A high-efficiency super-flexible organic solar cell with top incident structure

Abstract

The application discloses a kind of high-efficiency super-soft organic solar cell of top incidence structure, it includes flexible substrate, anode, anode modification layer, active layer, cathode modification layer, cathode and antireflection layer from bottom to top, wherein the cathode is based on the transparent electrode of ultrathin silver.Especially by preferred cathode modification layer and introducing not more than 2nm thick gold as seed layer, make ultrathin silver surface more smooth and uniform, the transparent electrode can further improve the photoelectric energy conversion efficiency (PCE) of organic solar cell.Meanwhile, using the wide adaptability of top incidence structure to different substrates, the organic solar cell can also achieve comparable PCE (17.32%) with mm level rigid glass substrate on the polyimide flexible substrate with thickness of only 1.3 μm.Therefore, the highest efficiency of super-soft organic solar cell so far is obtained, and the highest power density (39.72W g ‑1 ) in all photovoltaic technologies at present is also obtained.

Description

Technical Field

[0001] This invention relates to the field of solar cell technology, and more particularly to a high-efficiency, ultra-flexible organic solar cell with a top-incident structure. Background Technology

[0002] Organic solar cells have made groundbreaking progress in recent years. Currently, the highest power conversion efficiency (PCE) of single-junction and tandem organic solar cells has reached 19.6% and 20.1%, respectively, which can basically meet the efficiency requirements of practical applications (Nat. Mater. 2022, 21, 656; Joule 2022, 6, 1-14). Although organic solar cells still lag behind inorganic cells in efficiency, they have many unique advantages, including flexibility, light weight, tunable color, translucency, and low-cost solution processing (Nat. Energy 2021, 6, 1045; Adv. Mater. 2022, 34, 2200044). Therefore, the development of high-performance organic solar cells and the full utilization of their advantages to develop more diverse applications, such as wearable electronic devices, building or vehicle integrated photovoltaics, and biomedical devices, are of great significance to the development of organic solar cells (Nature 2018, 561, 516; Nat. Commun. 2021, 12, 2234).

[0003] However, the transparent electrodes commonly used in current organic solar cells are based on rare elements and the fragile indium tin oxide (ITO), which has become a major bottleneck preventing organic solar cells from fully realizing their flexibility and other unique features. Therefore, researchers have focused on developing various transparent electrode materials to replace ITO, such as metal nanowires (NWs), metal meshes, ultrathin metals, graphene, carbon nanotubes, and conductive polymers. Among these, silver nanowires have received the most research attention due to their high conductivity and good light transmittance (Adv. Mater. 2020, 32, 1908478; Adv. Mater. 2021, 2103017). However, the rough surface of silver nanowire electrodes may puncture the active layer, increasing the probability of short circuits. Furthermore, transparent electrodes based on ultrathin metal films (such as ultrathin silver) have also been extensively explored, exhibiting advantages such as high conductivity and strong light-trapping properties, and providing organic solar cells with superior flexibility and device area scaling capabilities (Adv. Mater. 2022, 34, 2200044). However, the deposition mechanism of ultrathin metal films on substrates generally follows an "island growth" method. Only when a certain thickness (≥10nm) is reached can metal atoms cover the entire substrate and form a complete conductive network. At the same time, the "island growth" method makes the metal particles in the film larger and the surface rougher, increasing the scattering of incident sunlight. Therefore, how to further improve the light transmittance of ultrathin metal films while maintaining their high conductivity has become a major challenge.

[0004] It is worth noting that fabricating organic solar cells on ultrathin flexible substrates (<10 μm) is a very promising development direction for broadening the applications of organic solar cells. This is because such ultrathin organic solar cells (also known as ultra-flexible organic solar cells) can enable devices to exhibit ultra-flexibility and ultra-lightweight characteristics, meeting the needs of different scenarios and even some extreme environments, such as the stringent requirements for high power density of solar cells in the aerospace field (Adv. Mater. 2022, 34, 2106683). However, the energy conversion efficiency of ultra-flexible organic solar cells still lags behind that of traditional rigid glass substrate organic solar cells. A major reason for this is that the tendency of ultrathin substrates to wrinkle severely affects the film quality of transparent electrodes deposited on them. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a high-efficiency ultra-flexible organic solar cell with a top-incident structure. This structure enables the transparent electrode based on ultrathin silver to simultaneously obtain high light transmittance and high conductivity, and keeps the ultrathin silver electrode away from the easily wrinkled ultrathin substrate, so as to achieve an ultra-flexible organic solar cell with high energy conversion efficiency and high power density.

[0006] The high-efficiency ultra-flexible organic solar cell of the present invention comprises, from bottom to top, a flexible substrate, an anode, an anode modification layer, an active layer, a cathode modification layer, a cathode, and an anti-reflection layer, wherein the cathode is a transparent electrode based on ultrathin silver.

[0007] The transparent electrode based on ultrathin silver is a 5-15 nm thick silver layer, and more preferably, it is a double-layer film consisting of a 5-15 nm thick silver layer and a gold layer no more than 2 nm thick underneath.

[0008] Preferably, the cathode modification layer is a 5-15 nm thick PFN-Br, PDINO, or Bis-FIMG, and their chemical structural formulas are (a), (b), and (c) respectively:

[0009]

[0010] Preferably, the active layer is a blend of polymer donor PM6 and non-fullerene acceptor L8-BO, with a thickness of 50-300 nm.

[0011] Preferably, the anode modification layer is a bilayer film consisting of a 10-30 nm thick PEDOT:PSS layer and a 3-8 nm thick PCP-2F-Li layer underneath.

[0012] Preferably, the antireflective layer is a TeO2 layer with a thickness of 20–100 nm;

[0013] Preferably, the anode is gold, silver, or copper with a thickness of 80–150 nm;

[0014] Preferably, the substrate is a 0.5-10 μm thick polyimide (PI), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polydimethylsiloxane (PDMS), polyurethane (TPU), or styrene-ethylene-butene-styrene block copolymer (SEBS).

[0015] The innovation of this invention lies in using a transparent electrode based on ultrathin silver and a top-incidence structure to fabricate an ultra-flexible organic solar cell, thereby bringing the following advantages:

[0016] 1. The advantage of a top-incidence structure is that incident light does not need to penetrate the substrate and is directly absorbed by the active layer. This makes the photovoltaic performance of the device independent of the optical properties of the substrate, thus enriching the choice of substrates. Therefore, different substrates can be selected to prepare different types of organic solar cells to meet the needs of various applications. In particular, in this invention, when a polymer substrate with good flexibility and high mechanical strength is selected to prepare an ultra-flexible organic solar cell, the top-incidence structure keeps the ultrathin silver electrode away from the easily wrinkled and low surface tension ultrathin polymer substrate. The ultrathin silver experiences less internal stress, allowing for the selection of a suitable electrode modification layer to achieve good wetting and ensuring film quality.

[0017] 2. The transparent electrode of this invention has a gold seed layer of about 1 nm under the traditional ultrathin silver electrode. In addition, the silver atoms interact with the cathode modification layer material below the electrode to form Ag-O and Ag-I. These factors induce the film formation mechanism of ultrathin silver to change from "island growth" to "layer by layer growth". Even with a thickness of only 8 nm, the ultrathin silver is still very flat, uniform, continuous and smooth. It improves the light transmittance while maintaining high conductivity, laying the foundation for realizing high-efficiency ultra-flexible organic solar cells.

[0018] Due to the aforementioned advantages, this invention achieves the highest power conversion efficiency (PCE = 17.32%) for ultra-flexible organic solar cells to date, and also the highest power density (39.72 W / g) among all current photovoltaic technologies. -1 ). Attached Figure Description

[0019] Figure 1 Transmittance curves based on transparent electrodes with different Ag thicknesses. The structure of the transparent electrode is glass (1.1 mm) / Bis-FIMG (10 nm) / Ag (9-13 nm).

[0020] Figure 2 Conductivity curves based on transparent electrodes with different Ag thicknesses. The structure of the transparent electrode is glass (1.1 mm) / Bis-FIMG (10 nm) / Ag (9-13 nm).

[0021] Figure 3 Transmittance curves of transparent electrodes with different cathode modification layers are presented. The structure of the transparent electrode is glass (1.1 mm) / cathode modification layer / Ag (9-13 nm).

[0022] Figure 4 Conductivity curves of transparent electrodes based on different cathode modification layers. The structure of the transparent electrode is glass (1.1 mm) / cathode modification layer / Ag (9-13 nm).

[0023] Figure 5 Current-voltage curves of an ultra-flexible organic solar cell fabricated with a top-incident structure under illumination are shown in Figure 1. The ultra-flexible substrate of this cell is a 1.3 μm thick polyimide, the anode is 100 nm Ag, the anode modification layer is 5 nm PCP-2F-Li / 15 nm PEDOT:PSS, the active layer is 90 nm PM6:L8-BO (weight ratio 1:1.2), the cathode modification layer is 10 nm Bis-FIMG, the antireflection layer is 55 nm TeO2, and the cathode of this cell is an ultrathin silver layer of 9-13 nm.

[0024] Figure 6 Current-voltage curves of the ultra-flexible organic solar cell fabricated under illumination under a top-incident structure are shown in Figure 2. The ultra-flexible substrate of this cell is a 1.3 μm thick polyimide, the anode is 100 nm Ag, the anode modification layer is 5 nm PCP-2F-Li / 15 nm PEDOT:PSS, the active layer is 90 nm PM6:L8-BO (weight ratio 1:1.2), the cathode is 9 nm Ag, the antireflection layer is 55 nm TeO2, and the cathode modification layer is 10 nm PFN-Br, PDINO, Bis-FIMG.

[0025] Figure 7 Current-voltage curves of the ultra-flexible organic solar cell fabricated under illumination under a top-incident structure are shown in Figure 3. The ultra-flexible substrate of this cell is a 1.3 μm thick polyimide, the anode is 100 nm Ag, the anode modification layer is 5 nm PCP-2F-Li / 15 nm PEDOT:PSS, the active layer is 90 nm PM6:L8-BO (weight ratio 1:1.2), the cathode modification layer is 10 nm Bis-FIMG, the cathode is 1 nm Au / 8 nm Ag, and the antireflection layer of this cell is 0-65 nm TeO2.

[0026] Figure 8 External quantum efficiency (EQE) spectrum of an ultra-flexible organic solar cell fabricated with a top-incident structure.

[0027] Figure 9 External quantum efficiency (EQE) spectrum of an ultra-flexible organic solar cell fabricated with a top-incident structure.

[0028] Figure 10 External quantum efficiency (EQE) spectrum of an ultra-flexible organic solar cell fabricated with a top-incident structure 3. Detailed Implementation

[0029] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific examples. The following examples are only used to explain the specific implementation of the present invention and do not constitute a limitation on the present invention.

[0030] Figure 1-4 The conductivity and light transmittance of the transparent electrode obtained by preparing the cathode modification layer and cathode structure of the present invention on a glass substrate.

[0031] Example 1

[0032] The glass substrate was treated with an ultraviolet ozone generator for 15 minutes. Then, a fluorinated polymer layer (Novec 1700:7100 = 1:8) was spin-coated onto the glass at 4000 rpm for 30 seconds, followed by thermal annealing at 80°C for 10 minutes. Before spin-coating the polyimide precursor, the glass / fluorinated polymer layer was treated with an ultraviolet ozone generator for 2 minutes. Then, the polyimide precursor was spin-coated onto the substrate at 8000 rpm for 30 seconds, followed by thermal annealing at 250°C for 2 hours to form a 1.3 μm thick polyimide substrate. A 100 nm thick layer of silver was then vacuum-deposited onto the polyimide substrate as the bottom electrode. Finally, a 5 nm thick PCP-2F-Li modification layer was spin-coated onto the bottom silver electrode using a 1 mg / mL PCP-2F-Li methanol solution. Then, a 15 nm thick layer of PEDOT:PSS was spin-coated onto the PCP-2F-Li modified layer at 4500 rpm, followed by annealing at 150 °C for 15 minutes. The wafer was then transferred to a glove box. A mixed solution of 1,8-diiodooctane (DIO) at 0.25% by volume and PM6:L8-BO (weight ratio 1:1.2) at a total concentration of 17.6 mg / mL in chloroform was spin-coated at 3500 rpm for 30 seconds to obtain a 90 nm thick active layer. The active layer was annealed at 80 °C for 5 minutes. Then, a 10 nm thick Bis-FIMG modified layer was spin-coated onto the active layer using a 1 mg / mL Bis-FIMG methanol solution. Next, a 9 nm ultrathin silver layer was vacuum-deposited onto the Bis-FIMG modified layer as a cathode. Finally, a 55 nm thick TeO2 antireflective layer was vacuum-deposited onto the ultrathin silver electrode. After peeling the device from the glass substrate, an effective area of ​​5.2 mm² is obtained. 2 Ultra-flexible organic solar cells.

[0033] 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 0.869V and a short-circuit current density of 24.06mA / cm². 2 The fill factor is 76.75%, and the PCE is 16.01%.

[0034] Figure 5 The device is given under illumination of 100 mW / cm². 2 The external quantum efficiency curve under simulated sunlight illumination in AM1.5.

[0035] Figure 8 The device is given under illumination of 100 mW / cm². 2 The AM1.5 simulated current-voltage curve under sunlight.

[0036] Example 2

[0037] The glass substrate was treated with an ultraviolet ozone generator for 15 minutes. Then, a fluorinated polymer layer (Novec 1700:7100 = 1:8) was spin-coated onto the glass at 4000 rpm for 30 seconds, followed by thermal annealing at 80°C for 10 minutes. Before spin-coating the polyimide precursor, the glass / fluorinated polymer layer was treated with an ultraviolet ozone generator for 2 minutes. Then, the polyimide precursor was spin-coated onto the substrate at 8000 rpm for 30 seconds, followed by thermal annealing at 250°C for 2 hours to form a 1.3 μm thick polyimide substrate. A 100 nm thick layer of silver was then vacuum-deposited onto the polyimide substrate as the bottom electrode. Finally, a 5 nm thick PCP-2F-Li modification layer was spin-coated onto the bottom silver electrode using a 1 mg / mL PCP-2F-Li methanol solution. Then, a 15 nm thick layer of PEDOT:PSS was spin-coated onto the PCP-2F-Li modified layer at 4500 rpm, followed by annealing at 150 °C for 15 minutes. The wafer was then transferred to a glove box. A mixed solution of 1,8-diiodooctane (DIO) at 0.25% by volume and PM6:L8-BO (weight ratio 1:1.2) at a total concentration of 17.6 mg / mL in chloroform was spin-coated at 3500 rpm for 30 seconds to obtain a 90 nm thick active layer. The active layer was annealed at 80 °C for 5 minutes. Then, a 10 nm thick Bis-FIMG modified layer was spin-coated onto the active layer using a 1 mg / mL Bis-FIMG methanol solution. Next, an 11 nm ultrathin silver layer was vacuum-deposited onto the Bis-FIMG modified layer as a cathode. Finally, a 55 nm thick TeO2 antireflective layer was vacuum-deposited onto the ultrathin silver electrode. After peeling the device from the glass substrate, an effective area of ​​5.2 mm² is obtained. 2 Ultra-flexible organic solar cells.

[0038] 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 0.870V and a short-circuit current density of 24.97mA / cm². 2 The fill factor is 78.34%, and the PCE is 17.02%.

[0039] Figure 5 The device is given under illumination of 100 mW / cm². 2 The external quantum efficiency curve under simulated sunlight illumination in AM1.5.

[0040] Figure 8 The device is given under illumination of 100 mW / cm². 2The AM1.5 simulated current-voltage curve under sunlight.

[0041] Example 3

[0042] The glass substrate was treated with an ultraviolet ozone generator for 15 minutes. Then, a fluorinated polymer layer (Novec 1700:7100 = 1:8) was spin-coated onto the glass at 4000 rpm for 30 seconds, followed by thermal annealing at 80°C for 10 minutes. Before spin-coating the polyimide precursor, the glass / fluorinated polymer layer was treated with an ultraviolet ozone generator for 2 minutes. Then, the polyimide precursor was spin-coated onto the substrate at 8000 rpm for 30 seconds, followed by thermal annealing at 250°C for 2 hours to form a 1.3 μm thick polyimide substrate. A 100 nm thick layer of silver was then vacuum-deposited onto the polyimide substrate as the bottom electrode. Finally, a 5 nm thick PCP-2F-Li modification layer was spin-coated onto the bottom silver electrode using a 1 mg / mL PCP-2F-Li methanol solution. Then, a 15 nm thick layer of PEDOT:PSS was spin-coated onto the PCP-2F-Li modified layer at 4500 rpm, followed by annealing at 150 °C for 15 minutes. The wafer was then transferred to a glove box. A mixed solution of 0.25% (v / v) 1,8-diiodooctane (DIO) and 17.6 mg / mL PM6:L8-BO (weight ratio 1:1.2) in chloroform was spin-coated at 3500 rpm for 30 seconds to obtain a 90 nm thick active layer. The active layer was annealed at 80 °C for 5 minutes. Next, a 10 nm thick Bis-FIMG modified layer was spin-coated onto the active layer using a 1 mg / mL Bis-FIMG methanol solution. Then, a 13 nm ultrathin silver layer was vacuum-deposited onto the Bis-FIMG modified layer as a cathode. Finally, a 55 nm thick TeO2 antireflective layer was vacuum-deposited onto the ultrathin silver electrode. After peeling the device from the glass substrate, an effective area of ​​5.2 mm² is obtained. 2 Ultra-flexible organic solar cells.

[0043] 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 0.869V and a short-circuit current density of 24.06mA / cm². 2 The fill factor is 76.75%, and the PCE is 16.01%.

[0044] Figure 5 The device is given under illumination of 100 mW / cm². 2 The external quantum efficiency curve under simulated sunlight illumination in AM1.5.

[0045] Figure 8 The device is given under illumination of 100 mW / cm². 2 The AM1.5 simulated current-voltage curve under sunlight.

[0046] Example 4

[0047] The glass substrate was treated with an ultraviolet ozone generator for 15 minutes. Then, a fluorinated polymer layer (Novec 1700:7100 = 1:8) was spin-coated onto the glass at 4000 rpm for 30 seconds, followed by thermal annealing at 80°C for 10 minutes. Before spin-coating the polyimide precursor, the glass / fluorinated polymer layer was treated with an ultraviolet ozone generator for 2 minutes. Then, the polyimide precursor was spin-coated onto the substrate at 8000 rpm for 30 seconds, followed by thermal annealing at 250°C for 2 hours to form a 1.3 μm thick polyimide substrate. A 100 nm thick layer of silver was then vacuum-deposited onto the polyimide substrate as the bottom electrode. Finally, a 5 nm thick PCP-2F-Li modification layer was spin-coated onto the bottom silver electrode using a 1 mg / mL PCP-2F-Li methanol solution. Then, a 15 nm thick layer of PEDOT:PSS was spin-coated onto the PCP-2F-Li modified layer at 4500 rpm, followed by annealing at 150 °C for 15 minutes. The wafer was then transferred to a glove box. A mixed solution of 1,8-diiodooctane (DIO) at 0.25% by volume and PM6:L8-BO (weight ratio 1:1.2) at a total concentration of 17.6 mg / mL in chloroform was spin-coated at 3500 rpm for 30 seconds to obtain a 90 nm thick active layer. The active layer was annealed at 80 °C for 5 minutes. Then, a 10 nm thick PFN-Br modified layer was spin-coated onto the active layer using a 0.5 mg / mL PFN-Br methanol solution. Next, a 9 nm ultrathin silver layer was vacuum-deposited onto the PFN-Br modified layer as a cathode. Finally, a 55 nm thick TeO2 antireflective layer was vacuum-deposited onto the ultrathin silver electrode. After peeling the device from the glass substrate, an effective area of ​​5.2 mm² is obtained. 2 Ultra-flexible 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 0.767V and a short-circuit current density of 21.03mA / cm². 2 The fill factor is 63.22%, and the PCE is 10.20%.

[0049] Figure 6 The device is given under illumination of 100 mW / cm². 2The external quantum efficiency curve under simulated sunlight illumination in AM1.5.

[0050] Figure 9 The device is given under illumination of 100 mW / cm². 2 The AM1.5 simulated current-voltage curve under sunlight.

[0051] Example 5

[0052] The glass substrate was treated with an ultraviolet ozone generator for 15 minutes. Then, a fluorinated polymer layer (Novec 1700:7100 = 1:8) was spin-coated onto the glass at 4000 rpm for 30 seconds, followed by thermal annealing at 80°C for 10 minutes. Before spin-coating the polyimide precursor, the glass / fluorinated polymer layer was treated with an ultraviolet ozone generator for 2 minutes. Then, the polyimide precursor was spin-coated onto the substrate at 8000 rpm for 30 seconds, followed by thermal annealing at 250°C for 2 hours to form a 1.3 μm thick polyimide substrate. A 100 nm thick layer of silver was then vacuum-deposited onto the polyimide substrate as the bottom electrode. Finally, a 5 nm thick PCP-2F-Li modification layer was spin-coated onto the bottom silver electrode using a 1 mg / mL PCP-2F-Li methanol solution. Then, a 15 nm thick layer of PEDOT:PSS was spin-coated onto the PCP-2F-Li modified layer at 4500 rpm, followed by annealing at 150 °C for 15 minutes. The wafer was then transferred to a glove box. A mixed solution of 0.25% (v / v) 1,8-diiodooctane (DIO) and 17.6 mg / mL PM6:L8-BO (weight ratio 1:1.2) in chloroform was spin-coated at 3500 rpm for 30 seconds to obtain a 90 nm thick active layer. The active layer was annealed at 80 °C for 5 minutes. Next, a 10 nm thick PDINO modified layer was spin-coated onto the active layer using a 1 mg / mL PDINO methanol solution. Then, a 9 nm ultrathin silver layer was vacuum-deposited onto the PDINO modified layer as a cathode. Finally, a 55 nm thick TeO2 antireflective layer was vacuum-deposited onto the ultrathin silver electrode. After peeling the device from the glass substrate, an effective area of ​​5.2 mm² is obtained. 2 Ultra-flexible organic solar cells.

[0053] 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 0.795V and a short-circuit current density of 23.91mA / cm². 2 The fill factor is 59.19%, and the PCE is 11.28%.

[0054] Figure 6The device is given under illumination of 100 mW / cm². 2 The external quantum efficiency curve under simulated sunlight illumination in AM1.5.

[0055] Figure 9 The device is given under illumination of 100 mW / cm². 2 The AM1.5 simulated current-voltage curve under sunlight.

[0056] Example 6

[0057] The glass substrate was treated with an ultraviolet ozone generator for 15 minutes. Then, a fluorinated polymer layer (Novec 1700:7100 = 1:8) was spin-coated onto the glass at 4000 rpm for 30 seconds, followed by thermal annealing at 80°C for 10 minutes. Before spin-coating the polyimide precursor, the glass / fluorinated polymer layer was treated with an ultraviolet ozone generator for 2 minutes. Then, the polyimide precursor was spin-coated onto the substrate at 8000 rpm for 30 seconds, followed by thermal annealing at 250°C for 2 hours to form a 1.3 μm thick polyimide substrate. A 100 nm thick layer of silver was then vacuum-deposited onto the polyimide substrate as the bottom electrode. Finally, a 5 nm thick PCP-2F-Li modification layer was spin-coated onto the bottom silver electrode using a 1 mg / mL PCP-2F-Li methanol solution. Then, a 15 nm thick layer of PEDOT:PSS was spin-coated onto the PCP-2F-Li modified layer at 4500 rpm, followed by annealing at 150 °C for 15 minutes. The wafer was then transferred to a glove box. A mixed solution of 1,8-diiodooctane (DIO) at 0.25% by volume and PM6:L8-BO (weight ratio 1:1.2) at a total concentration of 17.6 mg / mL in chloroform was spin-coated at 3500 rpm for 30 seconds to obtain a 90 nm thick active layer. The active layer was annealed at 80 °C for 5 minutes. Next, a 10 nm thick Bis-FIMG modified layer was spin-coated onto the active layer using a 1 mg / mL Bis-FIMG methanol solution. Then, a 1 nm Au / 8 nm Ag composite ultrathin metal layer was vacuum-deposited onto the Bis-FIMG modified layer as a cathode. Finally, a 55 nm thick TeO2 antireflective layer was vacuum-deposited onto the ultrathin silver electrode. After peeling the device from the glass substrate, an effective area of ​​5.2 mm² is obtained. 2 Ultra-flexible organic solar cells.

[0058] 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 0.869V and a short-circuit current density of 25.54mA / cm². 2The fill factor is 78.04%, and the PCE is 17.32%.

[0059] Furthermore, the power-to-weight ratio of this device is 39.72 g W. -1 .

[0060] Figure 6 The device is given under illumination of 100 mW / cm². 2 The external quantum efficiency curve under simulated sunlight illumination in AM1.5.

[0061] Figure 9 The device is given under illumination of 100 mW / cm². 2 The AM1.5 simulated current-voltage curve under sunlight.

[0062] Example 7

[0063] The glass substrate was treated with an ultraviolet ozone generator for 15 minutes. Then, a fluorinated polymer layer (Novec 1700:7100 = 1:8) was spin-coated onto the glass at 4000 rpm for 30 seconds, followed by thermal annealing at 80°C for 10 minutes. Before spin-coating the polyimide precursor, the glass / fluorinated polymer layer was treated with an ultraviolet ozone generator for 2 minutes. Then, the polyimide precursor was spin-coated onto the substrate at 8000 rpm for 30 seconds, followed by thermal annealing at 250°C for 2 hours to form a 1.3 μm thick polyimide substrate. A 100 nm thick layer of silver was then vacuum-deposited onto the polyimide substrate as the bottom electrode. Finally, a 5 nm thick PCP-2F-Li modification layer was spin-coated onto the bottom silver electrode using a 1 mg / mL PCP-2F-Li methanol solution. Then, a 15 nm thick layer of PEDOT:PSS was spin-coated onto the PCP-2F-Li modified layer at 4500 rpm, followed by annealing at 150 °C for 15 minutes. The wafer was then transferred to a glove box. A mixed solution of 0.25% (v / v) 1,8-diiodooctane (DIO) and 17.6 mg / mL PM6:L8-BO (weight ratio 1:1.2) in chloroform was spin-coated at 3500 rpm for 30 seconds to obtain a 90 nm thick active layer. The active layer was annealed at 80 °C for 5 minutes. Then, a 10 nm thick Bis-FIMG modified layer was spin-coated onto the active layer using a 1 mg / mL Bis-FIMG methanol solution. Finally, a 1 nm Au / 8 nm Ag composite ultrathin metal layer was vacuum-deposited onto the Bis-FIMG modified layer as a cathode. After peeling the device from the glass substrate, an effective area of ​​5.2 mm² was obtained. 2 Ultra-flexible organic solar cells.

[0064] At a light intensity of 100mW / cm2 Under AM1.5 simulated sunlight irradiation, the current-voltage curve of the device was tested, yielding an open-circuit voltage of 0.866V and a short-circuit current density of 16.78mA / cm². 2 The fill factor is 77.49%, and the PCE is 11.51%.

[0065] Figure 7 The device is given under illumination of 100 mW / cm². 2 The external quantum efficiency curve under simulated sunlight illumination in AM1.5.

[0066] Figure 10 The device is given under illumination of 100 mW / cm². 2 The AM1.5 simulated current-voltage curve under sunlight.

[0067] Example 8

[0068] The glass substrate was treated with an ultraviolet ozone generator for 15 minutes. Then, a fluorinated polymer layer (Novec 1700:7100 = 1:8) was spin-coated onto the glass at 4000 rpm for 30 seconds, followed by thermal annealing at 80°C for 10 minutes. Before spin-coating the polyimide precursor, the glass / fluorinated polymer layer was treated with an ultraviolet ozone generator for 2 minutes. Then, the polyimide precursor was spin-coated onto the substrate at 8000 rpm for 30 seconds, followed by thermal annealing at 250°C for 2 hours to form a 1.3 μm thick polyimide substrate. A 100 nm thick layer of silver was then vacuum-deposited onto the polyimide substrate as the bottom electrode. Finally, a 5 nm thick PCP-2F-Li modification layer was spin-coated onto the bottom silver electrode using a 1 mg / mL PCP-2F-Li methanol solution. Then, a 15 nm thick layer of PEDOT:PSS was spin-coated onto the PCP-2F-Li modified layer at 4500 rpm, followed by annealing at 150 °C for 15 minutes. The wafer was then transferred to a glove box. A mixed solution of 0.25% (v / v) 1,8-diiodooctane (DIO) and 17.6 mg / mL PM6:L8-BO (weight ratio 1:1.2) in chloroform was spin-coated at 3500 rpm for 30 seconds to obtain a 90 nm thick active layer. The active layer was annealed at 80 °C for 5 minutes. Next, a 10 nm thick Bis-FIMG modified layer was spin-coated onto the active layer using a 1 mg / mL Bis-FIMG methanol solution. Then, a 1 nm Au / 8 nm Ag composite ultrathin metal layer was vacuum-deposited onto the Bis-FIMG modified layer as a cathode. Finally, a 35 nm thick TeO2 antireflective layer was vacuum-deposited onto the ultrathin silver electrode. After peeling the device from the glass substrate, an effective area of ​​5.2 mm² is obtained. 2Ultra-flexible organic solar cells.

[0069] 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 0.866V and a short-circuit current density of 24.18mA / cm². 2 The fill factor is 77.65%, and the PCE is 16.24%.

[0070] Figure 7 The device is given under illumination of 100 mW / cm². 2 The external quantum efficiency curve under simulated sunlight illumination in AM1.5.

[0071] Figure 10 The device is given under illumination of 100 mW / cm². 2 The AM1.5 simulated current-voltage curve under sunlight.

[0072] Example 9

[0073] The glass substrate was treated with an ultraviolet ozone generator for 15 minutes. Then, a fluorinated polymer layer (Novec 1700:7100 = 1:8) was spin-coated onto the glass at 4000 rpm for 30 seconds, followed by thermal annealing at 80°C for 10 minutes. Before spin-coating the polyimide precursor, the glass / fluorinated polymer layer was treated with an ultraviolet ozone generator for 2 minutes. Then, the polyimide precursor was spin-coated onto the substrate at 8000 rpm for 30 seconds, followed by thermal annealing at 250°C for 2 hours to form a 1.3 μm thick polyimide substrate. A 100 nm thick layer of silver was then vacuum-deposited onto the polyimide substrate as the bottom electrode. Finally, a 5 nm thick PCP-2F-Li modification layer was spin-coated onto the bottom silver electrode using a 1 mg / mL PCP-2F-Li methanol solution. Then, a 15 nm thick layer of PEDOT:PSS was spin-coated onto the PCP-2F-Li modified layer at 4500 rpm, followed by annealing at 150 °C for 15 minutes. The wafer was then transferred to a glove box. A mixed solution of 1,8-diiodooctane (DIO) at 0.25% by volume and PM6:L8-BO (weight ratio 1:1.2) at a total concentration of 17.6 mg / mL in chloroform was spin-coated at 3500 rpm for 30 seconds to obtain a 90 nm thick active layer. The active layer was annealed at 80 °C for 5 minutes. Next, a 10 nm thick Bis-FIMG modified layer was spin-coated onto the active layer using a 1 mg / mL Bis-FIMG methanol solution. Then, a 1 nm Au / 8 nm Ag composite ultrathin metal layer was vacuum-deposited onto the Bis-FIMG modified layer as a cathode. Finally, a 45 nm TeO2 antireflective layer was vacuum-deposited onto the ultrathin silver electrode. After peeling the device from the glass substrate, an effective area of ​​5.2 mm² is obtained. 2 Ultra-flexible organic solar cells.

[0074] 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 0.870V and a short-circuit current density of 24.50mA / cm². 2 The fill factor is 78.57%, and the PCE is 16.73%.

[0075] Figure 6 The device is given under illumination of 100 mW / cm². 2 The external quantum efficiency curve under simulated sunlight illumination in AM1.5.

[0076] Figure 9 The device is given under illumination of 100 mW / cm². 2 The AM1.5 simulated current-voltage curve under sunlight.

[0077] Example 10

[0078] The glass substrate was treated with an ultraviolet ozone generator for 15 minutes. Then, a fluorinated polymer layer (Novec 1700:7100 = 1:8) was spin-coated onto the glass at 4000 rpm for 30 seconds, followed by thermal annealing at 80°C for 10 minutes. Before spin-coating the polyimide precursor, the glass / fluorinated polymer layer was treated with an ultraviolet ozone generator for 2 minutes. Then, the polyimide precursor was spin-coated onto the substrate at 8000 rpm for 30 seconds, followed by thermal annealing at 250°C for 2 hours to form a 1.3 μm thick polyimide substrate. A 100 nm thick layer of silver was then vacuum-deposited onto the polyimide substrate as the bottom electrode. Finally, a 5 nm thick PCP-2F-Li modification layer was spin-coated onto the bottom silver electrode using a 1 mg / mL PCP-2F-Li methanol solution. Then, a 15 nm thick layer of PEDOT:PSS was spin-coated onto the PCP-2F-Li modified layer at 4500 rpm, followed by annealing at 150 °C for 15 minutes. The wafer was then transferred to a glove box. A mixed solution of 1,8-diiodooctane (DIO) at 0.25% by volume and PM6:L8-BO (weight ratio 1:1.2) at a total concentration of 17.6 mg / mL in chloroform was spin-coated at 3500 rpm for 30 seconds to obtain a 90 nm thick active layer. The active layer was annealed at 80 °C for 5 minutes. Then, a 10 nm thick Bis-FIMG modified layer was spin-coated onto the active layer using a 1 mg / mL Bis-FIMG methanol solution. Next, a 1 nm Au / 8 nm Ag composite ultrathin metal layer was vacuum-deposited onto the Bis-FIMG modified layer as a cathode. Finally, a 65 nm thick TeO2 antireflective layer was vacuum-deposited onto the ultrathin silver electrode. After peeling the device from the glass substrate, an effective area of ​​5.2 mm² is obtained. 2 Ultra-flexible organic solar cells.

[0079] 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 0.870V and a short-circuit current density of 24.65mA / cm². 2 The fill factor is 78.15%, and the PCE is 16.76%.

[0080] Figure 7 The device is given under illumination of 100 mW / cm². 2 The external quantum efficiency curve under simulated sunlight illumination in AM1.5.

[0081] Figure 10The device is given under illumination of 100 mW / cm². 2 The AM1.5 simulated current-voltage curve under sunlight.

[0082] Refer to Example 1

[0083] The glass / ITO substrate was treated with an ultraviolet ozone generator for 15 minutes. Then, a 15 nm thick layer of PEDOT:PSS was spin-coated onto the glass / ITO substrate at 4500 rpm, followed by annealing at 150°C for 15 minutes. The substrate was then transferred to a glove box. A mixed solution of 0.25% (v / v) 1,8-diiodooctane (DIO) and PM6:L8-BO (weight ratio 1:1.2) in chloroform was spin-coated at 3500 rpm for 30 seconds to obtain a 90 nm thick active layer. The active layer was annealed at 80°C for 5 minutes. Then, a 10 nm thick Bis-FIMG modification layer was spin-coated onto the active layer using a 1 mg / mL Bis-FIMG methanol solution. Finally, a 100 nm thick Ag layer was vacuum-deposited onto the Bis-FIMG modification layer as the cathode, resulting in a rigid organic solar cell based on ITO as the transparent electrode. During testing, a metal mask was used to calibrate the device area, which was 4.73 mm². 2 .

[0084] 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 0.882V and a short-circuit current density of 26.39mA / cm². 2 The fill factor is 80.14%, and the PCE is 18.66%.

[0085] By comparing Example 6 and Reference Example 1, the power conversion efficiency (PCE = 17.32%) of the ultra-flexible organic solar cell based on the top-incidence structure of this invention is not much different from that of the rigid ITO organic solar cell.

Claims

1. A high-efficiency, ultra-flexible organic solar cell with a top-incident structure, comprising, from bottom to top, a flexible substrate, an anode, an anode modification layer, an active layer, a cathode modification layer, a cathode, and an anti-reflection layer, characterized in that, The cathode is a transparent electrode based on ultrathin silver; The ultrathin silver-based transparent electrode is a double-layer film consisting of silver with a thickness of 5-15 nm and gold with a thickness of no more than 2 nm underneath. The cathode modification layer is 5–15 nm thick PFN-Br, PDINO, or Bis-FIMG, and their chemical structural formulas are as follows: 。 2. The high-efficiency ultra-flexible organic solar cell with a top-incident structure according to claim 1, characterized in that, The active layer is a blend of polymer donor PM6 and non-fullerene acceptor L8-BO with a thickness of 50–300 nm.

3. The high-efficiency ultra-flexible organic solar cell with a top-incident structure according to claim 1, characterized in that, The anode modification layer is a bilayer film consisting of a 10-30 nm thick PEDOT:PSS layer and a 3-8 nm thick PCP-2F-Li layer underneath.

4. The high-efficiency ultra-flexible organic solar cell with a top-incident structure according to claim 1, characterized in that, The antireflective layer is a 20–100 nm thick TeO layer. 2。 5. A high-efficiency ultra-flexible organic solar cell with a top-incidence structure according to claim 1, characterized in that, The anode is gold, silver or copper with a thickness of 80 to 150 nm.

6. A high-efficiency ultra-flexible organic solar cell with a top-incident structure according to claim 1, characterized in that, The substrate is 0.5 to 10 µm thick and consists of polyimide (PI), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polydimethylsiloxane (PDMS), polyurethane (TPU), or styrene-ethylene-butene-styrene block copolymer (SEBS).

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