of the counter electrode layer, and the perovskite precursor solution enters the mesoporous structures of each layer inside the cell through capillary action to complete perovskite crystallization and realize the preparation of the device.

[0004] In the above preparation process, the formation of the mesoporous structure is achieved through high-temperature sintering, and there are many limitations in the current mesoporous process of the film. Taking the titanium dioxide layer of the mesoporous nanocrystal layer as an example, traditional high-temperature hot stage sintering only removes organic components such as pore-forming agents and solvents, and no high-quality lattice connection is formed between titanium dioxide grains; moreover, the film needs to be sintered at a high temperature for a long time to obtain the required mesoporous structure, with high energy consumption, low preparation efficiency, and long process time for the heating and cooling of the sintering furnace; in addition, since high-temperature sintering requires maintaining a stable temperature for a long time, it has high requirements for the processing environment; and it is difficult to achieve an absolute temperature stable state, and temperature fluctuations will cause uneven heating during film annealing, generating internal stress and affecting the repeatability of device preparation; and the film itself is prone to react with water and oxygen in the air, and its reaction intensifies under a long-term high-temperature state, greatly hindering the improvement of device efficiency. Such problems are more obvious after the device area is enlarged and are problems that need to be solved urgently for the transfer of mesoscopic perovskite solar cells from devices to industrial scale. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a laser-sintered perovskite solar cell and its preparation method. The high-energy laser beam promotes the melting and bonding between titanium dioxide grains, realizes better lattice connection of titanium dioxide, and further constructs an electrical interconnection structure between grains to promote the efficient transfer of carriers. At the same time, laser sintering eliminates organic components such as solvents and binders in the slurry, ensuring the mesoporous structure of the film. It solves the technical problems in the existing high-temperature sintering process, such as long film sintering time, large energy consumption, low preparation efficiency, high requirements for processing environment, poor preparation repeatability, and serious charge recombination in devices.

[0006] To solve the above technical problems, the technical solution of the present invention is as follows:

[0007] A preparation method of a laser-sintered perovskite solar cell includes the following steps:

[0008] (1) Prepare a hole blocking layer on a conductive substrate;

[0009] (2) Prepare a mesoporous nanocrystal layer on the hole blocking layer obtained in step (1), and sinter the mesoporous nanocrystal layer by laser;

[0010] (3) Prepare an insulating spacer layer on the mesoporous nanocrystal layer obtained in step (2);

[0011] (4) Prepare a counter electrode layer on the insulating spacer layer obtained in step (3), and sinter the insulating spacer layer and the counter electrode layer;

[0012] (5) Coat a perovskite precursor solution on the counter electrode layer obtained in step (4) to obtain a laser-sintered perovskite solar cell.

[0013] Preferably, in step (2), one of an ultraviolet laser, an infrared laser, and a visible light laser is used for laser sintering.

[0014] Preferably, in step (2), the laser wavelength for laser sintering is 0.35 - 10.8 μm;

[0015] Optionally, the laser power of the laser sintering is 0.08 - 275 W;

[0016] Optionally, the focal length of the laser sintering is 600 ± 40 mm;

[0017] Optionally, the filling method of the laser etching line for laser sintering is one of parallel same direction, parallel opposite direction, bow-shaped connection, and cross connection;

[0018] Optionally, the filling spacing of the laser etching line for laser sintering is 0.008 - 0.05 mm;

[0019] Optionally, the output power percentage of the laser for laser sintering is 25 - 75%;

[0020] Optionally, the laser frequency of the laser sintering is 10 - 85 kHz;

[0021] Optionally, the laser scanning speed of the laser sintering is 20 - 8000 mm / s;

[0022] Optionally, the number of laser scanning passes for the laser sintering is 1 - 10 passes;

[0023] Optionally, the laser scanning area of the laser sintering is 0.8 - 1024 cm 2 .

[0024] It should be noted that the laser wavelength, laser power, focal length, output power percentage of the laser, filling spacing, scanning speed, and laser frequency have a great influence on the effect of laser sintering.

[0025] Preferably, in step (2), laser sintering is carried out under an oxygen or ozone volume fraction of 45 - 99%.

[0026] Preferably, in step (1), a hole blocking layer is prepared on the conductive substrate by spraying;

[0027] Among them, the conductive substrate is one or more of conductive glass, metal oxides, carbon nanomaterials, and conductive polymers; the hole blocking layer is one or more of titanium dioxide and aluminum oxide;

[0028] Optionally, the thickness of the hole blocking layer is 1 - 50 nm.

[0029] Preferably, in step (2), preparing the mesoporous nanocrystalline layer includes the following steps: printing the mesoporous nanocrystalline layer slurry onto the hole blocking layer by screen printing, and drying to obtain the mesoporous nanocrystalline layer;

[0030] Among them, the mesoporous nanocrystalline layer slurry is one or more of titanium dioxide, tin dioxide, zinc oxide, barium stannate, strontium titanate, and nickel oxide;

[0031] Optionally, the thickness of the mesoporous nanocrystalline layer is 10 - 8000 nm.

[0032] Preferably, in step (3), preparing the insulating spacer layer includes the following steps: printing the insulating spacer layer slurry onto the mesoporous nanocrystalline layer by screen printing, and drying to obtain the insulating spacer layer;

[0033] Among them, the insulating spacer layer slurry is one or more of zirconium dioxide, aluminum oxide, and silicon dioxide;

[0034] Optionally, the thickness of the insulating spacer layer is 1-100 um.

[0035] Preferably, in step (4), preparing the counter electrode layer includes the following steps: screen-printing the counter electrode layer paste onto the insulating spacer layer and drying to obtain the counter electrode layer;

[0036] Wherein, the counter electrode layer paste is one or more of carbon black, graphite, carbon nanotubes, activated carbon, graphene, graphyne;

[0037] Optionally, the thickness of the counter electrode layer is 1-100 um;

[0038] Optionally, in step (4), the insulating spacer layer and the counter electrode layer are sintered at 300-400 °C for 30-50 min.

[0039] The present invention also provides a laser-sintered perovskite solar cell obtained by the preparation method of the laser-sintered perovskite solar cell described above.

[0040] Preferably, the laser-sintered perovskite solar cell includes a conductive substrate, a hole blocking layer, a mesoporous nanocrystal layer, an insulating spacer layer, and a counter electrode layer arranged in sequence, and perovskite crystallization is located in the mesoporous nanocrystal layer, the insulating spacer layer, and the counter electrode layer.

[0041] The above solution of the present invention has at least the following beneficial effects:

[0042] (1) The preparation method of the laser-sintered perovskite solar cell of the present invention includes the following steps: preparing a hole blocking layer on a conductive substrate; preparing a mesoporous nanocrystal layer on the hole blocking layer and laser-sintering the mesoporous nanocrystal layer; preparing an insulating spacer layer on the mesoporous nanocrystal layer; preparing a counter electrode layer on the insulating spacer layer and sintering the insulating spacer layer and the counter electrode layer; coating a perovskite precursor solution on the counter electrode layer to obtain a laser-sintered perovskite solar cell. The preparation method of the laser-sintered perovskite solar cell of the present invention utilizes the instantaneous high temperature generated by the laser to promote the interfacial bonding between mesoporous nanocrystals, thereby realizing the lattice connection structure between crystal particles. At the same time, the solvents and organic binders present in the paste are eliminated, and a large-area mesoporous film can be prepared in a very short time, replacing high-temperature sintering. This greatly reduces energy consumption, shortens the processing time, improves the preparation efficiency, improves the product preparation repeatability, reduces the requirements for the processing environment, is more conducive to the large-area and flexible preparation of devices, and further promotes the industrial development of mesoscopic perovskite solar cells.

[0043] Specifically, the laser excitation and generation require small energy consumption. High-energy lasers can be generated with relatively low energy, and the energy utilization rate is high. The laser excitation, generation, cut-off, and shutdown do not require preheating and preparation time. Moreover, due to the instantaneous high temperature of the laser, the mesoporous film can be fully sintered in an extremely short time, greatly shortening the required processing time. Because the laser output has strong stability and a fast preparation speed, the repeatability of product preparation is ensured. The laser sintering method abandons the use of a traditional high-temperature hot stage. The laser can generate an instantaneous high temperature and has a fast preparation speed. Therefore, the operable range of the temperature and humidity of the environment for device preparation is increased, breaking the limitation of the solid-state substrate of perovskite solar cells. The range affected by heat is small, reducing the environmental requirements for processing, which is very suitable for the application and preparation of flexible substrate devices. Thus, the preparation of all-low-temperature flexible devices can be achieved breakthroughly. The laser beam is concentrated and has high processing precision, making it more suitable for the treatment of thin films. Laser sintering is clean, energy-saving, time-saving, efficient, and a non-contact method, so it can avoid contaminants during contact sintering.

[0044] (2) In the preparation method of the laser-sintered perovskite solar cell of the present invention, by laser-sintering the mesoporous nanocrystal layer, due to the instantaneous nature of the laser, the grains of the mesoporous nanocrystal layer will form an oxygen-deficient state (metallization) due to rapid sintering, increasing the electron cloud density of the grains and promoting the transport of carriers.

[0045] (3) In the preparation method of the laser-sintered perovskite solar cell of the present invention, when the mesoporous nanocrystal layer is titanium dioxide, when the laser sweeps across a light spot, the titanium dioxide TiO2 crystal particles will not completely melt, which will cause the TiO2 crystal particles to form a solidified body (oxygen-deficient state) containing an unmelted (crystalline state) particle core structure. Therefore, the adjustment of the energy level position of the TiO2 grains is achieved. When oxygen or ozone is introduced during laser sintering, by controlling the oxygen / ozone partial pressure, the outermost layer of the particle core structure returns to the initial crystalline state, thereby changing the position distribution of the oxygen-deficient state in the TiO2 particle shell and forming an ideal multi-layer spherical shell structure with an internal crystalline state, an intermediate oxygen-deficient state, and an external crystalline state in the TiO2 grains.

[0046] (4) The preparation method of the laser-sintered perovskite solar cell of the present invention, by laser-sintering the mesoporous nanocrystal layer, the laser has a small penetration ability, and laser sintering has selectivity for its sintering object. Different substances have different absorption abilities for specific wavelength lasers. By adjusting parameters, sintering of a specified area can be achieved without affecting other parts. Therefore, the upper layer sintering does not affect the lower layer film during preparation, which is beneficial to the construction of the three-layer mesoporous film structure of the mesoscopic perovskite solar cell device. At the same time, the high-energy light beam can achieve the melting and bonding between TiO2 grains (external crystalline state), improve the electron extraction and transport ability of the mesoporous TiO2 layer, and contribute to the transfer of carriers. The present invention adopts the method of laser spot scanning regulation to form the wavy surface topological structure of the film, which is beneficial to realizing the three-dimensional interface contact between the film layers, improving the electron extraction and transport ability of the mesoporous TiO2 layer, thereby obtaining a TiO2 film with high mesoporosity and high conductivity, which is beneficial to the improvement of device efficiency.

[0047] (5) The preparation method of the laser-sintered perovskite solar cell of the present invention, by laser-sintering the mesoporous nanocrystal layer, the unique anisotropic shrinkage behavior of the semiconductor material during laser sintering can reduce the residual stress in the film and then reduce the film thickness, greatly increasing the film porosity and promoting the effective filling and attachment of the perovskite material.

[0048] (6) The preparation method of the laser-sintered perovskite solar cell of the present invention, in step (1) for preparing the hole blocking layer, and in step (4) for sintering the insulating spacer layer and the counter electrode layer, laser sintering can be used, thereby realizing the preparation of a flexible perovskite solar cell with low-temperature and all-laser sintering. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 is a schematic structural diagram of the laser-sintered perovskite solar cell of the present invention;

[0050] Figure 2 is a partially enlarged schematic view of the mesoporous nanocrystal layer of the high-temperature hot stage sintered perovskite solar cell obtained in Comparative Example 2 of the present invention;

[0051] Figure 3 is a partially enlarged schematic view of the mesoporous nanocrystal layer of the laser-sintered perovskite solar cell obtained in Example 1 of the present invention;

[0052] Figure 4 is a partially enlarged schematic view of the particles of the mesoporous nanocrystal layer of the laser-sintered perovskite solar cell obtained in Example 1 of the present invention;

[0053] Among them, 1, conductive substrate; 2, hole blocking layer; 3, mesoporous nanocrystal layer; 4, insulating spacer layer; 5, counter electrode layer. DETAILED DESCRIPTION OF THE INVENTION

[0054] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be fully conveyed to those skilled in the art.

[0055] Example 1

[0056] The preparation method of the laser-sintered perovskite solar cell of this embodiment includes the following steps:

[0057] (1) Take a conductive substrate, place it on a high-temperature hot stage, heat it to 450 °C, and prepare a hole-blocking layer on the conductive substrate by spraying; wherein, the conductive substrate is FTO conductive glass; the hole-blocking layer is titanium dioxide with a thickness of 1 nm.

[0058] (2) Prepare a mesoporous nanocrystal layer on the hole-blocking layer obtained in step (1), print the mesoporous nanocrystal layer slurry onto the hole-blocking layer, and dry it to obtain the mesoporous nanocrystal layer; then, laser-sinter the mesoporous nanocrystal layer under an oxygen volume fraction of 45%;

[0059] Among them, the mesoporous nanocrystal layer slurry is titanium dioxide; the laser wavelength of the laser sintering is 9.2 um; the laser power of the laser sintering is 275 W; the focal length of the laser sintering is 600 ± 40 mm; the filling method of the laser etching line of the laser sintering is parallel and reverse; the filling spacing of the laser etching line of the laser sintering is 0.008 mm; the output power percentage of the laser of the laser sintering is 25%; the laser frequency of the laser sintering is 60 kHz; the laser scanning speed of the laser sintering is 3000 mm / s; the number of laser scanning passes of the laser sintering is 2 passes; the laser scanning area of the laser sintering is 0.8 cm 2 。

[0060] It should be noted that a UV laser, an infrared laser, or a visible light laser can be used for laser sintering. For the purpose of implementing the present invention, the filling method of the laser etching line of the laser sintering, the number of laser scanning passes of the laser sintering, and the laser scanning area of the laser sintering are not unique, and those skilled in the art can select a suitable implementation method according to the situation (not elaborated below).

[0061] (3) Print and prepare an insulating spacer layer on the mesoporous nanocrystal layer obtained in step (2) and dry it; wherein, the insulating spacer layer slurry is zirconia.

[0062] (4) Print and dry the counter electrode layer on the insulating spacer layer obtained in step (3); then place it at 300 °C and sinter for 50 min to form a mesoporous structure for the insulating spacer layer and the counter electrode layer.

[0063] Among them, the counter electrode layer paste is a blend of carbon black and graphite, and carbon black and graphite are mixed according to a mass ratio of 1:1.

[0064] (5) Coat the perovskite precursor solution on the counter electrode layer obtained in step (4). The perovskite precursor solution enters the mesoporous nanocrystal layer, insulating spacer layer, and counter electrode layer with mesoporous structure through capillary action and grows and crystallizes, thereby obtaining a laser-sintered perovskite solar cell.

[0065] Among them, the solute of the perovskite precursor solution has the following general formula: ABX3; A is methylamine; B is lead, and X is iodine.

[0066] The laser-sintered perovskite solar cell obtained by the preparation method of the laser-sintered perovskite solar cell described in this embodiment, as Figure 1 shown, includes a conductive substrate 1, a hole blocking layer 2, a mesoporous nanocrystal layer 3, an insulating spacer layer 4, and a counter electrode layer 5 arranged in sequence, and perovskite crystallization is located in the mesopores of the mesoporous nanocrystal layer, insulating spacer layer, and counter electrode layer.

[0067] Example 2

[0068] The preparation method of the laser-sintered perovskite solar cell in this embodiment includes the following steps:

[0069] (1) Take a conductive substrate, place it on a high-temperature hot stage, heat it to 450 °C, and prepare a hole blocking layer on the conductive substrate by spraying; among them, the conductive substrate is ITO conductive glass; the hole blocking layer is aluminum oxide.

[0070] (2) Prepare a mesoporous nanocrystal layer on the hole blocking layer obtained in step (1) by screen printing and dry it; then, laser sinter the mesoporous nanocrystal layer under an ozone volume fraction of 99%.

[0071] Among them, the mesoporous nanocrystal layer paste is titanium dioxide; the laser wavelength of the laser sintering is 10.8 μm; the laser power of the laser sintering is 0.08 W; the focal length of the laser sintering is 600 ± 40 mm; the filling method of the laser etching line of the laser sintering is parallel and in the same direction; the filling spacing of the laser etching line of the laser sintering is 0.05 mm; the output power percentage of the laser of the laser sintering is 35%; the laser frequency of the laser sintering is 20 kHz; the laser scanning speed of the laser sintering is 3000 mm / s; the number of laser scanning passes of the laser sintering is 10 passes; the laser scanning area of the laser sintering is 1024 cm 2 .

[0072] It should be noted that one of an ultraviolet laser, an infrared laser, and a visible light laser can be used for laser sintering.

[0073] (3) Prepare an insulating spacer layer on the mesoporous nanocrystal layer obtained in step (2) by screen printing and dry it; among them, the insulating spacer layer paste is aluminum oxide.

[0074] (4) Prepare a counter electrode layer on the insulating spacer layer obtained in step (3) by screen printing and dry it; then place it at 400 °C and sinter it for 30 min to form a mesoporous structure for the insulating spacer layer and the counter electrode layer.

[0075] Among them, the counter electrode layer paste is a mixture of activated carbon and graphite, and carbon black and graphite are mixed in a mass ratio of 2:1.

[0076] (5) Coat a perovskite precursor solution on the counter electrode layer obtained in step (4), and the perovskite precursor solution enters the mesoporous nanocrystal layer, insulating spacer layer, and counter electrode layer with mesoporous structure through capillary action and grows and crystallizes, thereby obtaining a laser-sintered perovskite solar cell.

[0077] Among them, the solute of the perovskite precursor solution has the following general formula: ABX3; A is formamidine; B is lead, and X is iodine.

[0078] Example 3

[0079] The preparation method of the laser-sintered perovskite solar cell in this example includes the following steps:

[0080] (1) Take a conductive substrate, place it on a high-temperature hot stage, heat it to 450 °C, and prepare a hole blocking layer on the conductive substrate by spraying; among them, the conductive substrate is FTO conductive glass; the hole blocking layer is titanium dioxide.

[0081] (2) Prepare a mesoporous nanocrystal layer on the hole blocking layer obtained in step (1) by screen printing and dry it; then, laser sinter the mesoporous nanocrystal layer under an oxygen volume fraction of 72%;

[0082] Among them, the mesoporous nanocrystal layer slurry is zinc oxide; the laser wavelength of the laser sintering is 0.35um; the laser power of the laser sintering is 142W; the focal length of the laser sintering is 600±40mm; the filling method of the laser etching line of the laser sintering is bow-shaped connection; the filling spacing of the laser etching line of the laser sintering is 0.03mm; the output power percentage of the laser of the laser sintering is 45%; the laser frequency of the laser sintering is 50kHz; the laser scanning speed of the laser sintering is 4000mm / s; the number of laser scanning passes of the laser sintering is 5 passes; the laser scanning area of the laser sintering is 512cm 2 .

[0083] It should be noted that laser sintering can be carried out using one of ultraviolet lasers, infrared lasers, and visible light lasers.

[0084] (3) Prepare an insulating spacer layer on the mesoporous nanocrystal layer obtained in step (2) by screen printing and dry it; among them, the insulating spacer layer slurry is silica.

[0085] (4) Prepare a counter electrode layer on the insulating spacer layer obtained in step (3) by screen printing and dry it; then place it at 350°C and sinter for 40min to form a mesoporous structure of the insulating spacer layer and the counter electrode layer.

[0086] Among them, the counter electrode layer slurry is a blend of carbon black and graphene, and carbon black and graphite are mixed in a mass ratio of 1:3.

[0087] (5) Coat a perovskite precursor solution on the counter electrode layer obtained in step (4), and the perovskite precursor solution enters the mesoporous nanocrystal layer, insulating spacer layer, and counter electrode layer with a mesoporous structure through capillary action and grows and crystallizes, thereby obtaining a laser-sintered perovskite solar cell.

[0088] Among them, the solute of the perovskite precursor solution has the following general formula: ABX3; A is cesium; B is lead, and X is chlorine.

[0089] Example 4

[0090] The preparation method of the laser-sintered perovskite solar cell in this example includes the following steps:

[0091] (1) Take a conductive substrate, place it on a high-temperature hot stage, heat it to 450 °C, and prepare a hole-blocking layer on the conductive substrate by spraying; wherein, the conductive substrate is FTO conductive glass; the hole-blocking layer is titanium dioxide.

[0092] (2) Prepare a mesoporous nanocrystal layer on the hole-blocking layer obtained in step (1). Screen-print the mesoporous nanocrystal layer slurry onto the hole-blocking layer through a 200-mesh screen and dry it to obtain the mesoporous nanocrystal layer; then, laser-sinter the mesoporous nanocrystal layer under an oxygen volume fraction of 72%.

[0093] Among them, the mesoporous nanocrystal layer slurry is titanium dioxide; the laser wavelength of the laser sintering is 10 μm; the laser power of the laser sintering is 142 W; the focal length of the laser sintering is 600 ± 40 mm; the filling method of the laser etching line of the laser sintering is bow-shaped connection; the filling spacing of the laser etching line of the laser sintering is 0.03 mm; the output power percentage of the laser of the laser sintering is 50%; the laser frequency of the laser sintering is 50 kHz; the laser scanning speed of the laser sintering is 1000 mm / s; the number of laser scanning passes of the laser sintering is 3 passes; the laser scanning area of the laser sintering is 1.3 cm 2 .

[0094] It should be noted that one of an ultraviolet laser, an infrared laser, and a visible light laser can be used for laser sintering.

[0095] (3) Prepare an insulating spacer layer on the mesoporous nanocrystal layer obtained in step (2) by screen printing and dry it; wherein, the insulating spacer layer slurry is zirconia.

[0096] (4) Prepare a counter electrode layer on the insulating spacer layer obtained in step (3) by screen printing and dry it; then place it at 350 °C and sinter it for 40 min to form a mesoporous structure for the insulating spacer layer and the counter electrode layer.

[0097] Among them, the counter electrode layer slurry is a blend of carbon black, graphite, and activated carbon, and carbon black, graphite, and activated carbon are mixed according to a mass ratio of 1:3:1.

[0098] (5) Coat a perovskite precursor solution on the counter electrode layer obtained in step (4). The perovskite precursor solution enters the mesoporous nanocrystal layer, insulating spacer layer, and counter electrode layer with a mesoporous structure through capillary action and grows and crystallizes, thereby obtaining a laser-sintered perovskite solar cell.

[0099] Among them, the solute of the perovskite precursor solution has the following general formula: ABX3; A is methylamine; B is lead, and X is iodine.

[0100] As Figure 3 shown, it is a partially enlarged schematic diagram of the particles of the mesoporous nanocrystal layer of the laser-sintered perovskite solar cell in this embodiment. As Figure 4 shown, it is a partially enlarged schematic diagram of the particles of the mesoporous nanocrystal layer of the laser-sintered perovskite solar cell obtained in this embodiment.

[0101] Example 5

[0102] In this example, the laser-sintered perovskite solar cell was prepared by the same method as in Example 4, except that: in step (1), a conductive substrate was taken, and a hole-blocking layer was prepared on the conductive substrate by spraying, and then laser sintering was carried out;

[0103] The specific conditions of the laser sintering in step (1) are as follows: the laser wavelength of the laser sintering is 10 μm; the power of the laser of the laser sintering is 142 W; the focal length of the laser sintering is 600 ± 40 mm; the filling method of the laser etching line of the laser sintering is bow-shaped connection; the filling spacing of the laser etching line of the laser sintering is 0.03 mm; the output power percentage of the laser of the laser sintering is 50%; the laser frequency of the laser sintering is 50 kHz; the laser scanning speed of the laser sintering is 1000 mm / s; the number of laser scanning passes of the laser sintering is 3 passes; the laser scanning area of the laser sintering is 1.3 cm 2 .

[0104] Example 6

[0105] In this example, the laser-sintered perovskite solar cell was prepared by the same method as in Example 4, except that: in step (4), laser sintering was used instead of high-temperature sintering to form a mesoporous structure for the insulating spacer layer and the counter electrode layer;

[0106] The specific conditions of the laser sintering in step (4) are as follows: the laser wavelength of the laser sintering is 10 μm; the power of the laser of the laser sintering is 142 W; the focal length of the laser sintering is 600 ± 40 mm; the filling method of the laser etching line of the laser sintering is bow-shaped connection; the filling spacing of the laser etching line of the laser sintering is 0.03 mm; the output power percentage of the laser of the laser sintering is 50%; the laser frequency of the laser sintering is 50 kHz; the laser scanning speed of the laser sintering is 1000 mm / s; the number of laser scanning passes of the laser sintering is 3 passes; the laser scanning area of the laser sintering is 1.3 cm 2 .

[0107] Example 7

[0108] This example uses the same method as Example 4 to prepare a laser-sintered perovskite solar cell, except that: laser sintering is used in both step (1) and step (4).

[0109] Among them, the laser sintering in step (1) is the same as that in step (1) of Example 5; the laser sintering in step (4) is the same as that in step (4) of Example 6.

[0110] Example 8

[0111] This example uses the same method as Example 7 to prepare a laser-sintered perovskite solar cell, except that: in step (1), the conductive substrate uses poly(3,4-ethylenedioxythiophene) polystyrenesulfonate material.

[0112] Comparative Example 1

[0113] The preparation method of the perovskite solar cell in this comparative example is the same as that in Example 4, except that: in step (2), laser sintering is not used.

[0114] Step (2) is specifically as follows: A mesoporous nanocrystal layer is prepared by screen printing on the hole blocking layer obtained in step (1) and dried.

[0115] Comparative Example 2

[0116] The preparation method of the perovskite solar cell in this comparative example is the same as that in Example 4, except that: in step (2), laser sintering is not used, but the mesoporous nanocrystal layer is sintered at high temperature.

[0117] Step (2) is specifically as follows: A mesoporous nanocrystal layer is prepared by screen printing on the hole blocking layer obtained in step (1) and dried, and then, at 500 °C, it is sintered at high temperature for 45 min.

[0118] As Figure 2 shown, it is a partial enlarged schematic diagram of the mesoporous nanocrystal layer of the perovskite solar cell sintered at high temperature in this comparative example. Compared with the partial enlarged view in Figure 3 , the titanium dioxide crystal particles in Figure 3 are more fused, while the titanium dioxide crystal particles in Figure 2 have a poor fusion effect. The good fusion effect of titanium dioxide crystal particles can improve conductivity and is beneficial to charge transport. It can be seen that laser sintering can promote the interfacial adhesion between particles and achieve better electrical interconnection between crystal particles. In addition, the good fusion effect of titanium dioxide crystal particles also means that the solvents and organic binders present in the slurry are better eliminated during the sintering process.

[0119] Effect Comparative Example

[0120] To verify the technical effects of the preparation method of the laser-sintered perovskite solar cell described in the present invention, the following experiments were carried out:

[0121] The laser-sintered perovskite solar cells prepared in Examples 1-8 and Comparative Examples 1-2 were taken, and at room temperature of 25 °C and light intensity of 100 mW / cm -2 under simulated AM 1.5 solar illumination, the J-V curve (current density - light voltage curve) was measured, and based on the J-V curve, the open-circuit voltage (Voc / V), short-circuit photocurrent (Jsc / mA.cm -2 ) and fill factor (FF), photoelectric conversion efficiency (η / %) were obtained.

[0122] The experimental results are as follows:

[0123]

[0124]

[0125] From the comparison between Examples 1-4 and Comparative Examples 1-2, it can be seen that the photoelectric conversion efficiency of the obtained perovskite solar cell can be significantly improved by laser-sintering the mesoporous nanocrystal layer. From the comparison between Examples 4-6, it can be seen that not only the mesoporous nanocrystal layer, but also the hole blocking layer, the insulating spacer layer, and the counter electrode layer can improve the photoelectric conversion efficiency of the perovskite solar cell to a certain extent by laser-sintering; from the comparison between Example 8 and Comparative Examples 1-2, it can be seen that the preparation of a fully laser-sintered flexible perovskite battery can be realized.

[0126] The above are the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A preparation method of a laser sintered perovskite solar cell, characterized in that, It includes the following steps: (1) Prepare a hole blocking layer on a conductive substrate; (2) Prepare a mesoporous nanocrystal layer on the hole blocking layer obtained in step (1), and laser sinter the mesoporous nanocrystal layer; (3) Prepare an insulating spacer layer on the mesoporous nanocrystal layer obtained in step (2); (4) Prepare a counter electrode layer on the insulating spacer layer obtained in step (3), and sinter the insulating spacer layer and the counter electrode layer; (5) Coat a perovskite precursor solution on the counter electrode layer obtained in step (4) to obtain a laser-sintered perovskite solar cell; Among them, in step (2), the laser wavelength for laser sintering is 0.35 - 10.8 μm; The laser power of laser sintering is 0.08 - 275 W; The focal length of laser sintering is 600 ± 40 mm; The filling mode of the laser etching line for laser sintering is one of parallel in the same direction, parallel in the opposite direction, bow-shaped connection, and cross connection; The filling spacing of the laser etching line for laser sintering is 0.008 - 0.05 mm; The output power percentage of the laser for laser sintering is 25 - 75%; The laser frequency of laser sintering is 10 - 85 kHz; The laser scanning speed of laser sintering is 20 - 8000 mm / s; The number of laser scanning passes for laser sintering is 1 - 10 passes; The laser scanning area of laser sintering is 0.8 - 1024 cm 2 ; Adopt laser spot scanning regulation to realize the formation of the wavy surface topology of the thin film and realize the three-dimensional interface contact between the film layers; Among them, in step (2), laser sintering is carried out under an oxygen or ozone volume fraction of 45 - 99% to change the position distribution of oxygen vacancies in the TiO2 particle shell layer, and form a multi-layer spherical shell structure of internal crystalline state, intermediate oxygen vacancy state, and external crystalline state in the TiO2 crystal grains.

2. The preparation method of the laser sintered perovskite solar cell according to claim 1, characterized in that In step (2), one of an ultraviolet laser, an infrared laser, and a visible light laser is used for laser sintering.

3. The preparation method of the laser sintered perovskite solar cell according to claim 1, wherein In step (1), the hole blocking layer is prepared on the conductive substrate by spraying; Among them, the conductive substrate is one or more of conductive glass, metal oxide, carbon nanomaterial, and conductive polymer; the hole blocking layer is one or more of titanium dioxide and aluminum oxide; The thickness of the hole blocking layer is 1 - 50 nm.

4. The preparation method of the laser sintered perovskite solar cell according to claim 1, characterized in that In step (2), the preparation of the mesoporous nanocrystal layer includes the following steps: screen-print the mesoporous nanocrystal layer slurry onto the hole blocking layer and dry it to obtain the mesoporous nanocrystal layer; Among them, the mesoporous nanocrystal layer slurry is one or more of titanium dioxide, tin dioxide, zinc oxide, barium stannate, strontium titanate, and nickel oxide; The thickness of the mesoporous nanocrystal layer is 100 - 8000 nm.

5. The preparation method of the laser sintered perovskite solar cell according to claim 1, characterized in that, In step (3), the preparation of the insulating spacer layer includes the following steps: screen-print the insulating spacer layer slurry onto the mesoporous nanocrystal layer and dry it to obtain the insulating spacer layer; Among them, the insulating spacer layer slurry is one or more of zirconium dioxide, aluminum oxide, and silicon dioxide; The thickness of the insulating spacer layer is 2 - 100 μm.

6. The preparation method of the laser sintered perovskite solar cell according to claim 1, characterized in that, In step (4), the preparation of the counter electrode layer includes the following steps: screen-print the counter electrode layer slurry onto the insulating spacer layer and dry it to obtain the counter electrode layer; Among them, the counter electrode layer paste is one or more of carbon black, graphite, carbon nanotubes, activated carbon, graphene, and graphdiyne; The thickness of the counter electrode layer is 10 - 80 um; In step (4), the insulating spacer layer and the counter electrode layer are sintered at 300 - 400 °C for 30 - 50 min.

7. A laser-sintered perovskite solar cell obtained by the preparation method of the laser-sintered perovskite solar cell according to any one of claims 1 - 6.

8. The perovskite solar cell by laser sintering according to claim 7, characterized in that It includes a conductive substrate, a hole blocking layer, a mesoporous nanocrystal layer, an insulating spacer layer, and a counter electrode layer arranged in sequence, and perovskite crystallization is located in the mesoporous nanocrystal layer, the insulating spacer layer, and the counter electrode layer.

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