A crystalline silicon perovskite tandem cell

Abstract

The utility model discloses a kind of crystalline silicon perovskite laminated batteries, the utility model introduces a layer of metal seed thin layer with grid line pattern in the transparent conductive film and grid line electrode of laminated battery, on the one hand, the contact resistance of grid line electrode and transparent conductive film can be greatly reduced, and its contact resistance is reduced to 5% of original compared with the battery without metal seed thin layer;On the other hand, the binding force between grid line and transparent conductive film is improved, so that ultra-low temperature curing slurry and transparent conductive film can be fully bonded. In conclusion, the metal seed thin layer of grid line pattern introduced in the utility model achieves the purpose of simultaneously improving the conversion efficiency and stability of crystalline silicon perovskite laminated battery.

Description

Technical Field

[0001] This utility model belongs to the field of perovskite battery technology, specifically relating to a crystalline silicon perovskite tandem battery. Background Technology

[0002] Perovskite-crystalline silicon tandem solar cells are a novel type of solar cell structure that combines perovskite and crystalline silicon solar cells. This tandem structure is designed to improve solar energy conversion efficiency and achieve broader light absorption across the spectral range. The working principle of the perovskite-crystalline silicon tandem solar cell is that, in the tandem structure, the perovskite solar cell is located on the top layer to absorb high-energy light, while the crystalline silicon solar cell is located on the bottom layer to absorb low-energy light.

[0003] However, the thermal decomposition of perovskite solar cells limits the choice of electrode materials and fabrication methods. Currently, the mainstream method is to fabricate electrodes for crystalline silicon / perovskite tandem solar cells using screen printing of ultra-low temperature pastes (curing temperature not exceeding 120℃). However, none of the currently available ultra-low temperature pastes can achieve performance similar to traditional low temperature pastes (curing temperature around 200℃). Because ultra-low temperature curing pastes cannot fully bond with the transparent conductive film, excessive ohmic contact resistance results, making it difficult to improve the photoelectric conversion efficiency of the tandem solar cell. Therefore, a novel grid electrode structure needs to be developed. Utility Model Content

[0004] In order to overcome the problems existing in the prior art, one of the objectives of this utility model is to provide a crystalline silicon perovskite tandem solar cell.

[0005] This invention innovatively introduces a metal seed layer with a grid pattern between the transparent conductive film and the grid line electrode of the tandem solar cell. This not only significantly reduces the contact resistance between the grid line electrode and the transparent conductive film, solving the problem of the difficulty in improving the photoelectric conversion efficiency of the tandem solar cell, but also improves the bonding force between the grid line and the transparent conductive film, thereby achieving the goal of simultaneously improving the conversion efficiency and stability of the crystalline silicon / perovskite tandem solar cell.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows: The first aspect of this utility model provides a crystalline silicon perovskite tandem solar cell, comprising a perovskite solar cell, a crystalline silicon solar cell, and a composite layer; the composite layer is used to connect the top cell and the bottom cell in series. The perovskite solar cell includes a front metal grid electrode, a front metal seed layer, and a front transparent conductive film layer arranged sequentially; the crystalline silicon solar cell includes a back metal grid electrode, a back metal seed layer, and a back transparent conductive film layer arranged sequentially. The front and back metal seed layers are grid line structures 1; the front and back metal grid line electrodes are grid line structures 2; the grid line patterns of grid line structures 1 and 2 are the same.

[0007] In this invention, the grid pattern includes multiple main grids and multiple sub-grid lines perpendicular to them, with the main grids parallel to each other and the sub-grid lines also parallel to each other.

[0008] Preferably, the width of the gate line structure 2 is greater than or equal to the width of the gate line structure 1.

[0009] The metal seed layer is beneficial to enhance the conductivity between the silver grid line electrode and the transparent conductive film. However, if the seed layer is too wide (greater than the grid line width of the grid line electrode), it can easily affect the light absorption efficiency of the solar cell. In this invention, the grid line width of the grid line structure 2 is greater than or equal to the grid line width of the grid line structure 1, which can effectively balance the light absorption efficiency and electrical performance of the subsequently manufactured solar cell.

[0010] More preferably, when the gate width of the gate structure 2 is greater than the gate width of the gate structure 1, the front metal gate electrode / back metal gate electrode covers the front metal seed layer / back metal seed layer to form a bonded state, and the front metal gate electrode / back metal gate electrode is in contact with the front transparent conductive film layer / back transparent conductive film layer.

[0011] More preferably, when the gate width of the gate structure 2 is equal to the gate width of the gate structure 1, the front metal gate electrode / back metal gate electrode covers the top surface of the front metal seed layer / back metal seed layer.

[0012] Preferably, the thickness of the gate line structure 1 is 70-150 nm; the width of the gate line structure 1 is 30-50 μm; and the spacing between adjacent gate lines of the gate line structure 1 is 1-2 mm.

[0013] More preferably, the thickness of the gate structure 1 is 80-100 nm.

[0014] Preferably, the thickness of the gate structure 2 is 5-20 μm; the width of the gate structure 2 is 30-50 μm; and the spacing between adjacent gate lines of the gate structure 2 is 1-2 mm.

[0015] Preferably, the front and back metal seed layers are made of copper or a copper-nickel alloy.

[0016] Preferably, the raw materials for preparing the front metal grid electrode and the back metal grid electrode include one or more combinations of Ag and Cu.

[0017] Preferably, the front transparent conductive film layer and the back transparent conductive film layer are selected from one or two of ITO, IZO, IWO, and AZO.

[0018] Preferably, the thicknesses of the front transparent conductive film layer and the back transparent conductive film layer are 40-60nm and 80-120nm, respectively.

[0019] Preferably, the composite layer can be one or two of ITO, IZO, IWO, and AZO stacked together.

[0020] Preferably, the thickness of the composite layer is 10-30 nm.

[0021] Preferably, the crystalline silicon perovskite tandem solar cell includes, sequentially arranged, a front metal grid electrode, a front metal seed layer, a front transparent conductive film, an intermediate protective layer, an electron transport layer, a perovskite absorption layer, a hole transport layer, a composite layer, intrinsic amorphous silicon and phosphorus-doped amorphous silicon thin layers, a silicon substrate, intrinsic amorphous silicon and boron-doped amorphous silicon thin layers, a back transparent conductive film, a back metal seed layer, and a back metal grid electrode.

[0022] More preferably, the intermediate protective layer is a SnO2 layer.

[0023] More preferably, the thickness of the intermediate protective layer is 5-25 nm.

[0024] More preferably, the material of the electron transport layer includes at least one of fullerene (C60) and its derivatives, PCBM, SnO2, TiO2, and ZnO.

[0025] More preferably, the thickness of the electron transport layer is 10-30 nm.

[0026] More preferably, the perovskite light-absorbing layer comprises a perovskite material with an ABX3 structure, wherein A is selected from methylamino, formamidinyl, and Cs + , phenylethylamine, Ru + K + At least one of them, B is selected from Pb 2+ Sn 2+ Cu 2+ At least one of them, X is selected from I - ,Br - Cl - F - At least one of them.

[0027] More preferably, the thickness of the perovskite light-absorbing layer is 500-800 nm.

[0028] More preferably, the material of the hole transport layer includes at least one of spiro-OMeTAD, PTAA, NiOx, and PEDOT:PSS.

[0029] More preferably, the thickness of the hole transport layer is 5-15 nm.

[0030] More preferably, the thickness of the intrinsic amorphous silicon and phosphorus-doped amorphous silicon thin layer is 7-20 nm.

[0031] More preferably, the thickness of the silicon substrate is 50-150 μm.

[0032] More preferably, the silicon substrate has a textured surface on both sides.

[0033] More preferably, the thickness of the intrinsic amorphous silicon and boron-doped amorphous silicon thin layer is 10-30 nm.

[0034] The beneficial effects of this utility model are: This invention provides a crystalline silicon perovskite tandem solar cell. The invention introduces a metal seed layer with a grid pattern between the transparent conductive film and the grid electrodes of the tandem solar cell. This significantly reduces the contact resistance between the grid electrodes and the transparent conductive film, lowering it to 5% compared to a cell without the metal seed layer. Furthermore, it enhances the adhesion between the grid lines and the transparent conductive film, allowing for thorough bonding of the ultra-low temperature curing slurry to the transparent conductive film. In summary, this invention, by introducing a metal seed layer with a grid pattern, simultaneously improves the conversion efficiency and stability of the crystalline silicon / perovskite tandem solar cell. Attached Figure Description

[0035] Figure 1 This is a structural diagram of the crystalline silicon perovskite tandem solar cell of Embodiment 1 of this utility model; Figure 2 This is a structural diagram of the crystalline silicon perovskite tandem solar cell of Embodiment 2 of this utility model; Wherein: 1-front metal gate electrode, 2-front metal seed layer, 3-front transparent conductive film layer, 4-intermediate protective layer, 5-electron transport layer, 6-perovskite absorber layer, 7-hole transport layer, 8-composite layer, 9-intrinsic amorphous silicon and phosphorus-doped amorphous silicon thin layer, 10-silicon substrate, 11-intrinsic amorphous silicon and boron-doped amorphous silicon thin layer, 12-back transparent conductive film layer, 13-back metal seed layer, 14-back metal gate electrode. Detailed Implementation

[0036] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model. Unless otherwise defined, all technical terms used below have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of protection of this utility model. Unless otherwise specifically stated, all raw materials, reagents, instruments, and equipment used in this utility model can be purchased commercially or prepared by existing methods.

[0037] Example 1 This embodiment provides a crystalline silicon perovskite tandem solar cell, the structure of which consists of, sequentially arranged, a front metal grid electrode 1, a front metal seed layer 2, a front transparent conductive film layer 3, an intermediate protective layer 4, an electron transport layer 5, a perovskite absorber layer 6, a hole transport layer 7, a composite layer 8, an intrinsic amorphous silicon and phosphorus-doped amorphous silicon thin layer 9, a silicon substrate 10, an intrinsic amorphous silicon and boron-doped amorphous silicon thin layer 11, a back transparent conductive film layer 12, a back metal seed layer 13, and a back metal grid electrode 14; wherein the front metal seed layer 2 has a grid pattern, the same as that of the front metal grid electrode 1, but its grid line width is smaller than that of the front metal grid electrode 1; the back metal seed layer 13 has a grid pattern, the same as that of the back metal grid electrode 14, but its grid line width is smaller than that of the back metal grid electrode 14, specifically as follows. Figure 1 As shown.

[0038] The parameters of each layer and the preparation method of the crystalline silicon perovskite tandem solar cell are as follows: 1. The front metal grid line electrode is generally formed by screen printing pure silver paste or silver-coated copper paste and curing it at a temperature not exceeding 120℃. The grid line width is 20-30μm and the aspect ratio is above 0.3.

[0039] 2. The material of the front metal seed layer is pure copper (purity 99.99%) or copper-nickel alloy (copper wt%: nickel wt% = 99:1). Correspondingly, magnetron sputtering, thermal evaporation or ALD can be used to deposit the metal seed layer at room temperature through a mask to form a metal seed layer with a gate line pattern and a thickness of 10-100nm. The width of this layer is called the bottom layer width. The bottom layer width is smaller than the width of the metal gate line electrode, and the contact resistance between it and the front transparent conductive film is 0.35Ω.

[0040] The specific fabrication process of magnetron sputtering is as follows: The solar cell is placed on a carrier disk with a grid pattern mask. The shape of the grid pattern mask is the solar cell grid pattern, with an opening width of 40 μm, a spacing of 1.5 mm between adjacent openings, and a height of 0.5 mm between the mask and the solar cell. The solar cell is fed into the magnetron sputtering equipment via a carrier disk transfer method for deposition of a thin metal seed layer with a grid pattern. The preferred sputtering parameters are: sputtering vacuum degree of 0.3 Pa, silicon wafer temperature controlled at 60-80℃, and sputtering power density of 2 kW / m. Ionized argon ions bombard a copper target or a copper-nickel alloy target to deposit a thin copper or copper-nickel alloy seed layer with a grid pattern of approximately 100 nm thickness on the solar cell.

[0041] 3. The front transparent conductive film layer can be IZO with a thickness of 40-60nm. It is prepared by deposition at room temperature through magnetron sputtering, thermal evaporation or ALD. Generally, the sheet resistance is <150 Ω and the light transmittance is >90%.

[0042] 4. The intermediate protective layer can be SnO2, with a thickness of 5-25nm, and is prepared by thermal evaporation, PRD or ALD at low temperature.

[0043] 5. The electron transport layer can be C60 with a thickness of 10-30 nm, and can be prepared by magnetron sputtering, thermal evaporation, inkjet printing or doctor blade coating.

[0044] 6. The perovskite absorber layer has a material structure of ABX3, selected from the following components: Cs 0.05 (FA 0.85 MA 0.15 ) 0.95 Pb(I 0.85 Br 0.15 3. The film thickness is 500-800nm, and it is prepared by methods such as screen printing, slot coating, inkjet printing, doctor blade coating or chemical vapor deposition.

[0045] 7. The hole transport layer can be NiO. X With a thickness of 5-15 nm, it is prepared by methods such as magnetron sputtering, thermal evaporation, inkjet printing or doctor blade coating.

[0046] 8. The composite layer can be ITO with a thickness of 10-30nm, which is prepared by magnetron sputtering or RPD at a temperature of about 200℃. Generally, the sheet resistance is <150Ω and the transmittance is >90%.

[0047] 9. Intrinsic amorphous silicon and phosphorus-doped amorphous silicon thin films, with a thickness of 7-20 nm, are currently mainly prepared by PECVD or hot-wire CVD deposition.

[0048] 10. The silicon substrate has a thickness of 50-150μm, a minority carrier lifetime of ≥800μs, and a resistivity of 0.3-2.1Ω·cm. Both sides of the substrate need to be textured, with the textured surface size of the silicon surface adjacent to the front side being 0.5-0.8μm and the textured surface size of the silicon surface adjacent to the back side being 1-3μm.

[0049] 11. Intrinsic amorphous silicon and boron-doped amorphous silicon thin films, with a thickness of 10-30 nm, are currently mainly prepared by PECVD or hot-wire CVD deposition.

[0050] 12. The transparent conductive film layer on the back can be one or two of ITO, IZO, IWO, and AZO stacked together, with a thickness of 80-120nm. It is prepared by magnetron sputtering or RPD at a temperature of about 200℃, and generally has a sheet resistance of <40Ω and a light transmittance of >88%.

[0051] 13. The material of the back metal seed layer is pure copper (purity 99.99%) or copper-nickel alloy (copper wt%: nickel wt% = 99:1). Correspondingly, magnetron sputtering, thermal evaporation or ALD can be used to deposit the metal seed layer with a gate pattern at room temperature through a mask method to form a metal seed layer with a thickness of 10-100nm. The preparation method is the same as step 2 above. The width of this thin layer is called the bottom layer width. The bottom layer width is smaller than the width of the metal gate electrode. The contact resistance between the bottom layer and the back transparent conductive film is 0.35Ω.

[0052] 14. The back metal grid line electrodes are generally formed by screen printing pure silver paste or silver-coated copper paste and curing at a temperature not exceeding 120°C. The grid line width is 30-50um and the aspect ratio is above 0.3.

[0053] Example 2 This embodiment provides a crystalline silicon perovskite tandem solar cell, the structure of which consists of, sequentially arranged, a front metal grid electrode 1, a front metal seed layer 2, a front transparent conductive film layer 3, an intermediate protective layer 4, an electron transport layer 5, a perovskite absorber layer 6, a hole transport layer 7, a composite layer 8, an intrinsic amorphous silicon and phosphorus-doped amorphous silicon thin film 9, a silicon substrate 10, an intrinsic amorphous silicon and boron-doped amorphous silicon thin film 11, a back transparent conductive film layer 12, a back metal seed layer 13, and a back metal grid electrode 14; wherein the front metal seed layer 2 has a grid pattern, the same as that of the front metal grid electrode 1, and its grid line width is equal to the grid line width of the front metal grid electrode 1; the back metal seed layer 13 has a grid pattern, the same as that of the back metal grid electrode 14, and its grid line width is equal to the grid line width of the back metal grid electrode 14, specifically as follows. Figure 2 As shown.

[0054] The parameters and preparation method of each layer of the crystalline silicon perovskite tandem solar cell are basically the same as those in Example 1, except that: 2. The material of the front metal seed layer is pure copper (purity 99.99%) or copper-nickel alloy (copper wt%: nickel wt% = 99:1). Correspondingly, magnetron sputtering, thermal evaporation or ALD can be used to deposit the metal seed layer at room temperature through a mask to form a metal seed layer with a gate pattern and a thickness of 10-100nm. The width of this layer is called the bottom layer width, which is equal to the width of the metal gate electrode. The contact resistance between the bottom layer and the front transparent conductive film is 0.15Ω. 13. The bottom layer width of the metal seed layer on the back is equal to the width of the metal grid electrode, and the contact resistance between it and the transparent conductive film on the back is 0.15Ω.

[0055] Comparative Example 1 This comparative example provides a crystalline silicon perovskite tandem solar cell, the structure of which consists of, sequentially arranged, a front metal grid electrode, a front transparent conductive film layer, an intermediate protective layer, an electron transport layer, a perovskite absorption layer, a hole transport layer, a composite layer, an intrinsic amorphous silicon and phosphorus-doped amorphous silicon thin layer, a silicon substrate, an intrinsic amorphous silicon and boron-doped amorphous silicon thin layer, a back transparent conductive film layer, and a back metal grid electrode.

[0056] This comparative example does not include a thin layer of metal seeds.

[0057] Application testing The crystalline silicon perovskite tandem solar cells prepared in Examples 1-2 and Comparative Example 1 were subjected to relevant performance tests. The specific results are shown in Table 1. Among them, the short-circuit current density (Jsc), open-circuit voltage (Voc), conversion efficiency (Eff), fill factor (FF), and contact resistance were all measured under standard test conditions (AM1.5, 25℃, 1000W / m). 2 The result was measured below.

[0058] Table 1

[0059] As shown in Table 1, the Jsc, Voc, Eff and FF of the crystalline silicon perovskite tandem solar cells in Examples 1-2 are all better than those in Comparative Example 1. From the perspective of contact resistance, introducing a thin layer of metal seed with grid line pattern can significantly reduce the contact resistance between the grid line electrode and the transparent conductive film.

[0060] The above embodiments are preferred embodiments of the present utility model, but the embodiments of the present utility model are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present utility model shall be considered equivalent substitutions and shall be included within the protection scope of the present utility model.

Claims

1. A crystalline silicon perovskite tandem solar cell, characterized in that, It includes perovskite solar cells, crystalline silicon solar cells, and a composite layer; the composite layer is used to connect the top cell and the bottom cell in series. The perovskite solar cell includes a front metal grid electrode, a front metal seed layer, and a front transparent conductive film layer arranged sequentially; the crystalline silicon solar cell includes a back metal grid electrode, a back metal seed layer, and a back transparent conductive film layer arranged sequentially. The front and back metal seed layers are grid line structures 1; the front and back metal grid line electrodes are grid line structures 2; the grid line patterns of grid line structures 1 and 2 are the same.

2. The crystalline silicon perovskite tandem solar cell according to claim 1, characterized in that, The width of the gate line structure 2 is greater than or equal to the width of the gate line structure 1; And / or, the width of the gate line structure 1 is 30-50 μm; the width of the gate line structure 2 is 30-50 μm.

3. The crystalline silicon perovskite tandem solar cell according to claim 1, characterized in that, The thickness of the gate structure 1 is 70-150 nm; the spacing between adjacent gate lines of the gate structure 1 is 1-2 mm; And / or, the thickness of the gate structure 2 is 5-20 μm; the spacing between adjacent gate lines of the gate structure 2 is 1-2 mm.

4. The crystalline silicon perovskite tandem solar cell according to claim 1, characterized in that, The grid lines of the front and back metal seed layers are made of copper or a copper-nickel alloy.

5. The crystalline silicon perovskite tandem solar cell according to claim 1, characterized in that, The grid lines of the front metal grid electrode and the back metal grid electrode are independently made of copper or silver.

6. The crystalline silicon perovskite tandem solar cell according to claim 1, characterized in that, The front transparent conductive film layer and the back transparent conductive film layer are independently layered structures prepared by ITO, IZO, IWO or AZO.

7. The crystalline silicon perovskite tandem solar cell according to claim 1, characterized in that, The composite layer is a layered structure prepared from ITO, IZO, IWO or AZO.

8. The crystalline silicon perovskite tandem solar cell according to claim 1, characterized in that, The crystalline silicon perovskite tandem solar cell includes, in sequence, a front metal grid electrode, a front metal seed layer, a front transparent conductive film, an intermediate protective layer, an electron transport layer, a perovskite absorption layer, a hole transport layer, a composite layer, intrinsic amorphous silicon and phosphorus-doped amorphous silicon thin layers, a silicon substrate, intrinsic amorphous silicon and boron-doped amorphous silicon thin layers, a back transparent conductive film, a back metal seed layer, and a back metal grid electrode.

9. The crystalline silicon perovskite tandem solar cell according to claim 8, characterized in that, The electron transport layer is a layered structure prepared from fullerene (C60) and its derivatives, PCBM, SnO2, TiO2 or ZnO.

10. The crystalline silicon perovskite tandem solar cell according to claim 8, characterized in that, The hole transport layer is a layered structure prepared from spiro-OMeTAD, PTAA, NiOx, or PEDOT:PSS.

Images