A post-processing method for a transparent conductive layer in a perovskite solar cell, the transparent conductive layer, and the perovskite solar cell.

Abstract

This invention provides a post-processing method for a transparent conductive layer in a perovskite solar cell, the transparent conductive layer itself, and the perovskite solar cell. The post-processing method includes annealing the transparent conductive layer, located near the back electrode, using laser annealing. In this invention, by annealing the transparent conductive film layer in the perovskite solar cell using laser annealing, defects in the transparent conductive film layer can be removed, restoring lattice integrity and thus improving its conductivity and electrical performance. Simultaneously, since laser annealing can control the temperature at different depths of the film layer, it can avoid the adverse effects of high-temperature annealing on the perovskite light-absorbing layer, thereby improving the overall photoelectric conversion efficiency and stability of the perovskite solar cell. Furthermore, the processing method is simple and applicable to all perovskite solar cells containing a transparent conductive layer.

Description

Technical Field

[0001] This invention belongs to the field of perovskite battery technology, and relates to a post-processing method for a transparent conductive layer in a perovskite battery, the transparent conductive layer, and the perovskite battery. Background Technology

[0002] As a third-generation solar cell, perovskite solar cells have seen their photoelectric conversion efficiency rise steadily in recent years, attracting increasing attention from researchers. They possess advantages such as high theoretical conversion efficiency, good performance in low-light conditions, low material cost, and adjustable bandgap. The theoretical efficiency of perovskite-crystalline silicon tandem solar cells, formed by combining perovskite and crystalline silicon cells, has even exceeded 40%. In perovskite solar cells, the transparent conductive layer plays a crucial role in current transmission. Especially in tandem solar cells, the transparent conductive layer serves as both the intermediate composite layer and the top and bottom current collection layer, highlighting its paramount importance.

[0003] However, the transparent conductive layer can sometimes be damaged during fabrication. This damage is typically repaired through high-temperature annealing, but because perovskite materials are not heat-resistant, high-temperature annealing cannot be used to repair damage in perovskite solar cells. Therefore, existing technologies mostly focus on repairing other functional layers in perovskite solar cells or optimizing the fabrication process of the transparent conductive layer to improve the overall performance of the perovskite solar cell, while research on annealing the transparent conductive layer is relatively limited.

[0004] For example, CN116322072A discloses a method for fabricating a semi-transparent perovskite solar cell. This method uses a reactive plasma-deposited transparent conductive oxide film as the top transparent conductive layer, eliminating the need for annealing the top transparent electrode, making it suitable for perovskites that are not heat-resistant. However, this method only reduces damage but does not fundamentally solve the problem of how to repair the damage.

[0005] Therefore, how to anneal the transparent conductive layer in a perovskite solar cell while avoiding the adverse effects of high temperature on the perovskite light-absorbing layer is a technical problem that urgently needs to be solved. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a post-processing method for the transparent conductive layer in perovskite solar cells, the transparent conductive layer itself, and the perovskite solar cell. The post-processing method provided by this invention introduces a laser annealing process to anneal the transparent conductive layer in the perovskite solar cell. This allows for control of the temperature at different depths along the longitudinal direction of the film layer. While repairing damage to the transparent conductive film layer and improving its photoelectric performance, this method avoids high-temperature damage to other layers such as the perovskite light-absorbing layer, significantly improving the photoelectric conversion efficiency of the perovskite solar cell.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a post-processing method for a transparent conductive layer in a perovskite solar cell, the post-processing method comprising: annealing the transparent conductive layer by laser annealing;

[0009] The transparent conductive layer is located on the side closest to the back electrode.

[0010] In this invention, laser annealing is used to anneal the transparent conductive film layer in a perovskite solar cell. This process removes defects in the transparent conductive film layer and restores lattice integrity. During annealing, the chemical binding energy of oxygen in the film layer increases, forming oxygen-vacancy dual-ion donors, thereby improving the conductivity of the film layer and enhancing its spectral transmittance, thus improving its photoelectric performance. At the same time, since laser annealing can control the temperature at different depths of the film layer, it avoids the adverse effects of high-temperature annealing on the perovskite light-absorbing layer, thereby improving the overall photoelectric conversion efficiency and stability of the perovskite solar cell.

[0011] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The technical objectives and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0012] Preferably, the laser annealing temperature is 160℃~240℃, more preferably 160℃~210℃, such as 160℃, 170℃, 180℃, 190℃, 200℃, 210℃, 220℃, 230℃ or 240℃, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0013] In this invention, by controlling the laser annealing temperature between 160℃ and 240℃, the repair effect of laser annealing on the transparent conductive layer can be better exerted. This is mainly manifested in further promoting the rearrangement of atoms in the amorphous region, better restoring the lattice order, reducing defects in the transparent conductive layer crystal, thereby improving the carrier mobility and further improving the overall performance of the perovskite solar cell.

[0014] Preferably, the annealing process is performed on the surface of the transparent conductive layer away from the perovskite light-absorbing layer.

[0015] Preferably, during the laser annealing, the surface temperature of the transparent conductive layer near the perovskite light-absorbing layer is controlled to be below 100°C, such as 10°C, 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, or 90°C, but not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0016] Preferably, an infrared thermal imager is used to detect the interface temperature of the transparent conductive layer on the side near the perovskite light-absorbing layer.

[0017] Preferably, the power of the laser annealing is 50W to 800W, more preferably 100W to 600W, such as 50W, 100W, 200W, 300W, 400W, 500W, 600W, 700W or 800W, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0018] In this invention, temperature control at different depths of the transparent conductive layer can be achieved by adjusting the power of laser annealing.

[0019] Preferably, the laser annealing time is 10ms to 100ms, more preferably 20ms to 70ms, such as 10ms, 20ms, 30ms, 40ms, 50ms, 60ms, 70ms, 80ms, 90ms or 100ms, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0020] Preferably, the laser annealing is performed in a protective gas atmosphere, preferably a nitrogen atmosphere.

[0021] In this invention, laser annealing under a protective gas atmosphere is more conducive to reducing the sheet resistance of the thin film, further improving the electrical properties of the thin film and the photoelectric conversion efficiency of the perovskite, and enhancing the overall performance of the perovskite.

[0022] Preferably, the method for preparing the transparent conductive layer includes magnetron sputtering.

[0023] Preferably, the transparent conductive layer comprises a tin-doped indium oxide composite layer.

[0024] Preferably, the thickness of the transparent conductive layer is 20nm to 150nm, more preferably 30nm to 60nm, such as 20nm, 30nm, 40nm, 50nm, 60nm, 80nm, 100nm, 120nm, 130nm or 150nm, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0025] As a preferred technical solution, the post-processing method includes the following steps:

[0026] Under a nitrogen atmosphere, the transparent conductive layer in the prepared perovskite solar cell is subjected to laser annealing for 10ms to 100ms at a power of 50W to 600W and at 160℃ to 240℃, while the surface temperature of the transparent conductive layer near the perovskite light-absorbing layer is controlled to be below 100℃.

[0027] In this invention, different annealing times and annealing powers can be selected according to the thickness and degree of damage of the transparent conductive layer, thereby achieving a better repair effect on the damage to the transparent conductive layer and improving the overall performance of the perovskite solar cell.

[0028] In a second aspect, the present invention provides a transparent conductive layer in a perovskite solar cell, wherein the transparent conductive layer in the perovskite solar cell is obtained by the post-processing method for the transparent conductive layer in the perovskite solar cell described in the first aspect.

[0029] Thirdly, the present invention also provides a perovskite battery, the perovskite battery comprising a transparent conductive layer as described in the second aspect of the perovskite battery.

[0030] It is understood that the perovskite solar cell further includes a substrate layer, a first electron transport layer, a perovskite light-absorbing layer, a second electron transport layer, and a back electrode, with the transparent conductive layer located between the second electron transport layer and the back electrode.

[0031] Preferably, when the first electron transport layer is a hole transport layer, the second electron transport layer is an electron transport layer; when the first electron transport layer is an electron transport layer, the second electron transport layer is a hole transport layer.

[0032] It should be noted that this invention does not limit the type of perovskite battery, but is applicable to all perovskite batteries containing a transparent conductive layer, such as single-junction perovskite batteries or tandem perovskite batteries.

[0033] Preferably, the tandem perovskite solar cell comprises a crystalline silicon / perovskite tandem solar cell. Furthermore, this invention does not limit the fabrication method of the perovskite solar cell; exemplarily, this invention provides a method for fabricating a crystalline silicon / perovskite tandem solar cell, the method comprising the following steps:

[0034] (1) A 10 nm to 20 nm tin-doped indium oxide (ITO) composite layer was prepared on a semi-finished crystalline silicon bottom cell by magnetron sputtering as a tunneling composite layer.

[0035] (2) A hole transport layer liquid film was prepared on the tunneling composite layer by spin coating, and then annealed at 80℃~120℃ for 5min~15min to obtain the hole transport layer.

[0036] (3) The perovskite precursor solution is dropped onto the surface of the hole transport layer, and a perovskite liquid film is prepared by spin coating. Then the perovskite liquid film is annealed at 90℃~130℃ for 5min~15min to obtain a perovskite light-absorbing layer with a thickness of about 400nm~600nm.

[0037] (4) An electronic substrate layer with a thickness of 10 nm to 20 nm is prepared on the perovskite light-absorbing layer by a evaporation rate.

[0038] (5) A buffer layer with a thickness of 10 nm to 20 nm is prepared on the upper end of the electronic substrate layer by atomic deposition;

[0039] (6) A transparent conductive layer with a thickness of 20 nm to 150 nm is prepared on the buffer layer by magnetron sputtering.

[0040] (7) Set the power of laser annealing to 50W to 800W, perform laser annealing on the surface of the transparent conductive layer for 10ms to 100ms at 160℃ to 240℃, detect the temperature under the transparent conductive layer by infrared thermal imager, and control the temperature of the interface under the transparent conductive layer to be below 100℃.

[0041] (8) with The evaporation rate is such that a back electrode with a thickness of 500nm to 1000nm is deposited on the surface of the transparent conductive layer.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] In this invention, laser annealing is used to anneal the transparent conductive film layer in a perovskite solar cell. This process removes defects in the transparent conductive film layer, restores lattice integrity, and thus improves its conductivity and electrical performance. Furthermore, because laser annealing can control the temperature at different depths of the film layer, it avoids the adverse effects of high-temperature annealing on the perovskite light-absorbing layer. This overall improves the photoelectric conversion efficiency and stability of the perovskite solar cell. The method is simple and applicable to all perovskite solar cells containing a transparent conductive layer. Detailed Implementation

[0044] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments are merely illustrative of the present invention and should not be construed as limiting the invention.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this application; the terms “comprising” and “having” and any variations thereof in this application are intended to cover non-exclusive inclusion.

[0046] Example 1

[0047] This embodiment provides a crystalline silicon / perovskite tandem solar cell, and the fabrication method is as follows:

[0048] Step 1: Preparation of the tunneling composite layer

[0049] A 15nm thick ITO composite layer was prepared on a semi-finished crystalline silicon bottom cell using a magnetron sputtering device.

[0050] Step 2: Fabrication of the hole transport layer

[0051] Spin-coat a layer of (2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl)phosphonic acid (MeO-2PACZ) at a concentration of 0.5 mg / mL and anneal at 100 °C for 10 min.

[0052] Step 3: Preparation of the perovskite light-absorbing layer

[0053] The perovskite precursor solution contained 1.05 mol / L PbI2, 0.35 mol / L PbBr2, 0.03 mol / L CsI, 1.05 mol / L formamidinium hydroiodate (FAI), and 0.35 mol / L MABr, with a 4:1 volume ratio of dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) as the solvent. The perovskite precursor solution was dropped onto the surface of the MeO-2PACz layer and rotated at 1000 rpm for 10 s, followed by 5000 rpm for 30 s. At the initial moment of the 5000 rpm rotation, 140 μL of ethyl acetate was dropped onto the sample surface. After the rotation was completed, a perovskite liquid film was obtained. The perovskite liquid film was annealed at 110 °C for 10 min to obtain a perovskite film with a thickness of approximately 500 nm.

[0054] Step 4: Evaporation of C60 electron transport layer

[0055] A C60 electron transport layer was prepared by vapor deposition at a rate of [missing information]. The thickness is 15nm.

[0056] Step 5: Preparation of the tin dioxide electron transport layer

[0057] A tin dioxide thin film with a thickness of 15 nm was prepared on the upper part of the C60 electron transport layer using atomic deposition technology.

[0058] Step 6: Sputter a layer of transparent conductive material

[0059] A 50 nm thick ITO layer was prepared using a magnetron sputtering device.

[0060] Step 7: Laser high-temperature annealing

[0061] The annealing power of the laser instrument was controlled at 500W. The surface of the transparent conductive layer of the device was annealed for 60ms at 200℃. The temperature under the transparent conductive layer was detected by an infrared thermal imager, and the temperature of the interface under the transparent conductive layer was controlled to be below 100℃.

[0062] Step 8: Evaporation of silver metal electrodes

[0063] A silver metal electrode is deposited on the surface of the transparent conductive layer at a deposition rate of [missing information]. The thickness is 800nm.

[0064] Example 2

[0065] This embodiment provides a crystalline silicon / perovskite tandem solar cell, and the fabrication method is as follows:

[0066] Steps one through five are the same as in Example 1.

[0067] Step 6: Sputter a layer of transparent conductive material

[0068] A 60 nm thick ITO layer was prepared using a magnetron sputtering device.

[0069] Step 7: Laser high-temperature annealing

[0070] The annealing power of the laser instrument was controlled at 600W, and the surface of the transparent conductive layer of the device was annealed for 70ms at 210℃. The temperature under the transparent conductive layer was detected by an infrared thermal imager, and the temperature of the interface under the transparent conductive layer was controlled to be below 100℃.

[0071] Step 8 is the same as in Example 1.

[0072] Example 3

[0073] This embodiment provides a perovskite single-junction solar cell, and the fabrication method is as follows:

[0074] first step:

[0075] A 15 nm thick ITO layer was prepared on transparent conductive glass using a magnetron sputtering device.

[0076] Steps two through five are the same as in Example 1.

[0077] Step 6: Sputter a layer of transparent conductive material

[0078] A 30 nm thick ITO layer was prepared using a magnetron sputtering device.

[0079] Step 7: Laser high-temperature annealing

[0080] The annealing power of the laser instrument was controlled at 100W, and the surface of the transparent conductive layer of the device was annealed for 20ms at 160℃. The temperature under the transparent conductive layer was detected by an infrared thermal imager, and the temperature of the interface under the transparent conductive layer was controlled to be below 100℃.

[0081] Step 8 is the same as in Example 1.

[0082] Example 4

[0083] The difference between this embodiment and Embodiment 1 is that the laser annealing temperature in step seven is 160°C.

[0084] The remaining preparation methods and parameters are consistent with those in Example 1.

[0085] Example 5

[0086] The difference between this embodiment and Embodiment 1 is that the laser annealing temperature in step seven is 210°C.

[0087] The remaining preparation methods and parameters are consistent with those in Example 1.

[0088] Example 6

[0089] The difference between this embodiment and Embodiment 1 is that the laser annealing temperature in step seven is 100°C.

[0090] The remaining preparation methods and parameters are consistent with those in Example 1.

[0091] Example 7

[0092] The difference between this embodiment and Embodiment 1 is that the laser annealing temperature in step seven is 250°C.

[0093] The remaining preparation methods and parameters are consistent with those in Example 1.

[0094] Example 8

[0095] The difference between this embodiment and Embodiment 1 is that the laser annealing atmosphere in step seven is air.

[0096] The remaining preparation methods and parameters are consistent with those in Example 1.

[0097] Example 9

[0098] The difference between this embodiment and Embodiment 1 is that the laser annealing power in step seven is 50W.

[0099] The remaining preparation methods and parameters are consistent with those in Example 1.

[0100] Example 10

[0101] The difference between this embodiment and Embodiment 1 is that the laser annealing power in step 7 is 800W.

[0102] The remaining preparation methods and parameters are consistent with those in Example 1.

[0103] Example 11

[0104] The difference between this embodiment and Embodiment 1 is that the laser annealing time in step seven is 10ms.

[0105] The remaining preparation methods and parameters are consistent with those in Example 1.

[0106] Example 12

[0107] The difference between this embodiment and Embodiment 1 is that the laser annealing time in step seven is 100ms.

[0108] The remaining preparation methods and parameters are consistent with those in Example 1.

[0109] Comparative Example 1

[0110] The difference between this comparative example and Example 1 is that laser annealing is not used; instead, the perovskite solar cell obtained in step 6 is placed directly on a hot plate and annealed at 160°C for 10 minutes.

[0111] The remaining preparation methods and parameters are consistent with those in Example 1.

[0112] Comparative Example 2

[0113] The difference between this comparative example and Example 1 is that the high-temperature annealing in step seven is not performed.

[0114] The remaining preparation methods and parameters are consistent with those in Example 1.

[0115] Comparative Example 3

[0116] The difference between this comparative example and Example 3 is that the high-temperature annealing in step seven is not performed.

[0117] The remaining preparation methods and parameters are consistent with those in Example 3.

[0118] Performance testing

[0119] The perovskite solar cells prepared in Examples 1-12 and Comparative Examples 1-3 were subjected to current-voltage tests under standard sunlight. The photovoltaic parameters of the perovskite solar cells included open-circuit voltage (Voc), short-circuit current (Jsc), fill factor (FF), and power conversion efficiency (PCE).

[0120] The testing instruments mainly consist of a solar simulator and a digital light source meter. The solar simulator measures a light intensity of 1000 W / m². 2 The effective area of ​​the battery is 1 cm². 2 The test results are shown in Table 1:

[0121] Table 1

[0122]

[0123]

[0124] As can be seen from the comparison of Examples 1-3 and Comparative Examples 1-3 in Table 1, the laser annealing used in this invention to repair the damage to the transparent conductive layer can remove some of the defects caused by the sputtering process, restore the lattice integrity, and thus improve the conductivity and electrical performance of the transparent conductive layer. Compared with the traditional method of annealing on a hot stage, laser annealing can control the temperature at different depths of the transparent conductive layer, effectively avoiding the adverse effects of high temperature on the perovskite light-absorbing layer, effectively improving the on-state voltage and photoelectric conversion efficiency of the perovskite solar cell, and improving the overall performance of the perovskite solar cell.

[0125] As can be seen from the comparison between Examples 1 and 4-7 in Table 1, different laser annealing temperatures can be used to treat the transparent conductive layer in the perovskite solar cell to varying degrees to regulate the overall performance of the perovskite solar cell. Within the range of 160–240°C, the photoelectric conversion efficiency of the device can be effectively improved, with the regulation effect showing a pattern of first increasing and then decreasing, reaching its highest value at 190°C. However, when the annealing temperature is further increased to 250°C, the device efficiency decreases instead. This is presumably due to the escape of hydrogen from the intrinsic amorphous silicon layer in the heterojunction bottom cell at high temperatures, which weakens the passivation effect on the dangling bonds of the silicon substrate. This also indicates that in this invention, controlling the annealing temperature within the range of 160–240°C is more conducive to improving the overall performance of the perovskite solar cell.

[0126] As can be seen from the comparison between Example 1 and Example 8 in Table 1, annealing in a nitrogen atmosphere is better than annealing in an air atmosphere. This is because a nitrogen atmosphere is more conducive to reducing the sheet resistance of the thin film, which in turn is beneficial to improving the photoelectric performance of the battery.

[0127] As can be seen from the comparison between Example 1 and Examples 9-12 in Table 1, in this invention, the photoelectric performance of the perovskite solar cell changes when the laser annealing power and time of the transparent conductive film are changed. In practical applications, different annealing power and time can be selected according to the thickness and degree of damage of the transparent conductive film, so as to achieve a better repair effect on the damage of the transparent conductive film and improve the overall performance of the perovskite solar cell.

[0128] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for post-treatment of a transparent conductive layer in a perovskite cell, characterized in that, The post-processing method includes: annealing the transparent conductive layer using a laser annealing method; The transparent conductive layer is located on the side closest to the back electrode.

2. The method of post-treatment of transparent conductive layer in perovskite cell according to claim 1, characterized in that, The laser annealing temperature is 160℃~240℃, preferably 160℃~210℃.

3. The post-processing method for the transparent conductive layer in a perovskite solar cell according to claim 1 or 2, characterized in that, The annealing process is performed on the surface of the transparent conductive layer away from the perovskite light-absorbing layer. Preferably, during the laser annealing process, the surface temperature of the transparent conductive layer near the perovskite light-absorbing layer is controlled to be below 100°C.

4. The method of post-treatment of a transparent conductive layer in a perovskite cell according to any one of claims 1-3, characterized in that, The power of the laser annealing is 50W to 800W, preferably 100W to 600W.

5. The method of post-treatment of transparent conductive layer in perovskite cell according to any one of claims 1-4, characterized in that, The laser annealing time is 10ms to 100ms, preferably 20ms to 70ms.

6. The method of post-treatment of a transparent conductive layer in a perovskite cell according to any one of claims 1-5, characterized in that, The laser annealing is performed in a protective atmosphere, preferably a nitrogen atmosphere.

7. The method of post-treatment of transparent conductive layer in perovskite cell according to any one of claims 1-6, characterized in that, The method for preparing the transparent conductive layer includes magnetron sputtering. Preferably, the transparent conductive layer comprises a tin-doped indium oxide composite layer; Preferably, the thickness of the transparent conductive layer is 20nm to 150nm, and more preferably 30nm to 60nm.

8. The method of post-treatment of transparent conductive layer in perovskite cell according to claim 1, characterized in that, The post-processing method includes the following steps: Under a nitrogen atmosphere, the transparent conductive layer in the prepared perovskite solar cell is subjected to laser annealing for 10ms to 100ms at a power of 50W to 800W and a temperature of 160℃ to 240℃, while the surface temperature of the transparent conductive layer near the perovskite light-absorbing layer is controlled to be below 100℃.

9. A transparent conductive layer in a perovskite cell, characterized in that, The transparent conductive layer in the perovskite solar cell is obtained by the post-processing method for the transparent conductive layer in the perovskite solar cell according to any one of claims 1-8.

10. A perovskite cell, characterized in that, The perovskite solar cell includes the transparent conductive layer as described in claim 9.

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