A resin acid interfacial modified perovskite solar cell and a preparation method thereof

Abstract

The application discloses a resin acid interface modified perovskite solar cell, which comprises a transparent conductive electrode, an electron transport layer, a perovskite active layer, an interface modification layer, a hole transport layer and a metal electrode layer which are stacked in sequence; wherein the electron transport layer is a SnO2 film, the interface modification layer is a resin acid (C 19 H 29 COOH), and the perovskite active layer is MAPbI3 (CH3NH3PbI3); the perovskite cell has lower interface defects, can maintain higher photoelectric conversion efficiency under high humidity conditions, and has higher environmental stability. The application further provides a preparation method of the resin acid interface modified perovskite solar cell.

Description

Technical Field

[0001] This invention relates to the field of perovskite solar cells, and more specifically to a resin acid interface modified perovskite solar cell and its preparation method. Background Technology

[0002] In recent years, energy and environmental issues have received increasing attention. Perovskite solar cells, with their low cost and high efficiency, have been widely studied and are expected to replace silicon cells as the next generation of solar cells.

[0003] Despite significant progress in the energy conversion efficiency of perovskite solar cells, their poor stability limits their long-term use. Specifically, perovskite solar cells are prone to reacting with water under high humidity conditions, leading to perovskite degradation and decomposition, thus reducing device efficiency. Interface modification is an effective means to improve the resistance of perovskite to adverse environmental factors such as water and oxygen. Summary of the Invention

[0004] One of the objectives of this invention is to provide a resin acid interface-modified perovskite solar cell, which has low interface defects and good environmental stability, and can maintain high photoelectric conversion efficiency under high humidity conditions.

[0005] The second objective of this invention is to provide a method for preparing the above-mentioned perovskite solar cell.

[0006] To achieve the above objectives, the present invention adopts the following solution:

[0007] A resin-acid interface-modified perovskite solar cell includes a transparent conductive electrode, an electron transport layer, a perovskite active layer, an interface modification layer, a hole transport layer, and a metal electrode layer stacked sequentially; wherein the electron transport layer is a SnO2 thin film, and the interface modification layer is a resin acid (C 19 H 29 COOH (CAS No. 514-10-3), the perovskite active layer is MAPbI3 (CH3NH3PbI3).

[0008] Furthermore, the transparent conductive electrode is fluorine-doped tin oxide glass (FTO).

[0009] Furthermore, the thickness of the interface modification layer is 10–40 nm.

[0010] Furthermore, the thickness of the SnO2 thin film is 30–60 nm.

[0011] Furthermore, the thickness of the perovskite active layer is 300–450 nm.

[0012] Furthermore, the hole transport layer is Spiro-OMeTAD, with a thickness of 40–80 nm.

[0013] Furthermore, the metal electrode layer is gold, and its thickness is 80–100 nm.

[0014] The present invention also provides a method for preparing the above-mentioned resin acid interface modified perovskite solar cell, comprising the following steps: after surface treatment of a transparent conductive electrode, an electron transport layer, a perovskite active layer, and an interface modification layer are prepared sequentially by spin coating; then a hole transport layer and a metal electrode layer are prepared to obtain a resin acid interface modified perovskite solar cell.

[0015] As one embodiment of the present invention, the surface treatment method of the transparent conductive electrode is as follows: the FTO substrate is ultrasonically cleaned for 10 minutes each with detergent, deionized water and isopropanol, and then dried with nitrogen; finally, the cleaned and dried FTO substrate is subjected to ultraviolet-ozone surface treatment for 10 minutes.

[0016] As one embodiment of the present invention, the electron transport layer is prepared by spin-coating an aqueous solution of SnO2 nanoparticles onto a surface-treated transparent conductive electrode, and then performing an annealing treatment; preferably, the annealing treatment temperature is 150°C and the time is 30 min.

[0017] As one embodiment of the present invention, the perovskite active layer is prepared by dissolving PbI2 and MAI in a mixed solvent of DMF and DMSO, spin-coating the resulting mixed solution onto an electron transport layer, and annealing to obtain a MAPbI3 perovskite active layer.

[0018] Preferably, in the method for preparing the perovskite active layer, the volume ratio of DMF to DMSO in the mixed solvent is 4:1; the annealing temperature is 100°C and the annealing time is 10 min.

[0019] As one embodiment of the present invention, the method for preparing the interface modification layer is as follows: spin-coating a chlorobenzene solution of resin acid onto a perovskite active layer, followed by heat treatment to obtain a resin acid interface modification layer.

[0020] Preferably, in the method for preparing the interface modification layer, the concentration of the chlorobenzene solution of the resin acid is 2 mg / mL, the spin coating speed is 3000-6000 rpm, the heat treatment temperature is 100℃, and the heating time is 1 min.

[0021] As one embodiment of the present invention, the hole transport layer is prepared by dissolving Spiro-OMeTAD in chlorobenzene, adding 4-tert-butylpyridine (TBP) and lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI), and spin-coating the resulting mixed solution onto the interface modification layer to obtain the hole transport layer.

[0022] As one embodiment of the present invention, the preparation step of the metal electrode layer is as follows: gold particles are uniformly evaporated on the surface of the hole transport layer using an evaporation coating apparatus.

[0023] Preferably, the evaporation coating rate is

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] This invention introduces a resin acid material as an interface modification layer between the hole transport layer and the perovskite active layer of a perovskite solar cell. This effectively improves the stability of perovskite under high humidity, reduces carrier recombination, passivates perovskite surface defects, and improves the photoelectric conversion efficiency of the perovskite solar cell. This provides an effective way to achieve high-stability and high-efficiency perovskite solar cells.

[0026] Moreover, resin acid is a natural biomolecule with excellent hydrophobic properties, environmental friendliness, and low cost, making it very suitable for use in perovskite solar cells. Attached Figure Description

[0027] Figure 1 This is the device structure of the perovskite solar cell of the present invention;

[0028] Figure 2 Comparison of the microstructure of the perovskite active layer with and without the coating of resin acid interface modification layer;

[0029] Figure 3 The current density versus voltage curves for perovskite solar cell devices with and without resin acid interface modification are shown.

[0030] Figure 4 A comparison of the stability of resin-acid-modified perovskite solar cell devices and unmodified perovskite solar cell devices under a relative humidity of 85%. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to specific embodiments. These embodiments are only used to explain the present invention and are not intended to limit the scope of the present invention. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods; the materials and reagents used are commercially available unless otherwise specified.

[0032] Example 1

[0033] The perovskite solar cell device structure of the resin acid interface-modified perovskite layer in this embodiment is: FTO / SnO2 / MAPbI3 / resin acid / Spiro-OMeTAD / Au, see reference. Figure 1 The specific preparation process is as follows:

[0034] (1) The FTO substrate was ultrasonically cleaned for 10 min each with dish soap, deionized water and isopropanol, and then dried with nitrogen. The cleaned and dried FTO substrate surface was subjected to ultraviolet-ozone treatment for 10 min.

[0035] (2) Spin-coating an electron transport layer SnO2 onto the FTO surface treated in step (1), specifically: using SnO2 nanoparticle aqueous solution colloid purchased from Alfa, diluted 5 times with deionized water; spin-coating the diluted SnO2 nanoparticle aqueous solution onto the FTO substrate surface treated above, at a rotation speed of 3000 rpm for 30 s; then performing annealing treatment at a temperature of 150℃ for 30 min to obtain an electron transport layer with a thickness of 30-60 nm; after annealing, performing a 10-minute UV-ozone surface treatment to prepare for spin-coating a perovskite active layer.

[0036] (3) A perovskite active layer was prepared on the surface of the electron transport layer. Specifically, PbI2 and MAI were first dissolved in a 1:1 molar ratio in a 4:1 volume ratio of DMF and DMSO mixed solvent and stirred for 24 h to obtain a perovskite active layer solution with a concentration of 1.2 mol / L. The above solution was then spin-coated onto the surface of the electron transport layer. First, the solution was pre-spin-coated at a speed of 500 rpm for 3 s, and then uniformly spin-coated at a speed of 4000 rpm for 30 s. At the 10th s, 400 μL of chlorobenzene solution was added as an anti-solvent. Finally, the solution was annealed at 100 °C for 10 min to obtain a perovskite active layer with a thickness of 300–450 nm.

[0037] (4) A resin acid interface modification layer was prepared on the above perovskite active layer. Specifically, the resin acid was purchased from Sigma-Aldrich. 2-10 mg of resin acid powder was dispersed in chlorobenzene solution and heated and stirred at 80°C for 2 h to obtain a solution with a concentration of 2 mg / mL. The resin acid solution was spin-coated on the surface of the perovskite active layer at 5000 rpm for 30 s, and then heated at 100°C for 1 min to obtain an interface modification layer with a thickness of 10-40 nm.

[0038] (5) Preparation of hole transport layer: 72-73 mg spiro-OMeTAD, 17-18 μL of Li-TFSI with a concentration of 520 mg / mL and 28-29 μL of TBP are added to 1 mL of chlorobenzene solvent to prepare spiro-OMeTAD mixed solution; 40 μL of spiro-OMeTAD mixed solution is dropped onto the interface modification layer and spin-coated at 3000-5000 rpm for 30-50 s to obtain a hole transport layer with a thickness of 40-80 nm.

[0039] (6) Preparation of the metal electrode layer: Gold with a purity of 99.5%–99.9% is deposited using an evaporation coating apparatus. The metal electrode layer is thermally evaporated onto the hole transport layer at a rate of 80–100 nm to form a metal electrode layer.

[0040] Comparative Example 1

[0041] The difference between this comparative example and Example 1 is as follows:

[0042] Omit the above step (4), do not introduce a resin acid interface modification layer on the perovskite active layer, and directly prepare a hole transport layer on its surface.

[0043] See Figure 2 The figure shows the microstructure of the perovskite surface of the perovskite solar cell of Example 1 and the perovskite solar cell of Comparative Example 1. It can be seen that the interface modification layer of the present invention achieves uniform coverage on the perovskite surface, improving the roughness and particle size uniformity of the perovskite active layer surface.

[0044] See Figure 3 The figure shows the current density versus voltage curves for a resin-acid-modified perovskite solar cell device and an unmodified perovskite solar cell device; from Figure 3 It can be concluded that the open-circuit voltage, current density, fill factor, and photoelectric conversion efficiency of the unmodified resin acid perovskite solar cell device are 1.14V, 23.88mA / cm², and respectively. 2 The open-circuit voltage, current density, fill factor, and photoelectric conversion efficiency of the resin-modified perovskite solar cell were 1.14 V, 77.25%, and 21.11%, respectively.2 The percentages are 78.74% and 21.90%, respectively. This indicates that the resin acid interface modification layer of the present invention does not have an adverse effect on the electrical performance of the perovskite solar cell, but can instead improve the current density, fill factor and photoelectric conversion efficiency.

[0045] See Figure 4 The figure shows a statistical comparison of the efficiency of resin-acid-modified perovskite solar cell devices and unmodified perovskite solar cell devices after 30 days of aging at 85% relative humidity; from Figure 4 The results show that the perovskite solar cell with resin acid interface modification did not experience significant efficiency degradation after 30 days of aging, maintaining 85% of the initial efficiency, indicating that the resin acid interface modification layer can improve the stability of perovskite solar cells.

[0046] This invention can be summarized in other specific forms that do not depart from the spirit or main features of the invention. The above embodiments of the invention are merely illustrative and not restrictive. Therefore, any minor modifications, equivalent variations, and alterations made to the above embodiments based on the essential technology of this invention fall within the scope of the invention's technical solution.

Claims

1. A resin acid interface-modified perovskite solar cell, characterized in that, It includes a transparent conductive electrode, an electron transport layer, a perovskite active layer, an interface modification layer, a hole transport layer, and a metal electrode layer stacked sequentially; wherein, the electron transport layer is a SnO2 thin film, the interface modification layer is a resin acid, and the perovskite active layer is MAPbI3.

2. The perovskite solar cell according to claim 1, characterized in that, The thickness of the interface modification layer is 10–40 nm.

3. The perovskite solar cell according to claim 2, characterized in that, The transparent conductive electrode is fluorine-doped tin oxide glass; the thickness of the SnO2 thin film is 30–60 nm; the thickness of the perovskite active layer is 300–450 nm; the hole transport layer is Spiro-OMeTAD with a thickness of 40–80 nm; and the metal electrode layer is gold with a thickness of 80–100 nm.

4. A method for preparing a resin-acid interface-modified perovskite solar cell according to any one of claims 1 to 3, characterized in that, The process includes the following steps: after surface treatment of a transparent conductive electrode, an electron transport layer, a perovskite active layer, and an interface modification layer are sequentially prepared by spin coating. Then, a hole transport layer and a metal electrode layer are prepared to obtain a resin acid interface-modified perovskite solar cell. The interface modification layer is prepared by spin coating a chlorobenzene solution of resin acid onto the perovskite active layer and then heating it to obtain the resin acid interface modification layer. The concentration of the chlorobenzene solution of resin acid is 2 mg / mL, the spin coating speed is 3000~6000 rpm, the heating temperature is 100℃, and the heating time is 1 min.

5. The preparation method according to claim 4, characterized in that, The surface treatment method of the transparent conductive electrode is as follows: the FTO substrate is ultrasonically cleaned with detergent, deionized water and isopropanol in sequence, and then dried with nitrogen; finally, the cleaned and dried FTO substrate is subjected to ultraviolet-ozone surface treatment.

6. The preparation method according to claim 5, characterized in that, The electron transport layer is prepared by spin-coating an aqueous solution of SnO2 nanoparticles onto a surface-treated transparent conductive electrode, followed by annealing.

7. The preparation method according to claim 6, characterized in that, The method for preparing the perovskite active layer is as follows: PbI2 and MAI are dissolved in a mixed solvent of DMF and DMSO, the resulting mixed solution is spin-coated onto the electron transport layer, and after annealing, the MAPbI3 perovskite active layer is obtained.

8. The preparation method according to claim 7, characterized in that, The hole transport layer is prepared by dissolving Spiro-OMeTAD in chlorobenzene and adding 4-tert-butylpyridine and lithium bis(trifluoromethanesulfonylimide). The resulting mixed solution is then spin-coated onto the interface modification layer to obtain the hole transport layer. The metal electrode layer is prepared by uniformly evaporating gold particles onto the surface of the hole transport layer using an evaporation coating apparatus.

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