An asymmetrically end-capped electron acceptor material, ternary organic solar cell and preparation method thereof

Abstract

The application discloses an asymmetrically terminated electron acceptor material, a ternary organic solar cell and a preparation method thereof, and belongs to the field of photoelectric materials. The asymmetrically terminated electron acceptor material takes a benzothiadiazole ladder fused ring structure as a core, contains a straight-chain alkyl chain or a bifurcated alkyl chain, and double-halogen-substituted indanedione and double-chloro-substituted cyanoindanone are electron-withdrawing end groups. The organic solar cell based on the asymmetrically terminated electron acceptor material can realize a high open-circuit voltage of up to 1.018 V. The application further discloses a ternary organic solar cell, which comprises a substrate, an anode layer, an anode modification layer, an active layer based on a donor / multi-receptor system, a cathode modification layer and a cathode layer. The active layer is a blended film of an electron donor D18, a non-fullerene acceptor Y6 and the asymmetrically terminated electron acceptor material. The ternary organic solar cell has a high open-circuit voltage, a short-circuit current density and a fill factor, and the highest energy conversion efficiency is 19.19%.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of photoelectric materials, in particular to an asymmetrically terminated electron acceptor material, a ternary organic solar cell and a preparation method thereof. BACKGROUND

[0002] In recent years, with the design and development of high-efficiency photovoltaic materials combined with intelligent device engineering optimization, organic photovoltaic cells have developed rapidly. Organic photovoltaic cells use organic semiconductors as active materials to realize photoelectric conversion. Compared with inorganic solar cells, which have been commercialized, the photoelectric conversion efficiency of organic photovoltaic cells is relatively low, and the durability is insufficient. The three performance parameters (open-circuit voltage, short-circuit current density and fill factor) of the device are mutually balanced, which is one of the bottlenecks for achieving high efficiency of organic photovoltaic devices. In addition, compared with inorganic photovoltaic cells, energy loss is also one of the main factors limiting the high-efficiency photovoltaic performance and industrial development of organic photovoltaic cells. Multi-component strategy, through energy level regulation, spectral complementation and morphology optimization, has been proven to be a simple and efficient way to simultaneously improve the above three performance parameters. Therefore, the design and development of multifunctional third components, as well as the exploration of the energy loss working mechanism of multi-component systems, are crucial for promoting the industrial development of organic photovoltaic cells.

[0003] Non-fullerene acceptor materials have the advantages of simple synthesis, easy adjustment of energy level and band gap, and good morphology stability. Chinese patent document CN116375732A discloses a non-fullerene acceptor material and a preparation method and application thereof. The invention introduces ester groups and extends the conjugation length in the small molecule fused ring skeleton, designs and synthesizes a series of A-DA’D-A type small molecule acceptor materials, the structural formula of which is shown below. The small molecule acceptor material has good planarity, excellent film-forming property and strong light absorption in the ultraviolet-visible light region. It has more matched energy levels with existing common PM6:L8-BO binary systems, and can obtain higher open-circuit voltage and photoelectric conversion efficiency.

[0004]

[0005] In the design of non-fullerene acceptor materials, the electronic energy level distribution can be regulated by constructing asymmetric ends with different electron affinities, achieving a balance between open-circuit voltage and short-circuit current density. Chinese patent document CN115974895A discloses an asymmetric fused ring small molecule electron acceptor and a preparation method and application thereof. The structural general formula of the asymmetric fused ring small molecule electron acceptor is shown below. The invention uses the asymmetry strategy of the molecular structure to reduce the non-radiative charge recombination and voltage loss of the device, thereby improving the photoelectric performance of the organic solar cell.

[0006]

[0007] Combining the construction of asymmetric terminal and side chain engineering, end halogenation strategy, etc. is one of the feasible methods to realize the balance of the three performance parameters. In terms of energy loss, in addition to the inevitable above-bandgap radiative recombination loss, the energy loss of organic photovoltaic devices is mainly composed of below-bandgap radiative recombination loss and non-radiative recombination loss, which are caused by the recombination energy caused by the energy disorder of the system and the low electroluminescent efficiency caused by non-radiative transition, which are essentially the loss in the process of converting exciton state to charge state (Adv. Energy Mater. 2022, 12, 2201076). From exciton to charge state, the main place is the donor-acceptor phase interface. Especially in a multi-component system, the energy loss analysis process also becomes more complex due to the existence of more phase interfaces.

[0008] Therefore, in order to realize the balance of the open-circuit voltage, the short-circuit current density and the fill factor of the organic photovoltaic device, it is necessary to develop an asymmetric end-capped electron acceptor material and an efficient multi-component organic solar cell. SUMMARY

[0009] The application provides an asymmetric end-capped electron acceptor material, which takes a benzothiadiazole ladder fused ring structure as a core, contains a straight-chain alkyl chain or a branched alkyl chain, and double-halogen-substituted indanedione and double-chlorine-substituted cyanoindanone are electron-withdrawing end groups, respectively.

[0010] The specific technical solutions are as follows:

[0011] An asymmetric end-capped electron acceptor material has a chemical structure general formula as follows:

[0012]

[0013] In the formula, R1 is a straight-chain alkyl chain or a branched alkyl chain with a length of 9-20 carbons, R2 is a branched alkyl chain with a length of 8-20 carbons, and X is F or Cl.

[0014] The asymmetric end-capped electron acceptor material provided by the application has double-halogen-substituted indanedione and double-chlorine-substituted cyanoindanone as electron-withdrawing end groups, which reduces halogen substitution compared with the asymmetric end-capped electron acceptor material containing tetrahalogen-substituted indanedione, and can realize the improvement of the open-circuit voltage of the device; and the asymmetric end-capped electron acceptor material containing tetrahalogen-substituted indanedione has too strong crystallinity, which is not conducive to the solution preparation of the device, and causes the proportion sensitivity problem when used as a third component to construct a ternary device, and the asymmetric end-capped electron acceptor material in the application can overcome the above problems.

[0015] Preferably, R1 is 2-butyloctyl or undecyl, and R2 is 2-butyloctyl.

[0016] The application combines the construction of the asymmetric molecule end, the side chain engineering and the halogenation strategy, provides an asymmetric end-capped electron acceptor material, on the one hand, the benzothiadiazole ladder fused ring core structure is substituted by different side chain alkyl chains, the diversity of the molecular packing structure is realized, on the other hand, the construction of the asymmetric molecule end can bring the regulation of the energy level structure, so that the optimization of the material performance can be realized, and the organic solar cell device with excellent performance is prepared.

[0017] The application further provides a preparation method of the asymmetric end-capped electron acceptor material, comprising the following steps:

[0018] The first compound, the second compound, the third compound and chloroform are mixed, frozen by liquid nitrogen and thawed, pyridine is added in the thawed mixed system under the protection of nitrogen, Knoevenagel reaction is generated after heating, and column purification is carried out, so that the asymmetric end-capped electron acceptor material is obtained.

[0019] The structural formula of the first compound is as follows:

[0020]

[0021] The structural formula of the second compound is as follows:

[0022] The structural formula of the third compound is as follows:

[0023] The application further provides application of the asymmetric end-capped electron acceptor material in preparation of an organic solar cell device. Based on the asymmetric end-capped electron acceptor material, the organic solar cell can realize a high open circuit voltage of 1.018V.

[0024] The application further provides a ternary organic solar cell, comprising a substrate, an anode layer, an anode modification layer, an active layer based on a donor / multi-receptor system, a cathode modification layer and a cathode layer; the active layer is a blended film of an electron donor and two non-fullerene acceptors;

[0025] The electron donor is D18, the electron acceptor is Y6 and the asymmetric end-capped electron acceptor material.

[0026] The chemical structural formulae of D18 and Y6 are as follows:

[0027]

[0028] The asymmetric end-capped electron acceptor material is added as a third component into a D18:Y6 binary system, so that the energy loss can be reduced, the open circuit voltage can be improved, the spectral complementation can be realized, the short circuit current density can be improved, the morphology optimization can be realized, and the fill factor can be improved.

[0029] Preferably, the mass ratio of the electron donor to the non-fullerene acceptor in the active layer is 1:0.5-2, and the thickness of the active layer is 50-300 nm.

[0030] Preferably, in the non-fullerene acceptor, the mass ratio of Y6 to the asymmetrically capped electron acceptor material is 1:0.05-0.5, and further preferably 1:0.05-0.3.

[0031] Preferably, the substrate is glass; the anode is ITO; the anode modification layer is PEDOT:PSS; the cathode modification layer is PDINN; and the cathode is Ag.

[0032] The application also provides a preparation method of the ternary organic solar cell, characterized by comprising the following steps:

[0033] (1) preparing an anode modification layer on the anode layer on one side surface of the substrate;

[0034] (2) coating an active layer solution on the anode modification layer, and then performing annealing treatment to form the active layer;

[0035] (3) sequentially preparing a cathode buffer layer and a cathode layer on the active layer prepared in step (2) to obtain the ternary organic solar cell.

[0036] Preferably, the parameters of the annealing treatment are as follows: the annealing temperature is 80-200℃, and the annealing time is 5-60 min.

[0037] The total concentration of the electron donor and the electron acceptor in the active layer solution is 3-10 mg / mL; and the solvent of the active layer solution is a low-boiling halogen solvent, and the low-boiling halogen solvent includes chloroform.

[0038] Preferably, the active layer solution further comprises an additive, and the additive is 3,5-dichlorobenzyl bromide (DCBB), and the concentration of DCBB is 10 mg / mL.

[0039] Compared with the prior art, the application has the following beneficial effects:

[0040] (1) The application combines the construction of the asymmetric molecule end, the side chain engineering and the halogenation strategy, and provides an asymmetrically capped electron acceptor material. On the one hand, the benzothiadiazole ladder fused ring core structure is substituted by different side chain alkyl chains to realize the diversity of the molecular packing structure. On the other hand, the construction of the asymmetric molecule end can bring the regulation of the energy level structure, so that the performance of the material can be optimized, and an organic solar cell device with excellent performance can be prepared.

[0041] (2) The organic solar cell based on the asymmetrically capped electron acceptor material provided by the application can achieve a high open circuit voltage of up to 1.018V.

[0042] (3) The asymmetrically capped electron acceptor material is added as a third component to the D18:Y6 binary system, which not only can achieve a high open circuit voltage of about 0.862V, with an energy loss as low as 0.52eV, but also can achieve a high short circuit current density of 27mA / cm 2 2, and the PCE can be as high as 19.19%, which is much higher than that of the device based on the symmetric electron acceptor Y6 (18.11%). BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 The current-voltage curve of the organic solar cell in Examples 4, 8, 12, 16, 20, 24 and Comparative Example 1 under light irradiation.

[0044] Figure 2 The external quantum efficiency-wavelength curve of the organic solar cell in Examples 4, 8, 12, 16, 20, 24 and Comparative Example 1. DETAILED DESCRIPTION

[0045] The application will be further illustrated below in conjunction with the examples and drawings. It should be understood that these examples are only used to illustrate the application, and are not used to limit the scope of the application.

[0046] The benzothiadiazole-based ladder fused ring structure core containing a linear alkyl chain or a branched alkyl chain (the first compound) can be synthesized according to the reported literature (Joule, 2019, 3, 1140; Nat. Enerny 2021, 6, 605; which is currently commercialized and can be directly purchased), halogenated indanedione, and halogenated cyanoindanone are obtained by introducing malononitrile based on halogenated indanedione (which is currently commercialized and can be directly purchased).

[0047] Example 1

[0048] The specific synthesis routes of the asymmetrically capped electron acceptor materials BTP-SA1, BTP-SA2 and BTP-SA3 are as follows: wherein, compounds 1-5 are commercialized products, which are purchased from manufacturers.

[0049] (1) Synthesis of BTP-SA1

[0050]

[0051] Into a Schlenk tube was added compound 1 (0.21 g, 0.19 mmol), compound 3 (0.06 g, 0.3 mmol), compound 4 (0.08 g, 0.3 mmol) and chloroform (40 mL); frozen with liquid nitrogen, defrosted after three times of vacuum-pumping; 1 mL of pyridine was injected into the defrosted mixture under nitrogen protection, and the Knoevenagel reaction was carried out at 65 °C for 7 h; after the reaction was stopped, column purification was performed (eluent: petroleum ether: dichloromethane = 1:1, v / v) to obtain black solid BTP-SA1 (0.19 g, 55%).

[0052] The black solid BTP-SA1 was subjected to nuclear magnetic hydrogen spectrum determination: 1 H NMR (500 MHz, CDC13) δ = 9.18 (s, 1H), 8.80 (s, 1H), 8.25 (s, 1H), 8.03 (d, 2H), 7.96 (s, 1H), 4.77 (s, 4H), 3.23 (m, 4H), 2.12 (s, 2H), 1.89 (d, 5H), 1.60-1.45 (m, 19H), 1.31 (d, 82H), 1.12-0.74 (m, 60H), 0.67 (m, 15H).

[0053] The LUMO energy level of BTP-SA1 was -3.83 eV, the HOMO energy level was -5.64 eV, and the corresponding electrochemical band gap was 1.81 eV, which were measured by cyclic voltammetry (CV) method; the maximum absorption peak of BTP-SA1 was at 778 nm, the absorption band edge was 879 nm, and the optical band gap was 1.41 eV, which were measured by ultraviolet-visible absorption spectrum under thin film state.

[0054] (2) Synthesis of BTP-SA2

[0055]

[0056] Into a Schlenk tube was added compound 2 (0.22 g, 0.19 mmol), compound 3 (0.06 g, 0.3 mmol), compound 4 (0.08 g, 0.3 mmol) and chloroform (40 mL); frozen with liquid nitrogen, defrosted after three times of vacuum-pumping; 1 mL of pyridine was injected into the defrosted mixture under nitrogen protection, and the Knoevenagel reaction was carried out at 65 °C for 7 h; after the reaction was stopped, column purification was performed (eluent: petroleum ether: dichloromethane = 1:1, v / v) to obtain dark brown solid BTP-SA2 (0.2 g, 56%).

[0057] The dark brown solid BTP-SA2 was subjected to nuclear magnetic hydrogen spectrum determination: 1H NMR (500 MHz, CDC13) δ = 9.15 (s, 1H), 8.78 (s, 1H), 8.25 (s, 1H), 8.02 (d, 2H), 7.95 (s, 1H), 4.78 (d, 4H), 3.15 (dd, 5H), 2.16-2.04 (m, 5H), 1.56 (s, 4H), 1.50-1.38 (m, 10H), 1.40-1.30 (m, 12H), 1.25 (m, 20H), 1.11 (m, 11H), 1.07-0.90 (m, 24H), 0.86 (m, 20H), 0.66 (m, 14H).

[0058] The LUMO energy level of BTP-SA2 is -3.69 eV, the HOMO energy level is -5.49 eV, and the corresponding electrochemical band gap is 1.80 eV, which are measured by cyclic voltammetry (CV) method; the maximum absorption peak of BTP-SA2 is located at 771 nm, the absorption band edge is 856 nm, and the optical band gap is 1.44 eV, which are measured by ultraviolet-visible absorption spectrum.

[0059] (3) Synthesis of BTP-SA3

[0060]

[0061] Into a Schlenk tube was added compound 2 (0.22 g, 0.19 mmol), compound 5 (0.06 g, 0.3 mmol), compound 4 (0.08 g, 0.3 mmol) and chloroform (40 mL); frozen with liquid nitrogen, and then defrosted after three times of purging; 1 mL of pyridine was injected into the defrosted mixed system under nitrogen protection. The Knoevenagel reaction occurred when the reactants were refluxed at 65 °C for 7 h; after the reaction was stopped, column purification was performed (eluent: petroleum ether: dichloromethane = 1:1, v / v) to obtain dark brown solid BTP-SA3 (0.2 g, 56%).

[0062] The dark brown solid BTP-SA3 was subjected to nuclear magnetic hydrogen spectrum determination: 1 H NMR (500 MHz, CDC13) δ = 9.15 (s, 1H), 8.78 (s, 1H), 8.25 (s, 1H), 8.02 (d, 2H), 7.95 (s, 1H), 4.78 (d, 4H), 3.15 (dd, 5H), 2.16-2.04 (m, 5H), 1.56 (s, 4H), 1.50-1.38 (m, 10H), 1.40-1.30 (m, 12H), 1.25 (m, 20H), 1.11 (m, 11H), 1.07-0.90 (m, 24H), 0.86 (m, 20H), 0.66 (m, 14H).

[0063] The LUMO energy level of BTP-SA3 is -3.66 eV, the HOMO energy level is -5.46 eV, and the electrochemical band gap is 1.80 eV, which are measured by cyclic voltammetry (CV) method; the maximum absorption peak of BTP-SA3 is at 772 nm, the absorption band edge is 845 nm, and the optical band gap is 1.46 eV, which are measured by UV-visible absorption spectrum under thin film state.

[0064] Example 2

[0065] In this embodiment, the binary organic solar cell comprises the following structure which is stacked in sequence: a substrate, an anode layer, an anode modification layer, an active layer based on a donor / multi-receptor system, a cathode modification layer and a cathode layer; wherein the active layer is a blended film of D18 and the asymmetrically capped electron receptor material; and the specific preparation method is as follows:

[0066] (1) The transparent conductive glass with striped ITO (anode layer) etched on the surface is sequentially cleaned by ultrasonic oscillation with cleaning agent, deionized water, acetone and isopropanol, and then dried, and then treated with ultraviolet ozone for 15 minutes; then a layer of PEDOT:PSS is spin-coated at a speed of 4500 rpm, and after annealing treatment at 150°C for 20 minutes, an anode modification layer (20 nm thick) on the anode layer is obtained;

[0067] (2) D18 and BTP-SA1 are dissolved in chloroform containing DCBB (chloroform solution is chloroform solution added with 10 mg / mL of DCBB) at a mass ratio of 1:1.2 to obtain a D18:BTP-SA1 chloroform mixture with a total concentration of 4.5 mg / mL; the D18:BTP-SA1 chloroform mixture is spin-coated on the anode modification layer at a speed of 2500 rpm for 30 seconds, and then annealed at 100°C for 10 minutes to obtain an active layer with a thickness of about 100 nm;

[0068] (3) Then a 5 nm thick PDINN transport layer is prepared on the active layer by spin-coating a 1.0 mg / mL PDINN methanol solution, and finally a 100 nm thick Ag electrode (cathode layer) is evaporated by an evaporation instrument to obtain an organic solar cell with an effective area of 4 mm 2 .

[0069] Under the irradiation of AM1.5 simulated sunlight with an intensity of 100 mW / cm 2 , the current-voltage curve of the device is tested, and the open circuit voltage is 0.954 V, the short circuit current density is 17.22 mA / cm 2 , the fill factor is 62.04%, and the energy conversion efficiency (PCE) is 10.19%.

[0070] Example 3

[0071] The difference between the binary organic solar cell in this example and the binary organic solar cell in Example 2 is only that: D18 and BTP-SA1 are dissolved in chloroform at a mass ratio of 1:1.2 to obtain a D18:BTP-SA1 chloroform mixture with a total concentration of 3.5 mg / mL; the D18:BTP-SA1 chloroform mixture is coated on the anode modification layer at a rotation speed of 2500 rpm for 30 seconds, and then annealed at 100°C for 10 min to obtain an active layer with a thickness of about 100 nm; and the rest of the parameters and steps remain unchanged.

[0072] Under the irradiation of AM1.5 simulated sunlight with an intensity of 100 mW / cm 2 , the current-voltage curve of the device is tested, and the open-circuit voltage is 0.948 V, the short-circuit current density is 16.98 mA / cm 2 , the fill factor is 52.37%, and the energy conversion efficiency (PCE) is 8.43%.

[0073] Example 4

[0074] The difference between the binary organic solar cell in this example and the binary organic solar cell in Example 2 is only that: D18 and BTP-SA1 are dissolved in chloroform at a mass ratio of 1:1.4 to obtain a D18:BTP-SA1 chloroform mixture with a total concentration of 4.5 mg / mL; the D18:BTP-SA1 chloroform mixture is coated on the anode modification layer at a rotation speed of 2500 rpm for 30 seconds, and then annealed at 80°C for 10 min to obtain an active layer with a thickness of about 100 nm; and the rest of the parameters and steps remain unchanged.

[0075] Under the irradiation of AM1.5 simulated sunlight with an intensity of 100 mW / cm 2 , the current-voltage curve of the device is tested, and the open-circuit voltage is 0.963 V, the short-circuit current density is 17.70 mA / cm 2 , the fill factor is 62.93%, and the energy conversion efficiency (PCE) is 10.73%.

[0076] Example 5

[0077] The difference between the binary organic solar cell in this example and the binary organic solar cell in Example 2 is only that: D18 and BTP-SA2 are dissolved in chloroform at a mass ratio of 1:1.2 to obtain a D18:BTP-SA2 chloroform mixture with a total concentration of 4.5 mg / mL; the D18:BTP-SA2 chloroform mixture is coated on the anode modification layer at a rotation speed of 2500 rpm for 30 seconds, and then annealed at 80°C for 10 min to obtain an active layer with a thickness of about 100 nm; and the rest of the parameters and steps remain unchanged.

[0078] Under the irradiation of AM1.5 simulated sunlight with an intensity of 100 mW / cm2 The current-voltage curve of the device was tested under AM 1.5 simulated sunlight with an intensity of 100 mW / cm 2 , and the open circuit voltage was 0.998 V, the short circuit current density was 10.51 mA / cm 2 , the fill factor was 50.00%, and the power conversion efficiency (PCE) was 5.24%.

[0079] Example 6

[0080] The difference between the binary organic solar cell in this example and the binary organic solar cell in Example 2 is that D18 and BTP-SA2 were dissolved in chloroform at a mass ratio of 1:1.2 to obtain a D18:BTP-SA2 chloroform mixture with a total concentration of 3.5 mg / mL; the D18:BTP-SA2 chloroform mixture was coated on the anode modification layer at a rotation speed of 2500 rpm for 30 seconds, and an active layer with a thickness of about 100 nm was obtained by annealing at 100°C for 10 min; and the remaining parameters and steps were unchanged.

[0081] The current-voltage curve of the device was tested under AM 1.5 simulated sunlight with an intensity of 100 mW / cm 2 , and the open circuit voltage was 0.989 V, the short circuit current density was 9.43 mA / cm 2 , the fill factor was 45.31%, and the power conversion efficiency (PCE) was 4.31%.

[0082] Example 7

[0083] The difference between the binary organic solar cell in this example and the binary organic solar cell in Example 2 is that D18 and BTP-SA2 were dissolved in chloroform at a mass ratio of 1:1.4 to obtain a D18:BTP-SA2 chloroform mixture with a total concentration of 4.5 mg / mL; the D18:BTP-SA2 chloroform mixture was coated on the anode modification layer at a rotation speed of 2500 rpm for 30 seconds, and an active layer with a thickness of about 100 nm was obtained by annealing at 100°C for 10 min; and the remaining parameters and steps were unchanged.

[0084] The current-voltage curve of the device was tested under AM 1.5 simulated sunlight with an intensity of 100 mW / cm 2 , and the open circuit voltage was 0.999 V, the short circuit current density was 12.92 mA / cm 2 , the fill factor was 60.73%, and the power conversion efficiency (PCE) was 7.84%.

[0085] Example 8

[0086] The difference between the binary organic solar cell in this example and the binary organic solar cell in Example 2 is only that: D18 and BTP-SA2 are dissolved in chloroform at a mass ratio of 1:1.4 to obtain a D18:BTP-SA2 chloroform mixture with a total concentration of 4.5 mg / mL; the D18:BTP-SA2 chloroform mixture is coated on the anode modification layer at a rotation speed of 2500 rpm for 30 seconds, and an active layer with a thickness of about 100 nm is obtained by annealing at 80°C for 10 min; the remaining parameters and steps are unchanged.

[0087] Under the irradiation of AM1.5 simulated sunlight with an intensity of 100 mW / cm 2 , the current-voltage curve of the device is tested, and the open-circuit voltage is 1.009 V, the short-circuit current density is 13.30 mA / cm 2 , the fill factor is 62.19%, and the energy conversion efficiency (PCE) is 8.32%.

[0088] Example 9

[0089] The difference between the binary organic solar cell in this example and the binary organic solar cell in Example 2 is only that: D18 and BTP-SA2 are dissolved in chloroform at a mass ratio of 1:1.4 to obtain a D18:BTP-SA2 chloroform mixture with a total concentration of 4.5 mg / mL; the D18:BTP-SA2 chloroform mixture is coated on the anode modification layer at a rotation speed of 2500 rpm for 30 seconds, and an active layer with a thickness of about 100 nm is obtained by annealing at 80°C for 10 min; the remaining parameters and steps are unchanged.

[0090] Under the irradiation of AM1.5 simulated sunlight with an intensity of 100 mW / cm 2 , the current-voltage curve of the device is tested, and the open-circuit voltage is 1.009 V, the short-circuit current density is 13.30 mA / cm 2 , the fill factor is 62.19%, and the energy conversion efficiency (PCE) is 8.32%.

[0091] Example 10

[0092] The difference between the binary organic solar cell in this example and the binary organic solar cell in Example 2 is only that: D18 and BTP-SA2 are dissolved in chloroform at a mass ratio of 1:1.4 to obtain a D18:BTP-SA2 chloroform mixture with a total concentration of 4.5 mg / mL; the D18:BTP-SA2 chloroform mixture is coated on the anode modification layer at a rotation speed of 2500 rpm for 30 seconds, and an active layer with a thickness of about 100 nm is obtained by annealing at 80°C for 10 min; the remaining parameters and steps are unchanged.

[0093] Under the irradiation of AM1.5 simulated sunlight with an intensity of 100 mW / cm2 The current-voltage curve of the device was tested under AM 1.5 simulated sunlight with an intensity of 100 mW / cm 2 , and the open circuit voltage was 1.006 V, the short circuit current density was 13.21 mA / cm 2 , the fill factor was 62.72%, and the power conversion efficiency (PCE) was 8.31%.

[0094] Example 11

[0095] The difference between the binary organic solar cell in this example and the binary organic solar cell in Example 2 is that: D18 and BTP-SA3 were dissolved in chloroform at a mass ratio of 1:1.4 to obtain a D18:BTP-SA3 chloroform mixture with a total concentration of 4.5 mg / mL; the D18:BTP-SA3 chloroform mixture was coated on the anode modification layer at a rotation speed of 2500 rpm for 30 seconds, and the active layer was obtained by annealing at 80°C for 10 min; and the other parameters and steps were unchanged.

[0096] The current-voltage curve of the device was tested under AM 1.5 simulated sunlight with an intensity of 100 mW / cm 2 , and the open circuit voltage was 1.015 V, the short circuit current density was 12.97 mA / cm 2 , the fill factor was 60.80%, and the power conversion efficiency (PCE) was 8.00%.

[0097] Example 12

[0098] The difference between the binary organic solar cell in this example and the binary organic solar cell in Example 2 is that: D18 and BTP-SA3 were dissolved in chloroform at a mass ratio of 1:1.4 to obtain a D18:BTP-SA3 chloroform mixture with a total concentration of 4.5 mg / mL; the D18:BTP-SA3 chloroform mixture was coated on the anode modification layer at a rotation speed of 2500 rpm for 30 seconds, and the active layer was obtained by annealing at 80°C for 10 min; and the other parameters and steps were unchanged.

[0099] The current-voltage curve of the device was tested under AM 1.5 simulated sunlight with an intensity of 100 mW / cm 2 , and the open circuit voltage was 1.018 V, the short circuit current density was 13.88 mA / cm 2 , the fill factor was 62.06%, and the power conversion efficiency (PCE) was 8.76%.

[0100] Example 13

[0101] The ternary organic solar cell in the embodiment comprises the following structure which is stacked in sequence: a substrate, an anode layer, an anode modification layer, an active layer based on a donor / multi-receptor system, a cathode modification layer and a cathode layer; wherein the active layer is a blended film of D18, Y6 and the asymmetrically capped electron receptor material; and the specific preparation method is as follows:

[0102] (1) The transparent conductive glass with a striped ITO (anode layer) etched on the surface was cleaned with cleaning agent, deionized water, acetone and isopropyl alcohol by ultrasonic oscillation in sequence, and then dried and treated with ultraviolet ozone for 15 minutes; then a layer of PEDOT:PSS was spin-coated at a rotation speed of 4500 rpm, and after annealing treatment at 150°C for 20 minutes, an anode modification layer (20 nm thick) on the anode layer was obtained;

[0103] (2) D18, Y6 and BTP-SA1 were dissolved in chloroform at a mass ratio of 1:1.4:0.1 to obtain a D18:Y6:BTP-SA1 chloroform mixture with a total concentration of 3.5 mg / mL; the D18:Y6:BTP-SA1 chloroform mixture was spin-coated on the anode modification layer at a rotation speed of 3000 rpm for 30 seconds, and then 100°C thermal annealing was performed for 10 min to obtain an active layer with a thickness of about 80 nm;

[0104] (3) Then a 5 nm thick PDINN transport layer was prepared on the active layer by spin-coating a 1.0 mg / mL PDINN methanol solution, and finally a 100 nm thick Ag electrode (cathode layer) was evaporated by an evaporation instrument to obtain an organic solar cell with an effective area of 4 mm 2 .

[0105] Under the irradiation of AM1.5 simulated sunlight with an intensity of 100 mW / cm 2 , the current-voltage curve of the device was tested, and the open-circuit voltage was 0.847 V, the short-circuit current density was 26.89 mA / cm 2 , the fill factor was 78.33%, and the energy conversion efficiency (PCE) was 17.83%.

[0106] Embodiment 14

[0107] The ternary organic solar cell in the embodiment is different from the ternary organic solar cell in embodiment 13 only in that when preparing the active layer, D18, Y6 and BTP-SA1 were dissolved in chloroform at a mass ratio of 1:1.4:0.1 to obtain a D18:Y6:BTP-SA1 chloroform mixture with a total concentration of 4.5 mg / mL, and the D18:Y6:BTP-SA1 chloroform mixture was spin-coated on the anode modification layer at a rotation speed of 2500 rpm for 30 seconds, and then 80°C thermal annealing was performed for 10 min to obtain an active layer with a thickness of about 80 nm; the remaining parameters and steps were unchanged.

[0108] The current-voltage curve of the device was tested under AM1.5 simulated sunlight irradiation with an intensity of 100 mW / cm 2 , and the open-circuit voltage was 0.851 V, the short-circuit current density was 27.40 mA / cm 2 , the fill factor was 77.35%, and the power conversion efficiency (PCE) was 18.02%.

[0109] Example 15

[0110] The difference between the ternary organic solar cell in this example and the ternary organic solar cell in Example 13 is only that, when preparing the active layer, D18, Y6 and BTP-SA1 were dissolved in chloroform at a mass ratio of 1:1.4:0.1 to obtain a D18:Y6:BTP-SA1 chloroform mixture with a total concentration of 4.5 mg / mL, the D18:Y6:BTP-SA1 chloroform mixture was coated on the anode modification layer at a rotation speed of 3000 rpm for 30 seconds, and the active layer was obtained by 100°C thermal annealing for 10 min, and the thickness of the active layer was about 80 nm; the rest of the parameters and steps were unchanged.

[0111] The current-voltage curve of the device was tested under AM1.5 simulated sunlight irradiation with an intensity of 100 mW / cm 2 , and the open-circuit voltage was 0.859 V, the short-circuit current density was 27.09 mA / cm 2 , the fill factor was 78.42%, and the power conversion efficiency (PCE) was 18.25%.

[0112] Example 16

[0113] The difference between the ternary organic solar cell in this example and the ternary organic solar cell in Example 13 is only that, when preparing the active layer, D18, Y6 and BTP-SA1 were dissolved in chloroform at a mass ratio of 1:1.4:0.1 to obtain a D18:Y6:BTP-SA1 chloroform mixture with a total concentration of 4.5 mg / mL, the D18:Y6:BTP-SA1 chloroform mixture was coated on the anode modification layer at a rotation speed of 2500 rpm for 30 seconds, and the active layer was obtained by 80°C thermal annealing for 10 min, and the thickness of the active layer was about 100 nm; the rest of the parameters and steps were unchanged.

[0114] The current-voltage curve of the device was tested under AM1.5 simulated sunlight irradiation with an intensity of 100 mW / cm 2 , and the open-circuit voltage was 0.859 V, the short-circuit current density was 27.27 mA / cm 2 , the fill factor was 79.67%, and the power conversion efficiency (PCE) was 18.65%.

[0115] Example 17

[0116] The difference between the ternary organic solar cell in this example and the ternary organic solar cell in Example 13 is only that when preparing the active layer, D18, Y6 and BTP-SA2 are dissolved in chloroform at a mass ratio of 1:1.4:0.1 to obtain a D18:Y6:BTP-SA2 chloroform mixture with a total concentration of 3.5 mg / mL; the D18:Y6:BTP-SA2 chloroform mixture is coated on the anode modification layer at a rotation speed of 3000 rpm for 30 seconds, and a 80 nm-thick active layer is obtained by 100°C thermal annealing for 10 min; the rest of the parameters and steps remain unchanged.

[0117] Under the irradiation of AM1.5 simulated sunlight with an intensity of 100 mW / cm 2 , the current-voltage curve of the device is tested, and the open-circuit voltage is 0.840 V, the short-circuit current density is 26.63 mA / cm 2 , the fill factor is 77.49%, and the energy conversion efficiency (PCE) is 17.33%.

[0118] Example 18

[0119] The difference between the ternary organic solar cell in this example and the ternary organic solar cell in Example 13 is only that when preparing the active layer, D18, Y6 and BTP-SA2 are dissolved in chloroform at a mass ratio of 1:1.4:0.1 to obtain a D18:Y6:BTP-SA2 chloroform mixture with a total concentration of 3.5 mg / mL; the D18:Y6:BTP-SA2 chloroform mixture is coated on the anode modification layer at a rotation speed of 2500 rpm for 30 seconds, and a 100 nm-thick active layer is obtained by 80°C thermal annealing for 10 min; the rest of the parameters and steps remain unchanged.

[0120] Under the irradiation of AM1.5 simulated sunlight with an intensity of 100 mW / cm 2 , the current-voltage curve of the device is tested, and the open-circuit voltage is 0.855 V, the short-circuit current density is 27.03 mA / cm 2 , the fill factor is 78.27%, and the energy conversion efficiency (PCE) is 18.08%.

[0121] Example 19

[0122] The difference between the ternary organic solar cell in this example and the ternary organic solar cell in Example 13 is only that: when preparing the active layer, D18, Y6 and BTP-SA2 are dissolved in chloroform at a mass ratio of 1:1.4:0.1 to obtain a D18:Y6:BTP-SA2 chloroform mixture with a total concentration of 4.5 mg / mL; spin-coat the D18:Y6:BTP-SA2 chloroform mixture on the anode modification layer at a speed of 3000 rpm for 30 seconds, and then heat anneal at 80°C for 10 min to obtain an active layer with a thickness of about 80 nm; and the rest of the parameters and steps remain unchanged.

[0123] Under the irradiation of AM1.5 simulated sunlight with an intensity of 100 mW / cm 2 , the current-voltage curve of the device was tested, and the open-circuit voltage was 0.859 V, the short-circuit current density was 26.86 mA / cm 2 , the fill factor was 78.62%, and the energy conversion efficiency (PCE) was 18.12%.

[0124] Example 20

[0125] The difference between the ternary organic solar cell in this example and the ternary organic solar cell in Example 13 is only that: when preparing the active layer, D18, Y6 and BTP-SA2 are dissolved in chloroform at a mass ratio of 1:1.4:0.1 to obtain a D18:Y6:BTP-SA2 chloroform mixture with a total concentration of 4.5 mg / mL; spin-coat the D18:Y6:BTP-SA2 chloroform mixture on the anode modification layer at a speed of 2500 rpm for 30 seconds, and then heat anneal at 80°C for 10 min to obtain an active layer with a thickness of about 100 nm; and the rest of the parameters and steps remain unchanged.

[0126] Under the irradiation of AM1.5 simulated sunlight with an intensity of 100 mW / cm 2 , the current-voltage curve of the device was tested, and the open-circuit voltage was 0.864 V, the short-circuit current density was 26.68 mA / cm 2 , the fill factor was 79.88%, and the energy conversion efficiency (PCE) was 18.43%.

[0127] Example 21

[0128] The difference between the ternary organic solar cell in this example and the ternary organic solar cell in Example 13 is only that: when preparing the active layer, D18, Y6 and BTP-SA3 are dissolved in chloroform at a mass ratio of 1:1.4:0.1 to obtain a D18:Y6:BTP-SA3 chloroform mixture with a total concentration of 3.5 mg / mL; spin-coat the D18:Y6:BTP-SA3 chloroform mixture on the anode modification layer at a speed of 3000 rpm for 30 seconds, and then heat anneal at 100°C for 10 min to obtain an active layer with a thickness of about 80 nm; and the rest of the parameters and steps remain unchanged.

[0129] Under the irradiation of AM1.5 simulated sunlight with an intensity of 100 mW / cm 2 , the current-voltage curve of the device was tested, and the open-circuit voltage was 0.850 V, the short-circuit current density was 27.00 mA / cm 2 , the fill factor was 78.21%, and the energy conversion efficiency (PCE) was 17.94%.

[0130] Example 22

[0131] The difference between the ternary organic solar cell in this example and the ternary organic solar cell in Example 13 is only that: when preparing the active layer, D18, Y6 and BTP-SA3 are dissolved in chloroform at a mass ratio of 1:1.4:0.1 to obtain a D18:Y6:BTP-SA3 chloroform mixture with a total concentration of 4.0 mg / mL; spin-coat the D18:Y6:BTP-SA3 chloroform mixture on the anode modification layer at a speed of 3000 rpm for 30 seconds, and then heat anneal at 100°C for 10 min to obtain an active layer with a thickness of about 80 nm; and the rest of the parameters and steps remain unchanged.

[0132] Under the irradiation of AM1.5 simulated sunlight with an intensity of 100 mW / cm 2 , the current-voltage curve of the device was tested, and the open-circuit voltage was 0.857 V, the short-circuit current density was 26.56 mA / cm 2 , the fill factor was 80.37%, and the energy conversion efficiency (PCE) was 18.34%.

[0133] Example 23

[0134] The difference between the ternary organic solar cell in this example and the ternary organic solar cell in Example 13 is only that when preparing the active layer, D18, Y6 and BTP-SA3 are dissolved in chloroform at a mass ratio of 1:1.4:0.1 to obtain a D18:Y6:BTP-SA3 chloroform mixture with a total concentration of 4.5 mg / mL; the D18:Y6:BTP-SA3 chloroform mixture is coated on the anode modification layer at a rotation speed of 3000 rpm for 30 seconds, and an active layer with a thickness of about 80 nm is obtained by 80°C thermal annealing for 10 min; the remaining parameters and steps are unchanged.

[0135] Under the irradiation of AM1.5 simulated sunlight with an intensity of 100 mW / cm 2 , the current-voltage curve of the device is tested, and the open-circuit voltage is 0.863 V, the short-circuit current density is 26.93 mA / cm 2 , the fill factor is 79.96%, and the energy conversion efficiency (PCE) is 18.57%.

[0136] Example 24

[0137] The difference between the ternary organic solar cell in this example and the ternary organic solar cell in Example 13 is only that when preparing the active layer, D18, Y6 and BTP-SA3 are dissolved in chloroform at a mass ratio of 1:1.4:0.1 to obtain a D18:Y6:BTP-SA3 chloroform mixture with a total concentration of 4.5 mg / mL; the D18:Y6:BTP-SA3 chloroform mixture is coated on the anode modification layer at a rotation speed of 2500 rpm for 30 seconds, and an active layer with a thickness of about 100 nm is obtained by 80°C thermal annealing for 10 min; the remaining parameters and steps are unchanged.

[0138] Under the irradiation of AM1.5 simulated sunlight with an intensity of 100 mW / cm 2 , the current-voltage curve of the device is tested, and the open-circuit voltage is 0.862 V, the short-circuit current density is 27.52 mA / cm 2 , the fill factor is 81.01%, and the energy conversion efficiency (PCE) is 19.19%.

[0139] Comparative Example 1

[0140] (1) The transparent conductive glass with a striped ITO (anode layer) etched on the surface is sequentially cleaned by ultrasonic oscillation with cleaning agent, deionized water, acetone and isopropanol, and then dried and treated with ultraviolet ozone for 15 minutes; then a layer of PEDOT:PSS is spin-coated at a rotation speed of 4500 rpm, and an anode modification layer (20 nm thick) on the anode layer is obtained after annealing treatment at 150°C for 20 minutes;

[0141] (2) D18 and Y6 were dissolved in chloroform at a mass ratio of 1:1.4 to obtain a D18:Y6 chloroform mixture with a total concentration of 4.5 mg / mL; the D18:Y6 chloroform mixture was spin-coated on the anode modification layer at a rotation speed of 2500 rpm for 30 seconds, and then 80°C thermal annealing was performed for 10 min to obtain an active layer with a thickness of about 100 nm;

[0142] (3) Then, a 5 nm thick PDINN transport layer was prepared on the active layer by spin-coating a 1.0 mg / mL PDINN methanol solution, and finally, a 100 nm thick Ag electrode (cathode layer) was deposited by an evaporation instrument to obtain an organic solar cell with an effective area of 4 mm 2 .

[0143] Under AM1.5 simulated sunlight irradiation at an intensity of 100 mW / cm 2 , the current-voltage curve of the device was tested, and the open-circuit voltage was 0.851 V, the short-circuit current density was 26.94 mA / cm 2 , the fill factor was 78.89%, and the PCE was 18.10%.

[0144] Sample analysis

[0145] The current-voltage curves of the organic solar cells in Examples 4, 8, 12, 16, 20, 24 and Comparative Example 1 under AM1.5 simulated sunlight irradiation at an intensity of 100 mW / cm 2 are shown in Figure 1 , and the external quantum efficiency curves are shown in Figure 2 . Figure 1 As shown in the above, the binary device prepared by the asymmetrically terminated acceptor material of the application can achieve a high open-circuit voltage. In Comparative Example 1, a ternary organic solar cell was prepared by adding the asymmetrically terminated acceptor material prepared by the application, and the open-circuit voltage and short-circuit current density of the ternary organic solar cell were significantly improved, achieving a breakthrough in the photovoltaic performance of the device. Figure 2 The light response curve of the ternary device compared with Comparative Example 1 is significantly improved, which again proves the credibility of the high short-circuit current density of the ternary system and the efficiency breakthrough of the device.

[0146] The above examples have described the technical solutions of the application in detail, and it should be understood that the above examples are only specific embodiments of the application and are not intended to limit the application. Any modification, supplement or similar replacement within the principle range of the application should be included in the protection scope of the application.

Claims

1. A ternary organic solar cell, characterized by, The application relates to a ternary organic solar cell, which comprises a substrate, an anode layer, an anode modification layer, an active layer based on a donor / multi-acceptor system, a cathode modification layer and a cathode layer; the active layer is a blended film of an electron donor and two non-fullerene acceptors; The electron donor is D18, and the electron acceptors are Y6 and an asymmetrically-terminated electron acceptor material; The asymmetrically-terminated electron acceptor material has a chemical structure as shown in the general formula: ； In the formula, R1 is 2-butyloctyl or undecyl, R2 is 2-butyloctyl, and X is F or Cl; The mass ratio of the electron donor to the non-fullerene acceptor in the active layer is 1:0.5-2, and the thickness of the active layer is 50-300 nm; In the non-fullerene acceptor, the mass ratio of Y6 to the asymmetrically-terminated electron acceptor material is 1:0.05-0.

5.

2. The ternary organic solar cell according to claim 1, characterized in that The asymmetrically-terminated electron acceptor material is prepared by the following method: The first compound, the second compound, the third compound and chloroform are mixed, then frozen by liquid nitrogen and thawed, pyridine is added to the thawed mixed system under nitrogen protection, Knoevenagel reaction is carried out by heating, and the asymmetrically-terminated electron acceptor material is obtained by column purification; The first compound has a structural formula as shown in the formula: or ; The structural formula of the second compound is: or ; The third compound has the structural formula: .

3. The ternary organic solar cell according to claim 1, characterized in that, The substrate is glass, the anode is ITO, the anode modification layer is PEDOT:PSS, the cathode modification layer is PDINN, and the cathode is Ag.

4. The method of producing a ternary organic solar cell according to any one of claims 1 to 3, characterized by, The application further relates to a preparation method of the ternary organic solar cell, which comprises the following steps: (1) preparing an anode modification layer on the anode layer of the substrate on one side surface; (2) coating an active layer solution on the anode modification layer, and then performing annealing treatment to form the active layer; (3) sequentially preparing a cathode buffer layer and a cathode layer on the active layer prepared in step (2) to obtain the ternary organic solar cell.

5. The method for preparing a ternary organic solar cell according to claim 4, characterized in that, The total concentration of the electron donor and the electron acceptor in the active layer solution is 3-10 mg / mL; and the solvent of the active layer solution is chloroform.

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