Post-treatment method for preventing cell deterioration of perovskite solar cell modules and perovskite solar cell modules treated by this method

Abstract

The present invention relates to a cell degradation prevention post-treatment method that can prevent or minimize the problem of reduced solar cell efficiency due to thermal degradation of cells that inevitably occurs during the manufacturing process of perovskite solar cell modules, and to a perovskite solar cell post-treated by this method.

Description

[Technical Field]

[0001] The present invention relates to a cell degradation prevention post-treatment method that can prevent or minimize a decrease in the photovoltaic parameters (power, open circuit voltage, short circuit current, fill factor) of solar cells caused by the accumulation of cation and / or anion defects in the perovskite photoactive layer due to the high temperature and / or high pressure inevitably applied to the entire surface or localized regions of the cell during the manufacturing process of the solar cell module, and a perovskite solar cell module treated by this method. [Background technology]

[0002] 2. Description of the Related Art In order to solve the global environmental problems caused by the depletion of fossil energy and its use, active research is being conducted into renewable and clean alternative energy sources such as solar energy, wind power, and hydropower.

[0003] Among these, interest in solar cells that directly convert sunlight into electrical energy is increasing. Here, a solar cell refers to a cell that generates current and voltage by utilizing the photovoltaic effect, which absorbs light energy from sunlight and generates electrons and holes.

[0004] Currently, np diode-type silicon (Si) single crystal-based solar cells with a light energy conversion efficiency of over 20% can be manufactured and are actually used in solar power generation, and there are also solar cells that use compound semiconductors such as gallium arsenide (GaAs) that have even better conversion efficiency. However, these inorganic semiconductor-based solar cells require highly refined materials to achieve high efficiency, which consumes a lot of energy to refine the raw materials. In addition, the process of using the raw materials to turn them into single crystals or thin films requires expensive processing equipment, which limits the reduction in solar cell manufacturing costs and has hindered large-scale use.

[0005] Therefore, in order to manufacture solar cells at low cost, it is necessary to significantly reduce the costs of the materials or manufacturing processes used as the core of solar cells. As such, research is underway into perovskite solar cells, which can be manufactured using low-cost materials and processes as an alternative to inorganic semiconductor-based solar cells.

[0006] The general structural formula of perovskite is an ABX3 structure, where X represents an anion, A represents a large cation, and B represents a small cation.

[0007] Unlike crystalline materials, perovskite compounds, which are multi-component ionic solids, contain ionic defects. When devices made of perovskite are exposed to external environments (heat, light, bias, stress, moisture, etc.), these defects act as a factor that degrades the device's performance. This causes problems that complicate not only the stability of perovskite solar cells, but also the definition and accurate measurement of performance parameters under normal conditions.

[0008] After the cells are manufactured, solar cell modules must undergo processes such as tabbing and lamination, which require high temperature and pressure to be applied to the entire surface or local areas of the cells (commonly known as the modularization process). During this modularization process, the above-mentioned factors can cause thermal degradation, which significantly reduces the performance of the cells.

[0009] To solve this problem, a lot of research resources are being focused on methods to lower the process temperature and pressure in the modularization process. However, methods to lower the process temperature and pressure in the modularization process pose a problem that requires new verification of the suitability of the modularization process. Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention aims to provide a new stabilization post-treatment method for perovskite solar cell modules that can be implemented using the already verified materials and processes of existing solar cell modules, rather than a method of reducing the process temperature and pressure, which may reduce the reliability of the modularization process, and a perovskite solar cell module manufactured using this post-treatment method. [Means for solving the problem]

[0011] To solve the above problems, the present invention relates to a post-treatment method for preventing cell degradation of a perovskite solar cell module, in which a solar cell module is manufactured by performing a modularization process including tabbing, lay-up, laminating, and interconnecting a plurality of perovskite solar cells. The lamination process sequentially includes evacuating, melting, curing, and cooling, and the solar cell module after the curing process is subjected to one or more post-treatments selected from light irradiation and bias application, or the solar cell module after the cooling process is subjected to a heat treatment and then to one or more post-treatments selected from light irradiation and bias application.

[0012] In a preferred embodiment of the present invention, both light irradiation and bias application may be performed on the heat-treated solar cell module after the firing process or the cooling process.

[0013] In a preferred embodiment of the present invention, the temperature of the solar cell module after the firing process and the solar cell module after the cooling process, which are the targets of light irradiation and bias application, may be 50 to 100°C.

[0014] In a preferred embodiment of the present invention, the light irradiation is 100 to 200 mW / cm based on AM 1.5G. 2 This can be done by irradiating the solar cell module with light.

[0015] In a preferred embodiment of the present invention, the bias application is a variable voltage application (IV sweep), a constant current or a maximum power conversion voltage (V MPP ) can be applied to the module to execute it.

[0016] In a preferred embodiment of the present invention, the variable voltage application is performed in a range of 0.1V to (open circuit voltage value (V OC )+10.0)V range.

[0017] In a preferred embodiment of the present invention, the constant current application is performed at a value equal to or less than the short circuit current (I SC ) can be performed in the range of -50% to +50%.

[0018] In a preferred embodiment of the present invention, the plurality of perovskite solar cells include a photoactive layer containing a perovskite compound, and the perovskite compound may include a perovskite compound represented by Chemical Formula 1 below:

[0019] [Chemical formula 1]

[0020] A n (A') 1-n BX m (X') 3-m

[0021] In the formula 1, A and A' are independently formamidinium, methylammonium, cesium, rubidium, potassium, sodium, lithium, guanidinium, butylammonium, ethylammonium, or phenethylammonium; B is lead; X is tin, germanium, cadmium, zinc, or manganese; X and X' are independently iodide, bromide, chloride, fluoride, thiocyanate, cyanate, selenocyanate, formate, or acetate; n is a number satisfying 0≦n<1; and m is a number satisfying 0≦n<3.

[0022] In a preferred embodiment of the present invention, the perovskite solar cell module may be a pin-structured perovskite solar cell, an inverted structured perovskite solar cell, a tandem perovskite solar cell, or a tandem silicon / perovskite heterojunction solar cell module.

[0023] As a preferred embodiment of the present invention, a solar cell module post-treated by the cell degradation prevention post-treatment method can satisfy an increase rate of photoelectric conversion efficiency (PCE, power conversion efficiency) of 10.0 to 30.0% calculated by the following Equation 1.

[0024] [Formula 1] PCE increase rate (%) = (AB) / A × 100%

[0025] In Equation 1, A is the PCE (%) of a solar cell module that has not been treated to prevent cell degradation, and B is the PCE (%) of a module that has been post-treated to prevent cell degradation.

[0026] Another object of the present invention is to provide a perovskite solar cell module that has been treated using the above-mentioned cell degradation prevention post-treatment method.

[0027] Another object of the present invention is to provide a perovskite solar cell including a solar cell array including the perovskite solar cell module. [Effects of the Invention]

[0028] The cell degradation prevention post-treatment method of the present invention can be used without changing the materials and processes of existing solar cell modules, and can provide extremely efficient perovskite solar cell modules by dramatically recovering the thermal degradation that inevitably occurs during the high-temperature modularization process. [Brief explanation of the drawings]

[0029] [Figure 1] 1A and 1B are schematic diagrams illustrating thermal degradation of a cell that occurs during a cell lamination process during the manufacture of a solar cell module, and a schematic diagram illustrating a process of recovering the performance of the cell through a post-treatment process. [Figure 2] 1 is a schematic graph showing thermal changes during evacuating, melting, curing, and cooling processes in a lamination process. [Figure 3] 1 is a photograph of equipment equipped with a heat control device, a sunlight irradiation device, and a bias application device. [Figure 4] 1 shows measurement data of the current-voltage characteristics of the perovskite solar cell modules manufactured in Example 1 and the control group, i.e., photoelectric conversion efficiency (PCE, %), open circuit voltage (Voc, V), short circuit current density (Jsc, mA / cm2), and fill factor (FF, %), carried out in Experimental Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0030] The present invention will now be described in more detail.

[0031] In perovskite devices, the perovskite photoactive layer with the chemical composition ABX3 contains cation defects (A + , B + , V A ) and anionic defects (X - ) are mixed (see Fig. 1 for cationic defects with circular symbols and for anionic defects with square symbols).

[0032] In perovskite devices, an internal electric field (built-in electric field) is formed from the cathode to the anode. At room temperature, these ionic defects gradually migrate due to the internal electric field, with cationic defects moving toward the anode and anionic defects moving toward the cathode, and are accumulated at the junction interface between the perovskite layer and the charge transport layer (HTL: hole transport layer, ETL: electron transport layer).

[0033] The mobility of ionic defects that drift to the interface increases rapidly as the cell temperature increases, so ionic defects drift to the interface and accumulate in a short time during the lamination process, which is carried out at high temperatures (see Figure 1).

[0034] The problem is that ionic defects accumulated at the interface create an electric field that tends to cancel out the internal electric field, resulting in a built-in potential screen. This reduces all photovoltaic parameters of the module (power, open circuit voltage, short circuit current, fill factor) and leads to a significant drop in output. This phenomenon is also the cause of thermal degradation that typically occurs when modularizing perovskite solar cells.

[0035] Therefore, the post-conditioning or post-treatment method of the present invention is a treatment method that restores the performance of the module by returning the ionic defects accumulated at the interface to their original position (bulk region) in a direction that cancels out the internal electric field, as shown in Figure 1. In cells that have undergone this post-conditioning process, the ionic defects are once again uniformly distributed within the bulk, thereby restoring the photovoltaic parameters of the thermally deteriorated module to the initial performance level of the cell.

[0036] In order to return the ionic defects accumulated at the interface to their original positions (bulk region), 1) it is necessary to supply energy greater than the activation energy of the ionic defects to create a state of high mobility, and 2) it is necessary to impart directionality to the movement of the ionic defects so that they do not move randomly but drift in the desired direction. To achieve this, the present invention performs the following post-treatment.

[0037] In general, a solar cell module is manufactured by performing a modularization process including a tabbing process, an interconnecting process, a lay-up process, and a laminating process on a plurality of perovskite solar cell cells.

[0038] As shown in the schematic diagram of FIG. 2, the lamination process includes evacuating, melting, curing, and cooling processes in this order.

[0039] The post-treatment method for preventing cell degradation of a perovskite solar cell module of the present invention involves heat-treating the module in an uncooled or cooled state after the firing step of the lamination process to supply energy to ionic defects accumulated at the cell interface, and then applying light and / or a bias, preferably a forward bias (electric field), to impart directionality to the activated ionic defects.

[0040] In a preferred embodiment, a solar cell module that has undergone a firing process or a cooling process may be subjected to heat treatment, and then light irradiation and bias application may be performed in combination (see FIG. 3).

[0041] The temperature of the solar cell module after the firing process and the solar cell module after the cooling process, which are the targets of light irradiation and bias application, and the heat-treated solar cell module, is preferably 50 to 100°C, preferably 60 to 95°C, and more preferably 75 to 92°C. Here, if the temperature of the solar cell module is less than 50°C, the effect of performing the post-treatment may be zero or very little, and if the temperature exceeds 100°C, it is uneconomical and may cause problems such as a decrease in the workability of the light irradiation and / or bias application treatment processes.

[0042] The light irradiation can be performed by irradiating the solar cell module with light at 1 to 3 suns, preferably 1 to 2 suns, based on AM 1.5G.

[0043] The bias application is performed in the forward bias direction, and can be performed at a variable voltage (IV sweep), a constant current, or a maximum power conversion voltage (V MPP ) can be applied to the module to execute it.

[0044] In a preferred embodiment, the variable voltage (IV sweep) is applied in a range of 0.1V to an open circuit voltage (V OC ) + 10)V, preferably 0.1V to (V OC +5.0)V, more preferably 0.1V to (V OC It is best to operate in the range of +1.0V.

[0045] In addition, the constant current application (A) is a short-circuit current value (I sc , A), preferably, -50% to +50% of the short-circuit current value (I sc , A), more preferably, -30% to +30% of the short-circuit current value (Isc , A) It is best to perform it within the range of -10% to +10%.

[0046] In addition, the maximum power conversion voltage (V MPP ) is preferably applied in a maximum power conversion voltage tracking (MPPT) manner.

[0047] The solar cell module of the present invention is a module manufactured using a plurality of perovskite solar cells, and the plurality of perovskite solar cells include a photoactive layer containing a perovskite compound, and the perovskite compound may include a perovskite compound represented by Chemical Formula 1 below.

[0048] [Chemical formula 1] A n (A') 1-n BX m (X') 3-m

[0049] In the formula 1, A and A' are independently formamidinium, methylammonium, cesium, rubidium, potassium, sodium, lithium, guanidinium, butylammonium, ethylammonium, or phenethylammonium; B is lead; X is tin, germanium, cadmium, zinc, or manganese; X and X' are independently iodide, bromide, chloride, fluoride, thiocyanate, cyanate, selenocyanate, formate, or acetate; n is a number satisfying 0≦n<1; and m is a number satisfying 0≦n<3.

[0050] The perovskite solar cell module may be a pin-type structure perovskite solar cell, an inverted structure perovskite solar cell, a tandem type perovskite solar cell, or a tandem type silicon / perovskite heterojunction solar cell module.

[0051] The solar cell module post-treated using the above-described cell degradation prevention post-treatment method can satisfy an increase rate (or recovery rate) of photoelectric conversion efficiency (PCE, power conversion efficiency) calculated using the following formula 1 of 10.0 to 30.0%, preferably 10.5 to 29.0%, and more preferably 11.0 to 28.0%.

[0052] [Formula 1] PCE increase rate (%) = (AB) / A × 100%

[0053] In Equation 1, A is the PCE (%) of a solar cell module that has not been treated to prevent cell degradation, and B is the PCE (%) of a module that has been post-treated to prevent cell degradation.

[0054] Then, a perovskite solar cell can be manufactured by manufacturing a solar cell array using the perovskite solar cell module that has been subjected to the post-treatment process by the above-mentioned method.

[0055] Hereinafter, the present invention will be described in more detail through examples. However, the following examples should not be construed as limiting the scope of the present invention, but should be construed as being for the purpose of aiding in the understanding of the present invention.

[0056] <Example> Control group 1: Fabrication of silicon / perovskite tandem solar cells

[0057] A silicon / perovskite tandem solar cell was fabricated with a silicon lower cell and a perovskite upper cell as follows:

[0058] (1) Silicon lower cell The lower cell of a tandem solar cell uses a silicon cell with a PERC structure on the rear side of the wafer and a TOPCon structure on the front side, but lower cells with other polarities and other structures (e.g., HIT, Heterojunction with Intrinsic Thin Layer) can also be applied.

[0059] (2) Perovskite upper cell The upper cell of the tandem solar cell has a pin structure in which the hole transport layer is located below the perovskite absorber layer and the electron transport layer is located above the perovskite absorber layer. The hole transport layer is ITO / NiO x / Me-4PACz, where ITO and NiO x is deposited using sputtering, and Me-4PACz ((4-(3,6-Dimethyl-9H-carbazol-9-yl)butyl)phosphonic acid) is deposited on NiO through a spray process.x Coated on top.

[0060] The perovskite absorption layer is formed by coating a solution containing precursors (FAI, PbI2, CsBr, PbBr2, MACl). x Cs 1-x Pb(I y Br 1-y Cl z )3 composition.

[0061] The electron transport layer is LiF / C 60 / SnO x It consists of LiF and C 60 The layer was deposited by thermal evaporation and SnO x The layer was formed by atomic layer deposition (ALD).

[0062] Finally, the upper electrode of the tandem cell was made of ITO / Ag, where ITO was deposited using sputtering and Ag was formed using screen printing, resulting in the fabrication of a silicon / perovskite tandem solar cell.

[0063] Control group 2: Fabrication of silicon / perovskite tandem solar cell modules

[0064] The previously manufactured tandem solar cells of Control Group 1 were subjected to the tabbing process, layup fixing, and lamination processes as follows to manufacture a solar cell module.

[0065] (1)Tabbing process Tabbing was performed by dispensing an electrical conductive adhesive (ECA) onto the upper and lower electrodes of the cell, placing a metal wire on the conductive adhesive, and then heating it to 130°C to bond the cell and wire. An interconnecting process was then performed to connect the wire to the busbar.

[0066] (2) Lay-up process To modularize the tandem cell, an encapsulant, a sealing material, and the tandem solar cell that had been subjected to the tabbing process were laminated on the rear glass, an encapsulant, and a front glass in order to manufacture a laminate.

[0067] At this time, the sealing material was made of POE (Polyolefin), the sealing material was made of butyl rubber, and the front glass was made of low-iron tempered glass.

[0068] (3) Lamination process After the layup process, the laminate was compressed and subjected to a vacuum treatment process to remove all gases from inside the module. The module was then transferred to a melting chamber to perform cross-linking of the encapsulant.

[0069] Next, the resultant was transferred to a baking chamber capable of uniformly maintaining a temperature of 140°C, so that the encapsulant was finally crosslinked by 70% or more.

[0070] The module was then transferred to a cooling chamber and cooled to produce a silicon / perovskite tandem solar cell module.

[0071] Example 1: Post-treatment to prevent cell degradation of silicon / perovskite tandem solar cell modules (heat + light irradiation + bias application)

[0072] Using the same silicon lower cell and perovskite-based upper cell as in Control Group 1, the tabbing process, lay-up process, and lamination process were carried out using the same materials, conditions, and methods as in Control Group 2.

[0073] However, the module before cooling that had undergone the baking process in the lamination process of the control group 2 was placed in an apparatus equipped with a thermal control device, a sunlight irradiation device, and a bias application device as shown in FIG. 3, and the cell temperature was lowered from 100°C to 60°C at a rate of 4°C per minute. During the temperature decrease, sunlight was irradiated at 100mW / cm at AM 1.5. 2The cell was irradiated with light and a variable voltage (IV sweep) having a range of 0.1V to 1.8V was repeatedly applied until the cell temperature reached 60°C, thereby carrying out a post-treatment to prevent cell deterioration.

[0074] The solar cell module that had undergone the cell degradation prevention post-treatment was then subjected to the next cooling process in the same manner as control group 2, to manufacture a silicon / perovskite tandem solar cell module that had undergone the degradation prevention post-treatment.

[0075] The manufactured module size was a 1-inch single cell module.

[0076] Experimental example 1: Performance measurement of solar cell modules

[0077] The current-voltage characteristics of the tandem solar cell of Control Group 1, the tandem solar cell modules manufactured in Example 1 and Control Group 2, i.e., the photoelectric conversion efficiency (PCE, %), open circuit voltage (V oc , V), short circuit current density (J sc , mA / cm 2 The results are shown in Table 1 below and FIG. 4.

[0078] The photoelectric conversion efficiency (PCE) and open circuit voltage (V oc ), short circuit current density (J sc The increase rates of the fiber length (F) and fill factor (FF, %) were calculated using the following formulas.

[0079] [formula] Growth rate (%) = (AB) / A × 100%

[0080] In the formula, A is the measured value of the current-voltage characteristics of the control solar cell module that has not been treated to prevent cell degradation, and B is the measured value of the current-voltage characteristics of the module that has been treated to prevent cell degradation.

[0081] [Table 1]

[0082] From Table 1, it can be seen that Example 1, in which the internal electric field offset by the displacement of ionic defects inside the solar cell during the modularization process was restored by applying light irradiation and bias, had a significantly increased photoelectric conversion efficiency of 11.49% compared to Control 2. Furthermore, although the photoelectric conversion efficiency of Example 1 was somewhat lower than Control 1 due to a reduction in the short-circuit current of the module caused by light absorption and reflection in the encapsulant and front glass, it was confirmed that the performance of the solar cell, which had been reduced due to thermal degradation during the module manufacturing process, was largely restored.

[0083] Example 2: Post-treatment to prevent deterioration (heat + light irradiation + bias application)

[0084] The module before cooling, which was subjected to the lamination and firing processes of the control group 2 in the same manner as in Example 1, was cooled from a cell temperature of 100°C to 60°C at a rate of 4°C per minute. During the cooling process, sunlight was irradiated for 1 sun at AM 1.5 and the maximum power conversion voltage (V MPP ) was applied until the cell temperature reached 60°C, and post-treatment to prevent deterioration was performed.

[0085] The solar cell modules that had undergone the deterioration prevention post-treatment were then subjected to the next cooling step in the same manner as in Control Group 2 to manufacture tandem solar cell modules.

[0086] Experimental example 2: Performance measurement of solar cell modules

[0087] The current-voltage characteristics of the perovskite solar cell modules manufactured in Example 2 and the control group were measured in the same manner as in Experimental Example 1, and the results are shown in Table 2 below.

[0088] [Table 2]

[0089] As can be seen from Table 2, Example 2, in which the internal electric field offset by the displacement of ionic defects inside the solar cell during the modularization process was restored by applying light irradiation and bias, exhibited a significant increase in photoelectric conversion efficiency of 22.44% compared to Control 2.

[0090] Example 3: Cell Degradation Prevention Post-Processing (Heat + Bias Application)

[0091] The control group 2 module was subjected to the lamination and firing processes in the same manner as in Example 1, and the pre-cooling process was carried out by lowering the cell temperature from 100°C to 60°C at a rate of 4°C per minute. During the temperature reduction, a current value corresponding to the short-circuit current of the cell was applied until the cell temperature reached 60°C, thereby carrying out a post-treatment to prevent cell degradation.

[0092] The solar cell modules that had undergone the cell degradation prevention post-treatment were then subjected to the next cooling step in the same manner as in Control Group 2 to manufacture tandem solar cell modules.

[0093] Experimental example 3: Performance measurement of solar cell modules

[0094] The current-voltage characteristics of the tandem solar cell of Control Group 1, and the tandem solar cell modules manufactured in Example 3 and Control Group 2 were measured in the same manner as in Experimental Example 1, and the results are shown in Table 3 below.

[0095] [Table 3]

[0096] From Table 3, it can be seen that Example 3, in which the internal electric field offset by the displacement of ionic defects inside the solar cell during the modularization process was restored by applying light irradiation and bias, had a significantly increased photoelectric conversion efficiency of 26.57% compared to Control 2. Furthermore, Example 3 showed a solar cell efficiency that was even better than Control 1.

[0097] Example 4: Cell Degradation Prevention Post-Processing (Heat + Bias Application)

[0098] The module before cooling, which had undergone the lamination and firing processes of the control group 2 in the same manner as in Example 1, was cooled from a cell temperature of 100°C to 60°C at a rate of 4°C per minute, and a variable voltage (IV sweep) ranging from 0.1V to 1.8V was repeatedly applied during the temperature decrease, thereby performing a post-treatment to prevent cell degradation.

[0099] The solar cell modules that had undergone the cell degradation prevention post-treatment were then subjected to the next cooling process in the same manner as the control group to manufacture tandem solar cell modules.

[0100] Experimental example 4: Performance measurement of solar cell modules

[0101] The current-voltage characteristics of the tandem solar cell modules manufactured in Example 4 and Control 2 were measured in the same manner as in Experimental Example 1, and the results are shown in Table 4 below.

[0102] [Table 4]

[0103] As can be seen from Table 4, Example 4, in which the internal electric field offset by the displacement of ionic defects inside the solar cell during the modularization process was restored by applying light irradiation and bias, exhibited a significant increase in photoelectric conversion efficiency of 24.09% compared to Control 2.

[0104] Example 5: Cell Degradation Prevention Post-Treatment (Heat + Light Irradiation)

[0105] The module before cooling, which had been subjected to the lamination and firing processes in the same manner as in Example 1, for Control Group 2, was cooled from a cell temperature of 100°C to 60°C at a rate of 4°C per minute. During the temperature reduction, sunlight was irradiated at 200mW / cm at AM 1.5. 2 The cells were irradiated and post-processed to prevent deterioration.

[0106] The solar cell modules that had undergone the cell degradation prevention post-treatment were then subjected to the next cooling process in the same manner as the control group to manufacture tandem solar cell modules.

[0107] [Table 5]

[0108] From Table 5, it can be seen that Example 5, in which the internal electric field offset by the displacement of ionic defects inside the solar cell during the modularization process was restored by light irradiation, had a significantly increased photoelectric conversion efficiency of 11.97% compared to Control 2.

[0109] Examples 6 to 10: Post-treatment to prevent cell deterioration of tandem solar cell modules (heat + bias application)

[0110] In order to determine the minimum temperature of the cells within the module required for the cell degradation prevention post-treatment, the lamination and firing processes of Control Group 2 were performed in the same manner as in Example 1, and then cooled to room temperature, i.e., 25°C. The cooled modules were then heat-treated again to 50°C (Example 6), 60°C (Example 7), 70°C (Example 8), 80°C (Example 9), and 90°C (Example 10). While the temperature was being lowered to 25°C, a constant current corresponding to the short-circuit current of the cells was applied in the same manner as in Example 3, thereby performing the cell degradation prevention post-treatment to fabricate perovskite solar cell modules.

[0111] Experimental example 5: Performance measurement of solar cell modules

[0112] The current-voltage characteristics of the tandem solar cell of Control Group 1 and the tandem solar cell modules manufactured in Examples 6 to 10 and Control Group 2 were measured in the same manner as in Experimental Example 1, and the results are shown in Table 6 below. The cells of Control Group 1 and the modules of Control Group 2 were not subjected to heat treatment or post-treatment to prevent deterioration. The experimental data values ​​in Table 6 below are the average values ​​obtained by conducting the same experiment on three identical samples.

[0113] [Table 6]

[0114] Looking at the increase rate of photoelectric conversion efficiency in Table 6, it was confirmed that the post-treatment effect was observed even when the module temperature was at least 50° C. Furthermore, the modules of Examples 9 and 10, which underwent anti-degradation post-treatment at heat treatment temperatures of 80° C. and 90° C., showed a relatively higher increase rate of photoelectric conversion efficiency than the modules of Examples 6 to 8, which underwent anti-degradation post-treatment at heat treatment temperatures of 50 to 70° C.

[0115] Examples 11 to 14

[0116] To compare the effect of post-treatment to prevent degradation on cell size, a 1-inch single module (Example 11), a 3-inch single module (Example 12), an M6 single module (Example 13), and an M10 single module (Example 14) were manufactured using the same perovskite cells used to manufacture the module of Example 1.

[0117] When manufacturing each of the modules of Examples 11 to 14, the module before cooling, which had undergone the firing process in the lamination process, was cooled from a cell temperature of 100°C to 60°C at a rate of 4°C per minute, and a current value corresponding to the short-circuit current of the cell was applied during the temperature reduction, thereby performing a post-treatment to prevent cell degradation.

[0118] Experimental Example 6: Performance measurement of solar cell modules

[0119] The current-voltage characteristics of the perovskite solar cell modules manufactured in Examples 11 to 14 and the perovskite cells used in the manufacture of the modules were measured in the same manner as in Experimental Example 1. The photoelectric conversion efficiency (PCE) of the solar cell was measured. cell ) to the photoelectric conversion efficiency (PCE) of the solar cell module module ) are shown in Table 7 below.

[0120] [Table 7]

[0121] The photoelectric conversion efficiency (PCE) of the solar cell in Table 7cell ) to the photoelectric conversion efficiency (PCE) of the solar cell module module ) percentage measurements confirmed that the post-treatment process resulted in a consistent recovery rate of solar cell efficiency regardless of the size of the solar cell module.

[0122] Through the above examples and experimental examples, it has been confirmed that the thermal degradation of cells due to heat during the manufacturing process of a solar cell module can be drastically restored and recovered through the post-treatment process of the present invention, and that the reliability of perovskite solar cell modules, which have poor heat resistance, can be improved and mass-produced.

Claims

1. A process for manufacturing a solar cell module by performing a modularization process including a tabbing process, an interconnecting process, a lay-up process, and a lamination process on a plurality of perovskite solar cells, The lamination process includes a vacuum treatment process, a melting process, a curing process, and a cooling process, in that order. After the firing process, the solar cell module is subjected to one or more post-treatments selected from light irradiation and bias application, or The method for preventing cell degradation of a perovskite solar cell module comprises performing a heat treatment on the solar cell module after the cooling process, and then performing at least one post-treatment selected from light irradiation and bias application.

2. 2. The post-treatment method for preventing cell degradation of a perovskite solar cell module according to claim 1, wherein both light irradiation and bias application are performed on a solar cell module that has undergone a heat treatment after the firing step or the cooling step.

3. 2. The post-treatment method for preventing cell degradation of a perovskite solar cell module according to claim 1, wherein the temperature of the solar cell module subjected to heat treatment after the firing step and the cooling step is 50 to 100°C.

4. The light irradiation is 100 to 200 mW / cm based on AM 1.5G. ２ 2. The method for preventing cell degradation of a perovskite solar cell module according to claim 1, wherein the method is carried out by irradiating the solar cell module with light.

5. The bias application may be a variable voltage application (IV sweep), a constant current or a maximum power conversion voltage (V ＭＰＰ 2. The method for preventing cell degradation of a perovskite solar cell module according to claim 1, wherein the method is carried out by applying a voltage of 100 V to the module.

6. The variable voltage application is 0.1 V to (open voltage value (V ＯＣ ) +10.0) V range, The constant current application is performed by measuring the short circuit current value (I ＳＣ 6. The method for preventing cell degradation of a perovskite solar cell module according to claim 5, wherein the method is carried out within a range of −50% to +50% of the above.

7. the plurality of perovskite solar cells include a photoactive layer including a perovskite compound; 2. The method for preventing cell degradation of a perovskite solar cell module according to claim 1, wherein the perovskite compound comprises a perovskite compound represented by the following Chemical Formula 1: [Chemical formula 1] A ｎ (A') １－ｎ BX ｍ (X') ３－ｍ In the formula 1, A and A' are independently formamidinium, methylammonium, cesium, rubidium, potassium, sodium, lithium, guanidinium, butylammonium, ethylammonium, or phenethylammonium; B is lead; X is tin, germanium, cadmium, zinc, or manganese; X and X′ are independently iodide, bromide, chloride, fluoride, thiocyanate, cyanate, selenocyanate, formate, or acetate; n is a number satisfying 0≦n<1; and m is a number satisfying 0≦n<3.

8. 8. The method for preventing cell degradation of a perovskite solar cell module according to claim 7, wherein the perovskite solar cell module is a pin-type perovskite solar cell, an inverted type perovskite solar cell, a tandem type perovskite solar cell, or a tandem type silicon / perovskite heterojunction solar cell module.

9. The method for preventing cell degradation of a perovskite solar cell module according to any one of claims 1 to 8, wherein a solar cell module post-treated by the method for preventing cell degradation has an increase in photoelectric conversion efficiency of 10.0 to 30.0% as calculated by the following Equation 1: [Formula 1] PCE increase rate (%) = (A - B) / A x 100% In Equation 1, A is the PCE (%) of a solar cell module that has not been treated to prevent cell degradation, and B is the PCE (%) of a module that has been post-treated to prevent cell degradation.

10. A perovskite solar cell module, characterized by being treated by the deterioration prevention post-treatment method according to any one of claims 1 to 8.

11. A perovskite solar cell comprising a solar cell array including the perovskite solar cell module according to claim 10.

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