阅读说明：本技术 一种柔性单组分有机太阳能电池及其制备方法 (Flexible single-component organic solar cell and preparation method thereof ) 是由 李韦伟 谢程程 肖承义 陈巧梅 于 2021-09-03 设计创作，主要内容包括：本发明涉及有机太阳能电池器件技术领域,具体涉及一种柔性单组分有机太阳能电池及其制备方法。柔性单组分有机太阳能电池,从下至上依次包括塑料支撑层、柔性电极层、电子传输层、单组分光活性层、空穴传输层和顶电极层；单组分光活性层材料为双缆聚合物,双缆聚合物为给体骨架和受体亲核试剂通过共价键连接的双缆聚合物；柔性电极层为阴极,顶电极层为阳极。相对于本体异质型有机太阳能电池,本发明柔性单组分有机太阳能电池可以有效提升器件稳定性、储存稳定性和优异的抗弯曲变形能力；本发明还提供超薄柔性有机太阳能电池,不仅具有良好的能量转换效率,还具有优异的贴附作用,可在柔性可穿戴领域或生物检测应用领域具有良好的应用。(The invention relates to the technical field of organic solar cell devices, in particular to a flexible single-component organic solar cell and a preparation method thereof. The flexible single-component organic solar cell sequentially comprises a plastic supporting layer, a flexible electrode layer, an electron transport layer, a single-component light activity layer, a hole transport layer and a top electrode layer from bottom to top; the single-component optical active layer material is a double-cable polymer, and the double-cable polymer is a double-cable polymer formed by connecting a donor skeleton and an acceptor nucleophilic reagent through a covalent bond; the flexible electrode layer is a cathode, and the top electrode layer is an anode. Compared with a body heterogeneous organic solar cell, the flexible single-component organic solar cell can effectively improve the stability, storage stability and excellent bending deformation resistance of a device; the invention also provides an ultrathin flexible organic solar cell, which not only has good energy conversion efficiency, but also has excellent attaching effect, and can be well applied to the flexible wearable field or the biological detection application field.)

1. A flexible single-component organic solar cell sequentially comprises a plastic supporting layer, a flexible electrode layer, an electron transport layer, a single-component light activity layer, a hole transport layer and a top electrode layer from bottom to top; the single-component photoactive layer material is a double-cable polymer, and the double-cable polymer is a double-cable polymer formed by connecting a donor skeleton and an acceptor nucleophile through a covalent bond; the flexible electrode layer is a cathode, and the top electrode layer is an anode.

2. The flexible monocomponent organic solar cell according to claim 1, wherein the plastic support layer material is selected from one or more of polyethylene terephthalate, polycarbonate, polymethyl methacrylate, polyethylene naphthalate, polyethersulfone, polysulfone, polyamide, transparent polyimide, polyolefin, polysilane, acrylonitrile-butadiene-styrene copolymer.

3. The flexible monocomponent organic solar cell of claim 1, the plastic support layer having a thickness of 3 μm or less.

4. The flexible monocomponent organic solar cell of claim 1, the flexible electrode layer material being selected from metal oxides, doped metal oxides, metal nanowires, conductive polymers or carbon-based materials.

5. The flexible monocomponent organic solar cell of claim 1, the electron transport layer material including but not limited to ZnO, TiO₂、SnO₂PFN, PFN-Br, PDNIO or derivatives thereof.

6. The flexible mono-component organic solar cell according to claim 1, the donor backbone of the two-cord polymer being one of a pyrrolopyrroledione-benzodithiophene type backbone, an isoindigo type backbone, a thienopyrrolopyrroledione-benzodithiophene type backbone, a polyesterylthiophene type backbone and a benzodithiophenedione-benzodithiophene type backbone; the acceptor nucleophiles of the two-stranded polymer include, but are not limited to, perylene imide based nucleophiles or naphthalene imide based nucleophiles.

7. The flexible monocomponent organic solar cell of claim 1, the two-cord polymer including but not limited to the following structures:

8. the method for preparing a flexible mono-component organic solar cell according to any one of claims 1 to 7, comprising the steps of:

step 1: selecting a rigid substrate, and coating an adhesive layer on the surface of the rigid substrate;

step 2: adhering a plastic support layer to the surface of a rigid substrate, and then depositing a transparent conductive electrode material on the surface of the plastic support layer to obtain a flexible electrode layer;

and step 3: depositing an electron transport layer material on the surface of the flexible electrode layer to obtain an electron transport layer;

and 4, step 4: depositing a double-cable polymer solution on the surface of the electron transport layer, and annealing to obtain a single-component optical active layer;

and 5: depositing a hole transport layer material on the surface of the single-component optical active layer to obtain a hole transport layer;

step 6: depositing a top electrode material on the surface of the hole transport layer to obtain a top electrode layer;

and 7: the rigid substrate is peeled off.

9. The method for preparing a flexible monocomponent organic solar cell according to claim 8, wherein when the thickness of the plastic support layer is less than 3 μm, the plastic support layer is adhered to the surface of the rigid substrate in step 2 by placing the plastic support layer on a water surface and spreading the plastic support layer flatly, and slowly pulling the rigid substrate with the adhesive layer from the water surface or from the water surface; and then washing and drying the plastic supporting layer adhered with the rigid substrate, and placing the plastic supporting layer in an ultraviolet ozone cleaning machine for treatment.

10. Use of the flexible mono-component organic solar cell according to any one of claims 1 to 7 or the method of manufacturing a flexible mono-component organic solar cell according to any one of claims 8 to 9 in the field of solar energy conversion technology.

Technical Field

The invention relates to the technical field of organic solar cell devices, in particular to a flexible single-component organic solar cell and a preparation method thereof.

Background

With the progress of society and the development of science and technology, the demand of human beings on energy is increasing, and the excessive development of resources such as coal, petroleum and the like seriously influences the living environment of human beings and the ecological environment of the earth, so that a novel renewable energy source is required to be developed. Solar power generation is a technology capable of directly converting solar energy into electric energy, can directly or indirectly provide abundant energy support for people, is an important way for social forward development for development and utilization of solar technology, and gets wide attention in the scientific research field and the industrial field.

The rationale for the operation of solar cells stems from the photoelectric response characteristics of semiconductor materials, and the earliest development of solar cells dates back to the discovery of Becqurel photovoltaic effect by 1839 scientists. Since then, people are exploring and developing new solar cell materials and device processes, and solar cells based on silicon-based (single crystal, polycrystal and amorphous silicon) solar cells, cadmium sulfide, cadmium telluride, gallium arsenide and other inorganic compounds are emerged. Particularly, with the continuous development of solar cells and the development demand of human society, organic solar cell systems independent of inorganic solar cell systems are produced. Unlike inorganic solar systems, the advantages of light weight, thinness, flexibility, etc., of organic solar cells render organic solar cells irreplaceable for widespread use. Among the organic solar cells, the most widely used are rigid solar cells such as crystalline silicon cells. In some occasions where rigid batteries cannot be used, the flexible solar battery gains a place due to the unique and flexible characteristics and plays an irreplaceable role in various outdoor portable applications, particularly in the fields of scientific research, military industry and the like.

The physical and electrical properties of the photovoltaically active material are the primary factors in the fabrication of flexible organic solar cells. As for the photovoltaic active material, the bulk heterojunction type device becomes the mainstream of the current organic solar cell device structure due to its high energy conversion efficiency, however, the active layer of the bulk heterojunction type device structure is usually formed by blending a small molecule acceptor and a polymer donor, and the preparation condition of a fine control film is required to control the phase separation dimension formed by the acceptor, so as to ensure dissociation of excitons and transmission of charges, which has high requirements on the device preparation process and manual operation, and is not favorable for industrial practical application production and popularization. In addition, although the bulk heterogeneous solar cell has high conversion efficiency, the small molecular acceptor material has high degree of freedom in an active layer due to small size, and is easy to self-aggregate under the conditions of illumination and heating, and the performance attenuation of an inverted device is large in short time, so that the prepared organic solar cell device is very unstable and is difficult to produce and apply in a large area. At the present stage, the preparation based on the flexible organic solar cell is still based on the method that the bulk heterojunction is used as the active layer material, so that the process of the flexible organic solar cell is complicated, and the application and popularization of the flexible organic solar cell are limited to a certain extent due to the intrinsic instability of the bulk heterojunction.

The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Disclosure of Invention

Object of the Invention

In order to solve the main problems and defects of the flexible organic solar cell material in the prior art, the invention aims to provide a flexible single-component organic solar cell and a preparation method thereof. The double-cable polymer is used as the active material of the single-component organic solar cell, and the prepared flexible single-component organic solar cell has high energy conversion efficiency, excellent mechanical stability and good storage stability.

Solution scheme

In order to achieve the purpose of the invention, the embodiment of the invention provides the following technical scheme:

a flexible single-component organic solar cell sequentially comprises a plastic supporting layer, a flexible electrode layer, an electron transport layer, a single-component light activity layer, a hole transport layer and a top electrode layer from bottom to top; the single-component photoactive layer material is a double-cable polymer, and the double-cable polymer is a double-cable polymer formed by connecting a donor skeleton and an acceptor nucleophile through a covalent bond; the flexible electrode layer is a cathode, and the top electrode layer is an anode.

In one possible implementation, the plastic support layer material is selected from one or more of polyethylene terephthalate, polycarbonate, polymethyl methacrylate, polyethylene naphthalate, polyether sulfone (PES), Polysulfone (PS), polyamide, transparent polyimide, polyolefin, polysilane, acrylonitrile-butadiene-styrene copolymer. The plastic supporting layer is a main carrier for realizing flexible deformation of the solar cell, and the plastic supporting layer is used as a solar light incidence surface and has excellent transmittance.

In one possible implementation, the thickness of the plastic support layer is >50 μm, more preferably >100 μm.

In one possible implementation, the thickness of the plastic support layer is less than or equal to 3 μm.

In one possible implementation, the flexible electrode layer material is selected from a metal oxide, a doped metal oxide, a metal nanowire, a conductive polymer, or a carbon-based material; the metal oxide is preferably indium tin oxide; the metal nanowires include but are not limited to silver nanowires, gold nanowires, copper nanowires, preferably gold nanowires; the carbon-based material includes but is not limited to carbon nanotubes or graphene and derivative modified materials thereof; the flexible electrode layer resistance is less than 20 omega/sq, and the transmittance is more than 85%.

In one possible implementation, the electron transport layer material includes, but is not limited to, ZnO, TiO₂、SnO₂PFN, PFN-Br, PDNIO and their derivatives, preferably ZnO.

In one possible implementation, the electron transport layer has a thickness of 10-150 nm.

In one possible implementation, the donor backbone of the two-cord polymer includes one of a pyrrolopyrroledione-benzodithiophene type backbone, an isoindigo type backbone, a thienopyrrolopyrroledione-benzodithiophene type backbone, a polyesterylthiophene type backbone, and a benzodithiophenedione-benzodithiophene type backbone.

In one possible implementation, the acceptor nucleophile of the two-stranded polymer includes, but is not limited to, a perylene imide based nucleophile (PBI) or a naphthalimide based Nucleophile (NDI).

In one possible implementation, the twin-cable polymer includes, but is not limited to, the following structures:

in one possible implementation, the one-component photoactive layer has a thickness of 40nm to 120 nm.

In one possible implementation manner, the hole transport layer material is one or more of nickel oxide, molybdenum oxide, copper oxide, poly 3, 4-ethylenedioxythiophene and polystyrene sulfonate, and the thickness of the hole transport layer is 3-100 nm.

In one possible implementation, the top electrode layer material may be selected from silver, aluminum, gold, copper, eutectic gallium-indium alloy, or a polymer with an electrical conductivity greater than 1000S/cm; the thickness of the top electrode layer is 80-200 nm.

A preparation method of a flexible single-component organic solar cell comprises the following steps:

step 1: selecting a rigid substrate, and coating an adhesive layer on the surface of the rigid substrate;

step 2: adhering a plastic support layer to the surface of a rigid substrate, and then depositing a transparent conductive electrode material on the surface of the plastic support layer to obtain a flexible electrode layer;

and step 3: depositing an electron transport layer material on the surface of the flexible electrode layer to obtain an electron transport layer;

and 4, step 4: depositing a double-cable polymer solution on the surface of the electron transport layer, and annealing to obtain a single-component optical active layer;

and 5: depositing a hole transport layer material on the surface of the single-component optical active layer to obtain a hole transport layer;

step 6: depositing a top electrode material on the surface of the hole transport layer to obtain a top electrode layer;

and 7: the rigid substrate is peeled off.

In a possible implementation mode, the thickness of the plastic supporting layer is more than 50 microns, the plastic supporting layer is firstly cleaned by ultrasonic for 10-20min in the step 2, and the plastic supporting layer is placed in an ultraviolet ozone cleaning machine for treatment for 10-30min after being adhered to the surface of the rigid substrate.

In a possible implementation mode, the thickness of the plastic supporting layer is less than 3 μm, and the plastic supporting layer is adhered to the surface of the rigid substrate in the step 2 by placing the plastic supporting layer on a water surface and spreading the plastic supporting layer flatly, and slowly lifting the rigid substrate with the adhesive layer from the water surface or from the water surface; then, washing and drying the plastic supporting layer adhered with the rigid substrate, and placing the plastic supporting layer in an ultraviolet ozone cleaning machine for treatment for 10-30 min; the washing is to repeatedly wash for more than 3 times by adopting a cleaning agent, water, acetone or ethanol and isopropanol in sequence, and the drying temperature is 80-100 ℃.

In one possible implementation, the rigid substrate includes, but is not limited to, a silicon wafer, glass, plexiglass, a stainless steel plate, an iron plate, or an aluminum plate.

In one possible implementation manner, the adhesion layer may be a thin layer formed by coating a pouring sealant; the pouring sealant can be a polydimethylsiloxane solution which is not completely cured; the polydimethylsiloxane solution is prepared by mixing polydimethylsiloxane and a curing agent according to the weight ratio of 10: 1.

In a possible implementation manner, the pouring sealant is a polydimethylsiloxane solution diluted by toluene according to a volume ratio of 1: 1-2.

In one possible implementation mode, the plastic supporting layer is heated and cured after being adhered to the surface of the rigid substrate, the heating temperature is 80-150 ℃, and the heating time is 5-20 minutes.

In one possible implementation, the deposition includes, but is not limited to, spin coating, doctor blading, magnetron sputtering, vacuum evaporation, or atomic deposition.

In one possible implementation mode, the double-cable polymer solution is prepared by dissolving the double-cable polymer by using an organic solvent, and the concentration of the solution is 7-20 mg/mL.

In one possible implementation, the annealing condition in the step 4 is annealing at 25-200 ℃ for 10-30 minutes.

Advantageous effects

(1) Compared with a body heterogeneous organic solar cell, the single-component photoactive layer is a double-cable polymer which is a single component, so that the problem of self-aggregation of small molecule acceptor materials in an active layer of the body heterogeneous organic solar cell along with the lapse of time in an application environment can be avoided, and the stability of a device can be effectively improved; in addition, the bulk heterojunction type active layer comprises a small molecular receptor and a polymer donor which are blended, so that the micro defects of insufficient blending or uneven dispersion exist among the components in the active layer, and when the active layer is stressed to generate large deformation, local stress in the optical active layer is concentrated, so that the interlayer fracture phenomenon occurs; the photoactive layer of the invention is a single component, and has better storage stability and excellent bending deformation resistance.

(2) The preparation method of the flexible single-component solar cell provided by the embodiment of the invention is simple, convenient, effective and easy to control. And the preparation method is provided when the plastic supporting layer is less than or equal to 3 mu m, so that the ultrathin flexible organic solar cell is prepared, and the energy conversion efficiency is good. The ultrathin flexible organic solar cell has excellent attaching effect, can be attached to the surfaces of different objects, and has good application prospect in the future flexible organic solar cell integration application direction, such as the flexible wearable field and the biological detection application field.

Drawings

FIG. 1 is a schematic structural view of a flexible monocomponent organic solar cell according to example 1 of the present invention;

FIG. 2 is a physical diagram of a flexible monocomponent organic solar cell according to example 1 of the present invention;

FIG. 3 is a J-V curve of a flexible monocomponent organic solar cell of example 1 of the present invention and a rigid monocomponent organic solar cell of comparative example 1;

FIG. 4 is a J-V curve of the ultra-thin flexible mono-component organic solar cell of example 2;

FIG. 5 is a graph showing the storage stability of a flexible single-component organic solar cell according to example 1 of the present invention and a bulk heterogeneous organic solar cell according to comparative example 2;

fig. 6 is a bending test chart for testing an organic solar cell;

fig. 7 is a graph of stability of energy conversion efficiency of the flexible monocomponent organic solar cell of example 1 and the bulk hetero-type organic solar cell of comparative example 2 after 1000 times of different bending with different radii, respectively;

FIG. 8 is a schematic diagram of the ultrathin flexible single-component organic solar cell of example 2.

In the figure: 1. a top electrode layer; 2. a hole transport layer; 3. a single component photoactive layer; 4. an electron transport layer; 5. a flexible electrode layer; 6. a plastic support layer;

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are a part of the embodiments of the present invention, but not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Furthermore, in the following detailed description, numerous specific details are set forth in order to provide a better understanding of the present invention. It will be understood by those skilled in the art that the present invention may be practiced without some of these specific details. In some embodiments, materials, elements, methods, means, and the like that are well known to those skilled in the art are not described in detail in order to not unnecessarily obscure the present invention.

Throughout the specification and claims, unless explicitly stated otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element or component but not the exclusion of any other element or component.

Example 1.

As shown in fig. 1, a flexible monocomponent organic solar cell sequentially comprises a plastic support layer, a flexible electrode layer, an electron transport layer, a monocomponent photoactive layer, a hole transport layer and a top electrode layer; the single-component optical active layer material is a double-cable polymer which is formed by combining a benzodithiophene diketone-benzodithiophene polymer serving as a donor framework and a naphthalimide small molecule serving as an acceptor nucleophile through a covalent bond.

The structural formula of the benzodithiophene diketone-benzodithiophene polymer is as follows:

the structural formula of the naphthalimide micromolecules is shown as follows;

the structural formula of the double-cable polymer is as follows:

the preparation method comprises the following steps:

step 1: spin-coating polydimethylsiloxane potting adhesive (SYLGARD 184) on the surface of glass by a high-speed rotary coating machine at the rotating speed of 4000rpm, and then placing the glass on a heating table at 100 ℃ for heating and annealing for 7min to obtain a glass substrate with an adhesion layer;

step 2: selecting PET as a plastic supporting layer, wherein the thickness of the PET is 125 mu m, cutting the PET into pieces with the same size as a glass substrate, and then sequentially carrying out ultrasonic cleaning by using a detergent, water, acetone and isopropanol for 10 minutes; taking out the cleaned PET, and placing the PET in an oven at 80 ℃ for drying; adhering the cleaned PET to the surface of a rigid substrate flatly, and then placing the rigid substrate in an ultraviolet ozone cleaning machine for treatment for 15 minutes; diluting silver nanowires with water, wherein the diluted silver nanowires have a mass fraction of 0.2%, spin-coating the diluted silver nanowires on the surface of PET (polyethylene terephthalate) adhered to a glass substrate by a high-speed rotary coating machine, then placing the PET nanowires on the surface of a heating table, annealing for 10 minutes at 100 ℃, and repeating the steps of spin-coating the silver nanowires and heating and annealing to obtain a flexible electrode layer; patterning the flexible electrode layer by using a laser etching method;

and step 3: depositing an electron transport layer material ZnO on the surface of the flexible electrode layer to obtain an electron transport layer;

the method comprises the following steps of coating a sol-gel ZnO solution on the surface of a flexible electrode layer in a spin coating mode at the rotating speed of 3000rpm, placing the flexible electrode layer on a heating table, annealing for 10-30 minutes at 150 ℃, and repeating the steps of spin coating and heating annealing for 2 times to obtain the electron transmission layer. The preparation method of the sol-gel ZnO solution comprises the following steps: weighing 100 mg of zinc acetate dihydrate, placing into an ultra-clean bottle, sequentially adding 937 μ l of dimethoxyethanol and 29 μ l of ethanolamine, and stirring for more than two hours to obtain the final product;

and 4, step 4: weighing a certain amount of benzodithiophene dione-benzodithiophene-based double-cable polymer, adding the double-cable polymer into an ultra-clean bottle, transferring the double-cable polymer into a glove box, dissolving the double-cable polymer by using chlorobenzene as a solvent, controlling the concentration of a double-cable polymer solution to be 8mg/mL-12mg/mL, coating the double-cable polymer solution on the surface of an electronic transmission layer by using a high-speed rotary coating machine, then placing the electronic transmission layer on a heating table for annealing treatment at the annealing temperature of 150 ℃ for 10 minutes to obtain a single-component optical active layer;

and 5: transferring the device with the single-component active layer to a vacuum evaporation device, and starting to evaporate MoO when the vacuum degree reaches 10-7mbar₃Evaporating to form a film with the thickness of 4 nm; obtaining a hole transport layer;

step 6: after 30min, evaporating an Ag electrode on the device deposited with the hole transport layer in vacuum evaporation equipment, wherein the evaporation thickness is 100nm, and obtaining a top electrode layer;

and 7: the rigid glass substrate is peeled.

Example 2.

A single-component organic solar cell sequentially comprises a plastic supporting layer, a flexible electrode layer, an electron transport layer, a single-component light activity layer, a hole transport layer and a top electrode layer; the single-component optical active layer material is a benzodithiophene diketone-benzodithiophene two-cable polymer; the thickness of the plastic support layer is 1.3 μm.

The preparation method comprises the following steps:

step 1: spin-coating polydimethylsiloxane potting adhesive (SYLGARD 184) on the surface of glass by a high-speed rotary coating machine at the rotating speed of 4000rpm, and then placing the glass on a heating table at 100 ℃ for heating and annealing for 7min to obtain a glass substrate with an adhesion layer;

step 2: selecting a polyethylene naphthalate (PEN) film as a plastic supporting layer, wherein the size of the PEN film is larger than that of a glass substrate, placing the PEN film on a water surface to be flatly spread, and slowly lifting the glass substrate with an adhesion layer from the water surface to adhere the PEN film to the surface of the glass substrate; then repeatedly washing the plastic supporting layer adhered with the glass substrate by adopting a cleaning agent, water, acetone and isopropanol for 3 times in sequence, and placing the plastic supporting layer in an ultraviolet ozone cleaning machine for treatment for 10 min; diluting the silver nanowires with water, wherein the diluted silver nanowires have a mass fraction of 0.2%, spin-coating the diluted silver nanowires on the surface of PEN (PEN) adhered to a glass substrate by a high-speed rotary coating machine, then placing the diluted silver nanowires on the surface of a heating table, annealing at 100 ℃ for 10 minutes, and repeating the steps of spin-coating the silver nanowires and heating and annealing to obtain a flexible electrode layer; patterning the flexible electrode layer by using a laser etching method;

and step 3: depositing an electron transport layer material ZnO on the surface of the flexible electrode layer to obtain an electron transport layer;

the method comprises the following steps of coating a sol-gel ZnO solution on the surface of a flexible electrode layer in a spin coating mode at the rotating speed of 3000rpm, placing the flexible electrode layer on a heating table, annealing for 10-30 minutes at 150 ℃, and repeating the steps of spin coating and heating annealing for 2 times to obtain the electron transmission layer. The preparation method of the sol-gel ZnO solution comprises the following steps: weighing 100 mg of zinc acetate dihydrate, placing into an ultra-clean bottle, sequentially adding 937ul of dimethoxy ethanol and 29ul of ethanolamine, and fully stirring for more than two hours to obtain the zinc acetate dihydrate;

and 4, step 4: weighing a certain amount of benzodithiophene dione-benzodithiophene-based double-cable polymer, adding the double-cable polymer into an ultra-clean bottle, transferring the double-cable polymer into a glove box, dissolving the double-cable polymer by using chlorobenzene as a solvent, controlling the concentration of a double-cable polymer solution to be 8mg/mL-12mg/mL, coating the double-cable polymer solution on the surface of an electronic transmission layer by using a high-speed rotary coating machine, then placing the electronic transmission layer on a heating table for annealing treatment at the annealing temperature of 150 ℃ for 10 minutes to obtain a single-component optical active layer;

and 5: transferring the device with the single-component active layer to a vacuum evaporation device, and starting to evaporate MoO when the vacuum degree reaches 10-7mbar₃Evaporating to form a film with the thickness of 4 nm; obtaining a hole transport layer;

step 6: after 30min, evaporating an Ag electrode on the device deposited with the hole transport layer in vacuum evaporation equipment, wherein the evaporation thickness is 100nm, and obtaining a top electrode layer;

and 7: the rigid glass substrate is peeled.

And obtaining the ultrathin flexible single-component organic solar cell.

Comparative example 1.

A rigid single-component organic solar cell is prepared by the following steps:

step 1: selecting patterned ITO as a rigid electrode, carrying out ultrasonic cleaning for 10min by sequentially adopting a detergent, water, acetone and isopropanol, and then placing the ITO in an ultraviolet ozone processor for treatment for 20 min;

step 2: spin-coating a sol-gel ZnO solution on the surface of the cleaned rigid electrode, spin-coating a layer of ZnO at the rotating speed of 4000rpm, and placing the rigid electrode on a heating table to anneal for 10-30 minutes at 150 ℃ to obtain an electron transmission layer; the preparation method of the sol-gel ZnO solution is the same as that of example 1;

and step 3: coating the double-cable polymer solution on the surface of the electronic transmission layer by using a high-speed rotary coating machine, and then placing the electronic transmission layer on a heating table for annealing treatment at the annealing temperature of 150 ℃ for 10 minutes to obtain a single-component optical active layer; the preparation of the two-wire polymer solution was the same as in example 1;

and 4, step 4: transferring the device with the single-component active layer to a vacuum evaporation device, and starting to evaporate MoO when the vacuum degree reaches 10-7mbar₃Evaporating to form a film with the thickness of 4 nm; obtaining a hole transport layer;

and 5: and after 30min, evaporating the device deposited with the hole transport layer in a vacuum evaporation device to form an Ag electrode, wherein the evaporation thickness is 100nm, and thus obtaining the top electrode layer.

Comparative example 2.

A bulk heterogeneous organic solar cell has the same structure as in example 1. The preparation method comprises the following steps:

step 1: spin-coating polydimethylsiloxane potting adhesive (SYLGARD 184) on the surface of glass by a high-speed rotary coating machine at the rotating speed of 4000rpm, and then placing the glass on a heating table at 100 ℃ for heating and annealing for 7min to obtain a glass substrate with an adhesion layer;

step 2: selecting PET as a plastic supporting layer, cutting the PET into pieces with the same size as a glass substrate, and then sequentially carrying out ultrasonic cleaning by using a detergent, water, acetone and isopropanol for 10 minutes; taking out the cleaned PET, and placing the PET in an oven at 80 ℃ for drying; adhering the cleaned PET to the surface of a rigid substrate flatly, and then placing the rigid substrate in an ultraviolet ozone cleaning machine for treatment for 15 minutes; diluting silver nanowires with water, wherein the diluted silver nanowires have a mass fraction of 0.2%, spin-coating the diluted silver nanowires on the surface of PET (polyethylene terephthalate) adhered to a glass substrate by a high-speed rotary coating machine, then placing the PET nanowires on the surface of a heating table, annealing for 10 minutes at 100 ℃, and repeating the steps of spin-coating the silver nanowires and heating and annealing to obtain a flexible electrode layer; patterning the flexible electrode layer by using a laser etching method;

and step 3: depositing an electron transport layer material ZnO on the surface of the flexible electrode layer to obtain an electron transport layer;

the method comprises the following steps of coating a sol-gel ZnO solution on the surface of a flexible electrode layer in a spin coating mode at the rotating speed of 3000rpm, placing the flexible electrode layer on a heating table, annealing for 10-30 minutes at 150 ℃, and repeating the steps of spin coating and heating annealing for 2 times to obtain the electron transmission layer. The preparation method of the sol-gel ZnO solution comprises the following steps: weighing 100 mg of zinc acetate dihydrate, placing into an ultra-clean bottle, sequentially adding 937ul of dimethoxy ethanol and 29ul of ethanolamine, and fully stirring for more than two hours to obtain the zinc acetate dihydrate;

and 4, step 4: mixing a benzodithiophene dione-benzodithiophene polymer (PClBDB-T) and a naphthalimide small molecule (NDI-EH) according to a mass ratio of 1:1, dissolving the mixture with chlorobenzene at 80 ℃, and uniformly stirring to prepare a mixed solution with a total concentration of 14 mg/mL; the mixed solution is spin-coated on the surface of the electron transport layer in a high-speed spin coating mode without annealing treatment.

And 5: transferring the device treated in the step 4 into vacuum evaporation equipment, and starting to evaporate MoO when the vacuum degree reaches 10-7mbar₃Evaporating to form a film with the thickness of 4 nm; obtaining a hole transport layer;

step 6: after 30min, evaporating an Ag electrode on the device deposited with the hole transport layer in vacuum evaporation equipment, wherein the evaporation thickness is 100nm, and obtaining a top electrode layer;

and 7: the rigid glass substrate is peeled.

Data comparison

Firstly, testing energy conversion efficiency

The cell devices prepared in examples 1 to 2 and comparative example 1 were subjected to an energy conversion efficiency test using a solar simulator, and the test numerical results and J-V curves are shown in table 1, fig. 3 and fig. 4. As can be seen from table 1 and the J-V graph of fig. 3, the energy conversion efficiency of the flexible organic solar cell of example 1 of the present invention is 7.21%, which is the highest energy conversion efficiency of the current flexible monocomponent organic solar cell and is comparable to that of the rigid monocomponent organic solar cell (7.82%). As can be seen from fig. 4, the ultra-thin flexible monocomponent organic solar cell prepared in example 2 of the present invention still has high energy conversion efficiency, which is close to that of the rigid monocomponent organic solar cell.

TABLE 1

Second, storage stability test

The flexible single-component organic solar cell of example 1 and the bulk-heterojunction flexible organic solar cell of comparative example 2 were placed in a nitrogen atmosphere for storage at room temperature, and energy conversion efficiency tests were performed at intervals to evaluate the storage stability of the devices. The test results are shown in fig. 5. As can be seen from fig. 5, after 400h of storage, the efficiency of the flexible monocomponent organic solar cell of example 1 was hardly deteriorated, the efficiency could be stably maintained at 96% or more, and the storage stability of the bulk-heterojunction-type flexible organic solar cell of comparative example 2 was deteriorated to 80% or less.

Third, bending property test

The flexible single-component organic solar cell of example 1 and the bulk-heterojunction-type flexible organic solar cell of comparative example 2 were subjected to a bending performance test, as shown in fig. 6, both ends of the flexible single-component organic solar cell of example 1 and the bulk-heterojunction-type flexible organic solar cell of comparative example 2 were placed in a bending test jig, respectively, by setting a movement distance of the jig to achieve effects of bending at different radii, under conditions of different bending radii, the organic solar cells of example 1 and comparative example 2 were bent 1000 times, respectively, and then the energy conversion efficiency after bending was tested under a sunlight-simulated light source, with the test results shown in fig. 7. As can be seen from fig. 7, the energy conversion efficiency of the flexible monocomponent organic solar cell of example 1 is still stable to more than 95% after the flexible monocomponent organic solar cell is bent for 1000 times with a bending radius of 2.5mm, and the bulk heterojunction flexible organic solar cell of comparative example 2 shows different degrees of attenuation.

Fourth, adhesion Performance test

The ultra-thin flexible mono-component organic solar cell of example 2 was attached to different object surfaces as shown in fig. 8. It can be seen that the ultra-thin flexible monocomponent organic solar cell of example 2 has excellent adhesion to various object surfaces.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.