A semi-transparent organic photovoltaic cell

Abstract

The utility model relates to a kind of translucent organic photovoltaic cells, include by sequentially layering from bottom to top substrate, transparent cathode layer, cathode buffer layer, photoactive layer, anode buffer layer, metal seed layer and transparent anode layer, the anode buffer layer and metal seed layer thickness in battery structure are adjusted to realize excellent photoelectric conversion efficiency and average visible light transmittance.

Description

Technical Field

[0001] This utility model relates to the field of organic photovoltaic devices, and in particular to a semi-transparent organic photovoltaic cell. Background Technology

[0002] Compared to traditional solar cell types such as silicon, cadmium telluride, and gallium arsenide, organic photovoltaic cells have attracted widespread attention and research due to their numerous unique characteristics, including light weight, flexibility, solution-processability, and easily adjustable active layer material structure. In recent years, with the iteration of non-fullerene acceptor materials, the performance of organic photovoltaic cells has rapidly improved. Opaque devices, represented by Y-series acceptors, have achieved efficiencies exceeding 20%, demonstrating remarkable progress.

[0003] Compared to opaque organic photovoltaic (OPV) cells, semi-transparent organic photovoltaic (ST-OPV) cells combine multiple functions such as power generation and light transmission, demonstrating enormous application potential in building-integrated photovoltaics (BIPV), automotive photovoltaics, photovoltaic agriculture, and wearable electronic devices. Currently, based on new materials, multi-component formulations, additive strategies, and novel processing techniques, the photoelectric conversion efficiency of ST-OPV cells has been significantly improved. However, semi-transparent devices still face the challenge of a trade-off between photoelectric conversion efficiency (PCE) and average visible light transmittance (AVT). Visible light must either be absorbed and converted into electrical energy or pass through the device to maintain transmittance. Furthermore, there are photon losses due to reflection and parasitic absorption, making it very difficult to achieve high overall device performance.

[0004] The design of the transparent top electrode in semi-transparent organic photovoltaic (ST-OPV) cells can significantly affect the transmittance and photoelectric conversion efficiency. Ultrathin metal electrode layers (such as ultrathin Ag layers) are widely studied and the most commonly used transparent top electrodes. Among them, vapor-deposited Ag electrodes are employed in many ST-OPV projects due to their extremely low resistivity, high transmittance, and a degree of flexibility. However, while thinner Ag thickness is beneficial for improving device transmittance, it also introduces greater sheet resistance. Furthermore, the thickness of ultrathin Ag electrodes cannot be reduced indefinitely. When the Ag film thickness is reduced to below 10 nm, its sheet resistance may increase significantly due to morphological discontinuities, and its transmittance will not increase indefinitely due to scattering and other factors. This severely limits the development of ST-OPVs for high-transmittance (>30% AVT) applications. In addition, the efficiency and stability of its batteries also face the problem of rapid degradation. The efficiency degradation is mainly due to the phase separation change of the active layer morphology from metastable to steady state and the degradation behavior of the electrode. Therefore, the efficiency degradation of semi-transparent batteries that only adopt the ultra-thin metal electrode layer strategy is faster, which is a key bottleneck hindering their development and application.

[0005] Compared to traditional vapor-deposited metal electrodes, indium tin oxide (ITO) is a high-performance transparent electrode that maintains good transmittance while keeping the sheet resistance low. This helps to overcome the low transmittance limitation of traditional metal electrode devices and realize high-performance semi-transparent organic photovoltaic devices. Therefore, developing new top electrode structures represented by ITO is of great significance for the development of stable and efficient semi-transparent organic photovoltaic cells. Summary of the Invention

[0006] The purpose of this application is to provide a novel device structure for a semi-transparent organic photovoltaic cell, which can improve the photoelectric conversion efficiency and light transmittance of the semi-transparent organic photovoltaic cell.

[0007] To achieve the objectives of this application, the technical solution is as follows:

[0008] A semi-transparent organic photovoltaic cell comprises, from bottom to top, a substrate, a transparent cathode layer, a cathode buffer layer, a photoactive layer, an anode buffer layer, a metal seed layer, and a transparent anode layer; wherein the thickness of the anode buffer layer is selected from 20-40 nm; and the thickness of the metal seed layer is selected from 1-5 nm.

[0009] Furthermore, the thickness of the anode buffer layer is selected from 25-35 nm.

[0010] Specifically, the thickness of the anode buffer layer can be selected from 25nm, 30nm or 35nm.

[0011] Furthermore, the thickness of the metal seed layer is selected from 1-2 nm.

[0012] In one embodiment, the metal seed layer material is selected from silver (Ag), aluminum (Al), gold (Au), bismuth (Bi), or an alloy of the above metals.

[0013] Furthermore, the material of the metal seed layer is selected from aluminum (Al) or gold (Au).

[0014] In one specific embodiment, the metal seed layer material is selected as aluminum (Al).

[0015] In one embodiment, the anode buffer layer material is selected from molybdenum trioxide (MoO3).

[0016] In one embodiment, the anode buffer layer material is selected from molybdenum trioxide (MoO3); the metal seed layer material is selected from aluminum (Al).

[0017] Furthermore, the anode buffer layer material is selected from molybdenum trioxide (MoO3) with a thickness of 25-35 nm.

[0018] Furthermore, the metal seed layer material is selected from aluminum (Al), and the thickness is 1-2 nm.

[0019] In one embodiment, the thickness of the transparent anode layer is selected from 90-160 nm. Preferably, the thickness of the transparent anode layer is selected from 120-140 nm.

[0020] In one embodiment, the transparent anode layer is selected from conductive metal oxides.

[0021] Furthermore, the transparent anode layer material is selected from indium oxide, zinc oxide, tin oxide, indium tin oxide (ITO), fluorine-doped tin oxide (FTO), gallium-doped zinc oxide (GZO), aluminum-doped zinc oxide (AZO), indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), ITO / Ag / ITO, or ITO / Cu / ITO, etc.

[0022] In one specific embodiment, the transparent anode layer material is selected as indium tin oxide (ITO).

[0023] The advantages of selecting the transparent anode layer of the present invention from conductive metal oxide layers are: 1. It has good light transmittance and high conductivity; 2. It has good chemical stability, a matching band structure, and a mature mass production process.

[0024] In one embodiment, the substrate is selected from a light-transmitting substrate. Further, the substrate is selected from light-transmitting plastic or light-transmitting glass.

[0025] In one embodiment, the substrate is selected from transparent glass.

[0026] In another embodiment, the substrate is selected from translucent plastic.

[0027] The transparent plastic may include, but is not limited to, single-layer or multi-layer films such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyetheretherketone (PEEK), and polyimide (PI).

[0028] The selection of the substrate is based on the actual application requirements of organic photovoltaic cells. For example, flexible semi-transparent organic photovoltaic cell substrates are selected from light-transmitting plastics; rigid semi-transparent organic photovoltaic cell substrates are selected from light-transmitting glass.

[0029] In one embodiment, the transparent cathode layer is selected from conductive metal oxides.

[0030] Furthermore, the transparent cathode layer material is selected from indium oxide, zinc oxide, tin oxide, indium tin oxide (ITO), fluorine-doped tin oxide (FTO), gallium-doped zinc oxide (GZO), aluminum-doped zinc oxide (AZO), indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), ITO / Ag / ITO, or ITO / Cu / ITO, etc.

[0031] In one specific embodiment, the transparent cathode layer material is selected as indium tin oxide (ITO).

[0032] Furthermore, the thickness of the cathode buffer layer is preferably 1-200 nm; more preferably 10-40 nm.

[0033] In one embodiment, the cathode buffer layer can efficiently transfer electrons to the cathode, and its material can be a low work function metal oxide, fullerene derivative, polymer, or a composite thereof, such as titanium oxide (TiO2). x The cathode buffer layer material is selected from zinc oxide (ZnO), tin oxide (SnO2), polyethoxyethyleneimine (PEIE), polyetherimide (PEI), PFN, PFN-Br, PDINN, PDINO, PNDIT-F3N-Br, PNDIT-F3N, and ZnO-PEIE composites, PEI-Zn, PEI-Sn, ZnO-PEI composites, etc., but is not limited thereto. Preferably, the cathode buffer layer material is selected from zinc oxide (ZnO), tin oxide (SnO2), PEI-Zn, PEI-Sn, etc., but is not limited thereto.

[0034] The cathode buffer layer can be prepared by dissolving a photoactive material in an organic solvent and then coating the resulting solution by methods such as spin coating, dip coating, screen printing, gravure printing, spraying, doctor blade coating, slot coating, and inkjet printing, but is not limited thereto.

[0035] The thickness of the photoactive layer is preferably 50-500 nm; more preferably 100-200 nm. The photoactive layer comprises a photoactive layer donor material and a photoactive layer acceptor material.

[0036] In one embodiment, the photoactive layer donor material is selected from polymer donor materials. The polymer donor material may be selected from polythiophene material systems, such as P3AT, P3HT, P3OT, P3DDT, etc.; fluorene-containing polymer material systems, such as PF8BT, etc.; novel structural narrow bandgap polymer material systems, such as benzodithiophene (BDT), benzothiadiazoles (BT, BBT), quinoxalines (QU, PQ), pyrazines (TP, PQ), and copolymers with electron-rich groups (such as thiophene derivatives), such as PM6, PM7, PBDB-T, D18, D18-Cl, PTQ10, PTQ11, PBQx-TCl, PBQx-TF, PB2, PCE10, etc., but is not limited to these.

[0037] In one embodiment, the photoactive layer acceptor material is selected from one or more of the following: ITIC-based acceptor materials, including but not limited to: ITIC, ITIC-4F, ITIC-4Cl, ITIC-2F, ITIC-M, ITCC, ITCC-Cl, etc.; Y-type acceptor materials, including but not limited to: Y6, L8-BO, BTP-eC9, N3, N4, Y6-O, HDO-4Cl, BTP-H2, PY-IT, Z8, etc.; FCC-type acceptor materials, including but not limited to: FCC-Cl, FTCC-Br, etc.; and fullerene-based acceptor materials, including but not limited to: PC61BM ([6,6]-phenyl C61 butyrate methyl ester), PC71BM ([6,6]-phenyl C71 butyrate methyl ester), indene-containing fullerene, etc.

[0038] In one embodiment, the mass ratio of the photoactive layer donor material to the photoactive layer acceptor material in the photoactive layer is selected from 0.6:1.5-1.5:0.6; further, it is selected from 0.7:1.2-1:1.2; and even further, it is selected from 0.7:1.2.

[0039] The photoactive layer can be prepared by dissolving the photoactive material in an organic solvent and then coating the resulting solution by methods such as spin coating, dip coating, screen printing, gravure printing, spraying, doctor blade coating, slot coating, and inkjet printing, but not limited thereto.

[0040] Furthermore, the semi-transparent organic photovoltaic cell according to this utility model also includes an encapsulation layer, which comprises a sealant layer and a top cover plate. The top cover plate is located above the transparent anode layer, and the sealant layer is located above the substrate and adheres to the edges of the transparent cathode layer, cathode buffer layer, photoactive layer, anode buffer layer, metal seed layer, and transparent anode layer. The substrate, sealant layer, and top cover plate form a sealed space, encapsulating the edges of the semi-transparent organic photovoltaic cell. Alternatively, the sealant layer is located above the substrate and covers the edges of the transparent cathode layer, cathode buffer layer, photoactive layer, anode buffer layer, metal seed layer, and transparent anode layer, as well as the upper part of the transparent anode layer. The top cover plate is located above the sealant layer, and the substrate, sealant layer, and top cover plate form a full-surface encapsulation of the semi-transparent organic photovoltaic cell.

[0041] In one embodiment, the sealant layer material may be selected from sealant or a sealant film.

[0042] In one specific embodiment, the sealant material is selected from silicone, butyl rubber, epoxy resin, acrylic resin, UV-curable adhesive, or AB component adhesive, but is not limited thereto.

[0043] The top cover can be made of materials with excellent transparency, smooth surface, ease of operation, and water resistance. Specifically, it can be encapsulated in glass or in a flexible manner, such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyetheretherketone (PEEK), polyimide (PI), polyacrylate (PA), polycarbonate (PC), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), and thermoplastic polyurethane (TPU), but is not limited to these.

[0044] In one embodiment, the semi-transparent organic photovoltaic cell according to the present invention comprises, from bottom to top, a substrate, an ITO layer, an anode buffer layer, a photoactive layer, a MoO3 layer, an Al layer, and an ITO layer. Preferably, the MoO3 layer is selected from 25-35 nm; the Al layer is selected from 1-2 nm.

[0045] The semi-transparent organic photovoltaic cell according to this utility model includes one or more organic photovoltaic cell units. When the semi-transparent organic photovoltaic cell device includes multiple organic photovoltaic cell units, the multiple organic photovoltaic cell units are connected in series or in parallel.

[0046] In one specific embodiment, the semi-transparent organic photovoltaic cell comprises 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or more organic photovoltaic cell units. The specific number of organic photovoltaic units is selected according to the actual application requirements.

[0047] The semi-transparent organic photovoltaic cells described in this application can be applied to wearable devices, smart IoT, smart homes, smart agriculture, building photovoltaics, vehicle photovoltaics, and other fields.

[0048] Compared with the prior art, the significant advantages of this utility model are:

[0049] The semi-transparent organic photovoltaic cell described in this application achieves excellent photoelectric conversion efficiency and average visible light transmittance by adjusting the thickness of the anode buffer layer and the metal seed layer in the cell structure. This is because the large thickness of the metal layer in traditional semi-transparent organic photovoltaic cells results in low transmittance. This application creatively increases the thickness of the anode buffer layer while reducing the thickness of the metal seed layer. On the one hand, this effectively solves the problem of damage to the photoactive layer during anode sputtering, thereby improving the photoelectric conversion efficiency of the cell. On the other hand, it also greatly increases the transmittance of the cell, thus enabling the device to achieve high light utilization efficiency. Attached Figure Description

[0050] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0051] Figure 1 This is a schematic diagram of the semi-transparent organic photovoltaic cell structure of this application.

[0052] Figure 2 These are the JV curves of device embodiments 1-5 and device comparative embodiment 1 of this application.

[0053] Figure 3 These are transmittance curves of device embodiments 1-5 and device comparative embodiment 1 of this application.

[0054] Figure 4 These are the JV curves of device embodiments 3 and 6-7 and device comparative embodiments 2-3 of this application.

[0055] Figure 5 These are transmittance curves for device embodiments 3 and 6-7 and device comparative embodiments 2-3 of this application.

[0056] Figure 6 These are the JV curves of device embodiment 3 and device comparative embodiments 1, 3, and 4 of this application.

[0057] Figure 7 This is a transmittance curve of device embodiment 3 and device comparative embodiments 1, 3 and 4 of this application.

[0058] Figure 8 This is a schematic diagram of the structure of a semi-transparent organic photovoltaic cell with an encapsulation layer as described in this application.

[0059] Figure 9 This is a schematic diagram of another semi-transparent organic photovoltaic cell structure with an encapsulation layer according to this application.

[0060] Among them, 101 is the substrate, 102 is the transparent cathode layer, 103 is the cathode buffer layer, 104 is the photoactive layer, 105 is the anode buffer layer, 106 is the metal seed layer, 107 is the transparent anode layer, 108 is the sealant layer, and 109 is the top cover plate. Detailed Implementation

[0061] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0062] It should be noted that all directional indications (such as up, down, left, right, front, back, inside, outside, etc.) in the embodiments of this application are only used to explain the relative positional relationship between the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0063] In this application, the functionality of the semi-transparent organic photovoltaic cell can be achieved by combining the various layers described above, or by omitting some layers entirely, and may also include other layers not explicitly described. Within each layer, optimal performance can be achieved using a single material or a mixture of multiple materials.

[0064] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0065] Fabrication of semi-transparent organic photovoltaic cell devices

[0066] Device Example 1:

[0067] like Figure 1 As shown, the semi-transparent organic photovoltaic cell structure is as follows: substrate 101 / cathode 102 / cathode buffer layer 103 / photoactive layer 104 / anode buffer layer 105 / metal seed layer 106 / anode 107. Device area: 0.0477 cm². 2 .

[0068] The preparation method includes the following steps:

[0069] 1) Cleaning of ITO conductive glass (an ITO layer has been prepared on the substrate glass)

[0070] Clean the ITO conductive glass with detergent, rinse it thoroughly, and then ultrasonically clean it for 15 minutes with deionized water, acetone, and isopropanol. After that, dry it with nitrogen and treat it in a plasma cleaner for 5 minutes to further clean the surface and improve wettability.

[0071] 2) Preparation of cathode buffer layer

[0072] The PEI-Zn solution was uniformly spin-coated onto the ITO layer in air at a speed of 3500 rpm for 30 s, and then dried at 155 °C for 10 min to obtain a cathode buffer layer with a thickness of about 30 nm.

[0073] 3) Preparation of photoactive layer

[0074] In a glove box (inert gas atmosphere), the solvent for the photoactive layer material was uniformly spin-coated onto the cathode buffer layer at a rotation speed of 1800-4000 rpm to obtain a photoactive layer with a total thickness of approximately 110 nm. The device with the prepared photoactive layer was then placed on an 80°C hot stage for thermal annealing for 5 min.

[0075] The active layer material is prepared by dissolving the donor material and the acceptor material in chloroform to a total concentration of 14.25 mg / mL. The donor material is selected from PM6, and the acceptor material is selected from L8-BO. ​​The mass ratio of the donor material PM6 to the acceptor material L8-BO is 0.7:1.2.

[0076] 4) Preparation of the anode buffer layer

[0077] In high vacuum (1×10) -6 MoO3 was deposited onto the photoactive layer in millibars at a deposition rate of 0.4 Å / s to form an anode buffer layer with a thickness of approximately 20 nm.

[0078] 5) Preparation of metal seed layer 106

[0079] In high vacuum (1×10) -6 Al was deposited onto the anode buffer layer in millibars at a deposition rate of 0.2 Å / s, forming an ultrathin metallic Al layer, i.e., a metal seed layer 106, with a thickness of about 2 nm.

[0080] 6) Anode layer preparation

[0081] In an atmosphere of argon:oxygen = 95:5, under a vacuum (1×10⁻⁶), -3 ITO thin films were prepared by magnetron sputtering with a DC power supply under conditions of 0.2 kW deposition power and 1.6 Å / s sputtering rate. Before depositing the ITO film, the target was pre-sputtered for 5 min to remove any potential impurities. The ITO film deposited on the metal seed layer 106 had a thickness of approximately 120 nm, which constituted the anode layer. After sputtering the top electrode, the device was thermally annealed at 80 °C for 10 min in an inert gas atmosphere glove box.

[0082] 7) Packaging

[0083] The device is encapsulated in a nitrogen glove box using UV-cured resin.

[0084] Device Example 2:

[0085] The fabrication method of device embodiment 2 is the same as that of device embodiment 1, the difference being that the thickness of the anode buffer layer 105 is different, as detailed below:

[0086] In high vacuum (1×10) -6 MoO3 was deposited onto the photoactive layer in millibars at a deposition rate of 0.4 Å / s to form an anode buffer layer 105 with a thickness of approximately 25 nm.

[0087] Device Example 3:

[0088] The fabrication method of device embodiment 3 is the same as that of device embodiment 1, the difference being that the thickness of the anode buffer layer 105 is different, as detailed below:

[0089] In high vacuum (1×10) -6 MoO3 was deposited onto the photoactive layer in millibars at a deposition rate of 0.4 Å / s to form an anode buffer layer with a thickness of approximately 30 nm.

[0090] Device Example 4:

[0091] The fabrication method of device embodiment 4 is the same as that of device embodiment 1, the difference being that the thickness of the anode buffer layer 105 is different, as detailed below:

[0092] In high vacuum (1×10) -6 MoO3 was deposited onto the photoactive layer in millibars at a deposition rate of 0.4 Å / s to form an anode buffer layer with a thickness of approximately 35 nm.

[0093] Device Example 5:

[0094] The fabrication method of device embodiment 5 is the same as that of device embodiment 1, the difference being that the thickness of the anode buffer layer 105 is different, as detailed below:

[0095] In high vacuum (1×10) -6 MoO3 was deposited onto the photoactive layer in millibars at a deposition rate of 0.4 Å / s to form an anode buffer layer with a thickness of approximately 40 nm.

[0096] Device Comparison Example 1:

[0097] The fabrication method of the device in Comparative Example 1 is the same as that in Device Example 1, the difference being the thickness of the anode buffer layer 105, as detailed below:

[0098] In high vacuum (1×10) -6 MoO3 was deposited onto the photoactive layer in millibars at a deposition rate of 0.4 Å / s to form an anode buffer layer with a thickness of approximately 10 nm.

[0099] The device structures of specific device embodiments 1-5 and device comparative embodiment 1 are shown in Table 1:

[0100] Table 1

[0101]

[0102] The performance of the prepared semi-transparent organic photovoltaic cell was tested. Under AM1.5G standard light irradiation using a solar simulator, the current-voltage curve of the cell was measured, and the photoelectric conversion efficiency was calculated. The transmittance spectrum of the cell in the 300-1100 nm wavelength range was measured using a UV-Vis spectrophotometer, and the average visible light transmittance and light utilization efficiency were calculated. Figure 2 As shown in Figure 3. Specific values ​​are shown in Table 2:

[0103] Table 2

[0104]

[0105] Based on the data in Table 2, Figure 2 , Figure 3 It is evident that, when the semi-transparent organic photovoltaic cell described in this application uses a thicker MoO3 layer as the anode buffer layer, compared to traditional devices using a thinner MoO3 layer (10 nm), it exhibits significant improvements in open-circuit voltage, short-circuit current density, and fill factor. Consequently, the device's photoelectric conversion efficiency and light utilization efficiency are significantly improved compared to device comparison example 1. A comparison of devices 1-5 shows that the device exhibits optimal performance when the thickness of the anode buffer layer MoO3 is 25-35 nm. This is because an excessively thin MoO3 layer cannot prevent damage to the underlying photoactive layer from the plasma during anode sputtering, while an excessively thick MoO3 layer, due to its inherent optical properties, negatively impacts the device's short-circuit current density.

[0106] Device Example 6:

[0107] The fabrication method of device embodiment 6 is the same as that of device embodiment 3, the difference being the different thickness of the metal seed layer 106 (Al layer), as detailed below:

[0108] In high vacuum (1×10) -6 Al was deposited onto the anode buffer layer in millibars at a deposition rate of 0.2 Å / s, forming an ultrathin metallic Al layer, i.e., a metal seed layer 106, with a thickness of about 1 nm.

[0109] Device Example 7:

[0110] The fabrication method of device embodiment 7 is the same as that of device embodiment 3, the difference being the different thickness of the metal seed layer 106 (Al layer), as detailed below:

[0111] In high vacuum (1×10) -6 Al is deposited onto the anode buffer layer in millibars at a deposition rate of 0.2 Å / s, forming an ultrathin metallic Al layer, i.e., a metal seed layer, with a thickness of about 5 nm.

[0112] Device Comparison Example 2:

[0113] The fabrication method of device comparative example 2 is the same as that of device example 3, the difference being the thickness of the metal seed layer 106 (Al layer), as detailed below:

[0114] In high vacuum (1×10) -6 Al is deposited onto the anode buffer layer in millibars at a deposition rate of 0.2 Å / s, forming an ultrathin metallic Al layer, i.e., a metal seed layer, with a thickness of about 8 nm.

[0115] Device Comparison Example 3:

[0116] The fabrication method of the device in Comparative Example 3 is the same as that in Device Example 3, except that the thickness of the metal seed layer 106 (Al) is different, as detailed below:

[0117] In high vacuum (1×10) -6 Al is deposited onto the anode buffer layer in millibars at a deposition rate of 0.4 Å / s, forming an ultrathin metallic Al layer, or metal seed layer, with a thickness of about 10 nm.

[0118] The device structures of specific device embodiments 3, 6-7, and comparative device embodiments 2-3 are shown in Table 3:

[0119] Table 3

[0120]

[0121] The performance of the prepared semi-transparent organic photovoltaic cell was tested. Under AM1.5G standard light irradiation using a solar simulator, the current-voltage curve of the cell was measured, and the photoelectric conversion efficiency was calculated. The transmittance spectrum of the cell in the 300-1100 nm wavelength range was measured using a UV-Vis spectrophotometer, and the average visible light transmittance and light utilization efficiency were calculated. Figure 4 As shown in Figure 5, the specific values ​​are shown in Table 4:

[0122] Table 4

[0123]

[0124] pass Figure 4 , Figure 5As shown in Table 4, when the semi-transparent organic photovoltaic cell described in this application introduces an ultrathin Al layer of no more than 2 nm as a metal seed layer, its photovoltaic performance is basically equivalent to that of traditional devices using thicker (8-10 nm) ultrathin Al electrodes, but its average visible light transmittance is significantly higher. Furthermore, the device exhibits optimal performance when the thickness of the 106 metal seed layer is 1-2 nm. This is because when the Al layer is very thin and does not form a complete metal layer, it can act as a buffer without significantly affecting the device's transmittance, improving the interfacial contact between the anode buffer layer MoO3 and the upper sputtered anode, thus increasing efficiency. However, when the Al layer is thick enough to form a continuous layer, it acts as part of the electrode layer. Since Al is a metallic material, its performance as a transparent electrode, especially in terms of transmittance, is not superior to ITO, resulting in inferior device performance compared to thinner layers.

[0125] Device Comparison Example 4:

[0126] The fabrication method of device comparative example 4 is the same as that of device example 3, the difference being that the thickness of the anode buffer layer 105 and the metal seed layer 106 are different, as detailed below:

[0127] In high vacuum (1×10) -6 MoO3 was deposited onto the photoactive layer in a high vacuum (1×10⁻⁶ mbar) at a deposition rate of 0.4 Å / s, forming an anode buffer layer with a thickness of approximately 10 nm; -6 Al is deposited onto the anode buffer layer in millibars at a deposition rate of 0.4 Å / s, forming an ultrathin metallic Al layer, or metal seed layer, with a thickness of about 10 nm.

[0128] The device structures of specific device embodiment 3 and comparative device embodiments 1, 3, and 4 are shown in Table 5:

[0129] Table 5

[0130]

[0131] The performance of the prepared semi-transparent organic photovoltaic cell was tested. Under AM1.5G standard light irradiation using a solar simulator, the current-voltage curve of the cell was measured, and the photoelectric conversion efficiency was calculated. The transmittance spectrum of the cell in the 300-1100 nm wavelength range was measured using a UV-Vis spectrophotometer, and the average visible light transmittance and light utilization efficiency were calculated. Figure 6 As shown in Figure 7, the specific values ​​are shown in Table 6:

[0132] Table 6

[0133]

[0134] pass Figure 6 , Figure 7 As shown in Table 6, the semi-transparent organic photovoltaic device achieves optimal light utilization efficiency only when the anode buffer layer (MoO3) is relatively thick and the metal seed layer (Al) is relatively thin. In this case, the metallic Al only serves to improve the interface in the device structure and does not constitute a separate electrode layer. Therefore, the light utilization efficiency of the device is significantly improved compared to comparative embodiments 3 and 4. The thicker MoO3 layer can provide better protection against plasma damage during the vacuum magnetron sputtering anode process. Therefore, the open-circuit voltage and short-circuit current of device embodiment 3 are higher than those of comparative embodiments 1 and 4.

[0135] like Figure 8 As shown, the semi-transparent organic photovoltaic cell according to this utility model further includes an encapsulation layer, which includes a sealant layer 108 and a top cover plate 109. The top cover plate 109 is located above the transparent anode layer 107, and the sealant layer 108 is located above the substrate 101 and is attached to the edges of the transparent cathode layer 102, cathode buffer layer 103, photoactive layer 104, anode buffer layer 105, metal seed layer 106, and transparent anode layer 107. The substrate 101, sealant layer 108, and top cover plate 109 form a sealed space to encapsulate the edges of the semi-transparent organic photovoltaic cell.

[0136] like Figure 9 As shown, another encapsulation method of the semi-transparent organic photovoltaic cell according to the present invention is as follows: the sealant layer 108 is located on the upper part of the substrate 101 and covers the edges of the transparent cathode layer 102, cathode buffer layer 103, photoactive layer 104, anode buffer layer 105, metal seed layer 106 and transparent anode layer 107 as well as the upper part of the transparent anode layer 107. The upper cover plate 1109 is located on the upper part of the sealant layer 108. The substrate 101, the sealant layer 108 and the upper cover plate 109 form a full-surface encapsulation of the semi-transparent organic photovoltaic cell.

[0137] The above embodiments further illustrate the content of this application, but should not be construed as limiting this application. Modifications and substitutions made to the methods, steps, or conditions of this application without departing from the spirit and substance of this application are all within the scope of this application. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

Claims

1. A semi-transparent organic photovoltaic cell, comprising, from bottom to top, a substrate (101), a transparent cathode layer (102), a cathode buffer layer (103), a photoactive layer (104), an anode buffer layer (105), a metal seed layer (106), and a transparent anode layer (107), characterized in that: The thickness of the anode buffer layer (105) is selected from 20-40 nm; the thickness of the metal seed layer (106) is selected from 1-5 nm.

2. The semi-transparent organic photovoltaic cell according to claim 1, characterized in that: The thickness of the anode buffer layer (105) is selected from 25-35 nm.

3. The semi-transparent organic photovoltaic cell according to claim 2, characterized in that: The thickness of the metal seed layer (106) is selected from 1-2 nm.

4. The semi-transparent organic photovoltaic cell according to claim 1, characterized in that: The thickness of the transparent anode layer (107) is selected from 90-160 nm.

5. The semi-transparent organic photovoltaic cell according to claim 1, characterized in that: The thickness of the anode buffer layer is selected from 25-35 nm, and the material of the anode buffer layer (105) is selected from molybdenum trioxide.

6. The semi-transparent organic photovoltaic cell according to claim 5, characterized in that: The thickness of the metal seed layer (106) is selected from 1-2 nm, and the material of the metal seed layer (106) is selected from silver, aluminum, gold, bismuth or an alloy of the above metals.

7. The semi-transparent organic photovoltaic cell according to claim 6, characterized in that: The thickness of the transparent anode layer is selected from 90-160 nm; the transparent anode layer (107) and the transparent cathode layer (102) are selected from conductive metal oxides.

8. The semi-transparent organic photovoltaic cell according to claim 7, characterized in that: The transparent anode layer (107) and the transparent cathode layer (102) are selected from indium tin oxide.

9. The semi-transparent organic photovoltaic cell according to claim 1, characterized in that: The semi-transparent organic photovoltaic cell also includes an encapsulation layer, which includes a sealant layer (108) and a top cover plate (109). The top cover plate (109) is located on the upper part of the transparent anode layer (107), and the sealant layer (108) is located on the upper part of the substrate (101) and is attached to the edges of the transparent cathode layer (102), cathode buffer layer (103), photoactive layer (104), anode buffer layer (105), metal seed layer (106) and transparent anode layer (107). The substrate (101), sealant layer (108) and top cover plate (109) form a sealed space to encapsulate the edges of the semi-transparent organic photovoltaic cell.

10. The semi-transparent organic photovoltaic cell according to claim 1, characterized in that: The semi-transparent organic photovoltaic cell also includes an encapsulation layer, which includes a sealant layer (108) and a top cover plate (109). The sealant layer (108) is located on the upper part of the substrate (101) and covers the edges of the transparent cathode layer (102), cathode buffer layer (103), photoactive layer (104), anode buffer layer (105), metal seed layer (106), and transparent anode layer (107), as well as the upper part of the transparent anode layer (107). The top cover plate (109) is located on the upper part of the sealant layer (108). The substrate (101), sealant layer (108), and top cover plate (109) form a full-surface encapsulation of the semi-transparent organic photovoltaic cell.

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