Post-treatment method for preventing cell degradation of perovskite-based solar cell module and perovskite-based solar cell module treated thereby

Abstract

The present invention relates to a post-treatment method for preventing cell degradation, whereby the problem of reduced solar cell efficiency due to the thermal degradation of cells that inevitably occurs during the manufacturing process of perovskite-based solar cell modules can be prevented or minimized; and a perovskite-based solar cell post-treated by said method.

Description

Post-treatment method for preventing cell degradation of a perovskite solar cell module and a perovskite solar cell module treated by the method

[0001] The present invention relates to a post-treatment method for preventing cell degradation, which can prevent or minimize a decrease in photovoltaic parameters (power, open-circuit voltage, short-circuit current, and curve factor) of a solar cell due to ion accumulation of cationic defects and / or anionic defects in a perovskite photoactive layer caused by high temperature and / or high pressure inevitably applied to the front or local area of ​​a cell during the manufacturing process of a solar cell module, and to a perovskite solar cell module treated by the method.

[0002] To address the depletion of fossil fuels and the global environmental problems caused by their use, research is actively being conducted on renewable and clean alternative energy sources such as solar energy, wind power, and hydropower.

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

[0004] Currently, it is possible to manufacture np diode-type silicon (Si) single crystal-based solar cells with a light energy conversion efficiency of over 20%, and these are actually being used for solar power generation. There are also solar cells using compound semiconductors such as gallium arsenide (GaAs) with even better conversion efficiencies. However, these inorganic semiconductor-based solar cells require highly purified materials to achieve high efficiency, so a lot of energy is consumed in refining the raw materials. In addition, expensive processing equipment is required in the process of forming single crystals or thin films using the raw materials, which limits the cost of lowering the manufacturing cost of solar cells, and this has been an obstacle to large-scale utilization.

[0005] Accordingly, in order to manufacture solar cells at low cost, it is necessary to drastically reduce the cost of materials or manufacturing processes used as core components of solar cells, and research is being conducted on perovskite solar cells that can be manufactured using low-cost materials and processes as an alternative to inorganic semiconductor-based solar cells.

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

[0007] Unlike crystalline materials, perovskite compounds, which are multi-ionic solids, contain ionic defects, and when a device composed of perovskite is exposed to an external environment (heat / light / bias / stress / moisture, etc.), these defects act as factors that impair the performance of the device, which causes problems that complicate not only the stability of perovskite solar cells but also the definition of steady-state conditions and the accurate measurement of performance parameters.

[0008] After manufacturing the solar cell module, a process of applying high temperature and high pressure to the entire surface or local area of ​​the cell, such as tabbing and lamination, is essential (collectively referred to as a modularization process). During the modularization process, the above-mentioned factors cause a thermal degradation problem, which significantly reduces the performance of the cell.

[0009] To address this issue, significant research resources are being focused on lowering process temperatures and pressures in modularization processes. However, lowering process temperatures and pressures in modularization processes requires re-examining the suitability of the modularization process.

[0010] The present invention aims to provide a new stabilization post-treatment method for a perovskite solar cell module that can perform the existing solar cell module materials and processes that have already been verified, rather than a method of lowering the process temperature and process pressure that may lower the reliability of the modularization process, and a perovskite solar cell module manufactured by applying the post-treatment method.

[0011] The present invention, which aims to solve the above problem, relates to a post-treatment method for preventing cell degradation of a perovskite solar cell module, wherein, in a process of manufacturing a solar cell module by performing a modularization process including a tabbing process, a lay-up process, a laminating process, and an interconnecting process on a plurality of perovskite solar cell cells, the lamination process sequentially performs an evacuating process, a melting process, a curing process, and a cooling process, and at least one post-treatment selected from among light irradiation and bias application is performed on the solar cell module on which the curing process is completed, or after heat treatment of the solar cell module on which the cooling process is completed, at least one post-treatment selected from among light irradiation and bias application is performed.

[0012] As a preferred embodiment of the present invention, a solar cell module that has undergone the firing process or a solar cell module that has undergone the cooling process and has been heat-treated can be subjected to light irradiation and bias application simultaneously.

[0013] As a preferred embodiment of the present invention, the temperature of the solar cell module, which is the target of light irradiation and bias application, and the solar cell module that has undergone the firing process and the solar cell module that has undergone the cooling process and has been heat-treated, may be 50 to 100°C.

[0014] As 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 light onto a solar cell module.

[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 performed by authorizing the module.

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

[0017] In a preferred embodiment of the present invention, the constant current is applied to the solar cell module short-circuit current value (I sc ) can be performed in the range of -50% to +50%.

[0018] As a preferred embodiment of the present invention, the plurality of perovskite solar cell cells include a photoactive layer including a perovskite compound, and the perovskite compound may include a perovskite compound represented by the following chemical formula 1.

[0019] [Chemical Formula 1]

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

[0021] In the above chemical formula 1, A and A' are independently formamidinium, methylammonium, cesium, rubidium, potassium, sodium, lithium, guanidinium, butylammonium, ethylammonium or phenethylammonium, B is lead, tin, germanium, cadmium, zinc or manganese, and 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] As a preferred embodiment of the present invention, the perovskite solar cell module may be a module of a pin-structured perovskite solar cell, an inverse-structured perovskite solar cell, a tandem-type perovskite solar cell, or a tandem-type silicon / perovskite heterojunction solar cell.

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

[0024] [Formula 1]

[0025] PCE growth rate (%) = (AB) / A×100%

[0026] In Equation 1, A is the PCE (%) of the untreated solar cell module to prevent cell degradation, and B is the PCE (%) of the module to prevent cell degradation after treatment.

[0027] In addition, an object of the present invention is to provide a perovskite solar cell module treated with the cell degradation prevention post-treatment method described above.

[0028] In addition, an object of the present invention is to provide a perovskite solar cell including a solar cell array including the perovskite solar cell module.

[0029] The cell degradation prevention post-treatment method of the present invention can be used without changing the existing solar cell module materials and processes, and can provide a perovskite solar cell module with very high efficiency by dramatically recovering thermal degradation that inevitably occurs during the high-temperature modularization process.

[0030] Figure 1 is a schematic diagram of thermal deterioration of a cell that occurs during the cell lamination process during the manufacture of a solar cell module and a schematic diagram of the process by which cell performance is restored through a post-processing process.

[0031] Figure 2 is a schematic graph of thermal changes in the evacuating process, melting process, curing process, and cooling process in the lamination process.

[0032] Figure 3 is a photograph of the equipment equipped with a thermal control device, a solar irradiation device, and a bias application device.

[0033] Figure 4 shows the current-voltage characteristics, i.e., photoelectric conversion efficiency (PCE, %), open circuit voltage (V), of the perovskite solar cell modules manufactured in Example 1 and the control group in Experimental Example 1. oc , V), short-circuit current density (J sc , mA / cm 2 ), fill factor (FF, %) measurement data.

[0034] Hereinafter, the present invention will be described in more detail.

[0035] In perovskite devices, cationic defects (A) are present inside the perovskite photoactive layer with a chemical composition of ABX3. + , B + , V A ) and anionic defects (X - ) are mixed (refer to the circular symbol for cationic defects and the square symbol for anionic defects in Fig. 1).

[0036] Since the perovskite device has a built-in electric field that runs from the cathode to the anode, these ionic defects are slowly moved by the internal electric field at room temperature, 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), respectively.

[0037] Since the mobility of ionic defects drifting to the interface increases rapidly as the temperature of the cell increases, ionic defects drift to the interface and accumulate in a short time during the lamination process that is performed at high temperatures (see Fig. 1).

[0038] The problem is that the ionic defects accumulated at the interface generate an electric field that counteracts the internal electric field, thereby creating a built-in potential screen. This reduces all photovoltaic parameters of the module (power, open-circuit voltage, short-circuit current, and curvature factor), resulting in a significant drop in output. This phenomenon is a common cause of thermal degradation when modularizing perovskite solar cells.

[0039] Accordingly, the post-conditioning method (post-treatment) of the present invention is a treatment method that restores the performance of a module by returning ionic defects accumulated at the interface in a direction that offsets the internal electric field back to their original positions (bulk regions) as illustrated in Fig. 1, thereby restoring the offset internal electric field. In a cell that has undergone this post-treatment process, the ionic defects are uniformly distributed again within the bulk, and accordingly, the photovoltaic parameters of a thermally deteriorated module can be restored to the initial performance level of the cell.

[0040] In order to return the ionic defects accumulated at the interface to their original positions (bulk regions), 1) energy higher than the activation energy of the ionic defects must be supplied to create a state of high mobility, and 2) directionality must be given to the movement so that the ionic defects do not move in a disorderly manner but drift in a desired direction. To this end, the present invention performs the following post-processing.

[0041] Typically, solar cell modules are 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.

[0042] And, the lamination process is performed sequentially through an evacuating process, a melting process, a curing process, and a cooling process, as schematically shown in Fig. 2.

[0043] The post-treatment method for preventing cell degradation of a perovskite solar cell module of the present invention comprises, after the firing process of the lamination process is performed, heat-treating the module in an uncooled or cooled state to supply energy to ionic defects accumulated at the cell interface. Then, light irradiation and / or bias application, preferably forward bias (electric field) application, is performed to impart a movement direction to the activated ionic defects.

[0044] For example, a desirable implementation example can be performed by performing combined light irradiation and bias application on a solar cell module that has undergone a firing process or a solar cell module that has undergone a cooling process and has been heat-treated (see Fig. 3).

[0045] The temperature of the solar cell module, which is the target of light irradiation and bias application, the solar cell module that has undergone the firing process and the solar cell module that has undergone the cooling process and has been heat-treated, is preferably 50 to 100°C, preferably 60 to 95°C, and more preferably 75 to 92°C. At this time, if the temperature of the solar cell module is less than 50°C, the post-treatment effect may be absent or very minimal, and if it exceeds 100°C, it is uneconomical and there may be a problem of reducing the workability of the light irradiation and / or bias application treatment process.

[0046] In addition, the above light irradiation can be performed by irradiating light on the solar cell module under the condition of 1 to 3 suns based on AM 1.5G, preferably 1 to 2 suns.

[0047] In addition, the bias application is performed by forward bias application, and variable voltage (IV sweep), constant current or maximum power conversion voltage (V MPP ) can be performed by authorizing the module.

[0048] For example, in a preferred embodiment, the variable voltage (IV sweep) is applied from 0.1 V to (open circuit voltage value (V OC)+10) V, preferably 0.1 V ~ (V OC +5.0)V, more preferably 0.1V ~ (V OC It is recommended to perform in the +1.0)V range.

[0049] In addition, the above constant current application (A) is the short-circuit current value (I sc , A) -50% to +50%, preferably short-circuit current value (I sc , A) -30% to +30%, more preferably short-circuit current value (I sc , it is recommended to perform it in the range of -10% to +10% of A).

[0050] In addition, the maximum power conversion voltage (V MPP ) It is desirable to perform the approval using the maximum power point tracking (MPPT) method.

[0051] And, the solar cell module of the present invention is a module manufactured with a plurality of perovskite-based solar cell cells, wherein the plurality of perovskite-based solar cell cells include a photoactive layer including a perovskite compound, and the perovskite compound may include a perovskite compound represented by the following chemical formula 1.

[0052] [Chemical Formula 1]

[0053] A n (A') 1-n BX m (X') 3-m

[0054] In the above chemical formula 1, A and A' are independently formamidinium, methylammonium, cesium, rubidium, potassium, sodium, lithium, guanidinium, butylammonium, ethylammonium or phenethylammonium, B is lead, tin, germanium, cadmium, zinc or manganese, and 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.

[0055] In addition, the perovskite solar cell module may be a module of a pin-structured perovskite solar cell, an inverse-structured perovskite solar cell, a tandem-type perovskite solar cell, or a tandem-type silicon / perovskite heterojunction solar cell.

[0056] A solar cell module post-treated with a cell degradation prevention post-treatment method as described above can satisfy a photoelectric conversion efficiency (PCE, power conversion efficiency) increase rate (or recovery rate) of 10.0 to 30.0%, preferably 10.5 to 29.0%, and more preferably 11.0 to 28.0%, as calculated by Equation 1 below.

[0057] [Formula 1]

[0058] PCE growth rate (%) = (AB) / A×100%

[0059] In Equation 1, A is the PCE (%) of the solar cell module without cell degradation prevention treatment, and B is the PCE (%) of the module with cell degradation prevention post-treatment.

[0060] In addition, a perovskite solar cell can be manufactured by manufacturing a solar cell array using a perovskite solar cell module that has undergone a post-processing process using the method described above.

[0061]

[0062] Hereinafter, the present invention will be described in more detail through examples, but the following examples do not limit the scope of the present invention, and should be interpreted as helping to understand the present invention.

[0063] [Example]

[0064] Control 1: Fabrication of silicon / perovskite tandem solar cells

[0065] A silicon / perovskite tandem solar cell was manufactured with a silicon lower cell and a perovskite upper cell having the following structure.

[0066] (1) Silicon lower cell

[0067] The lower cell of the tandem solar cell uses a silicon cell with a PERC structure on the back of the wafer and a TOPCon structure on the front, but lower cells with other polarities and structures (e.g., HIT, Heterojunction with Intrinsic thin layer) can also be applied.

[0068] (2) Perovskite upper cell

[0069] The upper cell of the tandem solar cell has a pin structure in which the hole transport layer is placed below the perovskite absorbing layer and the electron transport layer is placed above the perovskite absorbing layer, and the hole transport layer is ITO / NiO. x / Me-4PACz is composed of ITO and NiO. xwas deposited using sputtering, and Me-4PACz ((4-(3,6-Dimethyl-9H-carbazol-9-yl)butyl)phosphonic acid) was deposited on NiO through a spray process. x Coated on top.

[0070] The perovskite absorber layer was formed by coating a solution containing a mixture of precursor materials (FAI, PbI2, CsBr, PbBr2, MACl), and the formed perovskite absorber layer was FA x Cs 1-x Pb(I y Br 1-y Cl z ) has a composition of 3.

[0071] The electron transport layer is LiF / C 60 / It is composed of SnOx and LiF and C 60 The layers were deposited by thermal evaporation and SnO x The layer was formed using the ALD (atomic layer deposition) method.

[0072] Finally, the upper electrode of the tandem cell is composed of ITO / Ag. ITO was deposited using sputtering, and Ag was formed using screen printing, thereby manufacturing a silicon / perovskite tandem solar cell.

[0073]

[0074] Control Group 2: Fabrication of Silicon / Perovskite Tandem Solar Cell Modules

[0075] A solar cell module was manufactured by performing tabbing process, layup fixing, and lamination process on the tandem solar cell of Control Group 1 manufactured previously in the same manner.

[0076] (1) Tabbing process

[0077] Tabbing was performed by dispensing electrical conductive adhesive (ECA) onto the upper and lower electrodes of the cell, placing metal wires on the conductive adhesive, and then heating to 130°C to bond the cell and wires. Subsequently, an interconnecting process was performed to connect the wires and busbars.

[0078] (2) Lay-up process

[0079] To modularize the tandem cell, the tandem solar cell, encapsulant, and front glass, which were subjected to encapsulant, sealant, and tabbing processes on the rear glass, were sequentially laminated to manufacture a laminate.

[0080] At this time, the encapsulating material used POE (Polyolefin), the sealing material used butyl rubber, and the front glass used low-iron reinforced glass.

[0081] (3) Lamination process

[0082] The laminated body, which has undergone the layup process, is compressed and subjected to a vacuum treatment process to expel all gases inside the module, and then the module is moved to a melting chamber to perform cross-linking of the encapsulant.

[0083] Next, it was transferred to a firing chamber that could maintain a uniform temperature of 140℃, so that the sealant was finally crosslinked by more than 70%.

[0084] Next, the module was transferred to a cooling chamber and cooled to fabricate a silicon / perovskite tandem solar cell module.

[0085]

[0086] Example 1: Post-treatment to prevent cell degradation of silicon / perovskite tandem solar cell modules (heat + light irradiation + bias application)

[0087] Using the same silicon lower cell and perovskite upper cell as Control Group 1, the tabbing process, layup process, and lamination process were performed using the same materials, conditions, and methods as Control Group 2.

[0088] However, in the lamination process of the control group 2, the module before cooling, which had undergone the firing process, was installed in equipment equipped with a heat control device, a solar irradiation device, and a bias application device, as shown in Fig. 3, and then the temperature of the cell was lowered from 100°C to 60°C at a rate of 4°C per minute, and during the lowering, sunlight was irradiated at 100 mW / cm with AM 1.5. 2 Post-treatment to prevent cell degradation was performed by repeatedly applying a variable voltage (IV sweep) with a range of 0.1 V to 1.8 V until the cell temperature reached 60°C.

[0089] Then, the solar cell module that had undergone post-treatment to prevent cell degradation was subjected to the same cooling process as control group 2, and a silicon / perovskite tandem solar cell module that had undergone post-treatment to prevent cell degradation was manufactured.

[0090] The manufactured module size was a 1-inch single-cell module.

[0091]

[0092] Experimental Example 1: Solar Cell Module Performance Measurement

[0093] Current-voltage characteristics, i.e., photovoltaic conversion efficiency (PCE, %), open circuit voltage (V), for tandem solar cell of control group 1 and tandem solar cell modules manufactured in Example 1 and control group 2 oc , V), short-circuit current density (J sc , mA / cm 2 ), the fill factor (FF, %) was measured, and the results are shown in Table 1 and Fig. 4 below.

[0094] And, the photoelectric conversion efficiency (PCE) and open circuit voltage (V) in Table 1 oc ), short-circuit current density (J sc), and the increase rate of fill factor (FF, %) is calculated using the following formula.

[0095] [ceremony]

[0096] Growth rate (%) = (AB) / A×100%

[0097] In the equation, A is the current-voltage characteristic measurement value of the control group, which is a solar cell module that has not been treated to prevent cell degradation, and B is the current-voltage characteristic measurement value of the module that has been post-treated to prevent cell degradation.

[0098] Photoelectric conversion efficiency (PCE, %) Open circuit voltage (V) oc , V) short-circuit current density (J sc , mA / cm 2 )Fill factor (FF, %) Control group 122.891.76119.4368.3 Control group 219.401.78618.7057.5 Example 121.631.75218.8164.3 Growth rate +11.49-1.90+0.59+11.83

[0099] Looking at Table 1 above, it was confirmed that Example 1, which restored the internal electric field that had been offset by the displacement of internal ionic defects of the solar cell during the modularization process by applying light irradiation and bias, had a significantly increased photoelectric conversion efficiency of 11.49% compared to Control Group 2. In addition, although the photoelectric conversion efficiency of Example 1 was somewhat lower than Control Group 1 due to a decrease in the short-circuit current of the module due to light absorption and reflection of the encapsulant and front glass, it was confirmed that the performance of the solar cell, which had been reduced due to thermal deterioration during the module manufacturing process, was greatly recovered.

[0100]

[0101] Example 2: Post-treatment to prevent thermal degradation (heat + light irradiation + bias application)

[0102] In the same manner as in Example 1, the module before cooling, which had undergone the firing process in the lamination process of the control group 2, was cooled from the cell temperature of 100°C to 60°C at a rate of 4°C per minute, and during the cooling process, 1 sun was irradiated with AM 1.5 and the maximum power conversion voltage (V MPP ) was applied until the cell temperature reached 60℃ to perform post-treatment to prevent deterioration.

[0103] Then, the solar cell module that had undergone post-treatment to prevent deterioration was subjected to the same cooling process as control group 2, thereby manufacturing a tandem solar cell module.

[0104]

[0105] Experimental Example 2: Solar Cell Module Performance Measurement

[0106] The current-voltage characteristics of the perovskite solar cell modules manufactured in Example 2 and the control group were measured using the same method as in Experimental Example 1, and the results are shown in Table 2 below.

[0107] Photoelectric conversion efficiency (PCE, %) Open circuit voltage (V) oc , V) short-circuit current density (J sc , mA / cm 2 )Fill factor (FF, %) Control group 218.45 1.77 4 18.17 5 7.2 Example 222.59 1.75 8 17.99 7 1.4 Increase rate +22.44 +0.93 -0.99 +24.83

[0108] Looking at Table 2 above, it was confirmed that Example 2, which restored the internal electric field that had been offset by the displacement of internal ionic defects of the solar cell during the modularization process by applying light irradiation and bias, showed a significantly increased photoelectric conversion efficiency of 22.44% compared to Control Group 2.

[0109]

[0110] Example 3: Post-processing to prevent cell degradation (heat + bias application)

[0111] In the same manner as in Example 1, the module before cooling, which had undergone a firing process in the lamination process of Control Group 2, was cooled from a cell temperature of 100°C to 60°C at a rate of 4°C per minute, and during the cooling process, a current value corresponding to the short-circuit current of the cell was applied until the cell temperature reached 60°C to perform post-treatment to prevent cell deterioration.

[0112] Then, the solar cell module that had undergone post-treatment to prevent cell degradation was subjected to the same cooling process as control group 2, thereby manufacturing a tandem solar cell module.

[0113]

[0114] Experimental Example 3: Solar Cell Module Performance Measurement

[0115] The current-voltage characteristics of the tandem solar cell of Control Group 1 and the tandem solar cell module 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.

[0116] Photoelectric conversion efficiency (PCE, %) Open circuit voltage (V) oc , V) short-circuit current density (J sc , mA / cm 2 )Fill factor (FF, %) Control group 121.81.76019.4363.7 Control group 217.51.78318.7551.8 Example 322.151.82118.6465.5 Increase rate +26.57+2.13-0.59+26.44

[0117] Looking at Table 3 above, it was confirmed that Example 3, which restored the internal electric field that had been offset by the displacement of internal ionic defects of the solar cell during the modularization process by applying light irradiation and bias, showed a significant increase in photoelectric conversion efficiency to 26.57% compared to Control Group 2. Furthermore, Example 3 showed a better solar cell efficiency than Control Group 1.

[0118]

[0119] Example 4: Post-processing to prevent cell degradation (heat + bias application)

[0120] In the same manner as in Example 1, the module before cooling, which had undergone a firing process in the lamination process of Control Group 2, 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) in the range of 0.1 V to 1.8 V was repeatedly applied during the cooling process to perform post-treatment to prevent cell deterioration.

[0121] Then, the solar cell module that had undergone post-treatment to prevent cell degradation was subjected to the same cooling process as the control group, thereby manufacturing a tandem solar cell module.

[0122]

[0123] Experimental Example 4: Solar Cell Module Performance Measurement

[0124] The current-voltage characteristics of the tandem solar cell modules manufactured in Example 4 and Control Group 2 were measured using the same method as Experimental Example 1, and the results are shown in Table 4 below.

[0125] Photoelectric conversion efficiency (PCE, %) Open circuit voltage (V) oc , V) short-circuit current density (J sc , mA / cm 2 )Fill factor (FF, %) Control group 218.141.80318.4454.5 Example 422.511.80617.6570.6 Increase rate +24.09 +0.11 -4.28 29.53

[0126] Looking at Table 4 above, it was confirmed that Example 4, which restored the internal electric field that had been offset by the displacement of internal ionic defects of the solar cell during the modularization process by applying light irradiation and bias, showed a significantly increased photoelectric conversion efficiency of 24.09% compared to Control Group 2.

[0127]

[0128] Example 5: Post-treatment to prevent cell degradation (heat + light irradiation)

[0129] In the same manner as in Example 1, the module before cooling, which had undergone the firing process in the lamination process of the control group 2, was cooled from a cell temperature of 100°C to 60°C at a rate of 4°C per minute, and during the cooling process, sunlight was irradiated at 200 mW / cm with AM 1.5. 2 We investigated and performed post-processing to prevent cell degradation.

[0130] Then, the solar cell module that had undergone post-treatment to prevent cell degradation was subjected to the same cooling process as the control group, thereby manufacturing a tandem solar cell module.

[0131] Photoelectric conversion efficiency (PCE, %) Open circuit voltage (V) oc , V) short-circuit current density (J sc , mA / cm 2 )Fill factor (FF, %) Control group 20.8 11.78 418.40 63.4 Example 5 23.30 1.74 618.12 73.6 Increase rate +11.97 - 2.14 - 1.52 + 16.09

[0132] Looking at Table 5 above, it was confirmed that Example 5, which recovered the internal electric field that had been offset by the displacement of internal ionic defects of the solar cell during the modularization process by irradiating light, showed a significantly increased photoelectric conversion efficiency of 11.97% compared to Control Group 2.

[0133]

[0134] Examples 6 to 10: Post-treatment to prevent cell degradation of tandem solar cell modules (heat + bias application)

[0135] In order to specify the minimum temperature of the cells within the module required for post-treatment to prevent cell degradation, the firing process was performed in the lamination process of the control group 2 in the same manner as in Example 1, and then cooled to room temperature of 25°C. Then, the cooled module was 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), and then, while cooling to 25°C, a constant current corresponding to the short-circuit current of the cell was applied in the same manner as in Example 3 to perform post-treatment to prevent cell degradation, thereby manufacturing a perovskite solar cell module, respectively.

[0136]

[0137] Experimental Example 5: Solar Cell Module Performance Measurement

[0138] The current-voltage characteristics of the tandem solar cell of Control Group 1, the tandem solar cell module 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 cell of Control Group 1 and the module of Control Group 2 were not subjected to heat treatment or deterioration prevention post-treatment. In addition, the experimental data values ​​in Table 6 below represent the average values ​​obtained by performing the same experiment on three identical samples.

[0139] Experimental temperature range, spectral photoelectric conversion efficiency (PCE, %), open circuit voltage (Voc, V), short circuit current density (Jsc, mA / cm) 2)Fill factor (FF, %)Leakage resistance (Ω·cm)50℃Control group 126.2281.85019.10674.1945.527Control group 222.4661.79818.05369.21310.150Example 622.9331.79818.02470.7749.475Increase rate 2.08%-0.01%-0.16%2.26%-6.66%60℃Control group 126.321.8518.6176.255.09Control group 222.651.7917.6571.619.94Example 723.251.8317.5472.317.56Increase rate 2.62%2.31%-0.66%0.97%-23.96%70℃Control 126.071.8618.8374.514.84Control 222.921.7917.8771.658.26Example 823.191.8417.4972.156.70Increase rate 1.16%2.64%-2.12%0.70%-18.89%80℃Control 125.341.7818.8075.825.21Control 221.391.7218.0369.1011.26Example 922.961.8017.5172.816.97Increase rate 7.35%4.91%-2.88%5.37%-38.08%90℃Control 125.201.8518.7472.645.81Control 220.941.7917.8765.3817.87Example 1022.691.8317.6270.247.74Increase rate 8.39%2.32%-1.40%7.44%-56.66%

[0140] Looking at the photoelectric conversion efficiency increase rate in Table 6 above, it was confirmed that the post-treatment effect was present starting from a module temperature of at least 50°C. In addition, the modules of Examples 9 and 10, in which post-treatment to prevent deterioration was performed at heat treatment temperatures of 80°C and 90°C, showed a relatively higher photoelectric conversion efficiency increase rate compared to Examples 6 to 8, in which post-treatment to prevent deterioration was performed at heat treatment temperatures of 50 to 70°C.

[0141]

[0142] Examples 11-14

[0143] In order to compare the effect of post-treatment for preventing degradation on the size of the cell, 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 cell used in the module manufacturing of Example 1.

[0144] And, when manufacturing each of the modules of the above 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 cooling process to perform post-processing to prevent cell deterioration.

[0145]

[0146] Experimental Example 6: Solar Cell Module Performance Measurement

[0147] The current-voltage characteristics of the perovskite solar cell modules manufactured in Examples 11 to 14 and the perovskite cells used in the module manufacturing were measured using the same method as Experimental Example 1. Then, the photovoltaic conversion efficiency (PCE) of the solar cell cell ) Photovoltaic conversion efficiency (PCE) of solar cell modules module ) are shown in Table 7 below.

[0148] Distinctive module size PCE module / PCE cell Example 111-inch single module 96% Example 123-inch single module 99% Example 13M6 single module 95% Example 14M10 single module 94%

[0149] The photovoltaic conversion efficiency (PCE) of the solar cell in Table 7 above cell ) Photovoltaic conversion efficiency (PCE) of solar cell modules module ) by measuring the percentage of solar cell efficiency, it was confirmed that the solar cell efficiency had a consistent recovery rate through the post-processing process regardless of the size of the solar cell module.

[0150] Through the above examples and experimental examples, it was confirmed that the efficiency of solar cells can be drastically restored and recovered through the post-processing process of the present invention in the process of manufacturing solar cell modules due to thermal deterioration of cells, and that it is possible to improve the reliability and mass-produce perovskite solar cell modules with low heat resistance.

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 laminating process on a plurality of perovskite solar cell cells, The above lamination process sequentially performs the evacuating process, melting process, curing process, and cooling process. Performing one or more post-processings selected from among light irradiation and bias application to the solar cell module on which the above firing process has been completed, or A post-treatment method for preventing cell degradation of a perovskite solar cell module, characterized in that after heat treatment of a solar cell module on which the above cooling process has been completed, at least one post-treatment selected from light irradiation and bias application is performed.

2. A post-treatment method for preventing cell degradation of a perovskite solar cell module, characterized in that in paragraph 1, a solar cell module in which the firing process has been completed or a solar cell module in which the cooling process has been completed is heat-treated is subjected to light irradiation and bias application simultaneously.

3. A post-treatment method for preventing cell deterioration of a perovskite solar cell module, characterized in that in paragraph 1, the temperature of the solar cell module in which the firing process has been completed and the solar cell module in which the cooling process has been completed are heat-treated is 50 to 100°C.

4. In the first paragraph, the light irradiation is 100 to 200 mW / cm based on AM 1.5G. 2 A post-treatment method for preventing cell deterioration of a perovskite solar cell module, characterized in that it is performed by irradiating light on the solar cell module.

5. In the first paragraph, the bias application is a variable voltage application (IV sweep), a constant current or a maximum power conversion voltage (V MPP ) is applied to the module to prevent cell deterioration of a perovskite solar cell module.

6. In the fifth paragraph, the variable voltage is applied from 0.1 V to (open circuit voltage value (V OC )+10.0)V range, The constant current is the short-circuit current value (I) of the solar cell module. sc ) is characterized by performing a post-treatment method for preventing cell degradation of a perovskite solar cell module in a range of -50% to +50%.

7. In the first paragraph, the plurality of perovskite solar cell cells include a photoactive layer including a perovskite compound, A method for preventing cell deterioration of a perovskite solar cell module, characterized in that 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 chemical formula 1, A and A' are independently Formamidinium, Methylammonium, Cesium, Rubidium, Potassium, Sodium, Lithium, Guanidinium, Butylammonium, Ethylammonium or Phenethylammonium, B is Lead, Tin, Germanium, Cadmium, Zinc or Magnesium, and 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. A method for preventing cell degradation of a perovskite solar cell module according to claim 7, characterized in that the perovskite solar cell module is a module of a pin-structured perovskite solar cell, an inverse-structured perovskite solar cell, a tandem-structured perovskite solar cell, or a tandem-structured silicon / perovskite heterojunction solar cell.

9. A method for preventing cell degradation post-treatment of a perovskite solar cell module, characterized in that the solar cell module post-treated with the method for preventing cell degradation in any one of claims 1 to 8 has an increase rate in power conversion efficiency of 10.0 to 30.0% calculated by Equation 1 below. [Formula 1] PCE growth rate (%) = (AB) / A×100% In Equation 1, A is the PCE (%) of the untreated solar cell module to prevent cell degradation, and B is the PCE (%) of the module to prevent cell degradation post-treatment.

10. A perovskite solar cell module characterized by being treated with a cell degradation prevention post-treatment method selected from any one of claims 1 to 8.

11. A perovskite solar cell characterized by including a solar cell array including the perovskite solar cell module of clause 10.

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