A full inorganic gaas / perovskite tandem stack cell with carbon material as a hole transport and conductive multifunctional intermediate composite layer and preparation thereof

Abstract

The application belongs to the technical field of series connection battery, and discloses a full-inorganic GaAs / perovskite series connection laminated battery with carbon material as a hole transport and conductive multifunctional intermediate composite layer and a preparation method thereof. The battery comprises, from bottom to top, a back electrode, a GaAs substrate layer, a carbon material layer, an inorganic perovskite top cell layer, a front ARC and a front electrode in sequence. The carbon material is used as a composite functional layer for hole transport of the GaAs bottom cell and intermediate interconnection and conduction between the bottom cell and the top cell. The application also discloses a preparation method of the battery. The application widens the efficiency theoretical limit of the GaAs single-junction battery. The GaAs bottom cell adopts a heterojunction battery, which reduces the cost compared with a homojunction battery. The carbon material is used as a composite multifunctional layer to reduce the intermediate conductive layer required by a traditional series connection battery, which can effectively reduce the cost and optimize the battery structure. The full-inorganic GaAs / perovskite battery can significantly improve the stability.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of GaAs tandem solar cells, and particularly relates to a full-inorganic GaAs / perovskite tandem solar cell with carbon material as a hole transport and conductive multifunctional intermediate composite layer and a preparation method thereof. BACKGROUND

[0002] In recent years, GaAs (Gallium Arsenide) solar cells have been widely used due to their direct band gap, excellent photoelectric conversion efficiency and radiation resistance. According to the Shockley-Queisser model, the photoelectric conversion efficiency of a single-junction GaAs solar cell can reach 30%.

[0003] In order to break through the limit efficiency of GaAs solar cells, GaAs / perovskite tandem cells have received extensive attention. Perovskite solar cells have the advantages of simple preparation process and low cost, and their band gap width range allows them to be used as a top cell in a multi-junction cell. Patent No. 202210046762.X discloses a four-terminal perovskite solar cell and a preparation method thereof. The tandem cell structure used in this patent is four-terminal, which requires the preparation of two complete cell structures and the pressing together through pressure, which inevitably makes the process complex and the cost significantly higher. Application No. 202210675836.6 discloses a perovskite / GaAs two-terminal mechanical tandem solar cell with a metal mesh interconnection layer. This application uses a metal mesh as an intermediate interconnection conductive layer between the GaAs bottom cell and the perovskite top cell, which is costly and increases the process flow. Moreover, the top cell uses an organic perovskite absorber layer, which has poor stability. SUMMARY

[0004] To overcome the above problems of complex structure, high cost and poor stability, the application provides a full-inorganic GaAs / perovskite tandem solar cell with carbon material as a hole transport and conductive multifunctional intermediate composite layer and a preparation method thereof. By using carbon material as a multifunctional composite layer for hole transport and intermediate conductive interconnection of the bottom cell, the application can simplify the cell structure and reduce the cost.

[0005] To solve the above technical problems, the technical solutions of the application are as follows:

[0006] A kind of carbon material is as hole transport and conductive multifunctional intermediate composite layer Full-inorganic GaAs / perovskite tandem stack cell, from bottom to top, including back electrode, GaAs substrate layer, carbon material layer, inorganic perovskite top cell layer, front ARC, front electrode;Wherein carbon material is as the hole transport and bottom cell and intermediate interconnection conductive composite function layer of bottom cell and top cell of GaAs bottom cell, inorganic perovskite top cell layer from bottom to top, including electron transport layer, perovskite absorption layer, hole transport layer;

[0007] The front electrode is arranged at both ends of the hole transport layer in the inorganic perovskite top cell layer, and the front ARC is arranged on the hole transport layer in the inorganic perovskite top cell layer and contacts the front electrodes at both ends;The electron transport layer is arranged on the carbon material layer.

[0008] The back electrode is an Au electrode, and the front electrode is an Ag electrode.

[0009] A preparation method of a full-inorganic GaAs / perovskite tandem cell with carbon material as a hole transport and conductive intermediate composite function layer, comprising the following steps:

[0010] 1) evaporating a back electrode on one surface of a GaAs substrate, annealing to form an ohmic contact, and then preparing a carbon material layer on the other surface of the GaAs substrate, to obtain a GaAs bottom cell;

[0011] 2) preparing an electron transport layer on the surface of the carbon material layer;

[0012] 3) preparing a perovskite absorption layer by preparing an inorganic perovskite precursor solution, spin-coating the solution on the surface of the electron transport layer using an anti-solvent method, and high-temperature annealing;

[0013] 4) preparing a hole transport layer on the surface of the perovskite absorption layer;

[0014] 5) evaporating a front electrode at both ends of the hole transport layer, and evaporating an anti-reflection coating on the hole transport layer not covered by the front electrode, to obtain a full-inorganic GaAs / perovskite tandem cell with carbon material as a hole transport and conductive intermediate composite function layer.

[0015] In step 1), the back electrode is an Au electrode, the thickness of the Au electrode is 100-120 nm, the annealing temperature is 300-330℃, and the annealing time is 15-30 s.

[0016] The carbon material is one or more of carbon nanotubes, graphene, carbon fibers, and carbon quantum dots.

[0017] The carbon material layer is prepared by thin film or material wet transfer of the carbon material through suction filtration, and the thickness is 100-200 nm.

[0018] The electron transport layer in step 2 is one or more of TiO2, SnO2, C60, BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) or PCBM (benzo[c][1,2,5]thiadiazole-4,7-dicarboximide).

[0019] The electron transport layer is prepared by magnetron sputtering, and the preparation conditions are: power 60-120 W, vacuum degree 0.4-0.7 Pa, and sputtering time 1-3 min.

[0020] The inorganic perovskite in step 3 is one or more of CsPbI3, CsPbBr3 and CsSnI3.

[0021] The precursors are CsI, PbI2, CsBr, PbBr2 and / or SnI2, and the solvent in the precursor solution is DMF and DMSO, and the volume ratio is (3-5):1.

[0022] The concentration of the precursor solution is 0.5-1.2 M.

[0023] The precursor solution is prepared by stirring the precursors and the solvent; the stirring temperature is 50-90℃, and the stirring time is 8-12 h.

[0024] In the preparation of the perovskite absorption layer, the substrate is preheated at 50-80℃ before the precursor is spin-coated, the preheating time is 3-5 min, the spin-coating speed of the precursor is 2000-3000 rpm, and the time is 20-60 s; the anti-solvent is added within 10-15 s before the rotation is completed.

[0025] The high-temperature annealing temperature is 200-340℃, and the time is 10-30 min.

[0026] The anti-solvent can be chlorobenzene, toluene, ethyl acetate, etc.

[0027] The volume ratio of the anti-solvent to the spin-coated perovskite precursor solution is 10-50:10.

[0028] The hole transport layer in step 4 is PEDOT (polyethylene dioxythiophene), Spiro-OMeTAD (2,2',7,7'-tetra[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene), P3HT (poly-3-hexylthiophene), 2PACz (2-[(2-chlorophenyl)(phenyl)amino]benzoic acid ethyl ester), etc.

[0029] The hole transport layer is prepared by spin coating and then annealing; the rotation speed is 4000-6000 rpm, the time is 30-60 s, the annealing temperature is 100-150℃, and the annealing time is 10-20 min.

[0030] The material of the hole transport layer is prepared into a solution, the solvent of the solution is isopropanol, and the concentration is 0.5-1.5 mg / mL; the thickness of the hole transport layer is 50-150 nm.

[0031] The ARC anti-reflective coating in step 5) is ITO, WO3, PMDS or the like.

[0032] The thickness of the ARC is 10-30 nm, and the thickness of the Ag electrode is 100-120 nm.

[0033] Compared with the prior art, the beneficial effects of the technical scheme of the present application are:

[0034] The GaAs bottom cell in the battery structure of the present application adopts a heterojunction cell, which has lower cost than a homojunction cell, wherein the carbon material is used as a composite functional layer to reduce the intermediate conductive layer required by the traditional series-connected battery, so that the cost can be effectively reduced and the battery structure can be optimized, and the all-inorganic GaAs / perovskite battery can significantly improve the stability and other advantages. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 The schematic diagram of the all-inorganic GaAs / perovskite series-connected stacked battery structure with the carbon material as a hole transport and conductive multifunctional intermediate composite layer; 1-back electrode, 2-GaAs substrate layer, 3-carbon material layer, 4-electron transport layer, 5-perovskite absorption layer, 6-hole transport layer, 9-front ARC, 7-front electrode; 8-inorganic perovskite top cell layer, the inorganic perovskite top cell layer includes the electron transport layer 4, the perovskite absorption layer 5 and the hole transport layer 6 from bottom to top;

[0036] Figure 2 The preparation flow chart of the all-inorganic GaAs / perovskite series-connected battery structure using graphene as a hole transport and conductive multifunctional intermediate composite layer for Example 2. DETAILED DESCRIPTION

[0037] The present application will be further described below in combination with the drawings and specific examples, but the examples do not limit the present application in any form. Unless otherwise specified, the reagents, methods and devices used in the present application are conventional reagents, methods and devices in the technical field. Unless otherwise specified, the reagents and materials used in the following examples are commercially available.

[0038] The structure schematic diagram of the all-inorganic GaAs / perovskite series-connected stacked battery with a carbon material as a hole transport and conductive multifunctional intermediate composite layer is as follows: Figure 1As shown, from bottom to top, it includes back electrode 1, GaAs substrate layer 2, carbon material layer 3, inorganic perovskite top cell layer 8, front ARC 9, and front electrode 7; wherein the carbon material is a composite functional layer for hole transport of GaAs bottom cell and interconnection conduction between bottom cell and top cell, and the inorganic perovskite top cell layer 8 includes, from bottom to top, electron transport layer 4, perovskite absorption layer 5, and hole transport layer 6.

[0039] The front electrode 7 is arranged at both ends of the hole transport layer 6 in the inorganic perovskite top cell layer, and the front ARC 9 is arranged on the hole transport layer 6 in the inorganic perovskite top cell layer and contacts the front electrode at both ends; the electron transport layer 4 is arranged on the carbon material layer 3.

[0040] The back electrode is an Au electrode; and the front electrode is an Ag electrode.

[0041] Embodiment 1

[0042] A preparation method of a full-inorganic GaAs / perovskite tandem stacked cell with carbon material as a hole transport and conductive multifunctional intermediate composite layer, comprising the following steps:

[0043] 1) Au back electrode (thickness of Au electrode: 120 nm) is evaporated on a surface of GaAs substrate, annealed at an annealing temperature of 330℃ for 30s to form an ohmic contact, and then a carbon nanotube layer (thickness of nanotube layer: 100 nm; carbon nanotubes are dispersed in water, and then a carbon nanotube layer is prepared by suction filtration) is prepared on the clean surface of GaAs substrate by suction filtration to obtain a GaAs bottom cell;

[0044] 2) A perovskite top cell is prepared on the surface of the GaAs bottom cell prepared in step 1), a TiO2 electron transport layer material is prepared on the nanotube layer by magnetron sputtering at a power of 60W, a vacuum degree of 0.47Pa, and a sputtering time of 2min;

[0045] 3) 0.5g of CsI and 0.8865g of PbI are weighed and dissolved in 3ml of DMF and DMSO mixed solvent (volume ratio of DMF:DMSO is 4:1) to obtain a precursor solution with a concentration of 0.65M, the stirring temperature is 70℃, and the stirring time is 8h; the substrate of step 2) is preheated at 50℃ for 3min, put into a spin coating device, the rotation speed is 3000rpm, the rotation time is 30s (the amount of precursor solution for spin coating is 10μL), 50μL of chlorobenzene anti-solvent is added at 15s before the rotation is completed, and then high-temperature annealing at 340℃ is carried out for 10min, and then rapid cooling is carried out to prepare a perovskite absorption layer;

[0046] 4) A layer of 2PACz hole transport layer material is prepared on the perovskite absorption layer by spin coating (2PACz solution solvent is isopropanol, concentration is 1 mg / mL, and the amount added is 10 μL), the rotation speed is 2000 rpm, and the time is 30 s. After spin coating, annealing is performed, the annealing temperature is 100°C, and the annealing time is 10 min;

[0047] 5) An ARC (WO3) and Ag electrode is evaporated on the surface of the hole transport layer, the ARC is located in the place not covered by the Ag electrode, and the Ag electrode is located at both ends. The thickness of the ARC is 30 nm, and the thickness of the Ag electrode is 120 nm. Thus, a full inorganic / perovskite tandem cell with carbon nanotubes as a hole transport and conductive intermediate composite functional layer is obtained.

[0048] Example 2

[0049] A full inorganic GaAs / perovskite tandem cell structure with graphene as a hole transport and conductive intermediate composite functional layer and a preparation method thereof, comprising the following steps:

[0050] 1) An Au back electrode is evaporated on a surface of a GaAs substrate, the thickness of the Au electrode is 120 nm, annealing is performed, the annealing temperature is 330°C, the annealing time is 30 s, an ohmic contact is formed, and then a graphene composite functional layer (the thickness of the graphene layer is 100 nm) is prepared on the surface of the clean GaAs substrate by using a wet transfer technology. Thus, a GaAs bottom cell is obtained.

[0051] 2) A perovskite top cell is prepared on the surface of the GaAs bottom cell prepared in step 1), a layer of SnO2 electron transport layer material is prepared by using a magnetron sputtering method, the power is 80 W, the vacuum degree is 0.47 Pa, and the sputtering time is 2.5 min;

[0052] 3) 0.5 g of CsI and 0.8865 g of PbI are dissolved in 3 ml of DMF and DMSO solvents (the volume ratio of DMF to DMSO is 4:1), the stirring temperature is 70°C, and the stirring time is 8 h. Thus, a precursor solution with a concentration of 0.65 M is obtained. The substrate prepared in step 2) is preheated at 80°C for 5 min, is placed in a spin coating device, the rotation speed is 3000 rpm, and the time is 30 s. At 15 s before the rotation is completed, chlorobenzene anti-solvent is added dropwise, high-temperature annealing is performed at 300°C for 10 min, and then rapid cooling is performed. Thus, a perovskite absorption layer is prepared.

[0053] 4) A layer of PEDOT hole transport layer material is prepared on the perovskite absorption layer by spin coating (the solvent of the PEDOT solution is isopropanol, and the volume fraction is 50%), the rotation speed is 6000 rpm, the time is 30 s, the annealing temperature is 140°C, and the annealing time is 10 min;

[0054] 5) Evaporate a layer of ARC (WO3) and Ag electrode on the surface of the hole transport layer, ARC on the hole transport layer not covered by Ag electrode and Ag electrode on both ends, ARC thickness is 20 nm, Ag electrode thickness is 120 nm, a full inorganic / perovskite tandem stacked battery with graphene as a hole transport conductive intermediate composite functional layer is obtained.

[0055] The preparation flow chart of the embodiment is shown in Figure 2

[0056] Comparative Example 1

[0057] Comparative Example 1 is different from Examples 1 and 2 in that the prepared battery is a GaAs / carbon nanotube single-junction battery, and no stacking operation with perovskite battery is performed.

[0058] The device parameters of the solar cell prepared by Example 1 and the solar cell prepared by Comparative Example 1 are shown in Table 1.

[0059] Table 1 Device performance parameters of the solar cells prepared by Examples 1 and Comparative Example 1

[0060] Parameter / sample Example 1 Comparative Example 1 Jsc(mA / cm 2 )]]> 12.26 8.35 V (v) 1.26 0.71 PCE (%) 9.42 3.56

[0061] The present application is not limited to the above-mentioned embodiments, and based on the technical solutions disclosed in the present application, those skilled in the art can make some substitutions and modifications to some technical features without creative labor, and these substitutions and modifications are all within the protection scope of the present application.​

Claims

1. A fully inorganic GaAs / perovskite tandem solar cell with carbon material as a multifunctional intermediate composite layer for hole transport and conduction, characterized in that: From bottom to top, it includes the back electrode, GaAs substrate layer, carbon material layer, inorganic perovskite top cell layer, front ARC, and front electrode. Carbon material serves as a composite functional layer for hole transport in GaAs bottom cells and for conducting electrical interconnection between bottom and top cells. The inorganic perovskite top cell layer consists of an electron transport layer, a perovskite absorption layer, and a hole transport layer from bottom to top. The front electrode is disposed at both ends of the hole transport layer in the inorganic perovskite top cell layer, and the front ARC is disposed on the hole transport layer in the inorganic perovskite top cell layer and in contact with the front electrodes at both ends; the electron transport layer is disposed on the carbon material layer. The method for preparing the all-inorganic GaAs / perovskite tandem solar cell, in which the carbon material serves as the intermediate composite functional layer for hole transport and conductivity, includes the following steps: 1) A back electrode is deposited on one surface of a GaAs substrate by vapor deposition, annealing is performed to form an ohmic contact, and then a carbon material layer is prepared on the other surface of the GaAs substrate to obtain a GaAs bottom cell; 2) An electron transport layer is prepared on the surface of a carbon material layer; 3) Prepare an inorganic perovskite precursor solution, spin-coat it onto the surface of the electron transport layer using an anti-solvent method, and anneal it at high temperature to obtain a perovskite absorption layer. 4) Prepare a hole transport layer on the surface of the perovskite absorber layer; 5) A front electrode is deposited at both ends of the hole transport layer, and an anti-reflection coating ARC is deposited on the hole transport layer not covered by the front electrode to obtain an all-inorganic GaAs / perovskite tandem cell with carbon material as the intermediate composite functional layer for hole transport and conduction. In step 3), the high-temperature annealing temperature is 300~340℃.

2. The all-inorganic GaAs / perovskite tandem solar cell with carbon material as a multifunctional intermediate composite layer for hole transport and conductivity according to claim 1, characterized in that: The back electrode is an Au electrode; the front electrode is an Ag electrode.

3. The all-inorganic GaAs / perovskite tandem solar cell with carbon material as a multifunctional intermediate composite layer for hole transport and conductivity according to claim 1, characterized in that: The carbon material mentioned in step 1) is one or more of carbon nanotubes, graphene, carbon fiber, and carbon quantum dots; The carbon material layer is obtained by preparing a thin film from carbon material through vacuum filtration or wet transfer, and the thickness of the carbon material layer is 100~200nm.

4. The all-inorganic GaAs / perovskite tandem solar cell with carbon material as a multifunctional intermediate composite layer for hole transport and conductivity according to claim 1, characterized in that: The back electrode mentioned in step 1) is an Au electrode with a thickness of 100~120nm; the annealing temperature in step 1) is 300~330℃ and the annealing time is 15~30s; The electron transport layer mentioned in step 2) is TiO2, SnO2, C60, BCP, or PCBM; The electron transport layer was prepared by magnetron sputtering under the following conditions: power of 60-120W, vacuum of 0.4-0.7Pa, and sputtering time of 1-3min.

5. The all-inorganic GaAs / perovskite tandem solar cell with carbon material as a multifunctional intermediate composite layer for hole transport and conductivity according to claim 1, characterized in that: The inorganic perovskite mentioned in step 3) is one or more of CsPbI3, CsPbBr3, and CsSnI3; In step 3), the perovskite precursor is CsI, PbI2, CsBr, PbBr2 and / or SnI2; the solvent in the solution after the precursor is prepared is DMF and DMSO, with a volume ratio of (3~5):

1. When the inorganic perovskite is CsPbI3, the perovskite precursors are CsI and PbI2; When the inorganic perovskite is CsPbBr3, the perovskite precursors are CsBr and PbBr2; When the inorganic perovskite is CsSnI3, the perovskite precursors are CsI and SnI2; The concentration of the precursor solution is 0.5~1.2M.

6. The all-inorganic GaAs / perovskite tandem solar cell with carbon material as a multifunctional intermediate composite layer for hole transport and conductivity according to claim 1, characterized in that: In the preparation of the perovskite absorber layer, the substrate is preheated at 50-80°C for 3-5 minutes before spin-coating the precursor solution; the spin-coating speed of the precursor is 2000-3000 rpm for 20-60 seconds; and the antisolvent is added 10-15 seconds before the end of the spin-coating process. In step 3), the high-temperature annealing time is 10~30 minutes; The antisolvent is one or more of chlorobenzene, toluene, and ethyl acetate.

7. The all-inorganic GaAs / perovskite tandem solar cell with carbon material as a multifunctional intermediate composite layer for hole transport and conductivity according to claim 1, characterized in that: The hole transport layer mentioned in step 4) is one or more of PEDOT, Spiro-OMeTAD, P3HT, and 2PACz; The hole transport layer is obtained by preparing a solution of the hole transport layer material, spin-coating it, and then annealing it. The spin-coating speed is 4000~6000 rpm, the spin time is 30~60s, the annealing temperature is 100~150℃, and the annealing time is 10~20min. The solvent in the solution is isopropanol with a concentration of 0.5~1.5mg / mL. The thickness of the hole transport layer is 50~150nm.

8. The all-inorganic GaAs / perovskite tandem solar cell with carbon material as a multifunctional intermediate composite layer for hole transport and conductivity according to claim 1, characterized in that: In step 5), the ARC anti-reflective coating consists of ITO, WO3, and PMDS. The thickness of the ARC is 10~30nm; the front electrode is an Ag electrode with a thickness of 100~120nm.

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