Solid additive materials for photoelectric converters, their applications and preparation

Abstract

This invention discloses a solid additive material for photoelectric converters, its application, and its preparation. The solid additive material for photoelectric converters comprises compounds having the structure shown in the following formula: the structure of the photoelectric converter, from bottom to top, includes a transparent substrate, a transparent electrode layer, a hole transport layer, a photoactive layer, an electron transport layer, and a metal electrode layer; the material of the photoactive layer includes a donor material, an acceptor material, and the solid additive material for photoelectric converters. The solid additive material for photoelectric converters of this invention can effectively control the morphology of the active layer, thereby improving the performance of photovoltaic devices. After addition, the acceptor molecules in the active layer are arranged more compactly and orderly, thereby improving the internal carrier physics processes, enhancing exciton dissociation, improving charge transport, and reducing charge recombination, thus significantly increasing the short-circuit current density and fill factor of the photoelectric converter, and obtaining higher photoelectric conversion efficiency.

Description

Technical Field

[0001] This invention relates to the field of photoelectric converter technology, and specifically to a solid additive material for photoelectric converters, a photoelectric converter using the same, and a method for preparing the same. Background Technology

[0002] Currently, the over-exploitation and consumption of fossil fuels (such as coal, oil, and natural gas) have led to a sharp decline in their reserves, while the large amounts of greenhouse gases produced during combustion further exacerbate global warming. Against this urgent backdrop, developing sustainable and clean energy alternatives is imperative. Organic solar cells (OSCs), due to their outstanding advantages such as light weight, flexibility, excellent indoor light conversion efficiency, and semi-transparency, are considered a highly promising next-generation photovoltaic technology.

[0003] Despite the rapid development of OSCs technology, improving device efficiency and operational stability remains a core objective. The key to achieving this lies in the precise control of the microstructure and condensed state of the active layer (photoactive layer). Adding solvent-based additives is one of the simplest and most direct methods to optimize the morphology of the active layer. The principle is to utilize the differential solubility characteristics of the additive for donor or acceptor materials to slow down the film drying process, thereby effectively improving phase separation and molecular alignment. However, the residue problem caused by the difficulty in completely removing high-boiling-point solvent additives severely restricts the long-term stability of devices and their large-scale commercial application.

[0004] Compared with liquid additives, solid volatile additives exhibit significant advantages: while retaining excellent morphology control capabilities, they can be efficiently volatilized during thin film processing, essentially avoiding the problem of residue accumulation, and thus are expected to simultaneously improve device performance and operating life.

[0005] Therefore, exploring and designing suitable solid-state additives to effectively optimize the active layer structure, improve the molecular stacking mode, thereby enhancing charge transport efficiency and ensuring the long-term stable operation of the device, is not only of great scientific value, but also of profound significance for promoting the practical application of organic solar cells. Summary of the Invention

[0006] Due to the aforementioned deficiencies in the existing technology, this invention provides a solid additive material for photoelectric converters. The solid additive material for photoelectric converters has a dioxazole structure linked by aryl groups, which can effectively regulate the morphology of the active layer to improve the performance of photovoltaic devices. After adding this solid additive material for photoelectric converters, the acceptor molecules are arranged more compactly and orderly in the active layer, thereby improving the internal carrier physics process, enhancing exciton dissociation, improving charge transport, and reducing charge recombination, thus significantly increasing the short-circuit current density and fill factor of the photoelectric converter and obtaining higher photoelectric conversion efficiency.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A solid additive material for a photoelectric converter, characterized in that it comprises a compound having the structure shown in (Ⅰ):

[0009]

[0010] (I)

[0011] Wherein, R1~R8 are each independently selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted amino, substituted or unsubstituted amide, substituted or unsubstituted cyclic imino, substituted or unsubstituted alkoxy, substituted or unsubstituted carboxyl, substituted or unsubstituted ester, substituted or unsubstituted carbonyl, and R1~R8 are not simultaneously H; the substituted substituents include fluorine, chlorine, bromine, iodine, C2~C 28 Hydroxyl group, C2-C 28 Ester group, C2-C 28 Carboxyl group, C2-C 28 Amino, C2-C 28 thiol group, C2-C 28 amide group, C2-C 28 carbonyl group, C2-C 28 Alkoxy, C6~C 28 Aryl, C4~C 28 heteroaryl, C2-C 28 Alkyl, C2-C 28 Heteroalkyl, C2-C 28 alkenyl groups and C2-C 28 Any one of the imino groups;

[0012] The Ar is selected from C2 to C3. 30 The conjugated aromatic ring is substituted with alkyl, alkoxy, alkenyl, phenyl, or benzyl groups, wherein the conjugated aromatic ring includes one or more combinations of alkenyl, alkynyl, phenyl, biphenyl, benzyl, naphthyl, and anthraceneyl groups.

[0013] The aforementioned material contains oxazole units, exhibiting excellent photostability, superior resistance to UV degradation, and reliable stability. It is particularly suitable for preparing high-efficiency UV-resistant films (i.e., photostable films). These films significantly absorb and block short-wavelength UV radiation from sunlight, greatly reducing UV damage to the internal photoelectric converter film and photoelectric converter unit. This effectively extends the overall lifespan of the photoelectric converter assembly and demonstrates advantages in improving the assembly's environmental tolerance and operational reliability.

[0014] As a preferred technical solution:

[0015] As described above, in a solid additive material for a photoelectric converter, R1 to R8 are each independently selected from H, substituted or unsubstituted C2 to C. 20 Alkyl, substituted or unsubstituted C2-C 20 Any of the alkenyl groups.

[0016] In the solid additive material for a photoelectric converter as described above, R1 to R8 are each independently selected from substituted or unsubstituted C2 to C3. 12 Any one of the alkyl groups.

[0017] The solid additive material for a photoelectric converter as described above comprises any one or a combination of at least two of the following compounds:

[0018] .

[0019] The present invention also provides a photoelectric converter, wherein the structure of the photoelectric converter, from bottom to top, includes a transparent substrate, a transparent electrode layer, a hole transport layer, a photoactive layer, an electron transport layer and a metal electrode layer;

[0020] The photoactive layer is made of donor materials, acceptor materials, and solid additive materials for photoelectric converters as described above.

[0021] As a preferred technical solution:

[0022] In the photoelectric converter described above, the donor material is PM6 or D18, and the acceptor material is L8-BO, Y6, or BTP-eC9.

[0023] In the photoelectric converter described above, when the donor material is PM6, the mass ratio of the donor material to the acceptor material is 1:1.2.

[0024] When the donor material is D18, the mass ratio of the donor material to the acceptor material is 1:1.6.

[0025] As described above, in a photoelectric converter, the amount of solid additive material added to the photoelectric converter is 1 to 30 wt% of the total weight of the donor material and the acceptor material.

[0026] Furthermore, the transparent substrate includes transparent glass, polymethyl methacrylate (PET) transparent film, polyimide (PI) transparent film, polyethersulfone (PES) transparent film, and polyethylene dicarboxylate (PEN) transparent film.

[0027] Furthermore, the transparent electrode includes inert tin oxide (ITO), fluorine-doped tin oxide (FTO), metal nanowires, low-dimensional carbon materials, and conductive polymer films (PEDOT).

[0028] Furthermore, the hole transport layer material includes PEDOT:PSS and NiO. x One or more of MOO3, CuSCN and 2PACz.

[0029] The electron transport layer material includes one or more of PFN-Br, PFN, PDINO, TiO2, SnO2, ZnO, PDINN, and PNDIT-F3N.

[0030] Preferably, the hole transport layer is PEDOT:PSS or 2PACz.

[0031] Preferably, the electron transport layer is PDINN or PNDIT-F3N.

[0032] Furthermore, the metal electrode layer includes inert tin oxide (ITO), gold, silver, copper, aluminum, calcium electrodes, silver nanowires, and a conductive polymer film.

[0033] Furthermore, the present invention also provides a method for preparing the photoelectric converter as described above, comprising the following steps:

[0034] (1) After marking the ITO conductive glass, place it in alcohol and sonicate at room temperature for 0.5~1h. Then, use cleaning solution, ultrapure water and ethanol as solvents to sonicate and clean it in sequence. After cleaning, dry it and perform ultraviolet-ozone treatment.

[0035] (2) Dissolve the hole transport layer material in a solvent to prepare a hole transport layer solution with a concentration of 0.1~3 mg / mL for later use. Take the hole transport layer solution and drop it onto the surface of ITO conductive glass. Spin-coat and place it on a hot table for annealing. The resulting film is the hole transport layer.

[0036] (3) Dissolve the donor material and acceptor material in a solvent, stir at 80~120℃ for 1~3.5h, add solid additive material for photoelectric converter and stir evenly to form a photoactive layer solution, take the photoactive layer solution and drop it onto the hole transport layer, spin coat and place it on a hot table for annealing to form a photoactive layer film.

[0037] (4) Dissolve the electron transport layer material in a solvent to prepare an electron transport layer solution with a concentration of 0.1~3 mg / mL for later use, and spin-coat it onto the photoactive layer film obtained in step (3) to form an electron transport layer;

[0038] (5) Transfer the wafer prepared in step (4) into the vacuum evaporation chamber and heat it at 10°C. -5Metal electrode layers are deposited on the electron transport layer under a vacuum of Pa.

[0039] The organic solar energy preparation method provided in this application achieves higher photoelectric conversion efficiency by systematically optimizing the concentration of solid additives, annealing temperature, and annealing time. Compared with traditional liquid additive photoelectric converter devices, the photoelectric conversion efficiency is significantly improved.

[0040] As a preferred technical solution:

[0041] In the preparation method described above, in step (3), the concentration of the donor material in the photoactive layer solution is 3~10 mg / mL, the concentration of the acceptor material is 3~10 mg / mL, and the concentration of the solid additive material for the photoelectric converter is 3~10 mg / mL.

[0042] Furthermore, in step (2), the spin coating speed is 200~6000 rpm, the spin coating time is 2~40s, the annealing temperature is 80~200℃, and the time is 5~30min.

[0043] Furthermore, the solvent in step (2) includes one or more of methanol, ethanol, water, tetrahydrofuran, chlorobenzene, and toluene.

[0044] Furthermore, in step (2), the volume of hole transport layer solution drawn is 15~30μL.

[0045] Furthermore, in step (3), the spin coating speed is 2000~6000 rpm, the spin coating time is 20~40s, the annealing temperature is 80~200℃, and the time is 5~30min.

[0046] The above technical solution is only one feasible technical solution of the present invention. The scope of protection of the present invention is not limited thereto. Those skilled in the art can reasonably adjust the specific design according to actual needs.

[0047] The above invention has the following advantages or beneficial effects:

[0048] The solid additive material for photoelectric converters of the present invention is a novel dioxazole-based solid additive. This solid additive material can effectively control the morphology of the active layer, thereby improving the performance of photovoltaic devices. After adding this solid additive material, the acceptor molecules in the active layer are arranged more compactly and orderly, thereby improving the internal carrier physics processes, enhancing exciton dissociation, improving charge transport, and reducing charge recombination. This significantly increases the short-circuit current density and fill factor of the photoelectric converter, resulting in higher photoelectric conversion efficiency. Compared with traditional liquid additives, this solid additive material can volatilize during film formation, avoiding the residue of harmful substances and thus improving the long-term stability of the device. Attached Figure Description

[0049] The invention, its features, shape, and advantages will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings. Like reference numerals denote like parts throughout the drawings. The drawings are not drawn to scale; the emphasis is on illustrating the gist of the invention.

[0050] Figure 1 This is a schematic diagram of the photoelectric converter provided in Example 2. Detailed Implementation

[0051] The present invention will be further described below with reference to specific embodiments, but these are not intended to limit the invention.

[0052] Example 1

[0053] A solid additive material Xa for a photoelectric converter has the following specific structural formula:

[0054] .

[0055] Its preparation method includes the following steps:

[0056] (1) Mix 4-isooctylphenol (206.22 g), nitric acid (50 ml) and acetic acid (500 ml), then stir overnight at room temperature under nitrogen protection. After the reaction is complete, pour the reaction solution into water, extract with dichloromethane, and then distill the extract under reduced pressure (< -0.08 MPa). Separate the extract by silica gel column to obtain 4-isooctyl-2-nitrophenol (yield 88%).

[0057]

[0058] (2) 4-Isooctyl-2-nitrophenol (150g), Pd / C (1g), hydrazine hydrate (80ml) and ethanol (500ml) were poured into a reaction flask and reacted at 78°C for 6h under N2 atmosphere. After the reaction was completed, the mixture was filtered and concentrated under reduced pressure to obtain 4-isooctyl-2-aminophenol (yield 92%).

[0059]

[0060] (3) The intermediate product (30g), terephthalic acid (10), and polyphosphoric acid (100ml) obtained in step (2) were added to the reactor and deoxygenated by nitrogen. Then, the reaction was carried out at 180°C for 5 hours under a nitrogen atmosphere. After the reaction was completed, the reaction solution was poured into water, extracted with ethyl acetate, concentrated by vacuum distillation, and separated by silica gel column chromatography to obtain solid additive material Xa for photoelectric converters (yield 70.1%). UV-vis spectrum (chloroform): λ max=352nm.

[0061]

[0062] Example 2

[0063] A method for fabricating a photoelectric converter includes the following steps:

[0064] (1) After marking the ITO conductive glass, place it in alcohol and sonicate at room temperature for 1 hour. Then, use cleaning solution, ultrapure water and ethanol as solvents to sonicate it in sequence. After cleaning, dry it and perform ultraviolet-ozone treatment.

[0065] (2) Dissolve the hole transport layer material (PEDOT:PSS) in a solvent (chlorobenzene) to prepare a hole transport layer solution with a concentration of 1.5 mg / mL for later use. Take 30 μL of the hole transport layer solution and drop it onto the surface of ITO conductive glass. After spin coating, place it on a hot stage for annealing. The resulting film is the hole transport layer. The spin coating speed is 3000 rpm and the spin coating time is 20 s. The annealing temperature is 140 ℃ and the time is 20 min.

[0066] (3) Dissolve the donor material (PM6) and acceptor material (L8-BO) in a solvent (chlorobenzene) (the mass ratio of PM6 to L8-BO is 1:1.2), stir at 100°C for 2.5 h, add the solid additive material for photoelectric converter prepared in Example 1 and stir evenly to form a photoactive layer solution. The amount of solid additive material for photoelectric converter added is 30 wt% of PM6 and L8-BO, and the concentration of PM6 in the photoactive layer solution is 6 mg / mL. Take the photoactive layer solution and drop it onto the hole transport layer. After spin coating, place it on a hot table for annealing to form a photoactive layer film. The spin coating speed is 3000 rpm and the spin coating time is 30 s. The annealing temperature is 140°C and the time is 20 min.

[0067] (4) Dissolve the electron transport layer material (PDINN) in a solvent to prepare an electron transport layer solution with a concentration of 1.5 mg / mL for later use, and spin-coat it onto the photoactive layer film obtained in step (3) to form an electron transport layer;

[0068] (5) Transfer the wafer prepared in step (4) into the vacuum evaporation chamber and heat it at 10°C. -5 Metal electrode layers (inert tin oxide (ITO)) are deposited on the electron transport layer under a vacuum of Pa.

[0069] The structure of the fabricated photoelectric converter is as follows Figure 1 As shown, from bottom to top, it includes a transparent substrate, a transparent electrode layer, a hole transport layer, a photoactive layer, an electron transport layer, and a metal electrode layer.

[0070] Those skilled in the art should understand that variations can be implemented by combining existing technology with the above embodiments, which will not be elaborated here. Such variations do not affect the essence of the present invention, and will not be elaborated here either.

[0071] The preferred embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and the devices and structures not described in detail should be understood as being implemented in a conventional manner in the art. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the scope of the present invention. This does not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the present invention's technical solutions still fall within the protection scope of the present invention.

Claims

1. A solid additive material for a photoelectric converter, characterized in that: Including compounds having the structure shown in (Ⅰ): (Ⅰ) Wherein, R1~R8 are each independently selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted amino, substituted or unsubstituted amide, substituted or unsubstituted cyclic imino, substituted or unsubstituted alkoxy, substituted or unsubstituted carboxyl, substituted or unsubstituted ester, substituted or unsubstituted carbonyl, and R1~R8 are not simultaneously H; the substituted substituents include fluorine, chlorine, bromine, iodine, C2~C 28 Hydroxyl group, C2-C 28 Ester group, C2-C 28 Carboxyl group, C2-C 28 Amino, C2-C 28 thiol group, C2-C 28 amide group, C2-C 28 carbonyl group, C2-C 28 Alkoxy, C6~C 28 Aryl, C4~C 28 heteroaryl, C2-C 28 Alkyl, C2-C 28 Heteroalkyl, C2-C 28 alkenyl groups and C2-C 28 Any one of the imino groups; The Ar is selected from C2 to C3. 30 The conjugated aromatic ring is substituted with alkyl, alkoxy, alkenyl, phenyl, or benzyl groups, wherein the conjugated aromatic ring includes one or more combinations of alkenyl, alkynyl, phenyl, biphenyl, benzyl, naphthyl, and anthraceneyl groups.

2. The solid additive material for a photoelectric converter according to claim 1, characterized in that, Each of R1 to R8 is independently selected from H, substituted or unsubstituted C2 to C8. 20 Alkyl, substituted or unsubstituted C2-C 20 Any of the alkenyl groups.

3. The solid additive material for a photoelectric converter according to claim 2, characterized in that, R1 to R8 are each independently selected from substituted or unsubstituted C2 to C8. 12 Any one of the alkyl groups.

4. The solid additive material for a photoelectric converter according to claim 1, characterized in that, The solid additive material for the photoelectric converter includes any one or a combination of at least two of the following compounds: 。 5. A photoelectric converter, characterized in that, The structure of the photoelectric converter, from bottom to top, includes a transparent substrate, a transparent electrode layer, a hole transport layer, a photoactive layer, an electron transport layer, and a metal electrode layer; The photoactive layer is made of donor material, acceptor material, and solid additive material for photoelectric converters as described in any one of claims 1 to 4.

6. A photoelectric converter according to claim 5, characterized in that, The donor material is PM6 or D18, and the acceptor material is L8-BO, Y6, or BTP-eC9.

7. A photoelectric converter according to claim 5, characterized in that, When the donor material is PM6, the mass ratio of the donor material to the acceptor material is 1:1.2; When the donor material is D18, the mass ratio of the donor material to the acceptor material is 1:1.

6.

8. A photoelectric converter according to claim 5, characterized in that, The amount of solid additive material added to the photoelectric converter is 1 to 30 wt% of the total weight of the donor and acceptor materials.

9. The method for preparing a photoelectric converter according to any one of claims 5 to 8, characterized in that, Includes the following steps: (1) After marking the ITO conductive glass, place it in alcohol and sonicate at room temperature for 0.5~1h. Then, use cleaning solution, ultrapure water and ethanol as solvents to sonicate and clean it in sequence. After cleaning, dry it and perform ultraviolet-ozone treatment. (2) Dissolve the hole transport layer material in a solvent to prepare a hole transport layer solution with a concentration of 0.1~3 mg / mL for later use. Take the hole transport layer solution and drop it onto the surface of ITO conductive glass. Spin-coat and place it on a hot table for annealing. The resulting film is the hole transport layer. (3) Dissolve the donor material and acceptor material in a solvent, stir at 80~120℃ for 1~3.5h, add solid additive material for photoelectric converter and stir evenly to form a photoactive layer solution, take the photoactive layer solution and drop it onto the hole transport layer, spin coat and place it on a hot table for annealing to form a photoactive layer film. (4) Dissolve the electron transport layer material in a solvent to prepare an electron transport layer solution with a concentration of 0.1~3 mg / mL for later use, and spin-coat it onto the photoactive layer film obtained in step (3) to form an electron transport layer; (5) Transfer the wafer prepared in step (4) into the vacuum evaporation chamber and heat it at 10°C. -5 Metal electrode layers are deposited on the electron transport layer under a vacuum of Pa.

10. The preparation method according to claim 9, characterized in that, In step (3), the concentration of the donor material in the photoactive layer solution is 3~10 mg / mL, the concentration of the acceptor material is 3~10 mg / mL, and the concentration of the solid additive material for the photoelectric converter is 3~10 mg / mL.

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