A translucent polymer solar cell and its preparation method

Abstract

The present invention belongs to the field of battery materials, and in particular relates to a translucent polymer solar cell and a method for preparing the same. The translucent polymer solar cell provided by the present invention comprises a transparent substrate covered with an ITO film, an electron transport layer, an active layer, a hole transport layer, a metal electrode layer, and a gasochromic layer, which are sequentially arranged; the gasochromic layer comprises a Nb2O5 film layer and Au nanoparticles distributed on the surface of the Nb2O5 film layer. The solar cell provided by the present invention uses a Nb2O5 film with Au nanoparticles distributed on the surface as the gasochromic layer, and can dynamically and reversibly adjust the color and average visible light transmittance of the translucent polymer solar cell; the solar cell can reversibly switch between a colored state and a bleached state, and can enhance photon capture within a wider wavelength range, has a high short-circuit current density and photoelectric conversion efficiency, and has a very broad market prospect.

Description

Technical Field

[0001] The invention belongs to the field of battery materials, and in particular relates to a semi-transparent polymer solar cell and a preparation method thereof. Background Art

[0002] Over the past decade, polymer solar cells (PSCs) have attracted widespread attention due to their advantages of solution processing, lightweight, low cost, and scalable production. Semi-transparent polymer solar cells (ST-PSCs), fabricated by sandwiching the active layer between two transparent electrodes, not only convert energy to electricity but also offer functions such as light shielding, cooling, energy saving, and privacy protection. They are considered an optimal choice for photovoltaic glazing in building-integrated photovoltaics (BIPVs). Furthermore, their flexible design and vibrant, tunable colors make them promising for applications in smart windows for aviation, railways, and automobiles. However, unlike traditional opaque polymer solar cells, the performance of ST-PSCs depends not only on their photoelectric conversion efficiency (PCE) but also on their average visible light transmittance (AVT) and color rendering index (CRI). Generally speaking, the AVT and PCE of semi-transparent polymer solar cells are mutually exclusive; ensuring high photoelectric conversion efficiency while maintaining good average visible light transmittance is crucial.

[0003] With the synthesis of new high-efficiency active layers and the maturity of device technology, semi-transparent polymer solar cells have now achieved a PCE of over 12% while ensuring an average visible light transmittance of 25%. However, the color and average visible light transmittance of the device depend on the active layer material and the color and thickness of the transparent electrode. As a result, after the ST-PSCs are prepared, the color and color rendering characteristics of the device are determined due to the absorption of photons in a specific wavelength range by the active layer material, and dynamic adjustment of the device color and average visible light transmittance cannot be achieved. Generally, the main method for adjusting the color of semi-transparent polymer solar cells is to improve the active layer material of ST-PSCs, that is, to adjust the absorption spectrum of the active layer material. However, this method of adjusting the color of ST-PSCs is not dynamically reversible and cannot intelligently change the color and AVT of the device. This greatly limits the widespread commercial application of semi-transparent polymer solar cells. Summary of the Invention

[0004] In view of this, the object of the present invention is to provide a translucent polymer solar cell and a preparation method thereof. The solar cell provided by the present invention uses a Nb2O5 film with Au nanoparticles distributed on the surface as a gaseous induced color layer, which can dynamically and reversibly adjust the color and average visible light transmittance of the translucent polymer solar cell; the solar cell can be reversibly switched between a colored state and a bleached state, and can enhance photon capture in a wider wavelength range, and has a high short-circuit current density and photoelectric conversion efficiency.

[0005] The present invention provides a semi-transparent polymer solar cell, comprising a transparent substrate covered with an ITO film, an electron transport layer, an active layer, a hole transport layer, a metal electrode layer and a gaseous induced color change layer, which are arranged in sequence;

[0006] The gaseous chromic layer includes a Nb2O5 film layer and Au nanoparticles distributed on the surface of the Nb2O5 film layer.

[0007] Preferably, the particle size of the Au nanoparticles is 30 to 100 nm.

[0008] Preferably, the thickness of the Nb2O5 film layer is 30 to 150 nm.

[0009] Preferably, the material of the electron transport layer is SnO2; the thickness of the electron transport layer is 10 to 30 nm.

[0010] Preferably, the donor material in the active layer is J71 and the acceptor material is IEICO-4F; or, the donor material in the active layer is PM6 and the acceptor material is Y6; or, the donor material in the active layer is PTB7-Th and the acceptor material is IEICO-4F; the thickness of the active layer is 80 to 120 nm.

[0011] Preferably, the material of the hole transport layer is MoO3; the thickness of the hole transport layer is 6 to 15 nm.

[0012] Preferably, the material of the metal electrode layer is Ag and / or Au; the thickness of the metal electrode layer is 8 to 20 nm.

[0013] The present invention provides a method for preparing the semi-transparent polymer solar cell described in the above technical solution, comprising the following steps:

[0014] a) sequentially stacking an electron transport layer, an active layer, a hole transport layer, a metal electrode layer and a Nb2O5 film layer on a surface of a transparent substrate covered with an ITO film;

[0015] b) coating a solution containing Au nanoparticles on the surface of the Nb2O5 film layer and drying the solution to obtain a semi-transparent polymer solar cell.

[0016] Preferably, step a) specifically includes:

[0017] a1) coating a solution containing an electron transport material on the surface of a transparent substrate covered with an ITO film, and annealing to form an electron transport layer;

[0018] a2) coating a solution containing a donor material and an acceptor material on the surface of the electron transport layer, and annealing to form an active layer;

[0019] a3) plating a hole transport material on the surface of the active layer to form a hole transport layer;

[0020] a4) plating a metal electrode material on the surface of the hole transport layer to form a metal electrode layer;

[0021] a5) plating Nb2O5 on the surface of the metal electrode layer to form a Nb2O5 film layer.

[0022] Preferably, in step a1), the annealing temperature is 120-180° C., and the annealing time is 10-60 min;

[0023] In step a2), the solution further contains 1-chloronaphthalene, the content of 1-chloronaphthalene in the solution is 0.2-0.6 vol%, the annealing temperature is 80-120° C., and the annealing time is 5-20 min;

[0024] In steps a3) to a5), the deposition method is evaporation, and the vacuum degree of the evaporation is 4×10 -4 ~9×10 - 5 Pa.

[0025] Compared with the prior art, the present invention provides a semi-transparent polymer solar cell and a preparation method thereof. The semi-transparent polymer solar cell provided by the present invention comprises a transparent substrate covered with an ITO film, an electron transport layer, an active layer, a hole transport layer, a metal electrode layer and a gaseous chromic layer arranged in sequence; the gaseous chromic layer comprises a Nb2O5 film layer and Au nanoparticles distributed on the surface of the Nb2O5 film layer. The present invention provides a solar cell device with a reversible color-changing function by arranging a Nb2O5 / Au gaseous chromic layer on the top electrode of the semi-transparent polymer solar cell, which is specifically manifested as follows: in a reducing hydrogen environment, the color of the Nb2O5 film layer can change from colorless to light blue; its chemical reaction mechanism is: Nb2O5 undergoes a reversible chemical reaction after contacting hydrogen under the catalysis of Au nanoparticles, and Nb 5+ Partially reduced to Nb 4+Because transition metal oxides exhibit different colors in different valence states, the color of the reacted Nb2O5 film changes from transparent to light blue with the introduction of hydrogen. In the present invention, by providing a Nb2O5 / Au gas-induced chromic layer on the top electrode of a semi-transparent polymer solar cell, the color and average visible light transmittance of the semi-transparent polymer solar cell can be dynamically and reversibly adjusted, allowing the solar cell to reversibly switch between a colored state and a bleached state. Furthermore, the provision of this functional layer allows photons across a wider wavelength range to be absorbed by the solar cell, enhancing photon trapping and thereby improving the solar cell's short-circuit current density and photoelectric conversion efficiency. Furthermore, the provision of the Nb2O5 / Au gas-induced chromic layer also forms a structure similar to an optical microcavity on the solar cell surface, further increasing the solar cell's light absorption capacity and improving photoelectric conversion efficiency. The semi-transparent polymer solar cell provided by the present invention can dynamically and reversibly adjust its color and visible light transmittance, exhibiting excellent optical and electrical properties. This solar cell combines the dual functions of power generation and color adjustment, allowing for color changes as needed, and has a very broad market prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0027] Figure 1 This is a schematic structural diagram of a semi-transparent polymer solar cell provided by the present invention;

[0028] Figure 2 This is an atomic force microscope (AFM) image of the semi-transparent polymer solar cell prepared in Example 1 provided by the present invention;

[0029] Figure 3 This is a digital photograph of a solar cell prepared in Examples 1 to 3 provided by the present invention without a gaseous chromic layer;

[0030] Figure 4 This is a digital photograph of the translucent polymer solar cell prepared in Example 1 of the present invention before and after hydrogen injection;

[0031] Figure 5 1 is a JV characteristic curve of the semi-transparent polymer solar cell prepared in Examples 1 to 3 provided by the present invention;

[0032] Figure 6 It is a characteristic curve diagram of the external quantum efficiency (EQE) of the semi-transparent polymer solar cells prepared in Examples 1 to 3 provided by the present invention. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0034] The present invention provides a semi-transparent polymer solar cell, comprising a transparent substrate covered with an ITO film, an electron transport layer, an active layer, a hole transport layer, a metal electrode layer and a gaseous induced color change layer, which are arranged in sequence;

[0035] The gaseous chromic layer includes a Nb2O5 film layer and Au nanoparticles distributed on the surface of the Nb2O5 film layer.

[0036] See also Figure 1 , Figure 1 This is a schematic structural diagram of the semi-transparent polymer solar cell provided by the present invention, wherein 1 is a transparent substrate covered with an ITO film, 2 is an electron transport layer, 3 is an active layer, 4 is a hole transport layer, 5 is a metal electrode layer, 6 is a Nb2O5 film layer, and 7 is Au nanoparticles.

[0037] The semi-transparent polymer solar cell provided by the present invention comprises a transparent substrate 1 covered with an ITO film, an electron transport layer 2, an active layer 3, a hole transport layer 4, a metal electrode layer 5 and a gaseous induced color change layer. Among them, the transparent substrate 1 covered with an ITO film is preferably a conductive glass covered with an ITO film; the thickness of the conductive glass covered with an ITO film is preferably 80 to 150 nm, specifically 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm or 150 nm; the square resistance of the conductive glass covered with an ITO film is preferably 5 to 20 Ω / sq, specifically 5 Ω / sq, 6 Ω / sq, 7 Ω / sq, 8 Ω / sq, 9 Ω / sq, 10 Ω / sq, 11 Ω / sq, 12 Ω / sq, 13 Ω / sq, 14 Ω / sq, 15 Ω / sq, 16 Ω / sq, 17 Ω / sq, 18 Ω / sq, 19 Ω / sq or 20 Ω / sq.

[0038] In the semi-transparent polymer solar cell provided by the present invention, the electron transport layer 2 is arranged on the surface of the transparent substrate 1 covered with the ITO film; the material of the electron transport layer 2 is preferably SnO2; the thickness of the electron transport layer 2 is preferably 10 to 30 nm, specifically 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, 20 nm, 21 nm, 22 nm, 23 nm, 24 nm, 25 nm, 26 nm, 27 nm, 28 nm, 29 nm or 30 nm.

[0039] In the semi-transparent polymer solar cell provided by the present invention, the active layer 3 is arranged on the surface of the electron transport layer 2; the acceptor material in the active layer 3 is preferably IEICO-4F or Y6, and the donor material is preferably J71, PM6 or PTB7-Th. In the present invention, narrow-bandgap non-fullerene materials IEICO-4F and Y6 are used as acceptors, which have strong light absorption in the visible light to near-infrared region (650-1050nm). After mixing with the donor materials J71, PM6, and PTB7-Th, the film exhibits relatively low light absorption in the visible light region and strong absorption in the near-infrared region. In one embodiment provided by the present invention, the donor material in the active layer 3 is J71, and the acceptor material is IEICO-4F. The mass ratio of the donor material to the acceptor material is preferably 1:(1~2), and more preferably 1:1.5; in another embodiment provided by the present invention, the donor material in the active layer 3 is PM6, and the acceptor material is Y6. The mass ratio of the donor material to the acceptor material is preferably 1:(1~1.5), and more preferably 1:1.2; in other embodiments provided by the present invention, the donor material in the active layer 3 is PTB7-Th, and the acceptor material is IEICO-4F. The mass ratio of the donor material to the acceptor material is preferably 1:(1~2), and more preferably 1:1.5. In the present invention, the thickness of the active layer 3 is preferably 80 to 120 nm, specifically 80 nm, 82 nm, 85 nm, 87 nm, 90 nm, 92 nm, 95 nm, 97 nm, 100 nm, 102 nm, 105 nm, 107 nm, 110 nm, 112 nm, 115 nm, 117 nm or 120 nm.

[0040] In the semi-transparent polymer solar cell provided by the present invention, the hole transport layer 4 is arranged on the surface of the active layer 3; the material of the hole transport layer 4 is preferably MoO3; the thickness of the hole transport layer 4 is preferably 6 to 15 nm, specifically 6 nm, 6.5 nm, 7 nm, 7.5 nm, 8 nm, 8.5 nm, 9 nm, 9.5 nm, 10 nm, 10.5 nm, 11 nm, 11.5 nm, 12 nm, 12.5 nm, 13 nm, 13.5 nm, 14 nm, 14.5 nm or 15 nm.

[0041] In the semi-transparent polymer solar cell provided by the present invention, the metal electrode layer 5 is arranged on the surface of the hole transport layer 4; the material of the metal electrode layer 5 is preferably Ag and / or Au; the thickness of the metal electrode layer 5 is preferably 8 to 20 nm, specifically 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm or 20 nm.

[0042] In the semi-transparent polymer solar cell provided by the present invention, the gasochromic layer is arranged on the surface of the metal electrode layer 5, and the gasochromic layer includes a Nb2O5 film layer 6 and Au nanoparticles 7 distributed on the surface of the Nb2O5 film layer 6; the particle size of the Au nanoparticles 7 is preferably 30 to 100 nm, specifically 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, 150 nm, 160 nm, 170 nm, 180 nm, 190 nm, 200 nm, 210 nm, 220 nm, 230 nm, 240 nm, 250 nm, 260 nm, 270 nm, 280 nm, 290 nm, 300 nm, 350 nm, 360 nm, 370 nm, 380 nm, 390 nm, 400 nm, 410 nm, 420 nm, 430 nm, 440 nm, 450 nm, 460 nm, 470 nm, 480 nm, 490 nm, 500 nm, 510 nm, 510 nm, 520 nm, 530 nm, 540 nm, 550 nm, 560 nm, 570 nm, 580 nm, 590 nm, 600 nm, 610 nm, 610 nm, 620 nm, 630 nm, 640 nm, 650 nm, nm or 100 nm; the thickness of the Nb2O5 film layer is preferably 30 to 150 nm, specifically 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, 105 nm, 110 nm, 115 nm, 120 nm, 125 nm, 130 nm, 135 nm, 140 nm, 145 nm or 150 nm.

[0043] The present invention also provides a method for preparing the semi-transparent polymer solar cell described in the above technical solution, comprising the following steps:

[0044] a) sequentially stacking an electron transport layer, an active layer, a hole transport layer, a metal electrode layer and a Nb2O5 film layer on a surface of a transparent substrate covered with an ITO film;

[0045] b) coating a solution containing Au nanoparticles on the surface of the Nb2O5 film layer and drying the solution to obtain a semi-transparent polymer solar cell.

[0046] In the preparation method provided by the present invention, an electron transport layer, an active layer, a hole transport layer, a metal electrode layer and a Nb2O5 film layer are first stacked in sequence on the surface of a transparent substrate covered with an ITO film, and the specific arrangement process preferably includes the following steps:

[0047] a1) coating a solution containing an electron transport material on the surface of a transparent substrate covered with an ITO film, and annealing to form an electron transport layer;

[0048] a2) coating a solution containing a donor material and an acceptor material on the surface of the electron transport layer, and annealing to form an active layer;

[0049] a3) plating a hole transport material on the surface of the active layer to form a hole transport layer;

[0050] a4) plating a metal electrode material on the surface of the hole transport layer to form a metal electrode layer;

[0051] a5) plating Nb2O5 on the surface of the metal electrode layer to form a Nb2O5 film layer.

[0052] In the above setting process provided by the present invention, in step a1), the transparent substrate covered with the ITO film is preferably surface treated before coating, and the specific steps of the surface treatment are preferably: washing, drying and ultraviolet light treatment in sequence.

[0053] In the above-mentioned setting process provided by the present invention, in step a1), the electron transport material in the solution is preferably SnO2, and the solvent is preferably water; the solution is preferably obtained by diluting a SnO2 hydrocolloid dispersion with water, and the SnO2 content in the SnO2 hydrocolloid dispersion is preferably 10-20wt%, specifically 15wt%, and the volume ratio of the SnO2 hydrocolloid dispersion to water is preferably 1:(8-15), specifically 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14 or 1:15; the coating method is preferably spin coating, and the spin coating speed is preferably The spin coating speed is preferably 3000-4000 rpm, and the spin coating time is preferably 30-60 s; the annealing temperature is preferably 120-180°C, specifically 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, 155°C, 160°C, 165°C, 170°C, 175°C or 180°C; the annealing time is preferably 10-60 min, specifically 10 min, 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min or 60 min.

[0054] In the above-mentioned setting process provided by the present invention, in step a2), if the donor material in the solution is J71 and the acceptor material is IEICO-4F, the mass ratio of the donor material to the acceptor material is preferably 1:(1-2), more preferably 1:1.5; the solvent in the solution is preferably chlorobenzene; the concentration of the solution is preferably 23-30 mg / mL, specifically 23 mg / mL, 24 mg / mL, 25 mg / mL, 26 mg / mL, 27 mg / mL, 28 mg / mL, 29 mg / mL or 30 mg / mL; the coating method is preferably spin coating, the spin coating speed is preferably 3000-4000 rpm, specifically 3500 rpm, and the spin coating time is preferably 40-90 s, specifically 60 s.

[0055] In the above-mentioned setting process provided by the present invention, in step a2), if the donor material in the solution is PM6 and the acceptor material is Y6, the mass ratio of the donor material to the acceptor material is preferably 1:(1-1.5), more preferably 1:1.2; the solvent in the solution is preferably chloroform; the concentration of the solution is preferably 15-22 mg / mL, specifically 15 mg / mL, 16 mg / mL, 17 mg / mL, 18 mg / mL, 19 mg / mL, 20 mg / mL, 21 mg / mL or 22 mg / mL; the coating method is preferably drip coating, and the speed of the glue spreader during the drip coating is preferably 2500-3500 rpm, specifically 3000 rpm, and the drip coating time is preferably 20-60 s, specifically 30 s.

[0056] In the above-mentioned setting process provided by the present invention, in step a2), if the donor material in the solution is PTB7-Th and the acceptor material is IEICO-4F, the mass ratio of the donor material to the acceptor material is preferably 1:(1-2), more preferably 1:1.5; the solvent in the solution is preferably chlorobenzene; the concentration of the solution is preferably 23-30 mg / mL, specifically 23 mg / mL, 24 mg / mL, 25 mg / mL, 26 mg / mL, 27 mg / mL, 28 mg / mL, 29 mg / mL or 30 mg / mL; the coating method is preferably spin coating, the spin coating speed is preferably 2000-3000 rpm, specifically 2500 rpm, and the spin coating time is preferably 40-90 s, specifically 60 s.

[0057] In the above-mentioned setting process provided by the present invention, in step a2), the solution preferably further contains a certain amount of 1-chloronaphthalene. The addition of the 1-chloronaphthalene can provide the material with more sufficient time to self-assemble and form a more ordered intermolecular stacking, thereby improving the arrangement of the BHJ donor and acceptor and forming a morphology in which the donor and acceptor are evenly mixed. The content of the 1-chloronaphthalene in the solution is preferably 0.2-0.6 vol%, specifically 0.2 vol%, 0.25 vol%, 0.3 vol%, 0.35 vol%, 0.4 vol%, 0.45 vol%, 0.5 vol%, 0.55 vol% or 0.6 vol%.

[0058] In the above-mentioned setting process provided by the present invention, in step a2), the annealing temperature is preferably 80-120°C, specifically 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C or 120°C; the annealing time is preferably 5-20 min, specifically 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, 16 min, 17 min, 18 min, 19 min or 20 min.

[0059] In the above-mentioned setting process provided by the present invention, in steps a3) to a5), the plating method is preferably evaporation; the vacuum degree of the evaporation is preferably 4×10 -4 ~9×10 -5 Pa.

[0060] In the preparation method provided herein, after an electron transport layer, an active layer, a hole transport layer, a metal electrode layer, and a Nb2O5 film layer are formed on the surface of a transparent substrate covered with an ITO film, a solution containing Au nanoparticles is coated on the surface of the Nb2O5 film layer. In the present invention, the solution containing Au nanoparticles is preferably prepared by the following steps: mixing a cationic surfactant, a catalyst, and a soluble Au source compound in a solvent to obtain a mixed solution; then adding a reducing agent to the mixed solution under stirring to react; and after the reaction, centrifuging and purifying the product, and then redissolving the purified product in a solvent to obtain a solution containing Au nanoparticles. Wherein, the cationic surfactant is preferably hexadecyltrimethylammonium chloride (CTAC); the catalyst is preferably citric acid; the soluble Au source compound is preferably HAuCl4; the final concentration of the cationic surfactant in the mixed solution is preferably 10 to 100 mmol / L, specifically 10 mmol / L, 30 mmol / L, 50 mmol / L, 70 mmol / L or 100 mmol / L; the final concentration of the catalyst in the mixed solution is preferably 1 to 10 mmol / L, specifically 1 mmol / L, 3 mmol / L, 5 mmol / L, 7 mmol / L or 10 mmol / L; the final concentration of the soluble Au source compound in the mixed solution is preferably 0.1 to 0.5 mmol / L, specifically 0.1 mmol / L, 0.15 mmol / L, 0.2 mmol / L, 0.25 mmol / L, 0.3 mmol / L, 0.35 mmol / L, 0.4 mmol / L, mol / L, 0.45mmol / L or 0.5mmol / L; the reducing agent is preferably an ice-cold reducing agent NaBH4 solution, and the concentration of the reducing agent solution is preferably 10 to 50mmol / L, specifically 10mmol / L, 15mmol / L, 20mmol / L, 25mmol / L, 30mmol / L, 35mmol / L, 40mmol / L, 45mmol / L or 50mmol / L; the reducing agent solution is preferably ice-cold reducing agent NaBH4 solution, and the concentration of the reducing agent solution is preferably 10 to 50mmol / L, specifically 10mmol / L, 15mmol / L, 20mmol / L, 25mmol / L, 30mmol / L, 35mmol / L, 40mmol / L, 45mmol / L or 50mmol / L; The volume ratio of the solvent in the mixed solution is preferably (0.1 to 0.5):10, specifically 0.1:10, 0.15:10, 0.2:10, 0.25:10, 0.3:10, 0.35:10, 0.4:10, 0.45:10 or 0.5:10; the volume of the solvent used to dissolve the purified product in the solvent again is preferably 0.5 to 2 times the volume of the solvent used to prepare the mixed solution, and more preferably the same volume of the solvent used; the solvent is preferably ultrapure water.In the present invention, the coating method is preferably spin coating, and the spin coating speed is preferably 2000-8000 rpm, specifically 2000 rpm, 3000 rpm, 4000 rpm, 5000 rpm, 6000 rpm, 7000 rpm, or 8000 rpm. The spin coating time is preferably 10-60 s, specifically 10 s, 20 s, 30 s, 40 s, 50 s, or 60 s. After coating, annealing is performed in air to obtain the semi-transparent polymer solar cell provided by the present invention. The annealing temperature is preferably 120-180°C, specifically 120, 130, 140, 150, 160, 170, or 180°C; the annealing time is preferably 5-20 min, specifically 5 min, 7 min, 10 min, 12 min, 15 min, 17 min, or 20 min.

[0061] The present invention provides a Nb2O5 / Au gas-induced color-changing layer on the top electrode of a semi-transparent polymer solar cell, so that the solar cell device has a reversible color-changing function. Specifically, in a reducing hydrogen environment, the color of the Nb2O5 film layer can change from colorless to light blue. The chemical reaction mechanism is as follows: Nb2O5 undergoes a reversible chemical reaction after contacting hydrogen under the catalysis of Au nanoparticles. 5+ Partially reduced to Nb 4+ Since transition metal oxides have different colors in different valence states, as hydrogen is introduced, the color of the Nb2O5 film after the reaction will change from transparent to light blue. Since the active layer material of the solar cell itself also has a certain color, the color change of solar cells using different active layer materials is also different. More specifically: for solar cells with an active layer of J71:IEICO-4F, when hydrogen is introduced, due to the gas-induced color change characteristics of the Nb2O5 film, the color of the solar cell quickly changes from cherry red to purple, and the Nb valence changes from its original +5 to +4. When the hydrogen injection is stopped and oxygen or air is introduced, the color of the solar cell changes from purple to cherry red, at this time, Nb is oxidized from +4 to +5. For solar cells with an active layer of PM6:Y6, when hydrogen is introduced, the color of the solar cell deepens on the basis of the original dark blue. When oxygen or air is introduced, the color of the solar cell returns to the original dark blue of the device, and the reaction that occurs is the same as the above reaction. For devices with an active layer of PTB7-Th:IEICO-4F, when hydrogen is introduced, the color of the solar cell changes from light green to cyan. When oxygen or air is introduced, the color of the solar cell changes from cyan to light green. The reaction that occurs is the same as the above reaction.

[0062] The technical solution provided by the present invention, by providing a Nb2O5 / Au gasochromic layer on the top electrode of a semi-transparent polymer solar cell, can dynamically and reversibly adjust the color and average visible light transmittance of the semi-transparent polymer solar cell, allowing the solar cell to reversibly switch between a colored state and a bleached state. Furthermore, the provision of this functional layer allows photons across a wider wavelength range to be absorbed by the solar cell, enhancing photon trapping and thereby improving the solar cell's short-circuit current density and photoelectric conversion efficiency. Furthermore, the provision of the Nb2O5 / Au gasochromic layer can also form a structure similar to an optical microcavity on the solar cell surface, further increasing the solar cell's light absorption capacity and improving photoelectric conversion efficiency. The semi-transparent polymer solar cell provided by the present invention can dynamically and reversibly adjust its color and visible light transmittance, exhibiting excellent optical and electrical properties. This solar cell combines the dual functions of power generation and color adjustment, allowing for color changes as needed, and has a very broad market prospect.

[0063] For the purpose of greater clarity, the present invention is described in detail with reference to the following examples.

[0064] In the following embodiments of the present invention, the conductive glass covered with ITO is provided by Shenzhen South China Xiangcheng Co., Ltd., and the material parameters are: 110nm, 10Ωsq -1 ;

[0065] In the following examples of the present invention, the donor materials and acceptor materials used were provided by Solarmer Materials Inc. (Beijing, China).

[0066] Example 1

[0067] A semi-transparent polymer solar cell is prepared according to the following steps:

[0068] 1) The conductive glass covered with ITO was ultrasonically cleaned with detergent (commercial detergent), ultrapure water, acetone, and ethanol for 15 minutes in sequence. The cleaned substrate was blown dry with nitrogen and then UV-treated for 15 minutes.

[0069] 2) A 15 wt% aqueous colloidal dispersion of SnO2 was diluted with ultrapure water at a dilution volume ratio of 1:13 and stirred for 30 minutes until fully dispersed; the dispersion was then spin-coated on an ITO-coated glass substrate at a speed of 3000 rpm for 30 seconds; and finally, the resulting film was annealed at 150°C for 30 minutes to form an electron transport layer with a thickness of approximately 20 nm.

[0070] 3) The donor material J71 and the acceptor material IEICO-4F were mixed in a mass ratio of 1:1.5 and dissolved in a mixed solvent of chlorobenzene and 1-chloronaphthalene (0.5 vol%) to obtain a mixed solution. The total concentration of the donor and acceptor materials in the mixed solution was 25 mg / mL. The mixed solution was then spin-coated on the electron transport layer under a nitrogen environment at a spin-coating speed of 3500 rpm for 60 s. Finally, the film was annealed at 100°C for 10 min to obtain an active layer with a thickness of approximately 100 nm.

[0071] 4) In 4×10 -4 ~9×10 -5 Under Pa vacuum conditions, a MoO3 film with a thickness of 8 nm was evaporated on the active layer as a hole transport layer;

[0072] 5) In 4×10 -4 ~9×10 -5 Under the vacuum condition of Pa, a 15 nm thick Au layer was evaporated on the hole transport layer as the electrode layer;

[0073] 6) In 4×10 -4 ~9×10 -5 Pa vacuum conditions, a Nb2O5 film with a thickness of 120nm was evaporated on the electrode layer;

[0074] 7) preparing a solution containing Au nanoparticles by sequentially introducing cetyltrimethylammonium chloride (CTAC), citric acid, and HAuCl4 into a 20 mL flask containing 10 mL of water, wherein the final concentrations of CTAC, citric acid, and HAuCl4 are 50 mmol / L, 5 mmol / L, and 0.25 mmol / L, respectively; rapidly adding 0.25 mL of freshly prepared 25 mmol / L ice-cold NaBH4 aqueous solution to the flask under vigorous stirring at room temperature, wherein ultrafine gold nanoparticles are formed during stirring, and the solution changes from yellow to brown; the solution is purified by multiple centrifugation steps and then dissolved in 10 mL of water to obtain a solution containing Au nanoparticles;

[0075] 8) The solution containing Au nanoparticles prepared in step 7) was spin-coated on the Nb2O5 film at a spin-coating speed of 4000 rpm for 30 seconds. After the spin-coating, the film was annealed in air at 150°C for 12 minutes to obtain Au nanoparticles uniformly distributed on the Nb2O5 film, thereby obtaining a semi-transparent polymer solar cell with a gaseous induced color change functional layer.

[0076] Example 2

[0077] A semi-transparent polymer solar cell is prepared according to the following steps:

[0078] 1) The conductive glass covered with ITO was ultrasonically cleaned with detergent (commercial detergent), ultrapure water, acetone, and ethanol for 15 minutes in sequence. The cleaned substrate was blown dry with nitrogen and then UV-treated for 15 minutes.

[0079] 2) A 15 wt% aqueous colloidal dispersion of SnO2 was diluted with ultrapure water at a dilution volume ratio of 1:13 and stirred for 30 minutes until fully dispersed; the dispersion was then spin-coated on an ITO-coated glass substrate at a speed of 3000 rpm for 30 seconds; and finally, the resulting film was annealed at 150°C for 30 minutes to form an electron transport layer with a thickness of approximately 20 nm.

[0080] 3) The donor material PM6 and the acceptor material Y6 were mixed in a mass ratio of 1:1.2 and dissolved in a mixed solvent of chloroform and 1-chloronaphthalene (0.5 vol%) to obtain a mixed solution with a total concentration of 16 mg / mL of the donor and acceptor materials in the mixed solution. The mixed solution was then drop-coated on the electron transport layer under a nitrogen atmosphere at a spin coater speed of 3000 rpm for 30 seconds. Finally, the film was annealed at 100°C for 10 minutes to obtain an active layer with a thickness of approximately 100 nm.

[0081] 4) In 4×10 -4 ~9×10 -5 Under Pa vacuum conditions, a MoO3 film with a thickness of 8 nm was evaporated on the active layer as a hole transport layer;

[0082] 5) In 4×10 -4 ~9×10 -5 Under the vacuum condition of Pa, a 15 nm thick Ag layer was evaporated on the hole transport layer as the electrode layer;

[0083] 6) In 4×10 -4 ~9×10 -5 Pa vacuum conditions, a Nb2O5 film with a thickness of 120nm was evaporated on the electrode layer;

[0084] 7) A solution containing Au nanoparticles was prepared according to the method described in Example 1, and the solution containing Au nanoparticles was spin-coated on the Nb2O5 film at a spin-coating speed of 4000 rpm for 30 s. After the spin-coating, the film was annealed in air at 150°C for 12 min to obtain Au nanoparticles uniformly distributed on the Nb2O5 film, thereby obtaining a translucent polymer solar cell with a gaseous induced color change functional layer.

[0085] Example 3

[0086] A semi-transparent polymer solar cell is prepared according to the following steps:

[0087] 1) The conductive glass covered with ITO was ultrasonically cleaned with detergent (commercial detergent), ultrapure water, acetone, and ethanol for 15 minutes in sequence. The cleaned substrate was blown dry with nitrogen and then UV-treated for 15 minutes.

[0088] 2) A 15 wt% aqueous colloidal dispersion of SnO2 was diluted with ultrapure water at a dilution volume ratio of 1:13 and stirred for 30 minutes until fully dispersed; the dispersion was then spin-coated on an ITO-coated glass substrate at a speed of 3000 rpm for 30 seconds; and finally, the resulting film was annealed at 150°C for 30 minutes to form an electron transport layer with a thickness of approximately 20 nm.

[0089] 3) The donor material PTB7-Th and the acceptor material IEICO-4F were mixed in a mass ratio of 1:1.5 and dissolved in a mixed solvent of chlorobenzene and 1-chloronaphthalene (0.5 vol%) to obtain a mixed solution. The total concentration of the donor and acceptor materials in the mixed solution was 25 mg / mL. The mixed solution was then spin-coated on the electron transport layer under a nitrogen environment at a spin coating speed of 2500 rpm and a spin coater rotation time of 60 s. Finally, the active layer was annealed at 100°C for 10 min. The resulting thin film was the active layer. The thickness of the active layer was approximately 100 nm.

[0090] 4) In 4×10 -4 ~9×10 -5 Under Pa vacuum conditions, a MoO3 film with a thickness of 8 nm was evaporated on the active layer as a hole transport layer;

[0091] 5) In 4×10 -4 ~9×10 -5 Under the vacuum condition of Pa, a 15 nm thick Ag layer was evaporated on the hole transport layer as the electrode layer;

[0092] 6) In 4×10 -4 ~9×10 -5 Pa vacuum conditions, a Nb2O5 film with a thickness of 120nm was evaporated on the electrode layer;

[0093] 7) A solution containing Au nanoparticles was prepared according to the method described in Example 1, and the solution containing Au nanoparticles was spin-coated on the Nb2O5 film at a spin-coating speed of 4000 rpm for 30 s. After the spin-coating, the film was annealed in air at 150°C for 12 min to obtain Au nanoparticles uniformly distributed on the Nb2O5 film, thereby obtaining a translucent polymer solar cell with a gaseous induced color change functional layer.

[0094] Example 4

[0095] (1) The gaseous chromic layer of the semi-transparent polymer solar cell prepared in Example 1 was observed by atomic force microscopy. The results are as follows: Figure 2 As shown, Figure 2 This is an atomic force microscope (AFM) image of the semi-transparent polymer solar cell prepared in Example 1 provided by the present invention. Figure 2 It can be seen that: Au nanoparticles are grown on the Nb2O5 film by spin-coating an Au nanoparticle solution. Au does not form a thin film on its surface, but exists in the form of nanoparticles and is evenly distributed. Therefore, after hydrogen is introduced into the solar cell, the Au nanoparticles can be used to dissociate the hydrogen, thereby accelerating the combination of hydrogen and Nb2O5 / Au metal oxide, which can act as a good catalyst and ultimately cause the semi-transparent polymer solar cell to undergo gas-induced discoloration.

[0096] (2) After completing step 5), the color of the solar cells prepared in Examples 1 to 3 without the gaseous chromic layer was observed. The results were as follows: Figure 3 The figure shows a digital photo of a solar cell without a gaseous chromic layer prepared in Examples 1 to 3 of the present invention. Figure 3 It can be seen that on the chrysanthemum substrate, the colors of the battery devices are cherry red, dark blue, and green, depending on the active layer materials.

[0097] (3) The color of the semi-transparent polymer solar cell prepared in Example 1 was observed before and after hydrogen injection. The results are as follows: Figure 4 As shown, Figure 4 This is a digital photo of the semi-transparent polymer solar cell prepared in Example 1 of the present invention before and after hydrogen injection. Figure 4 It can be seen that on the chrysanthemum substrate, the solar cell changes from its original cherry red to purple.

[0098] (4) At 100mW / cm 2 The JV characteristics of the semi-transparent polymer solar cells prepared in Examples 1 to 3 were analyzed under the conditions of AM1.5G standard sunlight illumination and without light irradiation. The results are as follows: Figure 5 As shown, Figure 5 The JV characteristic curves of the semi-transparent polymer solar cells prepared in Examples 1 to 3 of the present invention are shown in FIG. Figure 5 It can be seen that the solar cell of Example 1 is at 100mW / cm 2 Under simulated sunlight, the open circuit voltage is 0.770V and the short circuit current density is 11.18mA / cm 2 , the filling factor is 52.79%, and the photoelectric conversion efficiency is 4.55%; Example 2 solar cell at 100mW / cm 2Under simulated sunlight, the open circuit voltage is 0.712V and the short circuit current density is 16.64mA / cm 2 , the filling factor is 61.44%, and the photoelectric conversion efficiency is 7.19%; the solar cell of Example 3 is 100mW / cm 2 Under simulated sunlight, the open circuit voltage is 0.825V and the short circuit current density is 21.51mA / cm 2 , the filling factor is 71.82% and the photoelectric conversion efficiency is 12.75%.

[0099] (5) The external quantum efficiency (EQE) characteristics of the semi-transparent polymer solar cells prepared in Examples 1 to 3 were analyzed. The results are as follows: Figure 6 As shown, Figure 6 The figure is a graph showing the external quantum efficiency (EQE) characteristic curve of the semi-transparent polymer solar cells prepared in Examples 1 to 3 of the present invention. Figure 6 It can be seen that the EQE spectrum of the semi-transparent device is very consistent with the absorption spectrum of its active layer; taking Example 2 as an example, the maximum external quantum efficiency (EQE) of the semi-transparent device based on PM6:Y6 exceeds 60% in the wavelength range of 500-850nm, indicating that the semi-transparent device has low energy loss, which shows that the prepared semi-transparent device has good average visible light transmittance and can meet the needs of commercial applications.

[0100] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A semi-transparent polymer solar cell comprising a transparent substrate covered with an ITO film, an electron transport layer, an active layer, a hole transport layer, a metal electrode layer, and a gasochromic layer arranged in sequence; The gaseous chromic layer comprises a Nb2O5 film layer and Au nanoparticles distributed on the surface of the Nb2O5 film layer; the thickness of the Nb2O5 film layer is 30 to 150 nm; and the particle size of the Au nanoparticles is 30 to 100 nm.

2. The semi-transparent polymer solar cell according to claim 1, characterized in that: The material of the electron transport layer is SnO2; The thickness of the electron transport layer is 10 to 30 nm.

3. The semi-transparent polymer solar cell according to claim 1, characterized in that: The donor material in the active layer is J71, and the acceptor material is IEICO-4F; or, the donor material in the active layer is PM6, and the acceptor material is Y6; or, the donor material in the active layer is PTB7-Th, and the acceptor material is IEICO-4F; The thickness of the active layer is 80-120 nm.

4. The semi-transparent polymer solar cell according to claim 1, characterized in that: The material of the hole transport layer is MoO3; The thickness of the hole transport layer is 6-15 nm.

5. The semi-transparent polymer solar cell according to claim 1, characterized in that: The material of the metal electrode layer is Ag and / or Au; The thickness of the metal electrode layer is 8-20 nm.

6. A method for preparing the semitransparent polymer solar cell according to any one of claims 1 to 5, comprising the following steps: a) sequentially stacking an electron transport layer, an active layer, a hole transport layer, a metal electrode layer and a Nb2O5 film layer on a surface of a transparent substrate covered with an ITO film; b) coating a solution containing Au nanoparticles on the surface of the Nb2O5 film layer and drying the solution to obtain a semi-transparent polymer solar cell.

7. The preparation method according to claim 6, characterized in that Step a) specifically includes: a1) coating a solution containing an electron transport material on the surface of a transparent substrate covered with an ITO film, and annealing to form an electron transport layer; a2) coating a solution containing a donor material and an acceptor material on the surface of the electron transport layer, and annealing to form an active layer; a3) plating a hole transport material on the surface of the active layer to form a hole transport layer; a4) plating a metal electrode material on the surface of the hole transport layer to form a metal electrode layer; a5) plating Nb2O5 on the surface of the metal electrode layer to form a Nb2O5 film layer.

8. The preparation method according to claim 7, characterized in that In step a1), the annealing temperature is 120-180° C., and the annealing time is 10-60 min; In step a2), the solution further contains 1-chloronaphthalene, the content of 1-chloronaphthalene in the solution is 0.2-0.6 vol%, the annealing temperature is 80-120° C., and the annealing time is 5-20 min; In steps a3) to a5), the deposition method is evaporation, and the vacuum degree of the evaporation is 4×10 -4 ~9×10 -5 Pa.

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