A perovskite solar cell based on a curled P3HT hole transport layer and a preparation method thereof

Abstract

The invention discloses a perovskite solar cell based on a curled P3HT hole transport layer and a preparation method thereof. The perovskite solar cell based on the curled P3HT hole transport layer comprises a hole transport layer, and the material of the hole transport layer is a curled polythiophene. The curled polythiophene of the invention has a small packing density and can be used as a material for the hole transport layer to enhance carrier transport at the interface between polythiophene and perovskite, thereby improving the efficiency of the perovskite solar cell based on the curled P3HT hole transport layer, and in particular, the curled P3HT can further enhance carrier transport at the interface between P3HT and perovskite.

Description

Technical Field

[0001] The invention belongs to the technical field of solar cells, and in particular relates to a perovskite solar cell based on a curled P3HT hole transport layer and a preparation method thereof. Background Art

[0002] Energy, as one of the earliest natural resources used by humans, has promoted the progress of civilized society and the development of the economic field. In the face of the continuous consumption of non-renewable energy and the increasingly severe energy crisis, it is imperative to develop green renewable energy technology. Although traditional solar cells based on inorganic semiconductor materials such as silicon have been commercialized, their production process is complicated, the cost is too high, and there are defects such as inorganic materials are non-degradable and difficult to flexibly process, which limits their application scope. Solar energy, as a green renewable energy source that is inexhaustible, is one of the most promising photovoltaic technologies.

[0003] Among them, the power conversion efficiency (PCEs) of single-junction perovskite solar cells (PSCs) has reached 26%. Due to their low-cost manufacturing process and impressive optoelectronic performance, perovskite solar cells are considered to be an important resource for the next generation of photovoltaic cells. In a typical pin structure, hole transport materials (HTMs) are generally composed of nickel oxide (NiOX), poly [bis (4-phenyl) (2,4,6-trimethylphenyl) amine] (PTAA) and self-assembled molecules (SAM). However, NiOX, as a metal oxide, cannot achieve high-quality deposition in industrial production; PTAA is composed of triphenylamine, which has a high cost and the benzene ring has a certain instability; SAM is a small molecule, and its film-forming property and stability are lower than those of polymer materials.

[0004] In contrast, poly(3-hexylthiophene) (P3HT) is considered to be a promising hole transport material for high-performance, long-term durability and large-scale scalable perovskite solar cells due to its excellent carrier mobility, low-cost preparation and wide application in conjugated polymers. Therefore, it is of great significance to use P3HT as a hole transport material for the preparation of efficient and stable perovskite solar cells.

[0005] However, the efficiency of perovskite solar devices prepared with existing P3HT in powder, sheet and other morphologies as hole transport layers is not ideal. This may be because the existing P3HT in powder, sheet and other morphologies has general solubility, poor self-assembly ability and high stacking density, and cannot form excellent conjugated stacking, resulting in difficulty in carrier transport and obvious voltage and current losses. Summary of the invention

[0006] In view of the deficiencies in the above-mentioned prior art, the object of the present invention is to provide a perovskite solar cell based on a curled P3HT hole transport layer and a preparation method thereof. The curled polythiophene of the present invention has a small stacking density, which can enhance the carrier transport at the interface between polythiophene and perovskite, thereby improving the efficiency of the perovskite solar cell based on the curled P3HT hole transport layer, especially the curled P3HT can further enhance the carrier transport at the interface between P3HT and perovskite.

[0007] The object of the present invention is to provide a perovskite solar cell based on a curled P3HT hole transport layer, wherein the perovskite solar cell comprises a hole transport layer, and the material of the hole transport layer is a curled polythiophene.

[0008] Preferably, the curled polythiophene comprises curled P3HT.

[0009] Preferably, the bulk density of the curly polythiophene is ≤0.058 g / cm 3 .

[0010] More preferably, the bulk density of the curly polythiophene is 0.028 to 0.042 g / cm 3 .

[0011] Preferably, the perovskite solar cell further comprises a transparent substrate layer, a wetting layer, a perovskite active layer, an electron transport layer, a hole blocking layer and a metal electrode layer.

[0012] Preferably, the transparent substrate layer is transparent conductive glass ITO.

[0013] Preferably, the material of the wetting layer includes nano-aluminum oxide particles.

[0014] Preferably, the wetting layer is an island structure, and the shape of the island structure includes needle-shaped, cone-shaped, columnar, spherical or sheet-shaped.

[0015] Preferably, the material of the perovskite active layer includes lead formamidine iodide.

[0016] Preferably, the material of the electron transport layer includes PCBM.

[0017] Preferably, the material of the hole blocking layer includes BCP.

[0018] Preferably, the material of the metal electrode layer includes silver or gold.

[0019] Preferably, the thickness of the hole transport layer is 10-30 nm, specifically 10 nm, 15 nm, 20 nm, 25 nm, or 30 nm.

[0020] Preferably, the sheet resistance of the transparent substrate layer is ≤80Ω, specifically 80Ω, 60Ω, 50Ω, 40Ω, 30Ω, 20Ω, or 10Ω.

[0021] Preferably, the height of the island structure is 5 to 40 nm, and the horizontal width is 50 to 500 nm. The height of the island structure can be 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, and the horizontal width of the island structure is 50, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm.

[0022] Preferably, the thickness of the perovskite active layer is 600-700 nm, specifically 600 nm, 610 nm, 620 nm, 630 nm, 640 nm, 650 nm, 660 nm, 670 nm, 680 nm, 690 nm, or 700 nm.

[0023] Preferably, the thickness of the electron transport layer is 40 to 100 nm, specifically 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, or 100 nm.

[0024] Preferably, the hole blocking layer has a thickness of 5 to 10 nm, specifically 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, or 10 nm.

[0025] Preferably, the thickness of the metal electrode layer is 50-200 nm, specifically 50 nm, 70 nm, 100 nm, 120 nm, 140 nm, 150 nm, 160 nm, 170 nm, 180 nm, 190 nm, or 200 nm.

[0026] Another object of the present invention is to provide a method for preparing the perovskite solar cell based on the curled P3HT hole transport layer, comprising the following steps:

[0027] A hole transport layer, a wetting layer, a perovskite active layer, an electron transport layer, a hole blocking layer and a metal electrode layer are sequentially stacked on the transparent base layer.

[0028] Preferably, the method of preparing the hole transport layer, the wetting layer, the perovskite active layer, the electron transport layer and the hole blocking layer comprises spin coating.

[0029] Preferably, the concentration of the curled polythiophene is 0.2-1 mg / mL.

[0030] The curled polythiophene of the present invention can also be used in the preparation of devices such as perovskite light emitting diodes, perovskite X-ray detectors, and perovskite lasers.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] (1) The stacking density of the curled polythiophene of the present invention is small, which can enhance the carrier transport at the interface between polythiophene and perovskite, thereby improving the efficiency of perovskite solar cells based on the curled P3HT hole transport layer. In particular, the curled P3HT can further enhance the carrier transport at the interface between P3HT and perovskite. The curled P3HT provides a new idea for improving the performance of perovskite solar cells based on the curled P3HT hole transport layer, and is expected to be applied in industrial production.

[0033] (2) When the curled P3HT of the present invention is applied to a perovskite solar cell based on a curled P3HT hole transport layer, it can be used as a hole transport layer of a pin-type perovskite device, so that the perovskite solar cell based on the curled P3HT hole transport layer has higher efficiency.

[0034] (3) The curled P3HT of the present invention is synthesized into a commercial product and can be obtained in batches, which improves the efficiency of perovskite solar cells based on the curled P3HT hole transport layer, making the efficiency of perovskite solar cells based on the curled P3HT hole transport layer of the organic-inorganic hybrid system exceed 17%. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 . Schematic diagrams of the structures of perovskite solar cells based on curled P3HT hole transport layers in Examples 1 to 9.

[0036] Figure 2 .High-resolution scanning electron microscope top view of the perovskite solar cell based on the curled P3HT hole transport layer prepared in Example 3.

[0037] Figure 3 .High-resolution scanning electron microscope cross-sectional image of the perovskite solar cell based on the curled P3HT hole transport layer prepared in Example 3.

[0038] Figure 4 . JV characteristic curves of the perovskite solar cells based on the curled P3HT hole transport layer of Examples 1 to 5.

[0039] Figure 5 . Actual photos of powdered P3HT and curled 8L-P3HT. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0041] 1L-P3HT is curly P3HT, selected from Chain Walking New Materials Technology (Guangzhou) Co., Ltd., with a bulk density of 0.012g / cm 3 , product model is 1L-P3HT.

[0042] 2L-P3HT is curly P3HT, selected from Chain Walking New Materials Technology (Guangzhou) Co., Ltd., with a bulk density of 0.028g / cm 3 , product model is 2L-P3HT.

[0043] 3L-P3HT is curly P3HT, selected from Chain Walking New Materials Technology (Guangzhou) Co., Ltd., with a bulk density of 0.042g / cm 3 , product model is 3L-P3HT.

[0044] 4L-P3HT is curly P3HT, selected from Chain Walking New Materials Technology (Guangzhou) Co., Ltd., with a bulk density of 0.052g / cm 3 , product model is 4L-P3HT.

[0045] 8L-P3HT is curly P3HT, selected from Chain Walking New Materials Technology (Guangzhou) Co., Ltd., with a bulk density of 0.036g / cm 3 , product model is 8L-P3HT.

[0046] 0L-P3HT is powdered P3HT, selected from Lianxingxing New Materials Technology (Guangzhou) Co., Ltd., with a bulk density of 0.72g / cm 3 , brand name 0L-P3HT.

[0047] Example 1

[0048] The present invention provides a pin-type perovskite solar cell based on a curled P3HT hole transport layer, wherein the specific cell structure is ITO / P3HT / Al 2 O 3 / Perovskite active layer / PCBM / BCP / Ag (such as Figure 1 The specific implementation steps are as follows:

[0049] (1) Cleaning of the transparent substrate layer: First, take out the ITO transparent conductive glass with a square resistance of 30Ω, tear off the plastic protective film on the surface, first gently wipe the surface oil with detergent, then ultrasonically clean it in a low concentration of detergent aqueous solution, deionized water, and isopropanol for 15 minutes respectively, finally blow dry the isopropanol on the ITO surface with nitrogen, and put it in a box for later use;

[0050] (2) Preparation of hole transport layer (P3HT): 8L-P3HT was prepared into a 0.2 mg / mL precursor solution, the solvent was chlorobenzene, the cleaned ITO was first placed in an ultraviolet ozone cleaner for surface hydrophilic treatment, and then the precursor solution of P3HT was sucked out with a pipette and evenly covered on the surface of ITO, first spin-coated at 500 rpm / min for 3 seconds, then spin-coated at 3000 rpm / min for 20 seconds, and the solvent was dried to form a hole transport layer with a thickness of 30 nm;

[0051] (3) Preparation of wetting layer: The purchased aluminum oxide nanoparticle (<50 nm) dispersion (20%) was mixed with isopropanol at a volume ratio of 1:50 (aluminum oxide dispersion: isopropanol) to prepare an aluminum oxide precursor solution, and then the prepared aluminum oxide precursor solution was aspirated with a pipette and spread on the surface of the hole transport layer, first spin-coated at 100 rpm / min for 3 seconds, and then spin-coated at 5000 rpm / min for 20 seconds, and the solvent was dried to form an island-shaped wetting layer with a height of 5 to 40 nm and a horizontal width of 50 to 500 nm;

[0052] (4) Preparation of perovskite active layer: FAPbI 3 The system perovskite precursor solution was sucked out with a pipette and evenly covered on the surface of the wetting layer. It was first spin-coated at 1000 rpm / min for 3 seconds, and then at 5000 rpm / min for 30 seconds. At 21 seconds, 100 μL of chlorobenzene was added as an anti-solvent to form a perovskite active layer. It was then annealed at 100 °C on a hot stage for 30 to 60 minutes to form a perovskite active layer with a thickness of 650 nm.

[0053] (5) Preparation of electron transport layer: 20 mg of PCBM was weighed and added with 1 mL of chlorobenzene to prepare a precursor solution of the electron transport layer. The precursor solution of the electron transport layer was deposited on the surface of the perovskite active layer by spin coating (first at 500 rpm / min for 3 s, then at 2500 rpm / min for 20 s) to form an electron transport layer with a thickness of 60 nm;

[0054] (6) Preparation of hole blocking layer: 8 mg of BCP was weighed and 16 mL of isopropanol was added to prepare a precursor solution. The prepared precursor solution was then aspirated with a pipette and evenly covered on the surface of the hole blocking layer. The layer was first spin-coated at 100 rpm / min for 3 s and then at 5000 rpm / min for 20 s. The solvent was then dried to form a hole blocking layer with a thickness of 5 nm.

[0055] (7) Deposition of metal electrode layer: A 100 nm thick Ag film was thermally evaporated under high vacuum at an evaporation rate of: 20nm was deposited under the conditions, and then The deposition thickness is 100 nm and the deposition area is about 0.07 cm 2 .

[0056] Example 2

[0057] The difference from Example 1 is that 8L-P3HT is prepared into a 0.4 mg / mL precursor solution, and the solvent is chlorobenzene.

[0058] Example 3

[0059] The difference from Example 1 is that 8L-P3HT is prepared into a 0.6 mg / mL precursor solution, and the solvent is chlorobenzene.

[0060] Example 4

[0061] The difference from Example 1 is that 8L-P3HT is prepared into a 0.8 mg / mL precursor solution, and the solvent is chlorobenzene.

[0062] Example 5

[0063] The difference from Example 1 is that 8L-P3HT is prepared into a 1.0 mg / mL precursor solution, and the solvent is chlorobenzene.

[0064] Example 6

[0065] The difference from Example 4 is that 8L-P3HT is replaced by 1L-P3HT.

[0066] Example 7

[0067] The difference from Example 4 is that 8L-P3HT is replaced by 2L-P3HT.

[0068] Example 8

[0069] The difference from Example 4 is that 8L-P3HT is replaced by 3L-P3HT.

[0070] Example 9

[0071] The difference from Example 4 is that 8L-P3HT is replaced by 4L-P3HT.

[0072] Comparative Example 1

[0073] The difference between Comparative Example 1 and Example 4 is that 8L-P3HT is replaced by 0L-P3HT to prepare a 0.8 mg / mL precursor solution, and the solvent is chlorobenzene.

[0074] Performance test method of perovskite solar cells based on curled P3HT hole transport layer: using a solar simulator (Newport, 91160) by NREL using standard silicon solar cell equipment to calibrate the light intensity. The effective measurement area is 0.07 cm 2 , under reverse and forward bias scans, the scan rate was 100mV / s and the bias range was from -0.2V to 1.2V.

[0075] Table 1. Performance of perovskite solar cells of Examples 1-9 and Comparative Example 1.

[0076] sample <![CDATA[ Voc (V)]]> <![CDATA[ Jsc ( mA / cm 2 )]]> FF(%) PCE(%) Example 1 0.91 22.18 77.02 15.54 Example 2 0.95 21.64 75.01 15.41 Example 3 0.97 21.53 74.31 15.56 Example 4 0.97 23.29 76.34 17.20 Example 5 0.98 22.41 76.43 16.85 Example 6 0.96 21.53 75.98 15.70 Example 7 1.00 23.12 77.21 17.85 Example 8 1.01 23.14 77.24 18.05 Example 9 0.97 21.41 75.67 15.71 Comparative Example 1 0.86 20.06 77.01 13.28

[0077] As shown in Table 1, compared with the perovskite with 0L-P3HT as the hole transport layer material, the 8L-P3HT used in the present invention is used to prepare the perovskite solar cell based on the curled P3HT hole transport layer, which significantly improves the energy conversion efficiency of the perovskite solar cell based on the curled P3HT hole transport layer. 3 The efficiency of the perovskite of the system can exceed 17%, especially in the short-circuit current. The energy conversion efficiency of the perovskite solar cell based on the curled P3HT hole transport layer of the present invention is significantly improved. This is because the self-assembled curled P3HT increases the result of photogenerated carrier transfer.

[0078] The present invention provides a very effective way to improve the performance of devices such as perovskite solar cells based on a curled P3HT hole transport layer. At the same time, it also provides a new idea for improving the long-term stability of perovskite solar cells based on a curled P3HT hole transport layer, and has high practical significance and production value.

[0079] In addition, the present invention also plays a positive role in the research of ternary, binary, all-inorganic and tin-based perovskites. At the same time, the curled P3HT is not limited to the perovskite solar cell system based on the curled P3HT hole transport layer, but is also applicable to the entire perovskite optoelectronic field, including perovskite light-emitting diodes, perovskite X-ray detectors, perovskite lasers and other perovskite optoelectronic fields.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that after reading the specification of this application, the technicians can still modify or replace the specific implementation mode of the present invention with equivalents, but these modifications or changes do not deviate from the scope of protection of the pending claims of the present application.

Claims

1. A perovskite solar cell based on a curled P3HT hole transport layer, characterized in that: The perovskite solar cell comprises a hole transport layer, and the material of the hole transport layer is curled P3HT in a macroscopic manner.

2. The perovskite solar cell based on the curled P3HT hole transport layer according to claim 1, characterized in that: The bulk density of the curly P3HT is ≤0.058 g / cm 3 .

3. The perovskite solar cell based on the curled P3HT hole transport layer according to claim 2, characterized in that: The bulk density of the curly P3HT is 0.028 to 0.042 g / cm 3 .

4. The perovskite solar cell based on the curled P3HT hole transport layer according to claim 1, characterized in that: The perovskite solar cell also includes a transparent substrate layer, a wetting layer, a perovskite active layer, an electron transport layer, a hole blocking layer and a metal electrode layer.

5. The perovskite solar cell based on the curled P3HT hole transport layer according to claim 4, characterized in that: The transparent substrate layer is transparent conductive glass ITO; And / or, the material of the wetting layer includes nano-aluminum oxide particles; And / or, the infiltration layer is an island structure, and the shape of the island structure includes needle-shaped, cone-shaped, columnar, spherical or sheet-shaped; And / or, the material of the perovskite active layer includes lead formamidine iodide; And / or, the material of the electron transport layer includes PCBM; And / or, the material of the hole blocking layer includes BCP; And / or, the material of the metal electrode layer includes silver or gold.

6. The perovskite solar cell based on the curled P3HT hole transport layer according to claim 4, characterized in that: The thickness of the hole transport layer is 10 to 30 nm; And / or, the sheet resistance of the transparent substrate layer is ≤80Ω; And / or, the thickness of the perovskite active layer is 600-700 nm; And / or, the thickness of the electron transport layer is 40 to 100 nm; And / or, the thickness of the hole blocking layer is 5 to 10 nm; And / or, the thickness of the metal electrode layer is 50-200 nm.

7. The perovskite solar cell based on the curled P3HT hole transport layer according to claim 5, characterized in that: The island structure has a height of 5 to 40 nm and a horizontal width of 50 to 500 nm.

8. The method for preparing a perovskite solar cell based on a curled P3HT hole transport layer according to any one of claims 4 to 7, characterized in that: The steps include: A hole transport layer, a wetting layer, a perovskite active layer, an electron transport layer, a hole blocking layer and a metal electrode layer are sequentially stacked on the transparent base layer.

9. The method for preparing a perovskite solar cell based on a curled P3HT hole transport layer according to claim 8, characterized in that: The method of preparing the hole transport layer, the wetting layer, the perovskite active layer, the electron transport layer and the hole blocking layer includes spin coating.

10. The method for preparing a perovskite solar cell based on a curled P3HT hole transport layer according to claim 8, characterized in that: The concentration of the curled P3HT is 0.2-1 mg / mL.

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