TW201709540A - Method for preparing solar cell fulfilling a low manufacturing cost, a viable mass production, with low environmental impact, and a superb performance of the resulting perovskite layer - Google Patents

Abstract

To date, the known manufacturing process of the active layer (i.e. perovskite layer) of the perovskite solar cell is yet to be improved. The present disclosure provides a method simultaneously fulfilling a low manufacturing cost, a viable mass production, with low environmental impact, and a superb performance of the resulting perovskite layer.

Description

Method of preparing solar cell

The present disclosure relates generally to a method of making a solar cell, and more particularly to a method of preparing a perovskite type solar cell.

Humans have used petrochemical energy extensively since the industrial revolution, causing serious global warming effects and panic about limited petrochemical energy stocks. Therefore, finding low-carbon, high-efficiency and low-cost renewable energy is one of the most important issues today. Among them, the most important renewable energy sources include solar energy, wind energy, ocean energy and geothermal energy. Among them, solar energy has the advantages of no noise, no rotating components, less environmental constraints, and effective use of peak power.

So far, the solar photovoltaic industry is basically dominated by the 矽-based solar photovoltaic system, but because the system requires high-purity raw materials and extremely high-temperature processes, the cost is high, and it is impossible to effectively achieve the grid parity. The goal; the cost and efficiency of the newly developed thin-film solar systems such as CdTe and CIGS are not able to achieve the expected goals, so the solar photovoltaic industry has been unable to make breakthrough development.

In order to solve the above problems, in recent years, research and development has been carried out on many materials, and perovskite solar cells have received considerable attention in recent years. Perovskite solar cells are organic-inorganic blends whose active layer material is perovskite structure, and its advantages include: solution process, light, flexible and tonable (adjustable energy level), etc. Because of its high energy conversion efficiency and many advantages, it is expected to significantly reduce its production and system installation costs.

In order to achieve good energy conversion efficiency of the prepared perovskite solar cell, the perovskite layer material should be improved. At present, halogens in high-efficiency perovskite solar cells, mainly composed of iodine, can form triiodide perovskite, such as methylammonium lead triiodide (CH ₃ NH ₃ PbI _{3 ).} ), or formamidinium lead trihalide (NH ₂ CH=NH ₂ PbI ₃ ). Doping bromine in the perovskite material can adjust the band gap of the perovskite semiconductor material, thereby changing its color, etc., while doping chlorine in the perovskite material helps the surface morphology of the film. Increase the charge conduction distance, repair material defects, enhance crystallinity, etc.

However, among the current perovskite-doped perovskite materials, the chlorine content is extremely low, mostly accounting for less than 5 at% of all halogens, and even more than 0.1 at% of the measurement limit of general elemental instruments, so the perovskite The degree of modification of the material is limited. The reason for the low chlorine content is mainly due to the way of its process. During the post-heat treatment, methylammonium chloride (MACl) will sublimate and chlorine will leave the calcium. Titanium ore material.

In addition, in the development of perovskite solar cell process, the development of perovskite film process is also emphasized, for example, how to use different solution processes to obtain high quality, large grain, less defect perovskite film. Industrialized solution mass production coating processes, common: blade coating, spray coating, slot-die coating, screen printing, spray Ink coating, dip coating, etc., wherein the immersion coating is an industrial technology that is extremely fast, has a high material usage rate, and is inexpensive compared to other technical machines. Other currently known processes include: one-step processing, sequential deposition, solvent-vapor-assisted processing, hot casting, and the like. The hot casting method has great potential to be used in mass production processes.

The hot casting process was first published in the paper by Nie et al. (Nie et al., High-efficiency solution-processed perovskite solar cells with millimeter-scale grains. Science, 2015. 347: p. 522-525). It is revealed that the perovskite precursor solution is prepared by using methylammonium chloride (MACl) and lead iodide (PbI ₂ ), and spin coating is directly performed on the hot substrate to rapidly crystallize the perovskite precursor on the substrate. . The process described in the article can make the perovskite film have large-sized crystal grains, thereby reducing the loss caused by the grain boundary and achieving high efficiency. Moreover, this process does not require subsequent post-heat treatment, so the chlorine element can be successfully retained in the perovskite material. Since Nie et al. did not quantify the chlorine content inside the film, the inventors of the present invention repeated the above-described Nie et al. process and quantitatively analyzed the chlorine content inside the film, and estimated that the halogen element accounted for about 38 at% or more.

However, in addition to obtaining good perovskite precursors to improve the performance of the active layer of the perovskite solar cell (ie, the perovskite layer), the process of the perovskite layer should also avoid environmental impact. For example, in the process disclosed by Nie et al., the solvent used is dimethylformamide (hereinafter also referred to as DMF), and the EPA ranks the second type of poison, in the process. Volatilization can cause human toxicity, environmental pollution, and increased manufacturing costs.

In addition, the perovskite precursor used by Nie et al. is methylammonium chloride and lead iodide (PbI ₂ ), so during the rapid crystallization process, a large amount of methylammonium lead is produced. Tri-chloride, PbMACl ₃ ), this compound has been proven to have a very large energy level difference (>3 electron volts), so it is impossible to perform effective photoelectric conversion in the visible light and infrared light bands, and the overall performance of the component is Bad influence.

In view of the problems in the paper by Nie et al., Tsai et al. (Tsai, HH et al. Optimizing Composition and Morphology for Large-Grain Perovskite Solar Cells via Chemical Control. Chem. Mater. 27, 5570-5576 (2015)) improvement disclosed embodiment, based additives in the precursor I _2, in a balanced manner by chemical inhibition of generation PbMACl _3, to improve energy conversion efficiency. However, this method first uses toxic DMF as a solvent. Furthermore, the inventors of the present invention found that the method disclosed in the paper by Tsai et al. still fails to stably regulate the chlorine content.

In summary, it can be seen that there is still a need for a process that combines low manufacturing cost, mass production, low environmental impact, and good performance of the produced perovskite layer.

In view of the above problems, the present disclosure provides a perovskite precursor solution for fabricating a solar cell, and a method of preparing the same using the same. The present disclosure provides a perovskite precursor solution for manufacturing a solar cell comprising: a solute selected from the group consisting of methylammonium chloride, methylammonium bromide, and methylammonium iodide. Iodide), ethylammonium chloride, ethylammonium bromide, ethylammonium iodide, formanidinium chloride (NH ₂ CH=NH ₂ Cl) , formazinium bromide (NH ₂ CH=NH ₂ Br), formazinium iodide (NH ₂ CH=NH ₂ I), lead chloride (PbCl ₂ ), lead bromide (PbBr) ₂ ) a solute of a group consisting of lead iodide (PbI ₂ ), and any combination thereof, and a solvent selected from the group consisting of dimethyl sulfoxide (DMSO) and γ-butyrolactone ( Gamma-butyrolactone; GBL), dimethylformamide (DMF), N -methyl-2-pyrrolidone (NMP), acetonitrile, dimethylacetamide (DMAC), and any combination thereof The group consisting of.

In one embodiment, in the perovskite precursor solution of the present disclosure for manufacturing a solar cell, the solvent is selected from the group consisting of DMSO, GBL, NMP, acetonitrile, DMAC, and any combination thereof. Solvent.

For example, the solvent usable for the perovskite precursor solution may be, but is not limited to, DMSO: GBL = 1:9 to 9:1; NMP: GBL = 1:9 to 9:1. Or DMF: GBL = 1:9 to 9:1. Alternatively, the solvent of the perovskite precursor may be selected from the group consisting of DMSO, GBL, and a mixture of DMSO and GBL, wherein when the solvent of the perovskite precursor is DMSO plus a mixed solvent of GBL, GBL accounts for The volume % of the mixed solvent is more than 0% by volume and less than or equal to 90%, preferably 70%.

In a specific embodiment, the perovskite precursor solution for manufacturing a solar cell according to the present disclosure can be classified into a binary precursor solution and a multi-component precursor of a single organic group according to a solute composition. (multiple precursor-single organic group) solution, and a multiple precursor-multiple organic group solution.

When the perovskite precursor solution of the present disclosure is a binary precursor solution, the solute of the binary precursor solution may include: a binary precursor solution first solute, which is selected from the group consisting of : methylammonium chloride, methylammonium bromide, methylammonium iodide, chloride B Base ammonium, ethylammonium bromide, ethylammonium iodide, formamidine chloride, formamidine bromide, formamidine iodide; and a second precursor of a binary precursor solution selected from the following The group consisting of lead chloride, lead bromide, and lead iodide; however, at least one of the first solute and the second solute in the binary precursor solution must be iodide.

The molar ratio of the binary precursor first solute to the binary precursor second solute in the above binary precursor solution may be 1:2 to 2:1.

When the perovskite precursor solution of the present disclosure is a monolithic precursor solution of a single organic group, the solute component and component ratio of the monolithic precursor solution of the single organic group may be, for example but not limited to, the following:

1. (MAI+MACl): PbI ₂ = 1:1, MAI: MACl = 0.95: 0.05 to 0.05: 0.95

2. MAI: (PbI ₂ + PbCl ₂ ) = 1:1, PbI ₂ : PbCl ₂ = 0.95: 0.05 to 0.05: 0.95

3. (MAI+MACl): (PbI ₂ + PbCl ₂ ) = 1:1, (MAI + PbI ₂ ): (MACl + PbCl ₂ ) = 0.95: 0.05 to 0.05: 0.95

4. (MAI+MABr): PbI ₂ = 1:1, MAI: MABr = 0.95: 0.05 to 0.05: 0.95

_{5. MAI: (PbI 2 + PbBr} 2) = 1: 1, PbI 2: PbBr 2 = 0.95: 0.05 to 0.05: 0.95

6. (MAI + MABr) :( PbI 2 + PbBr 2) = 1: 1, (MAI + PbI 2) :( MABr + PbBr 2) = 0.95: 0.05 to 0.05: 0.95

7. MAI: (PbCl ₂ + PbBr ₂ ) = 1:1, PbCl ₂ : PbBr ₂ = 0.95: 0.05 to 0.05: 0.95

8. (MAI+MACl+MABr): PbI ₂ = 1:1, MAI: (MACl + MABr) = 0.95: 0.05 to 0.05: 0.95, MACl: MABr = 0.95: 0.05 to 0.05: 0.95

_{9. MAI: (PbI 2 + PbBr} 2 + PbCl 2) = 1: 1, PbI 2: (PbBr 2 + PbCl 2) = 0.95: 0.05 to _{0.05: 0.95, PbBr 2: PbCl} 2 = 0.95: 0.05 to 0.05: 0.95

10. (MAI + MABr + MACl) :( PbI 2 + PbBr 2 + PbCl 2) = 1: 1, (MAI + PbI 2) :( MACl + MABr + PbBr 2 + PbCl 2) = 0.95: 0.05 to 0.05: 0.95, (MABr + PbBr ₂ ): (MACl + PbCl ₂ ) = 0.95: 0.05 to 0.05: 0.95

11. (FAI + FACl): PbI 2 = 1: 1, FAI: FACl = 0.95: 0.05 to 0.05: 0.95

12. FAI: (PbI ₂ + PbCl ₂ ) = 1:1, PbI ₂ : PbCl ₂ = 0.95: 0.05 to 0.05: 0.95

13. (FAI + FACl) :( PbI 2 + PbCl 2) = 1: 1, (FAI + PbI 2) :( FACl + PbCl 2) = 0.95: 0.05 to 0.05: 0.95

14. (FAI+FABr): PbI ₂ = 1:1, FAI: FABr = 0.95: 0.05 to 0.05: 0.95

_{15. FAI: (PbI 2 + PbBr} 2) = 1: 1, PbI 2: PbBr 2 = 0.95: 0.05 to 0.05: 0.95

16. (FAI + FABr) :( PbI 2 + PbBr 2) = 1: 1, (FAI + PbI 2) :( FABr + PbBr 2) = 0.95: 0.05 to 0.05: 0.95

17. FAI: (PbCl ₂ + PbBr ₂ ) = 1:1, PbCl ₂ : PbBr ₂ = 0.95: 0.05 to 0.05: 0.95

18. (FAI+FACl+FABr): PbI ₂ = 1:1, FAI: (FACl + FABr) = 0.95: 0.05 to 0.05: 0.95, FACl: FABr = 0.95: 0.05 to 0.05: 0.95

_{19. FAI: (PbI 2 + PbBr} 2 + PbCl 2) = 1: 1, PbI 2: (PbBr 2 + PbCl 2) = 0.95: 0.05 to _{0.05: 0.95, PbBr 2: PbCl} 2 = 0.95: 0.05 to 0.05: 0.95

20. (FAI + FABr + FACl) :( PbI 2 + PbBr 2 + PbCl 2) = 1: 1, (FAI + PbI 2) :( FACl + FABr + PbBr 2 + PbCl 2) = 0.95: 0.05 to 0.05: 0.95, (FABr + PbBr ₂ ): (FACl + PbCl ₂ ) = 0.95: 0.05 to 0.05: 0.95

21. (EAI+EACl): PbI ₂ = 1:1, EAI: EACl = 0.95: 0.05 to 0.05: 0.95

22. EAI: (PbI ₂ + PbCl ₂ ) = 1:1, PbI ₂ : PbCl ₂ = 0.95: 0.05 to 0.05: 0.95

23. (EAI+EACl): (PbI ₂ + PbCl ₂ ) = 1:1, (EAI + PbI ₂ ): (EACl + PbCl ₂ ) = 0.95: 0.05 to 0.05: 0.95

24. (EAI+EABr): PbI ₂ = 1:1, EAI: EABr = 0.95: 0.05 to 0.05: 0.95

_{25. EAI: (PbI 2 + PbBr} 2) = 1: 1, PbI 2: PbBr 2 = 0.95: 0.05 to 0.05: 0.95

26. (EAI + EABr) :( PbI 2 + PbBr 2) = 1: 1, (EAI + PbI 2) :( EABr + PbBr 2) = 0.95: 0.05 to 0.05: 0.95

27. EAI: (PbCl ₂ + PbBr ₂ ) = 1:1, PbCl ₂ : PbBr ₂ = 0.95: 0.05 to 0.05: 0.95

28. (EAI+EACl+EABr): PbI ₂ = 1:1, EAI: (EACl + EABr) = 0.95: 0.05 to 0.05: 0.95, EACl: EABr = 0.95: 0.05 to 0.05: 0.95

_{29. EAI: (PbI 2 + PbBr} 2 + PbCl 2) = 1: 1, PbI 2: (PbBr 2 + PbCl 2) = 0.95: 0.05 to _{0.05: 0.95, PbBr 2: PbCl} 2 = 0.95: 0.05 to 0.05: 0.95

30. (EAI + EABr + EACl) :( PbI 2 + PbBr 2 + PbCl 2) = 1: 1, (EAI + PbI 2) :( EACl + EABr + PbBr 2 + PbCl 2) = 0.95: 0.05 to 0.05: 0.95, (EABr + PbBr ₂ ): (EACl + PbCl ₂ ) = 0.95: 0.05 to 0.05: 0.95

When the perovskite precursor solution of the present disclosure is a multi-organic precursor solution of multiple organic groups, the solute component and component ratio of the multi-organic precursor solution of the multiple organic group may be, for example but not limited to, the following:

1. (FAI+MAI): PbI ₂ = 1:1, FAI: MAI = 0.95: 0.05 to 0.05: 0.95

2. (FAI+MABr): PbI ₂ = 1:1, FAI: MABr = 0.95: 0.05 to 0.05: 0.95

3. (FAI + MABr) :( PbI 2 + PbBr 2) = 1: 1, (FAI + PbI 2) :( MABr + PbBr 2) = 0.95: 0.05 to 0.05: 0.95

4. (FAI+MACl): PbI ₂ = 1:1, FAI: MACl = 0.95: 0.05 to 0.05: 0.95

5. (FAI + MACl) :( PbI 2 + PbCl 2) = 1: 1, (FAI + PbI 2): (MACl + PbCl 2) = 0.95: 0.05 to 0.05: 0.95

6. (FAI+MAI+MABr): PbI ₂ = 1:1, FAI: (MAI + MABr) = 0.95: 0.05 to 0.05: 0.95, MAI: MABr = 0.95: 0.05 to 0.05: 0.95

7. (FAI + MAI + MABr) :( PbI 2 + PbI 2 + PbBr 2) = 1: 1, (FAI + PbI 2) :( MAI + PbI 2 + MABr + PbBr 2) = 0.95: 0.05 to 0.05: 0.95, (MAI + PbI ₂ ): (MABr + PbBr ₂ ) = 0.95: 0.05 to 0.05: 0.95

8. (FAI+MAI+MACl): PbI ₂ = 1:1, FAI: (MAI+MACl) = 0.95: 0.05 to 0.05: 0.95, MAI: MACl = 0.95: 0.05 to 0.05: 0.95

9. (FAI+MAI+MACl): (PbI ₂ + PbI ₂ + PbCl ₂ ) = 1:1, (FAI + PbI ₂ ): (MAI + PbI ₂ + MACl + PbCl ₂ ) = 0.95: 0.05 to 0.05: 0.95, (MAI + PbI ₂ ): (MACl + PbCl ₂ ) = 0.95: 0.05 to 0.05: 0.95

10. (FAI+MABr+MACl): PbI ₂ = 1:1, FAI: (MABr+MACl) = 0.95: 0.05 to 0.05: 0.95, MABr: MACl = 0.95: 0.05 to 0.05: 0.95

11. (FAI + MABr + MACl) :( PbI 2 + PbBr 2 + PbCl 2) = 1: 1, (FAI + PbI 2) :( MABr + PbBr 2 + MACl + PbCl 2) = 0.95: 0.05 to 0.05: 0.95, (MABr + PbBr ₂ ): (MACl + PbCl ₂ ) = 0.95: 0.05 to 0.05: 0.95

12. (FAI+MAI+FABr): PbI ₂ = 1:1, FAI: (MAI + FABr) = 0.95: 0.05 to 0.05: 0.95, MAI: FABr = 0.95: 0.05 to 0.05: 0.95

13. (FAI + MAI + FABr) :( PbI 2 + PbI 2 + PbBr 2) = 1: 1, (FAI + PbI 2) :( MAI + PbI 2 + FABr + PbBr 2) = 0.95: 0.05 to 0.05: 0.95, (MAI + PbI ₂ ): (FABr + PbBr ₂ ) = 0.95: 0.05 to 0.05: 0.95

14. (FAI+MAI+FACl): PbI ₂ = 1:1, FAI: (MAI + FACl) = 0.95: 0.05 to 0.05: 0.95, MAI: FACl = 0.95: 0.05 to 0.05: 0.95

15. (FAI+MAI+FACl): (PbI ₂ + PbI ₂ + PbCl ₂ ) = 1:1, (FAI + PbI ₂ ): (MAI + PbI ₂ + FACl + PbCl ₂ ) = 0.95: 0.05 to 0.05: 0.95, (MAI + PbI ₂ ): (FACl + PbCl ₂ ) = 0.95: 0.05 to 0.05: 0.95

16. (FAI+MABr+FABr): PbI ₂ = 1:1, FAI: (MABr + FABr) = 0.95: 0.05 to 0.05: 0.95, MABr: FABr = 0.95: 0.05 to 0.05: 0.95

17. (FAI + MABr + FABr) :( PbI 2 + PbBr 2 + PbBr 2) = 1: 1, (FAI + PbI 2) :( MABr + PbBr 2 + FABr + PbBr 2) = 0.95: 0.05 to 0.05: 0.95, (MABr + PbBr ₂ ): (FABr + PbBr ₂ ) = 0.95: 0.05 to 0.05: 0.95

18. (FAI+MACl+FACl): PbI ₂ = 1:1, FAI: (MACl + FACl) = 0.95: 0.05 to 0.05: 0.95, MACl: FACl = 0.95: 0.05 to 0.05: 0.95

19. (FAI+MACl+FACl): (PbI ₂ + PbCl ₂ + PbCl ₂ ) = 1:1, (FAI + PbI ₂ ): (MACl + PbCl ₂ + FACl + PbCl ₂ ) = 0.95: 0.05 to 0.05: 0.95, (MACl + PbCl ₂ ): (FACl + PbCl ₂ ) = 0.95: 0.05 to 0.05: 0.95

20. (FAI+MABr+FACl): PbI ₂ = 1:1, FAI: (MABr + FACl) = 0.95: 0.05 to 0.05: 0.95, MABr: FACl = 0.95: 0.05 to 0.05: 0.95

21. (FAI + MABr + FACl) :( PbI 2 + PbBr 2 + PbCl 2) = 1: 1, (FAI + PbI 2) :( MABr + PbBr 2 + FACl + PbCl 2) = 0.95: 0.05 to 0.05: 0.95, (MABr + PbBr ₂ ): (FACl + PbCl ₂ ) = 0.95: 0.05 to 0.05: 0.95

22. (FAI+MACl+FABr): PbI ₂ = 1:1, FAI: (MACl + FABr) = 0.95: 0.05 to 0.05: 0.95, MACl: FABr = 0.95: 0.05 to 0.05: 0.95

23. (FAI+MACl+FABr): (PbI ₂ + PbCl ₂ + PbBr ₂ ) = 1:1, (FAI + PbI ₂ ): (MACl + PbCl ₂ + FABr + PbBr ₂ ) = 0.95: 0.05 to 0.05: 0.95, (MACl + PbCl ₂ ): (FABr + PbBr ₂ ) = 0.95: 0.05 to 0.05: 0.95

In a specific embodiment, in the perovskite precursor solution for manufacturing a solar cell, the solute is a mixture of methylammonium chloride, methylammonium iodide and lead iodide, and the concentration of the solute. 0.1M to 1M, the solute is selected from methylammonium chloride, methylammonium bromide, methylammonium iodide, and formanidinium chloride (NH _{2 )} CH=NH ₂ Cl), formazinium bromide (NH ₂ CH=NH ₂ Br), formazinium iodide (NH ₂ CH=NH ₂ I), lead chloride (PbCl ₂ ) Solutes of the group consisting of lead bromide (PbBr ₂ ), and lead iodide (PbI ₂ ) and any combination thereof. In another embodiment, the solvent is a mixture of dimethyl hydrazine and γ-butyrolactone in a volume ratio of 3:7; and the solute is a methyl iodide 8:2:8:2 methyl iodide Ammonium (methylammonium chloride): methylammonium chloride: lead iodide (PbI ₂ ): lead chloride (PbCl ₂ ), or methylammonium chloride, methylammonium iodide and lead iodide Moerby is 8:2:10.

The perovskite precursor solution provided by the present disclosure can be adjusted in proportion to the composition of the precursor, and a part of methylammonium chloride (MACl) is replaced with methylammonium iodide (MAI) and then iodized. Lead (PbI ₂ ) is mixed as a precursor, and the replacement ratio ranges from 2 at% to 100 at%, and 10 at% to 20 at% has the best effect. After the addition, the film crystal size can be made larger under the same process conditions. Reduce the loss of the grain boundary on the component, and increase the crystallinity of the film, increase the absorption coefficient of the film, increase the charge migration distance, and finally increase the energy conversion efficiency of the component by about 5% to 8%, and improve the repeatability and yield. . The ratio of the chlorine content of the final formed film was analyzed to be between about 25 and 30 at%.

The present disclosure further provides a method for preparing a perovskite film for a solar cell, comprising: heating a material to be coated with a perovskite film to a temperature ranging between 25 and 300 ° C, and placing the heated material Soaking in a perovskite precursor solution as described above for 0.1 to 5 seconds, wherein the perovskite precursor solution has a temperature in the range of 25 to 250 ° C, and removing the material from the perovskite precursor solution And the perovskite precursor solution is rapidly dried and crystallized on the substrate by the temperature of the material to form a perovskite film, wherein the perovskite in the perovskite film has a structure represented by ABX ₃ , wherein A At least one of methyl ammonium ion, ethyl ammonium ion, and/or formazan ion (NH ₂ CH=NH ₂ ⁺ ), B is at least one of Pb, Ge, and Sn, and X is a group VII element. Mixing of two or more of at least one or Group VII elements.

Compared with the one-step and two-steps used in the current mainstream, the above-mentioned method for preparing a perovskite film for a solar cell requires only a single step of coating. There is no need to take tens of minutes to several hours of post-heat treatment, so it can be easily combined with roll-to-roll or sheet-to-piece continuous processes to speed up the process and increase productivity and equipment costs. In addition, the immersion coated machine is extremely inexpensive compared to other mass production coating processes. Moreover, the method successfully utilizes the mass production process to make the perovskite film have very large-sized crystal grains, and reduce the loss caused by the grain boundary to achieve high efficiency.

The present disclosure also provides a method of preparing a solar cell, comprising: providing a conductive substrate; forming a first carrier transport layer on the conductive substrate; and preparing the calcium titanium by using the method for preparing a perovskite film for a solar cell as described above a mineral precursor solution is coated on the first carrier transport layer to form a calcium titanium a mineral film; forming a second carrier transport layer on the perovskite film; a shape success function modifying layer on the second carrier transport layer; and forming an electrode layer on the work function reforming layer.

In one embodiment, the conductive substrate is a transparent conductive glass, a transparent conductive plastic, another transparent conductive substrate or an opaque conductive glass, an opaque conductive plastic, or other opaque conductive substrate.

In one embodiment, the first carrier transport layer is a hole transport layer or an electron transport layer, and the second carrier transport layer is a hole transport layer or an electron transport layer, and the electrode layer is a cathode layer or an anode layer.

In one embodiment, the material of the hole transport layer is polydioxyl thiophene: styrene sulfonic acid (PEDOT: PSS), 2, 2', 7, 7'-肆 [N, N- II (4-Methoxyphenyl)amino]-9,9'-spirobifluorene (spiro-OMeTAD), vanadium pentoxide (V ₂ O ₅ ), nickel oxide (NiO), tungsten trioxide (WO ₃ ) or molybdenum trioxide (MoO ₃ ).

In one embodiment, the material of the electron transport layer is lithium fluoride (LiF), calcium (Ca), 6,6-phenyl-C61-butyric acid methyl ester (6,6-phenyl-C61-butyric Acid methyl ester; PC ₆₁ BM), 6,6-phenyl-C71-butyric acid methyl ester (PC ₇₁ BM), 茚-carbon sixty-two double addition (Indene-C60 bisadduct; ICBA), cesium carbonate (Cs ₂ CO ₃ ), titanium dioxide (TiO ₂ ), 2,9-methyl-4,7-diphenyl-1,10-morpholine (bathocuproine, BCP) ), zirconia (ZrO), poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-茀)-alt-2,7-(9) , 9-dioctylfluorene)] (PFN) or zinc oxide (ZnO).

In one embodiment, the material of the work function modifying layer is polyethylenimine (PEI), polyethyleneimine ethoxylated (PEIE), poly[(9,9) -Bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)](PFN), PFN Derivatives (eg, PFN-OX, PFCn6: K+, PFEN-Hg, PBN, PFPA-1), HBPFN, or polycarbazole derivatives PC-P, PCP-EP, PCDTBT-N.

In one embodiment, the material of the electrode layer is calcium (Ca), aluminum (Al), silver (Ag), gold (Au), indium tin oxide, aluminum doped zinc oxide, silver nanowire, poly Dioxyethylthiophene: styrene sulfonic acid, graphene, graphene oxide, or a combination thereof.

The non-toxic solvent perovskite thin film solar cell preparation method provided by the present disclosure utilizes a hot casting method to coat a perovskite precursor dissolved in a non-toxic solvent. The method of preparing the perovskite film can avoid the use of the tube poison, reduce the toxicity to the human body, environmental pollution and manufacturing cost, and produce a film of a very large-sized grain structure, thereby effectively improving the photoelectric conversion efficiency.

It is to be understood that the foregoing description of the invention and the following examples of the invention are intended to provide an understanding of the nature of the invention and

1‧‧‧Electrical substrate

2‧‧‧First carrier transport layer

3‧‧‧Perovskite film absorption layer

4‧‧‧Second carrier transport layer

5‧‧‧Work function modification layer

6‧‧‧electrode layer

1 is a conventional mass production method and an embodiment of the present disclosure A comparison of the performance of a perovskite solar cell produced by a mass production method.

2 is a schematic view showing the construction of a solar cell fabricated by the method of the present disclosure.

Figure 3 is a comparison of the performance of perovskite solar cells made from different perovskite methylammonium replacement ratios of perovskite precursor solutions.

Figure 4 shows the grain size of different perovskite precursor solutions.

Figure 5 is a flow chart of a perovskite thin film solar cell fabricated using a non-toxic solvent.

Figure 6 is a comparison of the efficacy of a perovskite solar cell made with a poisonous and non-toxic solvent.

Figure 7A is a comparison of the crystallization of the resulting perovskite film obtained by X-ray diffraction techniques at different chlorine-containing precursor doping ratios.

Figure 7B shows the surface film morphology obtained by atomic force microscopy of the obtained perovskite film at different doping ratios of chlorine-containing precursors.

Figure 7C is a comparison of the effectiveness of a 0.09 square centimeter perovskite solar cell obtained with different chlorine-containing precursor doping ratios.

Fig. 7D shows the performance of the obtained area of 1 square centimeter of the solar cell with the ratio of the precursor C doping shown in Table 4-1.

Figure 7E shows the flow of a perovskite film by thermal immersion.

Reference will now be made in detail to the embodiments of the disclosure, which are described below One or more embodiments are described. The examples are provided to explain, not limit, the disclosure. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the teachings of the present disclosure without departing from the scope of the disclosure. For example, features illustrated or described as part of one embodiment can be used in combination with another embodiment to produce yet another embodiment. Therefore, the disclosure is intended to cover such modifications and variations as fall within the scope of the appended claims.

Those of ordinary skill in the art will appreciate that the present disclosure is only illustrative of the exemplary embodiments and is not intended to limit the scope of the disclosure.

All references to the singular characteristics or limitations are intended to include the corresponding plural features or limitations, and vice versa, unless otherwise indicated or explicitly indicated to the contrary.

Combinations of all methods or processing steps used herein may be performed in any order, unless otherwise indicated or specifically indicated to the contrary.

In addition, the following examples are provided to further describe the principles and operation of the disclosure. However, this embodiment should not be considered limiting in any way.

Example 1: Mass production method of perovskite thin film solar cell

First, the perovskite film has the general formula ABX ₃ , and the solute of the perovskite precursor solution contains at least one of AX or BX ₂ , and A is an alkali metal ion, a methyl ammonium ion, an ethyl ammonium ion, and an NH ₂ CH. At least one of =NH ₂ ion or alkylammonium ion, B is at least one of a group IV element (germanium, tin, lead), a group III element indium or a group V element bis, and X is a group VII element (fluorine, chlorine At least one of bromine, iodine, and possibly two or more of the Group VII elements may be mixed in any ratio.

For example, if a perovskite film of CH ₃ NH ₃ PbCl _3-x I _x is to be prepared, the solute of the perovskite precursor solution may be methylammonium chloride, methylammonium iodide and lead iodide, solvent. It may be DMF, and its preferred solution concentration is 0.4 M, and the actual concentration may be 0.1 M to 1 M.

The perovskite film of the present embodiment was prepared by hot casting combined with dip coating. The perovskite precursor solution can be heated from 25 to 250 ° C, and then the substrate is heated to a temperature of 150 ° C or 180 ° C, the actual heating temperature can be from 25 to 300 ° C, after which the hot substrate enters the perovskite precursor After the solution is briefly immersed and quickly leaves the solution, the perovskite solution can be rapidly dried and crystallized on the substrate due to the high temperature of the substrate.

The conductive substrate in this embodiment is fluorine-doped tin oxide (FTO), and the actual conductive substrate may be transparent conductive glass, transparent conductive plastic, other transparent conductive substrate or opaque conductive glass, opaque conductive plastic, and other opaque. Conductive substrate.

Then, the first carrier transport layer is formed on the conductive substrate by spin plating or other means. In the embodiment, the first carrier transport layer is a polyelectroxylthiophene: styrenesulfonate. Acid (PEDOT: PSS), 5,000 rpm, 30 seconds, was applied to a conductive substrate by a spin coating process, and baked at 150 ° C for 15 minutes after film formation. Next, the perovskite precursor solution is placed in a beaker, and the conductive substrate on which the hole conducting layer has been plated is heated to 180 ° C, and then the hot substrate is quickly introduced into the perovskite precursor solution for short soaking, rapidly After leaving the solution, the perovskite solution can be quickly dried and crystallized on the substrate due to the high temperature of the substrate. The solute of the perovskite precursor solution is methylammonium chloride and lead iodide, and the molar mixing ratio is 1:1. The solvent is DMF, and its preferred solution concentration is 0.4M. Next, the electron conducting layer 6,6-phenyl-C61-butyric acid methyl ester (PC ₆₁ BM) was spin-plated on the active layer at 1000 rpm for 30 seconds per minute. Coating. Finally, the work function modifying layer PEI is coated on the electron conducting layer by spin coating process at 3000 rpm for 30 seconds per minute, and then a silver electrode having a thickness of 100 nm is evaporated.

In this embodiment, the short-circuit current density of 12.78 mA/cm ² and 17.05 mA/cm ² , the open circuit voltages of 1063.78 and 1049.39 millivolts, and the fill factor of 48.56 and 51.90 can be obtained by using 150 ° C or 180 ° C, respectively. The perovskite thin film solar cells using hot-casting and immersion coating with photoelectric conversion efficiency of 6.60 and 9.28% (please refer to Fig. 1 and Table 1).

Example 2: Preparation and use of a perovskite precursor to produce a thin film solar cell (as shown in Figure 2)

In this embodiment, partial methylammonium chloride (MACl) is replaced with methylammonium iodide (MAI) and then mixed with lead iodide (PbI ₂ ) as a precursor, followed by heat. Coating is carried out by casting.

According to the above, the perovskite film of the present embodiment is prepared by hot casting method - the perovskite precursor solution is heated to an optimum temperature of 120 ° C, and the actual heating temperature can be from 25 to 250 ° C, and then heated immediately. The solution is plated on the heated substrate by spin coating, and the actual coating method is not limited to spin coating, such as blade coating, spray coating, slit coating (slot) -die coating), screen printing, inkjet printing, dip coating, the optimum substrate temperature is 180 ° C, the actual heating temperature can be from 25 to 300 °C.

This process is faster and more convenient than traditional vacuum processes and wet-coating one-step, two-steps processes, without the need for expensive vacuum equipment or the need for traditional wet processes. Large-grain and high-energy conversion efficiency can be achieved after annealing for a long time.

The conductive substrate in this embodiment is fluorine-doped tin oxide (FTO), and the actual conductive substrate may be transparent conductive glass, transparent conductive plastic, other transparent conductive substrate or opaque conductive glass, opaque conductive Plastic, other opaque conductive substrates.

Then, the first carrier transport layer is formed on the conductive substrate by spin plating or other means. In the embodiment, the first carrier transport layer is a polyelectroxylthiophene: styrenesulfonate. Acid (PEDOT: PSS), 5,000 rpm, 30 seconds, was applied to a conductive substrate by a spin coating process, and baked at 150 ° C for 15 minutes after film formation. Next, the perovskite precursor solution is heated to 120 ° C, while the conductive substrate plated with the hole conducting layer is heated to 180 ° C, and then the heated perovskite precursor solution is quickly dropped onto the heated conductive The substrate is coated by a spin coating process at 4000 rpm for 15 seconds per minute. The solute of the perovskite precursor solution is methylammonium chloride (MACl), methylammonium iodide (MAI) and Lead iodide (PbI ₂ ), the molar mixing ratio is 8:2:10 (may also be 10:0:10, 9.5:0.5:10, 9:1:10, 8:2:10, or 5:5) : 10), the solvent is dimethylformamide (DMF), the concentration is 0.4M. Next, the electron conducting layer 6,6-phenyl-C61-butyric acid methyl ester (PC ₆₁ BM) was spin-plated on the active layer at 1000 rpm for 30 seconds per minute. Coating. Finally, the work function modifying layer PEI is coated on the electron conducting layer by spin coating process at 3000 rpm for 30 seconds per minute, and then a silver electrode having a thickness of 100 nm is evaporated.

In this embodiment, by adjusting the optimum spin coating speed, solution concentration, carrier conductive layer material and electrode material, the short circuit current density is 19.21 mA/cm ² , the open circuit voltage is 1.00 V, and the fill factor is 80.76, a perovskite thin film solar cell with a photoelectric conversion efficiency of 15.56%.

Please refer to FIG. 3 and Table 2. Compared with the conventional perovskite solar cell, the present disclosure replaces part of methylammonium chloride (MACl) with methylammonium iodide (MAI). The range is between 2at% and 100at%. As shown in Figure 4, the grain size increases with the addition of MAI, but at 0.5:0.5:1, the grain does not form a continuous film covering all of it. surface. 10at% to 20at% has the best effect. After the addition, under the same process conditions, the loss of the grain boundary on the component is reduced, and the crystallinity of the film can be increased, the absorption coefficient of the film can be increased, the charge migration distance can be increased, and finally the component energy can be obtained. The conversion efficiency is increased by about 5% to 8%, and the repeatability and yield are improved.

Example 3: Preparation of a perovskite thin film solar cell from a non-toxic solvent

In this embodiment, the perovskite precursor is dissolved in a non-toxic solvent and then coated by hot casting. The simple flow diagram is shown in Figure 5.

For example, if a perovskite film of CH ₃ NH ₃ PbI ₃ is to be prepared, the solute of the perovskite precursor solution is methyl ammonium iodide and lead iodide, and the solvent is DMSO plus GBL, and the volume mixing ratio can be From 1:9 to 10:0, for example about 3:7, the actual preferred solution concentration can be, for example, from 0.1 M to 1 M, for example about 0.8 M.

According to the above, the perovskite film of the present embodiment is prepared by hot casting method - the perovskite precursor solution is heated to an optimum temperature of 120 ° C, and the actual heating temperature can be from 25 to 250 ° C, and then heated immediately thereafter. The solution is plated on the heated substrate by spin coating, and the actual coating method is not limited to spin coating, such as blade coating, spray coating, slit coating (slot) -die coating), screen printing, inkjet printing, dip coating, the optimum substrate temperature is 180 ° C, the actual heating temperature can be from 25 to 300 °C.

This process is faster and more convenient than traditional vacuum processes and wet-coating one-step, one-steps processes, without the need for expensive vacuum equipment or the long time required for traditional wet processes. After annealing, large grain and high energy conversion efficiency can be achieved.

The conductive substrate in this embodiment is fluorine-doped tin oxide (FTO), the actual conductive substrate can be transparent conductive glass, transparent conductive plastic, other transparent conductive substrate or opaque conductive glass, opaque conductive plastic, other opaque conductive substrate.

Then, the first carrier transport layer is formed on the conductive substrate by spin plating or other means. In the embodiment, the first carrier transport layer is a polyelectroxylthiophene: styrenesulfonate. Acid (PEDOT: PSS), 5,000 rpm, 30 seconds, was applied to a conductive substrate by a spin coating process, and baked at 150 ° C for 15 minutes after film formation. Next, the perovskite precursor solution is heated to 120 ° C, while the conductive substrate plated with the hole conducting layer is heated to 180 ° C, and then the heated perovskite precursor solution is quickly dropped onto the heated conductive On the substrate, the spin coating process is applied at 4000 rpm for 15 seconds per minute, and the solute of the perovskite precursor solution is methylammonium iodide (MAI) and lead iodide (PbI ₂ ), and the molar mixing ratio is For 1:1, the solvent is Dimethyl sulfoxide (DMSO) plus gamma-butyrolactone (GBL), the volume mixing ratio is 3:7, and the solution concentration is 0.8M. Next, the electron conducting layer 6,6-phenyl-C61-butyric acid methyl ester (PC ₆₁ BM) was spin-plated on the active layer at 1000 rpm for 30 seconds per minute. Coating. Finally, the work function modifying layer PEI is coated on the electron conducting layer by spin coating process at 3000 rpm for 30 seconds per minute, and then a silver electrode having a thickness of 100 nm is evaporated.

In this embodiment, by adjusting the optimum spin coating speed, solution concentration, carrier conductive layer material and electrode material, the short circuit current density is 20.87 mA/cm ² , the open circuit voltage is 0.94 V, and the fill factor is 80.2. A non-toxic solvent perovskite thin film solar cell with a photoelectric conversion efficiency of 15.73%.

Please refer to FIG. 6 and Table 3. Compared with the conventional perovskite solar cell, the non-toxic solvent perovskite thin film solar cell preparation method of the present disclosure can avoid the use of the tube poison to reduce the toxicity to the human body and the environment. Pollution and manufacturing costs and the use of hot-casting to produce a film of very large-sized grain structure, effectively improving the photoelectric conversion efficiency.

Example 4: Testing various perovskite precursor solutions having different compositions for producing perovskite thin film solar cells

The manner of preparation is the same as that of Examples 1 to 3 (the flow can be, for example, as shown in FIG. 7E), but in the perovskite precursor solution, the solute components and their proportions are as shown in Table 4-1 below, and the solvents are all A mixture of DMSO and GBL (3:7 by volume) was used.

As shown in the X-ray diffraction pattern shown in Fig. 7A, the addition of 3 to 5%, the diffraction intensity of PbMACl ₃ is still weak compared to the compound having a perovskite structure. The optimal proportion of chlorine precursors increases the charge conduction distance. The charge transmission distance measured by photoexcitation spectroscopy increases the electron transport distance from 500 nm by adding 5% chlorine compared to the non-chlorinated perovskite. To 660 nm, the electronics increased from 720 nm to 820 nm. Adding an appropriate proportion of the chlorine precursor can significantly make the film more even and uniform. As shown in the surface morphology observed by the atomic force microscope in Figure 7B, the surface becomes very flat after the addition of the chlorine precursor, compared to the surface without the addition of the chlorine precursor. The roughness is reduced from 200 nm to about 30 nm. Chlorine doping induces the formation of a small amount of secondary phase PbI ₂ , as shown by the X-ray diffraction spectrum of Figure 7A. The diffraction peak of PbI ₂ is not limited by theory, but it can be used for this secondary phase. Repair defects in perovskite materials and reduce charge loss. The optimal proportion of chlorine precursor doping induces the (110) crystal orientation of perovskite, which contributes to the conduction of charge, as shown in the X-ray diffraction pattern shown in Figure 7A, with the addition of a suitable chlorine precursor. Enhance (110) crystal diffraction intensity and reduce (020) crystal diffraction intensity. The above various effects are multiplied, and the energy conversion efficiency is 18.5% of the battery with an area of 0.09 square centimeter, and the energy conversion efficiency is 18.5% (Table 4-2), and the current density versus voltage as shown in FIG. 7C. Measurement results, this value surpasses all previous perovskite solar cells made by hot casting. We used precursor C to make a cell with a square centimeter area, and the energy was converted to 15.4%, as shown in Figure 7D. The measurement results surpass all current one square centimeter perovskite efficiency records.

All references cited in this specification are hereby incorporated by reference in their entirety in their entirety. The discussion of the references herein is only intended to summarize the claims of the authors of the references, and does not recognize that any reference constitutes prior art. Applicants reserve the right to challenge the accuracy and pertinence of the cited references.

Although the preferred embodiments of the present disclosure have been described using specific terms, devices, and methods, this description is for illustrative purposes only. The text used is explanatory text and not restrictive text. It should be understood that Changes and modifications may be made by those of ordinary skill in the art in the spirit and scope of the disclosure. In addition, it should be understood that aspects of the various embodiments may be substituted in whole or in part. The spirit and scope of the appended claims should not be limited by the description of the preferred forms contained herein.

Claims (15)

A perovskite precursor solution for manufacturing a solar cell, comprising: a solute selected from the group consisting of methylammonium chloride, methylammonium bromide, and methylammonium iodide Iodide), ethylammonium chloride, ethylammonium bromide, ethylammonium iodide, formanidinium chloride (NH ₂ CH=NH ₂ Cl) , formazinium bromide (NH ₂ CH=NH ₂ Br), formazinium iodide (NH ₂ CH=NH ₂ I), lead chloride (PbCl ₂ ), lead bromide (PbBr) _a solute of a group consisting of ₂ ), and lead iodide (PbI ₂ ), and any combination thereof, and a solvent selected from the group consisting of dimethyl sulfoxide (DMSO), γ-butyrolactone (gamma-butyrolactone; GBL), dimethylformamide (DMF), N -methyl-2-pyrrolidone (NMP), acetonitrile, dimethylacetamide (DMAC), and any combination thereof The group formed. A perovskite precursor solution according to claim 1 or 2, wherein the solvent is selected from the group consisting of DMSO, γ-butyrolactone, NMP, acetonitrile, DMAC, and any combination thereof. A perovskite precursor solution according to claim 1 or 2, wherein the solute concentration is from 0.1 M to 1 M, the solute is selected from the group consisting of methylammonium chloride, methylammonium bromide, and iodine. Methylammonium iodide, formanidinium chloride (NH ₂ CH=NH ₂ Cl), formazinium bromide (NH ₂ CH=NH ₂ Br), iodine methyl iodide the group _{(formanidinium iodide, NH 2 CH =} NH 2 I), lead chloride (PbCl _2), lead bromide (PbBr _2), and lead iodide (PbI _2), and any of their combination consisting of Solute. A perovskite precursor solution according to claim 1 or 2, wherein the solvent is a mixture of dimethyl hydrazine and γ-butyrolactone in a volume ratio of 3:7, the solute being a molar ratio of 8:2:8: 2 methylammonium iodide: methylammonium chloride: lead iodide (PbI ₂ ): lead chloride (PbCl ₂ ). A method for preparing a perovskite film for a solar cell, comprising: heating a material to be coated with a perovskite film to a temperature ranging between 25 and 300 ° C, and placing the heated material as required The perovskite precursor solution of any one of 1 to 4, wherein the perovskite precursor solution has a temperature ranging from 25 to 250 ° C, and the perovskite precursor is caused by the temperature of the material The solution is rapidly dried and crystallized on the substrate to form a perovskite film. The method of claim 5, wherein the perovskite in the perovskite film has a structure represented by ABX ₃ , wherein A is a methylammonium ion, an ethylammonium ion, and/or a formazan ion (NH _{2 )} At least one of CH=NH ₂ ⁺ ), B is at least one of Pb, Ge, and Sn, and X is a mixture of at least one of Group VII elements or two or more of Group VII elements. A method of preparing a solar cell, comprising: providing a conductive substrate; forming a first carrier transport layer on the conductive substrate; applying a perovskite precursor solution to the first method according to the method of claim 5 or a carrier transport layer to form a perovskite film; a second carrier transport layer formed on the perovskite film; a shape success function modifying layer on the second carrier transport layer; and forming an electrode layer on the work function On the modified layer. The method of claim 7, wherein the conductive substrate is a transparent conductive glass, a transparent conductive plastic, another transparent conductive substrate or an opaque conductive glass, an opaque conductive plastic, or another opaque conductive substrate. The method of claim 7, wherein the first carrier transport layer is a hole transport layer or an electron transport layer, and the second carrier transport layer is a hole transport layer or an electron transport layer, and the electrode layer is It is a cathode layer or an anode layer. The method of claim 7, wherein the material of the hole transport layer is polydioxyl thiophene: styrene sulfonic acid (PEDOT: PSS), 2, 2', 7, 7'-肆 [N, N- Bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene (spiro-OMeTAD), vanadium pentoxide (V ₂ O ₅ ), nickel oxide (NiO), tungsten trioxide (WO ₃ ) or molybdenum trioxide (MoO ₃ ). The method of claim 7, wherein the material of the electron transport layer is lithium fluoride (LiF), calcium (Ca), 6,6-phenyl-C61-butyric acid methyl ester (6,6-phenyl-C61- Butyric acid methyl ester; PC ₆₁ BM), 6,6-phenyl-C71-butyric acid methyl ester (PC ₇₁ BM), 茚-carbon sixty plus Indene-C60 bisadduct (ICBA), cesium carbonate (Cs ₂ CO ₃ ), titanium dioxide (TiO ₂ ), 2,9-methyl-4,7-diphenyl-1,10-morpholine (bathocuproine, BCP), zirconia (ZrO), poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-茀)-alt-2,7-( 9,9-dioctylfluorene)] (PFN), zinc oxide (ZnO), or tin oxide (SnO 2 ). The method of claim 7, wherein the material of the work function layer is polyethylenimine (PEI), polyethyleneimine ethoxylated (PEIE), poly[(9, 9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)](PFN), PFN-OX, PFCn6: K+, PFEN-Hg, PBN, PFPA-1, HBPFN or polycarbazole derivatives PC-P, PCP-EP, PCDTBT-N. The method of claim 7, wherein the material of the electrode layer is calcium (Ca), aluminum (Al), silver (Ag), gold (Au), indium tin oxide, aluminum-doped zinc oxide, silver nanometer. Line, polydioxyethylthiophene: styrene sulfonic acid, graphene, graphene oxide, or a combination thereof. A perovskite type solar cell produced by the perovskite precursor solution according to any one of claims 1 to 4. A perovskite type solar cell produced by the method of any one of claims 7 to 13.