Organic solar cell based on coumarin-based BODIPY derivative guest receptor material and preparation method thereof
By covalently bonding BODIPY with coumarin units, the design and synthesizing BDP-2C guest acceptor materials are solved, and the problems of insufficient spectral absorption and serious charge recombination in existing organic solar cells are achieved, and efficient photoelectric conversion efficiency is improved.
Patent Information
- Application Number
- CN202510412946.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-02
- Publication Date
- 2025-07-11
AI Technical Summary
In existing organic solar cells, narrow bandgap non-fullerene acceptor materials have problems such as insufficient spectral absorption and serious charge recombination, which limits the improvement of device efficiency. In addition, traditional guest acceptor materials are complex in synthesis, poor compatibility with main receptors, and insufficient thermal stability.
Knoevenagel condensation reaction was used to covalently bond BODIPY to coumarin units, and the guest acceptor material BDP-2C was designed to form an organic solar cell structure that matched the spectral complementary and energy level of the PM6 donor and Y6 acceptor, and BDP-2C was introduced as the guest acceptor material.
The photoelectric conversion efficiency has exceeded 15%, widened the light absorption range, promoted exciton dissociation and charge transmission, improved open circuit voltage and short circuit current, and improved device performance.
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Figure CN120302799A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of organic solar cells and their device preparation, and particularly relates to an organic solar cell based on a coumarin-based BODIPY derivative guest acceptor material and a preparation method thereof. Background Art
[0002] The development of green and renewable energy has become a global focus. Among many new energy technologies, organic solar cells (OSCs) have attracted much attention due to their advantages such as light weight, flexibility, solution processability, and low preparation cost. The bulk heterojunction (BHJ) type organic solar cell forms an active layer by blending an electron donor and an acceptor material, and its power conversion efficiency (PCE) has exceeded 20%. However, traditional fullerene derivative acceptors (such as PCBM) have been gradually replaced by non-fullerene acceptors (NFAs) due to defects such as narrow absorption range, difficult energy level regulation, and high synthesis cost. Although narrow-bandgap NFAs represented by Y6 have significantly improved the device efficiency, their single acceptor system still faces problems such as insufficient spectral absorption and serious charge recombination, which restricts the further improvement of performance.
[0003] In recent years, introducing guest acceptors to expand the light absorption range of the active layer and optimize the charge transport path has become an effective way to break through the efficiency bottleneck. However, existing guest acceptor materials generally have defects such as complex synthesis processes, poor compatibility with the host acceptor, and insufficient thermal stability. BODIPY derivatives are regarded as potential high-performance acceptor candidate materials due to their excellent photothermal stability, high molar extinction coefficient, and tunable energy level characteristics. However, the absorption spectra of BODIPY monomers mostly concentrate in the range of 500 - 600 nm, and the Stokes shift is small, which limits their application in the photovoltaic system. Coumarin derivatives, on the other hand, are outstanding in charge transport and exciton dissociation due to their broad absorption, high fluorescence quantum yield, and molecular planarity, but it is difficult to achieve full-spectrum coverage when used alone.
[0004] In view of the above problems, the present invention covalently bonds BODIPY and coumarin units through the Knoevenagel condensation reaction to design and synthesize the guest acceptor material BDP-2C. This material combines the strong near-infrared absorption (732 nm) of BODIPY and the visible light absorption (490 nm) of coumarin to form a dual-peak absorption characteristic, which is spectrally complementary to the PM6 donor and the Y6 acceptor; and its energy level matches that of the PM6 donor and the Y6 acceptor, which can effectively promote exciton dissociation and charge transport. Introducing it as a guest acceptor into the PM6:Y6 system finally achieves a device efficiency breakthrough of 15%, which provides a new idea for the development of efficient and stable organic solar cells and has good application prospects in the field of organic solar cells. Summary of the Invention
[0005] Objective of the Invention: Aiming at the deficiencies existing in the prior art, the objective of the present invention is to provide an organic solar cell based on a coumarin-based BODIPY derivative guest receptor material and a preparation method thereof, and to construct an efficient organic solar cell based on a polymer donor PM6: non-fullerene host receptor Y6: guest receptor BDP-2C system.
[0006] The present invention selects polymer PM6 as the donor material, non-fullerene molecule Y6 as the host receptor material, and coumarin-based BODIPY derivative BDP-2C as the guest receptor material; the guest receptor BDP-2C can form good energy level matching and optical absorption spectrum complementarity with the polymer donor PM6 and the narrow-bandgap receptor Y6, broadening the light absorption range of the active layer, thereby increasing the open-circuit voltage (V OC ) and short-circuit current (J SC ) of the device, effectively improving the photoelectric conversion efficiency of the device, and the obtained device can reach a photoelectric conversion efficiency of 15.09%.
[0007] Technical Solution: In order to achieve the above-mentioned objective of the invention, the technical solution adopted by the present invention is as follows:
[0008] An organic solar cell based on a coumarin-based BODIPY derivative guest receptor of the present invention is characterized in that it successively includes a transparent conductive substrate, a hole transport layer, an organic active layer, an electron transport layer, and a metal electrode Ag from bottom to top, and the organic active layer contains a polymer donor PM6, a host receptor Y6, and a guest receptor BDP-2C:
[0009] The molecular structural formulas of the polymer donor PM6, non-fullerene host receptor Y6, and guest receptor BDP-2C in the organic active layer are respectively shown as follows:
[0010]
[0011] The structural layers of the forward device of the organic solar cell are successively from bottom to top: ITO glass, poly(3,4-ethylenedioxythiophene) (PEDOT): poly(styrenesulfonic acid) (PSS) hole transport layer, organic active layer, polyfluorene derivative (PFN) electron transport layer, and metal Ag electrode.
[0012] The organic active layer is a bulk heterojunction (BHJ) composed of a ternary component (PM6: Y6: BDP-2C);
[0013] The mass ratio of PM6, Y6, and BDP-2C in the active layer is 1: 0.4 - 1.4: 0.1 - 0.4, preferably 1: 1.0: 0.2;
[0014] A preparation method of an organic solar cell based on a coumarin-based BODIPY derivative guest receptor of the present invention includes the following steps:
[0015] (1) The ITO glass substrate was ultrasonically cleaned three times successively with deionized water, acetone, and isopropyl alcohol, and the surface of the substrate was subjected to oxygen enrichment treatment using an ultraviolet ozone cleaner, and then dried under vacuum.
[0016] (2) PEDOT:PSS was spin-coated on the clean ITO substrate, and the film was annealed on a hot plate at 120 °C for 10 minutes.
[0017] (3) PM6, BDP-2C, and Y6 were dissolved together in a chloroform solvent in a certain mass ratio, stirred at 40 °C for 2 hours, and the mixed solution was spin-coated on PEDOT:PSS to form an active layer. All films were thermally annealed at 110 °C for 10 minutes.
[0018] (4) The PFBN-Br methanol solution was spin-coated on the active layer to form an electron transport layer.
[0019] (5) Ag was deposited on the surface of the film by vacuum evaporation.
[0020] In step (2), the spin-coating speed was 3500 rpm / min and the spin-coating time was 40 s.
[0021] In step (3), the spin-coating speed was 3000 rpm / min, the spin-coating time was 40 s, and the total concentration of the active layer solution was 14 mg / mL.
[0022] In step (4), the concentration of the PFBN-Br methanol solution was 0.5 mg / mL, contained 0.5% acetic acid (vol%), the spin-coating speed was 3500 rpm / min, and the spin-coating time was 40 s.
[0023] In step (5), the vacuum degree was lower than 10 -5 Pa, and the thickness was 100 nm.
[0024] Advantages of the present invention
[0025] Compared with the prior art, the coumarin-based BODIPY derivative guest receptor material organic solar cell and its preparation method of the present invention have the following advantages: (1) BDP-2C exhibits a double-peak strong absorption characteristic at 490 nm and 732 nm, and the molar extinction coefficient reaches 2.32×10 5 cm -1 M -1, and it forms a complementary absorption spectrum with the PM6 donor and the Y6 acceptor, which can effectively broaden the light absorption range and is beneficial to improving the short-circuit current density; (2) The HOMO and LUMO energy levels of the guest acceptor BDP-2C can form a good match with the energy levels of PM6 and Y6, which is beneficial to promoting the efficient dissociation of excitons and charge transport, can effectively improve the performance of organic solar cells, and has good application prospects in the field of organic solar cells. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 FIG. 6 is the ultraviolet-visible absorption spectrum of PM6, BDP-2C, and Y6 in the active layer of the organic solar cell of the present invention; wherein the abscissa is the wavelength, the unit is nm, and the ordinate is the absorbance (Abs).
[0027] Figure 2 FIG. 10 is the energy level diagram of PM6, BDP-2C, and Y6 in the active layer of the organic solar cell of the present invention, and the ordinate is the energy level, and the unit is ev.
[0028] Figure 3 FIG. 14 is the current-voltage (J-V) relationship diagram of the device based on the optimized PM6:BDP-2C, PM6:Y6, and PM6:Y6:BDP-2C active layers of the present invention under simulated sunlight (AM 1.5G, 100 mW / cm 2 ) irradiation. DETAILED DESCRIPTION OF THE INVENTION
[0029] The present invention will be further described below with reference to specific drawings, but the embodiments are only used to illustrate the present invention and not to limit the scope of the present invention.
[0030] The instruments used for detection are as follows: The ultraviolet-visible absorption spectrum (UV-Vis) was measured on a Shimadzu UV-2600 spectrophotometer, using a 1 cm quartz cuvette, and tested at room temperature. The cyclic voltammetry test was carried out using a CHI-730D electrochemical workstation, with dichloromethane as the solvent, 0.1 M tetrabutylammonium perchlorate as the supporting electrolyte, and a three-electrode system. The photoelectric conversion efficiency of the device was tested with a Keithley 2400 source meter.
[0031] PFBN-Br was dissolved in a methanol solution containing 0.5% acetic acid to prepare a solution with a concentration of 0.5 mg / mL for standby.
[0032] According to the mass ratio of PM6:Y6 of 1:0.4, 1:0.8, 1:1.2, and 1:1.4, PM6 and Y6 were weighed respectively, and then dissolved in chloroform to prepare an active layer solution with a concentration of 14 mg / mL for standby, which was used to prepare the bulk heterojunction device.
[0033] Weigh PM6 and BDP-2C respectively in the amounts with the mass ratios of PM6:BDP-2C being 1:0.4, 1:0.8, 1:1.2, and 1:1.4. Then add chloroform to dissolve them and prepare an active layer solution with a concentration of 14 mg / mL for standby, which is used to fabricate bulk heterojunction devices.
[0034] Weigh PM6, BDP-2C, and Y6 respectively in the amounts with the mass ratios of PM6:Y6:BDP-2C being 1:1.1:0.1, 1:1.0:0.2, and 1:0.8:0.4. Then add chloroform to dissolve them and prepare an active layer solution with a concentration of 14 mg / mL for standby, which is used to fabricate bulk heterojunction devices.
[0035] Preparation of Coumarin-based BODIPY Derivative Guest Receptor Material (BDP-2C) in Example 1
[0036] Under anhydrous conditions, a dry round-bottom flask equipped with a Dean-Stark apparatus was charged with 1,3,5,7-tetramethyl-8-(2,4,6-trimethylphenyl)-BODIPY (366 mg, 1 mmol), 7-(N,N-diethylamino)-3-formyl-coumarin (735 mg, 3 mmol), and p-toluenesulfonic acid (86 mg, 0.5 mmol). They were dissolved in 25 mL of toluene and 2 mL of piperidine, heated to reflux at 115 °C for 6 hours. After cooling to room temperature, it was extracted with dichloromethane, washed with water, the organic layers were combined, and the organic solvents were removed by distillation under reduced pressure. The residue was separated and purified by silica gel column chromatography, and the eluent was 100% dichloromethane to obtain a grayish-brown solid product BDP-2C (262 mg, 32%). 1 H NMR (600 MHz, CDCl3): δ 8.04 (s, 2H), 7.71 (s, 2H), 7.42 (s, 4H), 6.96 (d, J = 5.4 Hz, 2H), 6.79 - 6.56 (m, 4H), 6.51 (s, 2H), 3.45 (s, 8H), 2.35 (d, J = 5.4 Hz, 3H), 2.12 (d, J = 5.4 Hz, 6H), 1.44 (d, J = 4.2 Hz, 6H), 1.24 (s, 12H). Esi-HRMS: calculated for C 50 H 51 BF2N4O4: 820.3971; found: 820.4053 [M] + .
[0037] Example 2
[0038] The ITO glass substrate was successively cleaned three times each with deionized water, acetone, and isopropyl alcohol in an ultrasonic cleaner. After the substrate surface was subjected to oxygen-rich treatment using an ultraviolet ozone cleaner, PEDOT:PSS was spin-coated on the clean ITO substrate at a speed of 3500 rpm for 40 seconds. Subsequently, the film was annealed on a hot plate at 120 °C for 10 minutes. Using chloroform as the solvent, a solution was prepared according to the above-mentioned mass ratio of PM6:Y6 of 1:0.4, with a total concentration of 14 mg / mL, and stirred at 40 °C for 2 hours. The mixed solution was spin-coated at 3000 rpm for 40 seconds to cover the PEDOT:PSS to form an active layer. All the films were thermally annealed at 110 °C for 10 minutes. Subsequently, PFBN-Br was spin-coated at 3500 rpm for 40 seconds to cover the active layer. Finally, under the condition that the pressure was lower than 10 -5 Pa, 100 nm thick Ag was deposited on the film through a template, and the effective area of the device was 0.04 cm 2 .
[0039] Example 3
[0040] A control device was prepared according to the method of Example 1, except that the mass ratio of PM6:Y6 in the active layer of the bulk heterojunction device was 1:0.8.
[0041] Example 4
[0042] A control device was prepared according to the method of Example 1, except that the mass ratio of PM6:Y6 in the active layer of the bulk heterojunction device was 1:1.2.
[0043] Example 5
[0044] A control device was prepared according to the method of Example 1, except that the mass ratio of PM6:Y6 in the active layer of the bulk heterojunction device was 1:1.4.
[0045] Example 6
[0046] The ITO glass substrate was successively cleaned three times each with deionized water, acetone, and isopropyl alcohol in an ultrasonic cleaner. After the substrate surface was subjected to oxygen-rich treatment using an ultraviolet ozone cleaner, PEDOT:PSS was spin-coated on the clean ITO substrate at a speed of 3500 rpm for 40 seconds. Subsequently, the film was annealed on a hot plate at 120 °C for 10 minutes. Using chloroform as the solvent, a solution was prepared according to the above-mentioned mass ratio of PM6:BDP-2C of 1:0.4, with a total concentration of 14 mg / mL, and stirred at 40 °C for 2 hours. The mixed solution was spin-coated at 3000 rpm for 40 seconds to cover the PEDOT:PSS to form an active layer. All the films were thermally annealed at 110 °C for 10 minutes. Subsequently, PFBN-Br was spin-coated at 3500 rpm for 40 seconds to cover the active layer. Finally, under the condition that the pressure was lower than 10 -5Under the condition of [[Pa]], deposit 100 nm thick Ag on the thin film through a template, and make the effective area of the device be 0.04 cm 2 .
[0047] Example 7
[0048] Prepare a control device according to the method of Example 5, except that the mass ratio of the active layer PM6:BDP-2C of the bulk heterojunction device is 1:0.8.
[0049] Example 8
[0050] Prepare a control device according to the method of Example 5, except that the mass ratio of the active layer PM6:BDP-2C of the bulk heterojunction device is 1:1.2.
[0051] Example 9
[0052] Prepare a control device according to the method of Example 5, except that the mass ratio of the active layer PM6:BDP-2C of the bulk heterojunction device is 1:1.4.
[0053] Example 10
[0054] Clean the ITO glass substrate successively three times each with deionized water, acetone and isopropanol in an ultrasonic bath. After performing an oxygen-rich treatment on the substrate surface using an ultraviolet ozone cleaner, spin-coat PEDOT:PSS on the clean ITO substrate at a speed of 3500 rpm for 40 seconds. Subsequently, anneal the thin film on a hot plate at 120 °C for 10 minutes. Prepare a solution with chloroform as the solvent in an amount according to the mass ratio of PM6:BDP-2C:Y6 of 1:0.1:1.1, with a total concentration of 14 mg / mL, and stir at 40 °C for 2 hours. Spin-coat the mixed solution at 3000 rpm for 40 seconds to cover the PEDOT:PSS to form an active layer. Anneal all thin films at 110 °C for 10 minutes. Subsequently, spin-coat PFBN-Br at 3500 rpm for 40 seconds to cover the active layer. Finally, under the condition of a pressure lower than 10 -5 Pa, deposit 100 nm thick Ag on the thin film through a template, and make the effective area of the device be 0.04 cm 2 .
[0055] Example 11
[0056] Prepare a control device according to the method of Example 9, except that the mass ratio of the active layer PM6:BDP-2C:Y6 of the bulk heterojunction device is 1:0.2:1.0.
[0057] Example 12
[0058] The control device was prepared according to the method of Example 9, except that the mass ratio of PM6:BDP-2C:Y6 in the active layer of the bulk heterojunction device was 1:0.4:0.8.
[0059] Photovoltaic performance test of the device
[0060] The light source was AM 1.5G, and the sunlight intensity was 100 mW / cm 2 of simulated sunlight. The intensity of the light source was tested and calibrated with a standard silicon cell, and the test instrument was a Keithley 2400 source meter.
[0061] By testing, the device current (J sc )-voltage (V oc ) curves of the devices based on in the solar cells of Examples 4, 8, and 11 were obtained, as Figure 3 shown.
[0062] The device performances of Examples 1-11 prepared by testing are shown in the following table: including open-circuit voltage (V oc ), short-circuit current (J sc ), fill factor (FF), and power conversion efficiency (PCE), where: PCE = (V oc * J sc * FF) / P in , and P in is the illumination intensity of the incident light.
[0063]
Claims
1. An organic solar cell based on a polymer donor PM6, a non-fullerene acceptor Y6, and a coumarin-based BODIPY derivative guest receptor BDP-2C, characterized in that, It includes, from bottom to top, a transparent conductive substrate, a hole transport layer, an organic active layer, an electron transport layer, and a metal electrode Ag. The organic active layer contains a polymer donor PM6, a non-fullerene host acceptor Y6, and a guest acceptor BDP-2C; The molecular structural formulas of the polymer donor PM6, the non-fullerene acceptor Y6, and the guest acceptor BDP-2C in the organic active layer are as follows:
2. The organic solar cell based on the coumarin-based BODIPY derivative guest receptor according to claim 1, wherein The organic active layer is a PM6:BDP-2C:Y6 bulk heterojunction.
3. An organic solar cell based on a coumarin-based BODIPY derivative guest receptor according to claim 2, characterized in that, In the active layer, the mass ratio of PM6:Y6:BDP-2C is 1.0:0.4 - 1.4:0.1 - 0.
4.
4. The preparation method of an organic solar cell based on a coumarin-based BODIPY derivative guest receptor according to claim 1, characterized in that It includes the following steps: (1) The ITO glass substrate is successively cleaned three times with deionized water, acetone, and isopropanol in an ultrasonic bath, and the surface of the substrate is subjected to oxygen-rich treatment using an ultraviolet ozone cleaner; (2) PEDOT:PSS is spin-coated on the clean ITO substrate, and the film is annealed on a hot plate at 120°C for 10 minutes; (3) PM6, BDP-2C, and Y6 are dissolved together in a chloroform solvent according to the mass ratio, stirred at 40°C for 2 hours, and the mixed solution is spin-coated on PEDOT:PSS to form an organic active layer. All films are thermally annealed at 110°C for 10 minutes; (4) A PFBN-Br methanol solution is spin-coated on the active layer to form an electron transport layer; (5) An Ag electrode is deposited by vacuum evaporation.
5. The preparation method according to claim 5, characterized in that, In step (3), the spin-coating speed is 3000 rpm / min, the spin-coating time is 40 s, and the total concentration of the active layer solution is 14 mg / mL.
6. An organic solar cell based on a coumarin-based BODIPY derivative guest receptor material according to claim 1, characterized in that, Using PM6 as the donor material of the organic active layer, Y6 as the host acceptor, and BDP-2C as the guest acceptor as the active layer acceptor material and applying it to an organic solar cell, the best photovoltaic performance active layer PM6:Y6:BDP-2C blend mass ratio is 1.0:1.0:0.2, and the optimized photoelectric conversion efficiency is 15.09%.