High-efficiency organic solar cells prepared by solid additive-assisted stepwise deposition method

Abstract

This invention discloses a high-efficiency organic solar cell prepared by a solid additive-assisted stepwise deposition method, comprising, from bottom to top, a substrate, an anode, an anode modification layer, an active layer, a cathode modification layer, and a cathode; the active layer is composed of an electron donor and a solid additive composite film and an electron acceptor film sequentially deposited on the anode modification layer; the solid additive is a solid fatty acid FA-C as shown in the following formula. n Where n is 9 to 17: The present invention can use a simple spin coating process to gradually deposit the active layer in order to achieve a controllable vertical phase separation structure and a high-efficiency organic solar cell in the active layer.

Description

Technical Field

[0001] This invention relates to the field of organic solar cells, and more specifically to a high-efficiency organic solar cell prepared by a solid additive-assisted stepwise deposition method. Background Technology

[0002] Organic solar cells have attracted widespread attention due to their colorfulness, translucency, low cost, flexibility, and ability to be fabricated over large areas. Recently, the energy conversion efficiency of single-junction cells has exceeded 19%, reaching the standard for large-scale industrial production (Nat. Mater. 21(6), 656-663(2022)).

[0003] Besides developing new molecules with excellent photovoltaic performance, constructing suitable active layer morphology is just as important as material research in device fabrication. Currently, the best-performing organic solar cells are based on bulk heterojunctions prepared by hybrid deposition, where electron donors and acceptors are simultaneously dissolved in a solvent and spin-coated to obtain the active layer. Therefore, the phase separation of donors and acceptors during spin-coating is highly dependent on their spontaneous thermodynamic and kinetic behavior, making the degree of phase separation difficult to control. Inappropriate morphology can lead to charge recombination. Holes are extracted by the anode along the donor phase transport channel, and electrons are extracted by the cathode along the acceptor phase transport channel. Therefore, the degree of phase separation has a significant impact on charge generation and transport: on the one hand, the limited exciton diffusion length of organic semiconductors necessitates sufficient donor-acceptor interface area, i.e., smaller phase separation is required for exciton dissociation; on the other hand, larger phase separation means a smaller interface area and higher phase purity, which may slow down the recombination of holes and electrons. Therefore, appropriate phase separation is necessary for charge transport and collection without affecting exciton dissociation. However, precisely controlling the nanoscale structure and phase separation of donors and acceptors is challenging and limits the industrial production of organic solar cells.

[0004] Currently, quasi-planar heterojunctions with pin structures prepared by stepwise deposition are increasingly considered a more ideal structure than bulk heterojunctions. In this structure, the donor is enriched at the top and the acceptor at the bottom, which can effectively suppress charge recombination during the transport of charges to the anode and cathode (Adv. Mater. 33(43), e2103091(2021); Nat. Commun. 12(1), 468(2021); Adv. Mater. 33(12), e2007231(2021)). In addition, during stepwise deposition, the acceptor permeates into the donor membrane and forms phase separation, resulting in a concentration gradient distribution in the vertical direction, which is beneficial for charge transport and extraction. However, a significant drawback of stepwise deposition alone is that the diffusion of the acceptor during deposition is uncontrollable. Furthermore, due to the simultaneous effects of solvation and interdiffusion, the degree of phase separation is also difficult to control. Therefore, achieving controllable vertical phase separation and regulating the degree of phase separation to match the exciton diffusion length and charge transport distance has important scientific research and application value. Summary of the Invention

[0005] In view of the above-mentioned technical problems and the shortcomings of the field, the present invention provides a high-efficiency organic solar cell prepared by solid additive-assisted stepwise deposition method, which can use a simple spin coating process to stepwise deposit the active layer to achieve a controllable vertical phase separation structure in the active layer and a high-efficiency organic solar cell.

[0006] A high-efficiency organic solar cell prepared by a solid additive-assisted stepwise deposition method includes a substrate, an anode, an anode modification layer, an active layer, a cathode modification layer, and a cathode arranged sequentially from bottom to top.

[0007] The active layer is composed of an electron donor and solid additive composite film and an electron acceptor film sequentially deposited on the anode modified layer;

[0008] The solid additive is a solid fatty acid FA-C as shown in the following formula. n Where n is 9 to 17:

[0009]

[0010] This invention utilizes electron donors and FA-C n (n = 9–17) Pre-constructed phase separation allows the receptor to smoothly enter FA-C nIn the channels formed by (n = 9~17), the active layer has an ideal vertical phase separation structure, that is, a donor-enriched phase is formed at the anode modification layer interface, an acceptor-enriched phase is formed at the cathode modification layer interface, and a suitable phase separation size is formed between the donor and acceptor in the middle. Therefore, the binary organic solar cell obtained by this invention achieves a synergistic improvement in short-circuit current and fill factor, and its energy conversion efficiency exceeds that of binary organic solar cells prepared by hybrid deposition and stepwise deposition methods. The binary organic solar cell based on PM6:Y6 achieved a maximum efficiency of 18.16%; the binary organic solar cell based on the PM6:L8-BO system achieved an efficiency of 19.02%, which is also one of the highest efficiencies of binary organic solar cells to date.

[0011] This invention can be adapted to various donor-acceptor systems by changing the number of carbon atoms and the amount of the solid additive. In a preferred embodiment, the mass ratio of the electron donor to the solid additive is 100:5 to 15, more preferably 100:5 to 10, and the solid additive is FA-C. 12 When the mass ratio of the solid additive to the electron donor increases from 5:100 to 15:100, the resulting binary organic solar cells exhibit excellent performance. In particular, when the mass ratio of the solid additive to the electron donor is 10:100, the binary organic solar cells based on PM6:Y6 and PM6:L8-BO achieve the best performance.

[0012] Preferably, the electron donor is a p-type semiconductor, selected from wide-bandgap polymer donors, specifically PM6 or D18.

[0013]

[0014] In the molecular structures of PM6 and D18 mentioned above, n represents the degree of polymerization. In PM6, n = 17 to 33; in D18, n = 31 to 47.

[0015] Preferably, the electron acceptor is an n-type semiconductor, selected from organic small molecule fused ring acceptors, specifically Y6 or L8-BO.

[0016]

[0017] In a preferred embodiment, the electron donor and solid additive composite film is spin-coated from a chloroform solution of a mixture of electron donor and solid additive with a total concentration of 7-13 mg / mL.

[0018] In a preferred embodiment, the electron acceptor film is spin-coated from a chloroform solution of an electron acceptor at a concentration of 8-15 mg / mL.

[0019] Preferably, the total thickness of the active layer is 95-250 nm, wherein the mass ratio of electron donor to electron acceptor is 1:1.1-1.3.

[0020] In a preferred embodiment, 1-chloronaphthalene (CN) is further added to the electron acceptor solution as an additive, and the volume of 1-chloronaphthalene added is 0.5% to 0.7% of the volume of the electron acceptor solution.

[0021]

[0022] In another preferred embodiment, 1,8-diiodooctane (DIO) is also added to the electron acceptor solution as an additive, wherein the volume of 1,8-diiodooctane added is 0.2% to 0.3% of the volume of the electron acceptor solution.

[0023]

[0024] Preferably, after sequentially depositing an electron donor and solid additive composite film and an electron acceptor film on the anode modification layer, an annealing treatment is performed at a temperature of 80–100°C for 5–8 minutes.

[0025] In a preferred embodiment, the substrate is transparent glass; the anode is indium tin oxide (ITO); the anode modification layer is poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS); the cathode modification layer is N,N'-Bis{3-[3-(Dimethylamino)propylamino]propyl}perylene-3,4,9,10-tetraca rboxylic diimide (PDINN); and the cathode is Ag.

[0026] The innovation of this invention lies in the use of a solid additive-assisted stepwise deposition method, that is, mixing solid fatty acid FA-C into the electron donor solution. n (n = 9 to 17), thus bringing the following advantages:

[0027] 1. Due to FAC n (n = 9–17) exhibits suitable compatibility with polymer electron donors, therefore, during the deposition of the first electron donor-solid additive composite film, FA-C n (n = 9–17) forms an ideal phase-separated morphology with the electron donor beforehand. During the deposition of the second electron acceptor film, chloroform dissolves the solid additive, allowing the electron acceptor to smoothly enter the FA-C phase. nThe channels constructed with n = 9–17 allow for an ideal phase-separated structure between the polymer electron donor and the organic small-molecule fused-ring electron acceptor. This provides sufficient donor-acceptor interface area for exciton dissociation and sufficient phase purity to ensure smooth charge transport and collection. Therefore, the resulting organic solar cell achieves a simultaneous improvement in short-circuit current and fill factor.

[0028] 2. When spin-coating organic small molecule fused-ring electron acceptors in solution, due to FA-C n (n=9~17) As small molecules, they can be rapidly dissolved in chloroform, while polymeric electron donors can only swell. Furthermore, FA-C n (n=9~17) as impurities disrupt the regular packing of polymer chains, increasing the amorphous state of the chains, therefore FA-C n The introduction of (n=9~17) can promote the penetration and diffusion of electron acceptors, so that the active layer has an ideal pin morphology structure, that is, a donor-enriched phase (p) is formed at the interface of the anode modified layer, an acceptor-enriched phase (n) is formed at the interface of the cathode modified layer, and the middle is a heterojunction (i) with good mixing of donors and acceptors and an ideal vertical phase separation structure.

[0029] Due to the aforementioned advantages, the binary organic solar cell PM6:Y6 prepared by this invention achieves a power conversion efficiency of 18.16%, which is higher than that of binary organic solar cells prepared by the corresponding stepwise deposition method (17.52%) and the hybrid deposition method (16.80%). In the PM6:L8-BO system, the binary organic solar cell prepared by this invention achieves a power conversion efficiency of 19.02%, which is also one of the highest efficiencies of binary organic solar cells to date, significantly better than binary organic solar cells prepared by the corresponding stepwise deposition method (PM6:L8-BO, 18.73%) and binary organic solar cells prepared based on the hybrid deposition method (PM6:L8-BO, 18.56%).

[0030] Furthermore, the method of the present invention is also universal, and by changing the number of carbon atoms and the amount of solid additive, different donor-acceptor systems can achieve the optimal degree of phase separation. Attached Figure Description

[0031] Figure 1 This diagram illustrates the preparation of the active layer of an organic solar cell using a hybrid deposition method, a step-by-step deposition method, and a solid additive-assisted step-by-step deposition method, as described in a specific embodiment of the present invention. In the diagram, "donor" represents an electron donor, and "acceptor" represents an electron acceptor.

[0032] Figure 2The images show the current-voltage curves of PM6:Y6 organic solar cells prepared using different processes under illumination. The active layer prepared using a mixed deposition method has a thickness of approximately 100 nm. During preparation, 0.5% (by volume) of 1-chloronaphthalene was added to the active layer solution. The total weight ratio of PM6 to Y6 in the active layer was 1:1.2, and the cell was annealed at 80°C for 8 minutes. The active layer prepared using a stepwise deposition method has a thickness of approximately 95 nm. During preparation, 0.5% (by volume) of 1-chloronaphthalene was added to the acceptor. PM6 was first spin-coated into the active layer, followed by Y6, and the cell was annealed at 80°C for 8 minutes. The active layer prepared using a solid additive-assisted stepwise deposition method has a thickness of approximately 95 nm. During preparation, 0.5% (by volume) of 1-chloronaphthalene was added to the acceptor. The donor and solid additive composite was first spin-coated into the active layer, followed by Y6. The mass ratio of solid additive to donor varied from 5:100 to 15:100, and the cell was annealed at 80°C for 8 minutes. Detailed Implementation

[0033] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Operating methods not specifically specified in the following embodiments are generally performed under conventional conditions reported in the literature or under conditions recommended by the manufacturer.

[0034] Example 1

[0035] Transparent conductive glass coated with ITO (anode) was sequentially ultrasonically cleaned with cleaning agent, deionized water, acetone, isopropanol, and anhydrous ethanol for 15 min, dried, and then treated with ultraviolet ozone for 20 min. A 15 nm thick layer of PEDOT:PSS was then spin-coated onto the conductive glass surface at 4500 rpm, followed by annealing at 150 °C for 15 min. The wafer was then transferred to a glove box. For the mixed deposition method, a mixed solution of PM6:Y6 (mass ratio 1:1.2) in chloroform with 0.5% 1-chloronaphthalene (CN) added (total concentration 16 mg / mL) was spin-coated at 3000 rpm for 25 s to obtain a 100 nm thick active layer. The active layer was annealed at 80 °C for 8 min. Then, a 5 nm thick PDINN modification layer was spin-coated onto the active layer using a 1 mg / mL PDINN methanol solution. Finally, a 100 nm thick Ag electrode (cathode) was deposited using an evaporator, resulting in an effective area of ​​6 mm². 2 Organic solar cells.

[0036] At a light intensity of 100mW / cm 2Under AM1.5 simulated sunlight irradiation, the current-voltage curve of the device was tested, yielding an open-circuit voltage of 0.85V and a short-circuit current density of 26.66mA / cm². 2 The fill factor is 74.1%, and the PCE is 16.80%.

[0037] Figure 2 The device is given under illumination of 100 mW / cm². 2 The AM1.5 simulated current-voltage curve under sunlight.

[0038] Example 2

[0039] Transparent conductive glass coated with ITO (anode) was sequentially ultrasonically cleaned with cleaning agent, deionized water, acetone, isopropanol, and anhydrous ethanol for 15 min, dried, and then treated with ultraviolet ozone for 20 min. A 15 nm thick layer of PEDOT:PSS was then spin-coated onto the conductive glass surface at 4500 rpm, followed by annealing at 150 °C for 15 min. The sheet was then transferred to a glove box. For stepwise deposition: a PM6 solution with a concentration of 7 mg / mL in chloroform was spin-coated at 2500 rpm for 25 s to obtain a 55 nm thick donor layer. Next, a Y6 solution with a total concentration of 8 mg / mL (containing 0.5% by volume of 1-chloronaphthalene (CN)) in chloroform was spin-coated at 2500 rpm for 25 s to obtain an active layer with a total thickness of 95 nm. The active layer was annealed at 80 °C for 8 min. Then, a 5 nm thick PDINN modification layer was spin-coated onto the active layer using a 1 mg / mL PDINN methanol solution. Finally, a 100 nm thick Ag electrode (cathode) was deposited using an evaporator, resulting in an effective area of ​​6 mm². 2 Organic solar cells.

[0040] At a light intensity of 100mW / cm 2 Under AM1.5 simulated sunlight irradiation, the current-voltage curve of the device was tested, yielding an open-circuit voltage of 0.85V and a short-circuit current density of 26.81mA / cm². 2 The fill factor is 76.5%, and the PCE is 17.52%.

[0041] Figure 2 The device is given under illumination of 100 mW / cm². 2 The AM1.5 simulated current-voltage curve under sunlight.

[0042] Example 3

[0043] Transparent conductive glass coated with ITO (anodide) was sequentially ultrasonically cleaned with cleaning agent, deionized water, acetone, isopropanol, and anhydrous ethanol for 15 min, dried, and then treated with ultraviolet ozone for 20 min. A 15 nm thick layer of PEDOT:PSS was then spin-coated onto the conductive glass surface at 4500 rpm, followed by annealing at 150℃ for 15 min. The wafer was then transferred to a glove box. Solid additive-assisted stepwise deposition method: PM6:FA-C with a total concentration of 7 mg / mL was added. 12 A donor layer of 55 nm thick was obtained by spin-coating a solution of Y6 in chloroform (mass ratio 100:5) at 2500 rpm for 25 s. Next, an active layer of 95 nm thick was obtained by spin-coating a solution of Y6 in chloroform with 0.5% (v / v) 1-chloronaphthalene (CN) at a total concentration of 8 mg / mL at 2500 rpm for 25 s. The active layer was then annealed at 80 °C for 8 min. A 5 nm thick PDINN modification layer was then spin-coated onto the active layer using a 1 mg / mL PDINN methanol solution. Finally, a 100 nm thick Ag electrode (cathode) was deposited using a vapor deposition apparatus, resulting in an effective area of ​​6 mm². 2 Organic solar cells.

[0044] At a light intensity of 100mW / cm 2 Under AM1.5 simulated sunlight irradiation, the current-voltage curve of the device was tested, yielding an open-circuit voltage of 0.85V and a short-circuit current density of 26.78mA / cm². 2 The fill factor is 77.3%, and the PCE is 17.65%.

[0045] Figure 2 The device is given under illumination of 100 mW / cm². 2 The AM1.5 simulated current-voltage curve under sunlight.

[0046] Example 4

[0047] Transparent conductive glass coated with ITO (anodide) was sequentially ultrasonically cleaned with cleaning agent, deionized water, acetone, isopropanol, and anhydrous ethanol for 15 min, dried, and then treated with ultraviolet ozone for 20 min. A 15 nm thick layer of PEDOT:PSS was then spin-coated onto the conductive glass surface at 4500 rpm, followed by annealing at 150℃ for 15 min. The wafer was then transferred to a glove box. Solid additive-assisted stepwise deposition method: PM6:FA-C with a total concentration of 7 mg / mL was added. 12A donor layer of 55 nm thickness was obtained by spin-coating a solution of Y6 in chloroform (mass ratio 100:10) at 2500 rpm for 25 s. Next, an active layer of 95 nm thickness was obtained by spin-coating a solution of Y6 in chloroform with 0.5% (v / v) 1-chloronaphthalene (CN) at a total concentration of 8 mg / mL at 2500 rpm for 25 s. The active layer was then annealed at 80 °C for 8 min. A 5 nm thick PDINN modification layer was then spin-coated onto the active layer using a 1 mg / mL PDINN methanol solution. Finally, a 100 nm thick Ag electrode (cathode) was deposited using a vapor deposition apparatus, resulting in an effective area of ​​6 mm². 2 Organic solar cells.

[0048] At a light intensity of 100mW / cm 2 Under AM1.5 simulated sunlight irradiation, the current-voltage curve of the device was tested, yielding an open-circuit voltage of 0.85V and a short-circuit current density of 27.74mA / cm². 2 The fill factor is 76.7%, and the PCE is 18.16%.

[0049] Figure 2 The device is given under illumination of 100 mW / cm². 2 The AM1.5 simulated current-voltage curve under sunlight.

[0050] Example 5

[0051] Transparent conductive glass coated with ITO (anodide) was sequentially ultrasonically cleaned with cleaning agent, deionized water, acetone, isopropanol, and anhydrous ethanol for 15 min, dried, and then treated with ultraviolet ozone for 20 min. A 15 nm thick layer of PEDOT:PSS was then spin-coated onto the conductive glass surface at 4500 rpm, followed by annealing at 150℃ for 15 min. The wafer was then transferred to a glove box. Solid additive-assisted stepwise deposition method: PM6:FA-C with a total concentration of 7 mg / mL was added. 12 A donor layer of 55 nm thick was obtained by spin-coating a solution of Y6 in chloroform (mass ratio 100:15) at 2500 rpm for 25 s. Next, an active layer of 95 nm thick was obtained by spin-coating a solution of Y6 in chloroform with 0.5% (v / v) 1-chloronaphthalene (CN) at a total concentration of 8 mg / mL at 2500 rpm for 25 s. The active layer was then annealed at 80 °C for 8 min. A 5 nm thick PDINN modification layer was then spin-coated onto the active layer using a 1 mg / mL PDINN methanol solution. Finally, a 100 nm thick Ag electrode (cathode) was deposited using a vapor deposition apparatus, resulting in an effective area of ​​6 mm². 2 Organic solar cells.

[0052] At a light intensity of 100mW / cm 2 Under AM1.5 simulated sunlight irradiation, the current-voltage curve of the device was tested, yielding an open-circuit voltage of 0.85V and a short-circuit current density of 26.66mA / cm². 2 The fill factor is 76.6%, and the PCE is 17.36%.

[0053] Figure 2 The device is given under illumination of 100 mW / cm². 2 The AM1.5 simulated current-voltage curve under sunlight.

[0054] Example 6

[0055] Transparent conductive glass coated with ITO (anode) was sequentially ultrasonically cleaned with cleaning agent, deionized water, acetone, isopropanol, and anhydrous ethanol for 15 min, dried, and then treated with ultraviolet ozone for 20 min. A 15 nm thick layer of PEDOT:PSS was then spin-coated onto the conductive glass surface at 4500 rpm, followed by annealing at 150 °C for 15 min. The wafer was then transferred to a glove box. For solid additive-assisted stepwise deposition: a solution of PM6:FA-C9 (mass ratio 100:10) at a total concentration of 7 mg / mL in chloroform was spin-coated at 2500 rpm for 25 s to obtain a 55 nm thick donor layer. Next, a solution of Y6 at a total concentration of 8 mg / mL (containing 0.5% by volume of 1-chloronaphthalene (CN)) in chloroform was spin-coated at 2500 rpm for 25 s to obtain an active layer with a total thickness of 95 nm. The active layer was annealed at 80 °C for 8 min. Then, a 5 nm thick PDINN modification layer was spin-coated onto the active layer using a 1 mg / mL PDINN methanol solution. Finally, a 100 nm thick Ag electrode (cathode) was deposited using an evaporator, resulting in an effective area of ​​6 mm². 2 Organic solar cells.

[0056] At a light intensity of 100mW / cm 2 Under AM1.5 simulated sunlight irradiation, the current-voltage curve of the device was tested, yielding an open-circuit voltage of 0.85V and a short-circuit current density of 27.12mA / cm². 2 The fill factor is 75.3%, and the PCE is 17.40%.

[0057] Example 7

[0058] Transparent conductive glass coated with ITO (anodide) was sequentially ultrasonically cleaned with cleaning agent, deionized water, acetone, isopropanol, and anhydrous ethanol for 15 min, dried, and then treated with ultraviolet ozone for 20 min. A 15 nm thick layer of PEDOT:PSS was then spin-coated onto the conductive glass surface at 4500 rpm, followed by annealing at 150℃ for 15 min. The wafer was then transferred to a glove box. Solid additive-assisted stepwise deposition method: PM6:FA-C with a total concentration of 7 mg / mL was added. 16 A donor layer of 55 nm thickness was obtained by spin-coating a solution of Y6 in chloroform (mass ratio 100:10) at 2500 rpm for 25 s. Next, an active layer of 95 nm thickness was obtained by spin-coating a solution of Y6 in chloroform with 0.5% (v / v) 1-chloronaphthalene (CN) at a total concentration of 8 mg / mL at 2500 rpm for 25 s. The active layer was then annealed at 80 °C for 8 min. A 5 nm thick PDINN modification layer was then spin-coated onto the active layer using a 1 mg / mL PDINN methanol solution. Finally, a 100 nm thick Ag electrode (cathode) was deposited using a vapor deposition apparatus, resulting in an effective area of ​​6 mm². 2 Organic solar cells.

[0059] At a light intensity of 100mW / cm 2 Under AM1.5 simulated sunlight irradiation, the current-voltage curve of the device was tested, yielding an open-circuit voltage of 0.84V and a short-circuit current density of 27.17mA / cm². 2 The fill factor is 77.0%, and the PCE is 17.57%.

[0060] Example 8

[0061] Transparent conductive glass coated with ITO (anode) was sequentially ultrasonically cleaned with cleaning agent, deionized water, acetone, isopropanol, and anhydrous ethanol for 15 min, dried, and then treated with ultraviolet ozone for 20 min. A 15 nm thick layer of PEDOT:PSS was then spin-coated onto the conductive glass surface at 4500 rpm, followed by annealing at 150 °C for 15 min. The wafer was then transferred to a glove box. For stepwise deposition: a solution of PM6 at 7 mg / mL in chloroform was spin-coated at 2500 rpm for 25 s to obtain a 55 nm thick donor layer. Next, a solution of L8-BO at 8 mg / mL in chloroform with 0.25% (v / v) of 1,8-diiodooctane (DIO) was spin-coated at 2500 rpm for 25 s to obtain an active layer with a total thickness of 95 nm. The active layer was annealed at 80 °C for 8 min. Then, a 5 nm thick PDINN modification layer was spin-coated onto the active layer using a 1 mg / mL PDINN methanol solution. Finally, a 100 nm thick Ag electrode (cathode) was deposited using an evaporator, resulting in an effective area of ​​6 mm². 2 Organic solar cells.

[0062] At a light intensity of 100mW / cm 2 Under AM1.5 simulated sunlight irradiation, the current-voltage curve of the device was tested, yielding an open-circuit voltage of 0.88V and a short-circuit current density of 26.76mA / cm². 2 The fill factor is 79.2%, and the PCE is 18.73%.

[0063] Example 9

[0064] Transparent conductive glass coated with ITO (anodide) was sequentially ultrasonically cleaned with cleaning agent, deionized water, acetone, isopropanol, and anhydrous ethanol for 15 min, dried, and then treated with ultraviolet ozone for 20 min. A 15 nm thick layer of PEDOT:PSS was then spin-coated onto the conductive glass surface at 4500 rpm, followed by annealing at 150℃ for 15 min. The wafer was then transferred to a glove box. Solid additive-assisted stepwise deposition method: PM6:FA-C with a total concentration of 7 mg / mL was added. 12A donor layer of 55 nm thickness was obtained by spin-coating a solution of 100:10 PDINN in chloroform at 2500 rpm for 25 s. Next, an active layer of 95 nm thickness was obtained by spin-coating a solution of 1,8-diiodooctane (DIO) at 0.25% by volume and L8-BO at a total concentration of 8 mg / mL in chloroform. The active layer was then annealed at 80 °C for 8 min. A 5 nm thick PDINN modification layer was then spin-coated onto the active layer using a 1 mg / mL PDINN methanol solution. Finally, a 100 nm thick Ag electrode (cathode) was deposited using a vapor deposition apparatus, resulting in an effective area of ​​6 mm². 2 Organic solar cells.

[0065] At a light intensity of 100mW / cm 2 Under AM1.5 simulated sunlight irradiation, the current-voltage curve of the device was tested, yielding an open-circuit voltage of 0.88V and a short-circuit current density of 26.68mA / cm². 2 The fill factor is 80.5%, and the PCE is 19.02%.

[0066] Example 10

[0067] Transparent conductive glass coated with ITO (anodide) was sequentially ultrasonically cleaned with cleaning agent, deionized water, acetone, isopropanol, and anhydrous ethanol for 15 min, dried, and then treated with ultraviolet ozone for 20 min. A 15 nm thick layer of PEDOT:PSS was then spin-coated onto the conductive glass surface at 4500 rpm, followed by annealing at 150℃ for 15 min. The wafer was then transferred to a glove box. Solid additive-assisted stepwise deposition method: PM6:FA-C with a total concentration of 13 mg / mL was added. 12 A donor layer of 150 nm thick was obtained by spin-coating a solution of 1,8-diiodooctane (DIO) in chloroform at a mass ratio of 100:10 for 25 s at 2800 rpm. Next, an active layer of 250 nm thick was obtained by spin-coating a solution of 1,8-diiodooctane (DIO) at a volume ratio of 0.25% and L8-BO at a total concentration of 15 mg / mL in chloroform. The active layer was then annealed at 80 °C for 8 min. A 5 nm thick PDINN modification layer was then spin-coated onto the active layer using a 1 mg / mL PDINN methanol solution. Finally, a 100 nm thick Ag electrode (cathode) was deposited using a vapor deposition apparatus, resulting in an effective area of ​​6 mm². 2 Organic solar cells.

[0068] At a light intensity of 100mW / cm 2Under AM1.5 simulated sunlight irradiation, the current-voltage curve of the device was tested, yielding an open-circuit voltage of 0.88V and a short-circuit current density of 27.30mA / cm². 2 The fill factor is 69.0%, and the PCE is 16.44%.

[0069] Furthermore, it should be understood that after reading the above description of the present invention, those skilled in the art can make various alterations or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims.

Claims

1. A high efficiency organic solar cell prepared by a solid additive assisted gradual deposition method, characterized in that, The active layer is composed of an electron donor and a solid additive compound film and an electron acceptor film deposited on the anode modification layer in sequence. The mass ratio of the electron donor and the solid additive is 100:5-10. The solid additive is a solid fatty acid FA-C of the following formula n wherein n is 9 to 17:

2. The highly efficient organic solar cell according to claim 1, characterized in that The electron donor is a p-type semiconductor selected from wide-bandgap polymer donors, specifically PM6 or D18.

3. The highly efficient organic solar cell according to claim 1, characterized in that, The electron acceptor is an n-type semiconductor selected from organic small molecule fused ring acceptors, specifically Y6 or L8-BO. The electron donor and solid additive compound film is spin-coated from a chloroform solution of an electron donor and solid additive mixture with a total concentration of 7-13 mg / mL.

4. The highly efficient organic solar cell according to claim 1, characterized in that, The electron acceptor film is spin-coated from a chloroform solution of an electron acceptor with a concentration of 8-15 mg / mL.

5. The highly efficient organic solar cell according to claim 1, characterized in that, The total thickness of the active layer is 95-250 nm, and the mass ratio of the electron donor to the electron acceptor is 1:1.1-1.

3.

6. The highly efficient organic solar cell according to claim 1, characterized in that 1-Chloronaphthalene is also added as an additive in the electron acceptor solution, and the volume of 1-chloronaphthalene added is 0.5%-0.7% of the volume of the electron acceptor solution.

7. The highly efficient organic solar cell according to claim 5, characterized in that 1,8-Diiodooctane is also added as an additive in the electron acceptor solution, and the volume of 1,8-diiodooctane added is 0.2%-0.3% of the volume of the electron acceptor solution.

8. The highly efficient organic solar cell according to claim 5, characterized in that After depositing the electron donor and solid additive compound film and the electron acceptor film on the anode modification layer in sequence, annealing treatment is performed, the annealing temperature is 80-100℃, and the annealing time is 5-8 min.

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

10. The highly efficient organic solar cell according to claim 1, characterized in that ​

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