Use of asymmetric boron / nitrogen / sulfur spiro-omphalos multiple resonance-thermal activated delayed fluorescence materials in organic solar cells

Abstract

This invention belongs to the field of organic solar cells, specifically disclosing the application of an asymmetric boron / nitrogen / sulfur helicene-type multiple resonance-thermally activated delayed fluorescence material in organic solar cells. This multiple resonance-thermally activated delayed fluorescence material has a sulfur pseudoplanar helicene structure, composed of different donor units such as phenothiazine and diphenyl acridine. For the first time, it is used as a solid photovoltaic promoter, doped into fullerene or non-fullerene binary organic solar cell devices, significantly improving the energy conversion efficiency and stability of the devices. Specifically, when doped into PM6:Y6 binary non-fullerene organic solar cells, the energy conversion efficiency of the organic solar cell increased from 16.01% to 17.17%, and when doped into PM6:PC... 71 In BM binary fullerene organic solar cells, the energy conversion efficiency of organic solar cells increased from 8.49% to 9.30%.

Description

Technical Field

[0001] This invention belongs to the field of organic solar cells, and specifically discloses the application of an asymmetric boron / nitrogen / sulfur helixene-type multiple resonance-thermally activated delayed fluorescence material in organic solar cells. Background Technology

[0002] Bulk heterojunction organic solar cells (BHJ-OSCs) are currently the most extensively studied organic solar cells (OSCs). Their structural characteristics are: First, the donor and acceptor materials are blended in the active layer, increasing the donor / acceptor contact area while achieving phase separation at a certain scale, significantly improving the dissociation process of photogenerated excitons. Second, the nano-interpenetrating network structure formed by the blending of donor and acceptor materials creates highly efficient charge transport channels, enhancing the degree of exciton dissociation and suppressing recombination quenching effects. To better leverage the structural advantages of BHJ-OSCs, solvent additives and solid additives are typically employed during device fabrication to improve the morphology and other properties of the photoactive layer, thereby optimizing device performance.

[0003] In addition to optimizing the morphology of blended films in the same way as solvent additives, solid additives also have the following characteristics: First, they can promote increased molecular crystallinity, improve charge transport, and inhibit charge recombination; second, they can improve the molecular packing of the blended film, making the structure more ordered, promoting charge extraction, and thus increasing the short-circuit current of the device (J). SC The photovoltaic performance of binary OSCs has been improved through solid-state additive strategies. However, the selection of solid-state additives mainly focuses on simple small molecules such as benzene rings and organic small molecule materials with structures similar to the donor / acceptor materials of the system. When the donor / acceptor materials of the active layer change, the device efficiency suffers from poor reproducibility. Therefore, the development of novel solid-state additives is of great significance. Summary of the Invention

[0004] To enrich the types of solid additives and address the issues that solid additives may have in improving the repeatability and stability of device efficiency, this invention implements an asymmetric boron / nitrogen / sulfur helicene-type MR-TADF material, BNS-H1, as a special solid additive, which is applied to binary fullerene or non-fullerene BHJ-OSCs to simultaneously improve the high-efficiency energy conversion efficiency and stability of the device.

[0005] This invention uses the asymmetric boron / nitrogen / sulfur helicene-type MR-TADF material BNS-H1 as a solid photovoltaic promoter. Firstly, it is doped into PM6:Y6 binary non-fullerene OSCs at a ratio of 0.5-1.5 wt%, resulting in an increase in the device's power conversion efficiency from 16.01% to 17.17%. The device's nitrogen environment stability remains at 90% after 75 days (PM6:Y6 binary devices maintain 82%), and its T80 thermal stability remains at 72% after 350 hours (PM6:Y6 binary devices maintain 65%). Secondly, it is doped into PM6:PC at a ratio of 0.5-1.5 wt%. 71 In BM binary fullerene OSCs, the energy conversion efficiency of the device increased from 8.49% to 9.30%. Therefore, this invention provides a new method for using the asymmetric boron / nitrogen / sulfur helicene-type MR-TADF material BNS-H1 as a solid photovoltaic promoter in OSCs to effectively improve the energy conversion efficiency and stability of the device.

[0006] The asymmetric boron / nitrogen / sulfur helixene-type MR-TADF material BNS-H1 involved in this invention has the following molecular structure:

[0007]

[0008] This invention also provides an application of the MR-TADF material BNS-H1 in OSCs, wherein the OSC device structure is: ITO / PEDOT:PSS (30nm) / PM6:Y6 or PC 71 BM:BNS-H1 (100nm) / PDINN or PFN-Br (5nm) / Ag (100nm). The active layer is BNS-H1:PM6:Y6, where the doping mass of BNS-H1 is 0.5wt%-1.5wt% (relative to the mass of the donor material PM6). The device efficiency is optimal when the doping mass is 1.0wt%, and the mass ratio of the donor material PM6 to the acceptor material Y6 is 1:1.2.

[0009] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0010] (1) In this invention, the asymmetric boron / nitrogen / sulfur helicene-type MR-TADF material BNS-H1 is selected as a special solid additive, namely a solid photovoltaic promoter, which is of great significance for enriching the types of solid additives and solid additives applicable to non-fullerene / fullerene systems.

[0011] (2) In this invention, the asymmetric boron / nitrogen-hexane type MR-TADF material BNS-H1 is used as a solid photovoltaic promoter. The same processing solvent as the main system is selected, and the device fabrication process is simple and low in cost.

[0012] (3) The OSCs prepared by the present invention using the asymmetric boron / nitrogen helicene type MR-TADF material BNS-H1 as a solid photovoltaic promoter can significantly improve the energy conversion efficiency and stability of the device. Attached image description:

[0013] Figure 1 The images show the UV-Vis absorption spectra of the BNS-H1, PM6, and Y6 solid films prepared in Example 1 of this invention.

[0014] Figure 2 This refers to the energy level arrangement of BNS-H1, PM6, and Y6 in Embodiment 1 of the present invention.

[0015] Figure 3 The JV curves and EQE spectra of different devices in Embodiment 2 and Comparative Embodiment 1 of the present invention are shown.

[0016] Figure 4 J represents the different devices in Embodiment 2 and Comparative Embodiment 1 of the present invention. ph -V eff curve.

[0017] Figure 5 The light intensity dependence of different devices in Embodiment 2 and Comparative Embodiment 1 of the present invention: V OC -P light Curve and J SC -P light curve.

[0018] Figure 6 The mobility of different devices in Embodiment 2 and Comparative Embodiment 1 of the present invention: J 1 / 2 -V curves (a) for electronic devices and (b) for hole devices.

[0019] Figure 7 These are the stability parameters of different devices in Embodiment 2 and Comparative Embodiment 1 of the present invention under N2 environment.

[0020] Figure 8 These are the stability parameters of different devices in Embodiment 2 and Comparative Embodiment 1 of the present invention under an 80°C heating environment.

[0021] Figure 9 The PL spectra of PM6:BNS-H1 blend films with different doping masses in Examples 7-11 and Comparative Example 3 of the present invention are shown.

[0022] Figure 10 The PL spectra are those of the PM6 thin film in this invention, the PM6:Y6 (1:1.2) blend film in Comparative Example 1, and the 1.0 wt% doped PM6:Y6:BNS-H1 blend film in Example 2.

[0023] Figure 11 The transient PL spectra are those of the PM6 film, BNS-H1 film, and 1.0 wt% doped PM6:BNS-H1 blend film in Example 2 of this invention.

[0024] Figure 12 The PL spectra of Y6:BNS-H1 blend films with different doping masses in Examples 12-15 and Comparative Example 4 of the present invention are shown.

[0025] Figure 13 The PL spectra are those of the Y6 thin film of the present invention, the PM6:Y6 (1:1.2) blend film in Comparative Example 1, and the 1.0 wt% doped PM6:Y6:BNS-H1 blend film in Example 2.

[0026] Figure 14 The contact angles are those of the PM6 film, Y6 film, BNS-H1 film, PM6:BNS-H1 (1:0.01) blend film and Y6:BNS-H1 (1:0.01) blend film in Example 2, PM6:Y6 (1:1.2) blend film in Comparative Example 1, and 1.0 wt% doped PM6:Y6:BNS-H1 blend film in Example 2 in this invention.

[0027] Figure 15 The AFM of PM6 thin film, Y6 thin film, PM6:BNS-H1 (1:0.01) blend film, Y6:BNS-H1 (1:0.01) blend film, PM6:Y6 (1:1.2) blend film in Comparative Example 1 and PM6:Y6:BNS-H1 blend films with different doping mass ratios in this invention.

[0028] Figure 16 The AFM of the PM6:Y6 (1:1.2) blend film in Comparative Example 1 and the 1.0wt% doped PM6:Y6:BNS-H1 blend film in Example 2 under heating at 80°C for 24h, 72h, 120h and 384h is shown. Detailed Implementation

[0029] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments and accompanying drawings, further clarifies the invention. Those skilled in the art should understand that the specific details described below are illustrative rather than restrictive, and should not be construed as limiting the scope of protection of the present invention.

[0030] In this invention, the preparation methods are conventional unless otherwise specified. Except for the symmetric boron / nitrogen-hexane type MR-TADF material BNS-H1, all raw materials used can be obtained from publicly available commercial sources unless otherwise specified.

[0031] Example 1

[0032] Using the asymmetric boron / nitrogen / sulfur helicene-type MR-TADF material BNS-H1 as a solid photovoltaic promoter, the device structure of binary non-fullerene organic solar cells (OSCs) doped with different mass ratios is: ITO / PEDOT:PSS (30nm) / PM6:Y6:BNS-H1 (100nm) / PDINN (5nm) / Ag (100nm). The mass ratio of the active layer PM6:Y6:BNS-H1 is 1:1.2:0.005, and its fabrication scheme is as follows:

[0033] Cleaning and pretreatment of ITO substrates

[0034] The ITO substrate was cleaned sequentially in an ultrasonic cleaner using a cleaning solution (Decon 90, UK) for 20 min, deionized water for 10 min x 4, acetone for 20 min, and isopropanol for 20 min, and then dried overnight in an oven (80°C). Before use, the ITO was subjected to a 15 min UV ozone surface treatment and then cooled to room temperature.

[0035] Spin coating of hole transport layer poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS)

[0036] A 1.5 wt% poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS) solution was spin-coated onto the treated substrate at 4800 r / min for 30 s in ambient air, annealed at 150 °C for 15 min, and then cooled at room temperature for 15 min to form a uniform and smooth film.

[0037] Spin coating of active layer material

[0038] In a glove box under nitrogen atmosphere, the mixture PM6:Y6 at a mass ratio of 1:1.2 and a donor concentration of 6 mg / mL was dissolved in chloroform. 0.5% chloronaphthalene (CN) was added, and the mixture was stirred at 45°C for 2 h. Before spin coating, BNS-H1 was added in proportion, and the mixture was spin coated on the hole transport layer at a speed of 1750 r / min for 30 s. The mixture was then annealed at 80°C for 5 min and cooled to room temperature for 10 min to form a uniform and smooth active layer film.

[0039] Spin coating of electron transport layer PDINN and vapor deposition of cathode Ag

[0040] In a glove box under a nitrogen atmosphere, PDINN (perylene diimide derivative, solvent: methanol) at a concentration of 1 mg / mL was spin-coated onto the active layer at 3000 r / min for 30 s to prepare a uniform and smooth PDINN film. The device with the spin-coated PDINN film was then placed in a vacuum evaporation chamber and evaporated at 3 × 10⁻⁶ rpm. -4Organic solar cell (OSC) devices were obtained by vapor deposition of a 100 nm metal electrode Ag at Pa.

[0041] Device performance testing

[0042] The prepared OSCs devices were tested under standard conditions (AM1.5, 100mW / cm²). 2 The test was conducted, and the specific data is shown in Table 1.

[0043] Example 2

[0044] The mass ratio of the active layer PM6:Y6:BNS-H1 is 1:1.2:0.01, and other parameters are the same as in Example 1.

[0045] Example 3

[0046] The mass ratio of the active layer PM6:Y6:BNS-H1 is 1:1.2:0.015, and other parameters are the same as in Example 1.

[0047] Table 1. Photovoltaic performance parameters of non-fullerene devices with different doping ratios in Examples 1-3 and Comparative Example 1 of the present invention.

[0048]

[0049] Table 2. Contact angle, surface energy, and interaction parameters of the single-component and blend films in Examples 1-3 of this invention.

[0050]

[0051] Comparative Example 1

[0052] The device structure of the PM6:Y6 binary bulk heterojunction solar cell (BHJ-OSCs) is: ITO / PEDOT:PSS (30nm) / PM6:Y6 (100nm) / PDINN (5nm) / Ag (100nm). The mass ratio of PM6:Y6 in the active layer is 1:1.2. The fabrication scheme is as follows:

[0053] Cleaning and pretreatment of ITO substrates

[0054] The ITO substrate was cleaned sequentially in an ultrasonic cleaner using a cleaning solution (Decon 90, UK) for 20 min, deionized water for 10 min x 4, acetone for 20 min, and isopropanol for 20 min, and then dried overnight in an oven (80°C). Before use, the ITO was subjected to a 15 min UV ozone surface treatment and then cooled to room temperature.

[0055] Spin coating of hole transport layer poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS)

[0056] A 1.5 wt% poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS) solution was spin-coated onto the treated substrate at 4800 r / min for 30 s in ambient air, annealed at 150 °C for 15 min, and then cooled at room temperature for 15 min to form a uniform and smooth film.

[0057] Spin coating of active layer material

[0058] In a glove box under nitrogen atmosphere, the mixture PM6:Y6 at a mass ratio of 1:1.2 and a donor concentration of 6 mg / mL was dissolved in chloroform. Chloronaphthalene (CN) at a volume ratio of 0.5% was added, and the mixture was stirred at 45°C for 2 h. The mixture was then spin-coated onto the active layer at a speed of 1750 r / min for 30 s, annealed at 80°C for 5 min, and cooled to room temperature for 10 min to form a uniform and smooth active layer film.

[0059] Spin coating of electron transport layer PDINN and vapor deposition of cathode Ag

[0060] In a glove box under a nitrogen atmosphere, PDINN (perylene diimide derivative, solvent: methanol) at a concentration of 1 mg / mL was spin-coated onto the active layer at 3000 r / min for 30 s to prepare a uniform and smooth PDINN film. The device with the spin-coated PDINN film was then placed in a vacuum evaporation chamber and evaporated at 3 × 10⁻⁶ rpm. -4 Organic solar cell (OSC) devices were obtained by vapor deposition of a 100 nm metal electrode Ag at Pa.

[0061] Device performance testing

[0062] The prepared OSCs devices were tested under standard conditions (AM1.5, 100mW / cm²). 2 The test was conducted, and the specific data is shown in Table 1.

[0063] Example 4

[0064] Using the asymmetric boron / nitrogen / sulfur helixene-type MR-TADF material BNS-H1 as a solid photovoltaic promoter, the device structure of binary fullerene organic solar cells (OSCs) doped with different mass ratios is: ITO / PEDOT:PSS (30nm) / PM6:PC 71 BM: BNS-H1 (100nm) / PFN-Br (5nm) / Al (100nm). The active layer PM6 is composed of PC. 71 The mass ratio of BM:BNS-H1 is 1:1.5:0.005. The manufacturing process is as follows:

[0065] Cleaning and pretreatment of ITO substrates

[0066] The ITO substrate was cleaned sequentially in an ultrasonic cleaner using a cleaning solution (Decon 90, UK) for 20 min, deionized water for 10 min x 4, acetone for 20 min, and isopropanol for 20 min, and then dried overnight in an oven (80°C). Before use, the ITO was subjected to a 15 min UV ozone surface treatment and then cooled to room temperature.

[0067] Spin coating of hole transport layer poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS)

[0068] A 1.5 wt% poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS) solution was spin-coated onto the treated substrate at 4800 r / min for 30 s in ambient air, annealed at 150 °C for 15 min, and then cooled at room temperature for 15 min to form a uniform and smooth film.

[0069] Spin coating of active layer material

[0070] In a glove box under a nitrogen atmosphere, a mixture of PM6:PC was placed... 71 BM was dissolved in chlorobenzene at a mass ratio of 1:1.5 and a donor concentration of 10 mg / mL. DIO (1,8-diiodooctane) at a volume ratio of 0.5% was added, and the mixture was stirred overnight at 40°C. Before spin coating, BNS-H1 was added at a mass ratio, and the mixture was spin coated on the active layer at a speed of 2000 r / min for 30 s. Vacuum was then removed for 30 min to prepare a uniform and smooth active layer film.

[0071] Spin coating of electron transport layer PFN-Br and evaporation of cathode Al

[0072] In a glove box under a nitrogen atmosphere, PFN-Br (poly[(9,9-di(3'-(N,N-dimethylamino)propyl)fluorenyl-2,7-diyl)-alt-[(9,9-di-n-octylfluorenyl-2,7-diyl)bromo, solvent: methanol) with a concentration of 0.5 mg / mL was spin-coated onto the active layer for 30 s at a speed of 3000 r / min to prepare a uniform and smooth PFN-Br film. The device with the spin-coated PFN-Br film was then placed in a vacuum evaporation chamber and subjected to 3 × 10⁻⁶ ppm vapor deposition. -4 Organic solar cell (OSC) devices were obtained by evaporating a 100 nm metal electrode Al at Pa.

[0073] Device performance testing

[0074] The prepared OSCs devices were tested under standard conditions (AM1.5, 100mW / cm²). 2 The test was conducted, and the specific data is shown in Table 3.

[0075] Example 5

[0076] Active layer PM6:PC 71 The mass ratio of BM:BNS-H1 is 1:1.5:0.01, and other parameters are the same as in Example 4.

[0077] Example 6

[0078] Active layer PM6:PC 71 The mass ratio of BM:BNS-H1 is 1:1.5:0.015, and other parameters are the same as in Example 4.

[0079] Comparative Example 2

[0080] PM6:PC 71 The device structure of the BM binary bulk heterojunction solar cell (BHJ-OSCs) is: ITO / PEDOT:PSS (30nm) / PM6:PC 71 BM (100nm) / PFN-Br (5nm) / Al (100nm). The active layer is PM6:PC. 71 The mass ratio of BM is 1:1.5. Its manufacturing process is as follows:

[0081] Cleaning and pretreatment of ITO substrates

[0082] The ITO substrate was cleaned sequentially in an ultrasonic cleaner using a cleaning solution (Decon 90, UK) for 20 min, deionized water for 10 min x 4, acetone for 20 min, and isopropanol for 20 min, and then dried overnight in an oven (80°C). Before use, the ITO was subjected to a 15 min UV ozone surface treatment and then cooled to room temperature.

[0083] Spin coating of hole transport layer poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS)

[0084] A 1.5 wt% poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS) solution was spin-coated onto the treated substrate at 4800 r / min for 30 s in ambient air, annealed at 150 °C for 15 min, and then cooled at room temperature for 15 min to form a uniform and smooth film.

[0085] Spin coating of active layer material

[0086] In a glove box under a nitrogen atmosphere, a mixture of PM6:PC was placed... 71BM was dissolved in chlorobenzene at a mass ratio of 1:1.5 and a donor concentration of 10 mg / mL. DIO (1,8-diiodooctane) at a volume ratio of 0.5% was added, and the mixture was stirred overnight at 40°C. The mixture was then spin-coated onto the hole transport layer at a speed of 2000 r / min for 30 s and vacuum-extracted for 30 min to form a uniform and smooth active layer film.

[0087] Spin coating of electron transport layer PFN-Br and evaporation of cathode Al

[0088] In a glove box under a nitrogen atmosphere, PFN-Br (poly[(9,9-di(3'-(N,N-dimethylamino)propyl)fluorenyl-2,7-diyl)-alt-[(9,9-di-n-octylfluorenyl-2,7-diyl)bromo, solvent: methanol) with a concentration of 0.5 mg / mL was spin-coated onto the active layer for 30 s at a speed of 3000 r / min to prepare a uniform and smooth PFN-Br film. The device with the spin-coated PFN-Br film was then placed in a vacuum evaporation chamber and subjected to 3 × 10⁻⁶ ppm vapor deposition. -4 Organic solar cell (OSC) devices were obtained by evaporating a 100 nm metal electrode Al at Pa.

[0089] Device performance testing

[0090] The prepared OSCs devices were tested under standard conditions (AM1.5, 100mW / cm²). 2 Tests were conducted, and the active layer PM6:PC ratio was measured. 71 The device data for a BM quality ratio of 1:1.5 is: V oc =0.95V, J sc =11.93mA / cm 2 , FF=74.78%, PCE=8.49%.

[0091] Note: The specific experimental steps above are the manufacturing process of the device with the best effect.

[0092] Table 3. Photovoltaic performance parameters of fullerene devices with different doping ratios in Examples 4-6 and Comparative Example 2 of the present invention.

[0093]

[0094] Example 7

[0095] Cleaning and pretreatment of quartz substrate

[0096] The quartz substrate was cleaned sequentially in an ultrasonic cleaner using a cleaning solution (Decon 90, UK) for 20 min, deionized water for 10 min x 4, acetone for 20 min, and isopropanol for 20 min, and then dried overnight in an oven (80°C). Before use, the quartz substrate was subjected to a 15 min UV ozone surface treatment and then cooled to room temperature.

[0097] Spin coating of active layer material

[0098] In a glove box under nitrogen atmosphere, the mixture PM6:BNS-H1 at a mass ratio of 1:0.005 and the donor PM6 concentration of 10 mg / mL were dissolved in chloroform. The mixture was stirred at 45°C for 2 h and then spin-coated on a quartz plate at 1500 r / min for 30 s to form a uniform and smooth active layer film.

[0099] Example 8

[0100] The mass ratio of PM6 to BNS-H1 in the active layer is 1:0.01, and other aspects are the same as in Example 7.

[0101] Example 9

[0102] The mass ratio of PM6 to BNS-H1 in the active layer is 1:0.015, and other aspects are the same as in Example 7.

[0103] Example 10

[0104] The mass ratio of PM6 to BNS-H1 in the active layer is 1:0.04, and other parameters are the same as in Example 7.

[0105] Example 11

[0106] The mass ratio of PM6 to BNS-H1 in the active layer is 1:0.08, and other parameters are the same as in Example 7.

[0107] Comparative Example 3

[0108] Cleaning and pretreatment of quartz substrate

[0109] The quartz substrate was cleaned sequentially in an ultrasonic cleaner using a cleaning solution (Decon 90, UK) for 20 min, deionized water for 10 min x 4, acetone for 20 min, and isopropanol for 20 min, and then dried overnight in an oven (80°C). Before use, the quartz substrate was subjected to a 15 min UV ozone surface treatment and then cooled to room temperature.

[0110] Spin coating of active layer material

[0111] In a glove box under nitrogen atmosphere, the donor material PM6 was dissolved in chloroform at a concentration of 10 mg / mL, stirred at 45°C for 2 h, and then spin-coated on a quartz plate at a speed of 1500 r / min for 30 s to form a uniform and smooth active layer film.

[0112] Example 12

[0113] Cleaning and pretreatment of quartz substrate

[0114] The quartz substrate was cleaned sequentially in an ultrasonic cleaner using a cleaning solution (Decon 90, UK) for 20 min, deionized water for 10 min x 4, acetone for 20 min, and isopropanol for 20 min, and then dried overnight in an oven (80°C). Before use, the quartz substrate was subjected to a 15 min UV ozone surface treatment and then cooled to room temperature.

[0115] Spin coating of active layer material

[0116] In a glove box under nitrogen atmosphere, the mixture Y6:BNS-H1 was dissolved in chloroform at a mass ratio of 1:0.005 and the concentration of acceptor Y6 was 10 mg / mL. The mixture was stirred at 45°C for 2 h and then spin-coated on a quartz plate at 1500 r / min for 30 s to form a uniform and smooth active layer film.

[0117] Example 13

[0118] Cleaning and pretreatment of quartz substrate

[0119] The quartz substrate was cleaned sequentially in an ultrasonic cleaner using a cleaning solution (Decon 90, UK) for 20 min, deionized water for 10 min x 4, acetone for 20 min, and isopropanol for 20 min, and then dried overnight in an oven (80°C). Before use, the quartz substrate was subjected to a 15 min UV ozone surface treatment and then cooled to room temperature.

[0120] Spin coating of active layer material

[0121] In a glove box under nitrogen atmosphere, the mixture Y6:BNS-H1 was dissolved in chloroform at a mass ratio of 1:0.005 and the concentration of acceptor Y6 was 10 mg / mL. The mixture was stirred at 45°C for 2 h and then spin-coated on a quartz plate at 1500 r / min for 30 s to form a uniform and smooth active layer film.

[0122] Example 14

[0123] The mass ratio of active layer Y6:BNS-H1 is 1:0.01, and other aspects are the same as in Example 12.

[0124] Example 15

[0125] The mass ratio of active layer Y6:BNS-H1 is 1:0.015, and other aspects are the same as in Example 12.

[0126] Example 16

[0127] The mass ratio of active layer Y6:BNS-H1 is 1:0.04, and other parameters are the same as in Example 12.

[0128] Comparative Example 4

[0129] Cleaning and pretreatment of quartz substrate

[0130] The quartz substrate was cleaned sequentially in an ultrasonic cleaner using a cleaning solution (Decon 90, UK) for 20 min, deionized water for 10 min x 4, acetone for 20 min, and isopropanol for 20 min, and then dried overnight in an oven (80°C). Before use, the quartz substrate was subjected to a 15 min UV ozone surface treatment and then cooled to room temperature.

[0131] Spin coating of active layer material

[0132] In a glove box under nitrogen atmosphere, the acceptor material Y6 was dissolved in chloroform at a concentration of 10 mg / mL, stirred at 45°C for 2 h, and then spin-coated on a quartz plate at a speed of 1500 r / min for 30 s to form a uniform and smooth active layer film.

[0133] (Note: Implementation cases 7-11 and 12-15 are compared with implementation cases 3 and 4 and are used for PL testing only.)

[0134] Although the invention has been described in conjunction with preferred embodiments, the invention is not limited to the above embodiments, and it should be understood that the appended claims summarize the scope of the invention. Guided by the inventive concept, those skilled in the art should recognize that any modifications made to the various embodiments of the invention will be covered by the spirit and scope of the claims.

Claims

1. The application of an asymmetric boron / nitrogen / sulfur helixene-type multiple resonance-thermally activated delayed fluorescence material in organic solar cells, characterized in that, Asymmetric boron / nitrogen / sulfur helixene-type multiple resonance-thermally activated delayed fluorescence material as a solid photovoltaic promoter for organic solar cells; The chemical structure of the asymmetric boron / nitrogen / thiohexaene-type multiple resonance-thermally activated delayed fluorescence material is shown below: ； Asymmetric boron / nitrogen / thiospirene-type multiple resonance-thermally activated delayed fluorescence materials are doped into active layers based on polymer donor PM6 and non-fullerene acceptor Y6, or based on polymer donor PM6 and fullerene acceptor PC. 71 In the active layer of BM, binary non-fullerene / fullerene organic solar cells are fabricated.

2. The application of the asymmetric boron / nitrogen / sulfur helicene-type multiple resonance-thermally activated delayed fluorescence material according to claim 1 in organic solar cells, characterized in that: The mass ratio of asymmetric boron / nitrogen / sulfur helixene-type multiple resonance-thermally activated delayed fluorescence material doped into the photoactive layer is 0.5-1.5 wt%.

3. The application of the asymmetric boron / nitrogen / sulfur helicene-type multiple resonance-thermally activated delayed fluorescence material according to claim 1 in organic solar cells, characterized in that: The device structure of organic solar cells is: ITO / PEDOT:PSS / PM6:Y6 or PC. 71 BM: BNS-H1 / PDINN or PFN-Br / Ag; where PEDOT: PSS thickness is 30 nm; PM6: Y6 or PC 71 BM:BNS-H1 has a thickness of 100 nm; PDINN or PFN-Br has a thickness of 5 nm; Ag has a thickness of 100 nm.

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