A compound conductive carbon slurry with tunable energy level, preparation method and application

Abstract

This invention relates to a tunable composite conductive carbon paste, its preparation method, and its applications, belonging to the technical field of perovskite solar cell materials. By controlling the composition of the conductive carbon paste, this invention improves conductivity while simultaneously increasing the work function of the carbon electrode, optimizing energy level alignment to solve problems such as energy level mismatch at the carbon electrode and perovskite thin film interface, thereby improving the photoelectric conversion efficiency of perovskite solar cells. This invention utilizes scandium trifluoromethanesulfonate Sc(OTf)3 to replace PSS (photosensitive conductive sand). － H + Furthermore, by employing a strong electron-pulling effect (P-type doping), the electron cloud density of the PEDOT chain is rearranged, effectively improving the work function of both the PEDOT:PSS and the final carbon electrode. This energy level modulation enables the carbon electrode to form a good ohmic or quasi-ohmic contact with the top of the perovskite valence band, eliminating the Shockley barrier and significantly reducing energy loss at the interface, thereby increasing the open-circuit voltage of the battery.

Description

Technical Field

[0001] This invention relates to the field of perovskite solar cell materials technology, specifically to a tunable composite conductive carbon paste, its preparation method, and its application. Background Technology

[0002] Metal halide perovskite solar cells (PSCs) have attracted widespread attention in recent years due to their advantages such as high photoelectric conversion efficiency, solution-based fabrication, and low cost. The structure of a perovskite solar cell mainly includes a transparent conductive substrate, an electron transport layer, a perovskite light-absorbing layer, a hole transport layer, and a counter electrode. The back electrode, as the core component for charge collection, accounts for 30-40% of the total module cost and urgently requires breakthrough material solutions. Furthermore, perovskite materials themselves possess bipolar properties, serving as both a light-absorbing layer and a hole transport layer. This allows PSCs to still achieve effective photoelectric conversion even after removing the hole transport layer.

[0003] Carbon-based back electrodes are widely recognized as the most promising technology for industrialization due to their three main advantages: low raw material cost, chemical inertness that isolates them from environmental corrosion, and low-temperature processing compatible with flexible substrates. Carbon electrodes are typically obtained by coating conductive carbon paste into a film and then drying it. Common carbon pastes are usually composed of carbon black, natural graphite or its derivatives (such as graphene and carbon nanotubes), and are supplemented with polymer binders to form a printable paste.

[0004] However, this system suffers from an energy level mismatch with the perovskite absorber layer of perovskite solar cells. The valence band top of the perovskite absorber layer is located at 5.4–5.6 eV, while the intrinsic work function of carbon materials is only 4.7–5.0 eV, resulting in a hole extraction barrier >0.4 eV at the interface. According to the Shockley diode equation, this barrier directly leads to an open-circuit voltage (…). V OC Work function loss has become a major bottleneck limiting battery efficiency. Existing technologies all have significant drawbacks: adding high work function oxides (WO3 / MoO3) results in large coating thickness deviations due to particle agglomeration; and the cost reduction of metal grid composite solutions is limited because the amount of precious metals used cannot be reduced.

[0005] Therefore, in order to improve the efficiency of carbon electrode-based perovskite solar cells, a composite carbon paste with tunable energy levels and high conductivity is prepared by controlling the composition of conductive carbon paste, which will further promote the manufacturing of high-performance perovskite solar cells. Summary of the Invention

[0006] In view of the above problems, this invention proposes a tunable composite conductive carbon paste, its preparation method, and its application in perovskite solar cells. By controlling the composition of the conductive carbon paste, the conductivity is improved while the work function of the carbon electrode is increased, and the energy level alignment is optimized to solve the problem of energy level mismatch between the carbon electrode and the perovskite thin film interface, thereby improving the photoelectric conversion efficiency of perovskite solar cells.

[0007] This invention provides a method for preparing a composite conductive carbon paste with tunable energy levels, comprising the following steps: S1. Preparation of conductive polymer composite material PEDOT:PSS organic dilution solution; S2. Add Lewis acid dopant to the organic dilution of the conductive polymer composite material PEDOT:PSS to perform acid doping and obtain a mixed system. The mixture was heated and stirred under inert gas protection to obtain the modified conductive polymer composite material PEDOT:PSS solution. S3. Add a film-forming polymer binder to the modified conductive polymer composite material PEDOT:PSS solution and mechanically stir to obtain a viscous and homogeneous composite polymer matrix solution. S4. Weigh two-dimensional graphite, conductive carbon black and one-dimensional nanotubes respectively, and mix them to obtain multi-scale composite conductive carbon filler. Multi-scale composite conductive carbon filler was added to the composite polymer matrix solution in batches and pre-dispersed and stirred by a high-speed planetary mixer to form a preliminary paste. S5. Transfer the initial mixed paste to a ball mill jar, add zirconium oxide ball milling beads with different particle size ratios, and ball mill to obtain a composite conductive carbon paste with tunable energy levels.

[0008] Optionally, the specific steps of S1 include: mixing the conductive polymer composite material PEDOT:PSS with dipropylene glycol methyl ether, and dispersing it by magnetic stirring or ultrasonic assistance to form an organic dilution of the conductive polymer composite material PEDOT:PSS. The conductive polymer composite material PEDOT:PSS comprises the following components: 60-70 parts of poly(3,4-ethylenedioxythiophene) PEDOT and 30-40 parts of polystyrene sulfonate PSS.

[0009] Optionally, the mass ratio of dipropylene glycol methyl ether to the conductive polymer composite material PEDOT:PSS is 1-10:10.

[0010] Optionally, the Lewis acid dopant is scandium trifluoromethanesulfonate Sc(OTf)3 or zinc bis(trifluoromethanesulfonyl)imide Zn(TFSI)2.

[0011] Optionally, the mass ratio of the Lewis acid dopant to the conductive polymer composite material PEDOT:PSS is 1-20:100.

[0012] Optionally, the film-forming polymer binder is an acrylic resin, epoxy resin, phenolic resin, ethyl cellulose, or hydroxypropyl cellulose.

[0013] Optionally, the mass ratio of the two-dimensional graphite, conductive carbon black, and one-dimensional nanotubes is 5~10:1~5:0~0.1.

[0014] The second objective of this invention is to provide an energy-level tunable composite conductive carbon paste, comprising the following components: conductive polymer composite material PEDOT:PSS: 100 parts; dipropylene glycol methyl ether: 10–100 parts; Lewis acid dopant: 0.01–0.2 parts; film-forming polymer binder: 1–10 parts; multi-scale composite conductive carbon filler: 5–15 parts; Optionally, the boiling point of the dipropylene glycol methyl ether is 180℃~200℃.

[0015] The third objective of this invention is to provide an application of a composite conductive carbon paste in perovskite solar cells; A carbon electrode is formed by coating a composite conductive carbon paste onto the surface of a perovskite thin film, followed by drying and curing.

[0016] Optionally, the photoelectric conversion efficiency of the perovskite solar cell is ≥14.05%.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects: (1) The present invention replaces PSS with scandium trifluoromethanesulfonateSc(OTf)3. － H + Furthermore, the strong electron-pulling effect of P-type doping rearranges the electron cloud density of the PEDOT chain, effectively improving the work function of PEDOT:PSS and the final carbon electrode (from approximately 4.8 eV to over 5.0 eV). This energy level tuning enables the carbon electrode to form a good ohmic or quasi-ohmic contact with the top of the perovskite valence band, eliminating the Shockley barrier, significantly reducing energy loss at the interface, and improving the open-circuit voltage of the battery. (2) The present invention adopts a multi-scale composite system of two-dimensional sheet graphite-zero-dimensional particulate carbon black-one-dimensional tubular carbon nanotubes: graphite serves as the main skeleton, providing in-plane high conductivity and mechanical strength; carbon black particles are small in size, which can effectively fill the gaps between graphite sheets, forming a large number of point contacts, avoiding conductive islands, and significantly reducing contact resistance; carbon nanotubes have a high aspect ratio and excellent conductivity, "bridging" between graphite sheets to construct a through three-dimensional conductive tunnel, which greatly improves the migration efficiency of charge carriers in the vertical and lateral directions, forming a three-dimensional network structure combining "point-line-surface", ensuring that the carbon electrode can obtain high conductivity with low filler content, while maintaining good rheological properties and film-forming properties of the slurry; (3) The present invention uses dipropylene glycol methyl ether as a solvent. Its high boiling point can prevent excessive drying during subsequent coating and heat treatment, effectively avoiding defects such as cracks and pinholes in the film layer, thereby forming a dense and flat electrode film. (4) The entire operation process of this invention is simple, the materials are fully utilized, and it is easy to mass-produce. It has greater potential in the preparation of perovskite solar cells, with higher photoelectric conversion efficiency and good stability. Attached Figure Description

[0018] The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention.

[0019] Figure 1 This is a schematic diagram of a flowchart illustrating the preparation method of composite conductive carbon paste for perovskite solar cells in an embodiment of the present invention. Detailed Implementation

[0020] To better understand the above-described objectives, features, and advantages of the present invention, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other. Furthermore, the present invention can be implemented in other ways different from those described herein; therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0021] A specific embodiment of the present invention, such as Figure 1 A method for preparing a composite conductive carbon paste with tunable energy levels is disclosed, comprising the following steps: S1. Preparation of conductive polymer composite material PEDOT:PSS organic dilution solution; Optionally, the specific steps of S1 include: mixing the conductive polymer composite material PEDOT:PSS with dipropylene glycol methyl ether, and dispersing it by magnetic stirring or ultrasonic assistance to form a uniform conductive polymer composite material PEDOT:PSS organic dilution solution. Optionally, the conductive polymer composite material PEDOT:PSS comprises the following components: 60-70 parts of poly(3,4-ethylenedioxythiophene) PEDOT and 30-40 parts of polystyrene sulfonate PSS. Optionally, the boiling point of the dipropylene glycol methyl ether is 180℃~200℃.

[0022] Optionally, the mass ratio of dipropylene glycol methyl ether to the conductive polymer composite material PEDOT:PSS is 1-10:10.

[0023] S2. Add Lewis acid dopant to the organic dilution of the conductive polymer composite material PEDOT:PSS to perform acid doping and obtain a mixed system. The mixture was heated and stirred under inert gas protection to obtain the modified conductive polymer composite material PEDOT:PSS solution. Optionally, the Lewis acid dopant is scandium trifluoromethanesulfonate Sc(OTf)3 or zinc bis(trifluoromethanesulfonyl)imide Zn(TFSI)2; Optionally, the mass ratio of the Lewis acid dopant to the conductive polymer composite material PEDOT:PSS is 1-20:100; The heating temperature is 30℃~80℃, and the inert gas is nitrogen or argon at 10~50 sccm; the stirring time is 1~10h.

[0024] S3. Add a film-forming polymer binder to the modified conductive polymer composite material PEDOT:PSS solution and mechanically stir to obtain a viscous and homogeneous composite polymer matrix solution. Optionally, the film-forming polymer binder is an acrylic resin, epoxy resin, phenolic resin, ethyl cellulose, or hydroxypropyl cellulose; Optionally, the mass ratio of the film-forming polymer binder to dipropylene glycol methyl ether is 1:1-10; Optionally, the temperature of mechanical stirring is 30-80℃; the time of mechanical stirring is 1-10h.

[0025] S4. Weigh two-dimensional graphite, conductive carbon black and one-dimensional nanotubes respectively, and mix them to obtain multi-scale composite conductive carbon filler. Multi-scale composite conductive carbon filler was added to the composite polymer matrix solution in batches and pre-dispersed and stirred by a high-speed planetary mixer to form a preliminary paste. Optionally, the two-dimensional graphite may be flake graphite; the one-dimensional nanotube may be carbon nanotube; Flake graphite has a sheet-like structure with sizes ranging from micrometers to millimeters; The particle size of conductive carbon black is <100 nm; One-dimensional nanotubes have diameters ranging from 0.4 to 100 nm.

[0026] Optionally, the mass ratio of the two-dimensional graphite, conductive carbon black and one-dimensional nanotubes is 5~10:1~5:0~0.1; the pre-dispersion stirring speed is 100~1000 rpm, and the pre-dispersion stirring time is 0.5~3 hours.

[0027] S5. Transfer the initial mixed paste to a ball mill jar, add zirconium oxide ball milling beads with different particle size ratios, and ball mill to obtain a composite conductive carbon paste with tunable energy levels.

[0028] Optionally, the ball-to-particle ratio of the milling beads to the initial mixed paste is 1-10:1; the milling speed is 100-1000 rpm; and the milling time is 1-10 hours.

[0029] Another objective of this invention is to provide an energy-level tunable composite conductive carbon paste, comprising the following components: conductive polymer composite material PEDOT:PSS: 100 parts; dipropylene glycol methyl ether: 10–100 parts; Lewis acid dopant: 0.01–0.2 parts; film-forming polymer binder: 1–10 parts; multi-scale composite conductive carbon filler: 5–15 parts; The conductive polymer composite material PEDOT:PSS comprises the following components: 60-70 parts of poly(3,4-ethylenedioxythiophene) PEDOT and 30-40 parts of polystyrene sulfonate PSS. The boiling point of the dipropylene glycol methyl ether is 180℃~200℃.

[0030] The Lewis acid dopant is scandium trifluoromethanesulfonate Sc(OTf)3 or zinc bis(trifluoromethanesulfonyl)imide Zn(TFSI)2; The film-forming polymer binder is acrylic resin, epoxy resin, phenolic resin, ethyl cellulose, or hydroxypropyl cellulose; The two-dimensional graphite can be flake graphite; the one-dimensional nanotube can be carbon nanotube; wherein, the mass ratio of the two-dimensional graphite, conductive carbon black and one-dimensional nanotube is 5~10:1~5:0~0.1; The composite conductive carbon paste for perovskite solar cells in this invention comprises a Lewis acid-doped PEDOT:PSS organic matrix, an acrylic resin binder, a multi-scale composite conductive carbon filler, and a high-boiling-point organic solvent (dipropylene glycol methyl ether). By controlling the energy level structure of PEDOT:PSS through Lewis acid doping, a highly efficient conductive network is constructed using multi-scale carbon fillers (flake graphite, conductive carbon black, and carbon nanotubes), and the acrylic resin enhances film-forming properties and mechanical strength, achieving synergistic optimization of the paste's performance.

[0031] This invention employs molecular-level doping of Sc(OTf)3-doped PEDOT:PSS to achieve a uniform and controllable increase in work function. By constructing a highly efficient network using multi-scale carbon fillers, this invention maintains excellent conductivity while ensuring sufficient polymer content (to maintain film formation and adhesion).

[0032] The third objective of this invention is to provide an application of a composite conductive carbon paste in perovskite solar cells; Optionally, a carbon electrode is formed by coating a conductive carbon paste onto the surface of a perovskite thin film and then drying and curing it. It is understood that the energy level tunability is achieved by precisely adjusting the work function of the carbon electrode, i.e. the energy level position, through material design and process control, so that it achieves the best match with the valence band top HOMO of the perovskite light absorption layer, thereby significantly reducing the interface charge extraction barrier and improving the photoelectric conversion efficiency of the perovskite solar cell.

[0033] The perovskite solar cell has a photoelectric conversion efficiency of ≥14.05% under standard test conditions of AM 1.5G, 1000 W / m², and 25°C.

[0034] The transparent conductive oxide of the perovskite solar cell is FTO, the electron transport layer is TiO2, the perovskite light absorption layer is CsPbI3, and the carbon electrode is Carbon.

[0035] Example 1: Slurry preparation: Dipropylene glycol methyl ether and acrylic resin were mixed and dissolved in a mass ratio of 13:3. After stirring at 60°C for 3 hours, flake graphite, conductive carbon black and carbon nanotubes in a mass ratio of 7:3:0.01 were added to the mixture. The mixture was then ball-milled at 400 rpm for 4 hours with zirconia ball milling beads in a ball-to-material ratio of 1:1 to obtain conductive carbon slurry C-1. Cell Fabrication and Testing: A conductive paste was coated onto the surface of a perovskite thin film using a blade coating method to obtain a carbon-based perovskite solar cell with an FTO / TiO2 / CsPbI3 / Carbon structure. In this structure, FTO is a transparent conductive oxide, TiO2 is the electron transport layer, CsPbI3 is the perovskite light-absorbing layer, and Carbon is the carbon electrode. The effective light-active area of ​​the carbon-based perovskite solar cell is 0.0625 cm². 2 Performance was measured under standard test conditions, as shown in Table 2.

[0036] Example 2: Slurry preparation: PEDOT:PSS with dipropylene glycol methyl ether at a mass ratio of 1:45 was mixed and stirred; subsequent steps were the same as in Example 1 to obtain conductive carbon slurry C-2.

[0037] Battery preparation and testing: Same as in Example 1.

[0038] Example 3: Slurry preparation: Sc(OTf)3 at a mass ratio of 1:740 was directly dissolved in dipropylene glycol methyl ether; subsequent steps were the same as in Example 1 to obtain conductive carbon slurry C-3.

[0039] Battery preparation and testing: Same as in Example 1.

[0040] Example 4: Slurry preparation: PEDOT:PSS and dipropylene glycol methyl ether were mixed at a mass ratio of 1:45, and Sc(OTf)3 was added. The amount of Sc(OTf)3 added was 5~20% of the mass of PEDOT:PSS. The mixture was reacted at 60°C for 4 hours under N2 protection. The subsequent steps are the same as in Example 1, to obtain conductive carbon paste C-4.

[0041] Battery preparation and testing: Same as in Example 1.

[0042] Table 1. Performance test results of the conductive carbon pastes prepared in Examples 1-5

[0043] Table 2. Battery performance test results of devices in Examples 1-5

[0044] Based on the above analysis, we can see that: 1. The work function is positively correlated with the conductivity: C-4 (PEDOT:PSS+Sc(OTf)3) has a work function of -5.07 eV and the lowest resistivity (23.22 mΩ·cm); C-3 (Sc(OTf)3 only) has a work function of -4.78 eV and the highest resistivity (33.02 mΩ·cm). This indicates that the amount of Sc(OTf)3 added and the synergistic effect of the PEDOT:PSS matrix are crucial for adjusting the work function.

[0045] 2. Work function and perovskite valence band matching degree: The valence band top energy of CsPbI3 perovskite is approximately 5.4-5.6 eV; The work function of C-4, -5.07 eV, best matches the top of the valence band of perovskite (with a difference of approximately 0.33 eV). The work function of C-3, -4.78 eV, has the worst match with the top of the perovskite valence band (difference of approximately 0.62 eV).

[0046] 3. Open-circuit voltage (VOC) is positively correlated with work function: C-4 (work function -5.07 eV): VOC = 1.124 V (maximum); C-3 (work function -4.78 eV): VOC = 1.008 V (minimum).

[0047] 4. Photovoltaic conversion efficiency (PCE) is highly correlated with work function: C-4 (work function -5.07 eV): PCE = 15.94% (highest); C-3 (work function -4.78 eV): PCE = 13.07% (lowest); Compared to traditional carbon electrodes (PCE of approximately 10.18%), C-4 exhibits a PCE improvement of approximately 56%.

[0048] 5. Contribution of PEDOT:PSS: The PCE of C-2 (PEDOT:PSS only) is 14.86%, which is 5.4% higher than that of C-1 (14.05%), indicating that PEDOT:PSS has the effect of improving performance; the surface -OH / -COOH groups of PEDOT:PSS can passivate the perovskite surface and inhibit interfacial charge recombination. The enhancement effect of Sc(OTf)3: The PCE of C-4 (PEDOT:PSS+Sc(OTf)3) is 0.98% higher than that of C-2 (PEDOT:PSS only), indicating that the doping of Sc(OTf)3 further optimizes the energy level matching; Sc(OTf)3 deprotonates the PEDOT chain through the Lewis acid effect, thereby increasing its conductivity and work function.

[0049] 6. Resistivity is positively correlated with JSC / FF: C-4 has the lowest resistivity (23.22 mΩ·cm), JSC has the highest (18.30 mA / cm²), and FF has the highest (0.775). C-3 has the highest resistivity (33.02 mΩ·cm), JSC has the lowest (17.55 mA / cm²), and FF has the lowest (0.739). Mechanism for improving conductivity: Low resistivity (high conductivity) indicates higher carrier transport efficiency.

[0050] Energy level tuning is key to improving the performance of carbon-based perovskite solar cells: the matching degree between the work function of the carbon electrode and the top of the perovskite valence band (difference <0.4 eV) is the decisive factor in determining VOC and PCE.

[0051] In this invention, PEDOT:PSS provides interface passivation, and Sc(OTf)3 significantly improves work function and conductivity through Lewis acid doping. The combination of the two optimizes energy level matching. A multi-scale carbon filler system provides basic conductivity: a composite system of flake graphite (two-dimensional flakes), conductive carbon black (zero-dimensional particles), and carbon nanotubes (one-dimensional tubular structures) constructs a three-dimensional conductive network of "point-line-surface," ensuring high conductivity with low filler content.

[0052] This invention achieves a breakthrough in the performance of carbon-based perovskite solar cells: increasing the PCE from 10.18% of traditional carbon electrodes to 15.94%, an improvement of 56%, reaching the international advanced level of carbon-based perovskite solar cells.

[0053] This invention proposes a method for preparing a composite conductive carbon paste for perovskite solar cells with energy level control functionality. By controlling the composition of the conductive carbon paste, the method solves the problems of easy agglomeration of conductive carbon paste fillers and energy level mismatch with the perovskite thin film interface, significantly improving the photoelectric conversion efficiency of perovskite solar cells and showing good commercial potential.

[0054] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a tunable composite conductive carbon paste, characterized in that, Includes the following steps: S1. Preparation of conductive polymer composite material PEDOT:PSS organic dilution solution; S2. Add Lewis acid dopant to the organic dilution of the conductive polymer composite material PEDOT:PSS to perform acid doping and obtain a mixed system. The mixture was heated and stirred under inert gas protection to obtain the modified conductive polymer composite material PEDOT:PSS solution. S3. Add a film-forming polymer binder to the modified conductive polymer composite material PEDOT:PSS solution and mechanically stir to obtain a viscous and homogeneous composite polymer matrix solution. S4. Weigh two-dimensional graphite, conductive carbon black and one-dimensional nanotubes respectively, and mix them to obtain multi-scale composite conductive carbon filler. Multi-scale composite conductive carbon filler was added to the composite polymer matrix solution in batches and pre-dispersed and stirred by a high-speed planetary mixer to form a preliminary paste. S5. Transfer the initial mixed paste to a ball mill jar, add zirconium oxide ball milling beads with different particle size ratios, and ball mill to obtain a composite conductive carbon paste with tunable energy levels.

2. The method for preparing the energy level tunable composite conductive carbon paste according to claim 1, characterized in that, The specific steps of S1 include: mixing the conductive polymer composite material PEDOT:PSS with dipropylene glycol methyl ether, and dispersing it by magnetic stirring or ultrasonic assistance to form an organic dilution of the conductive polymer composite material PEDOT:PSS. The conductive polymer composite material PEDOT:PSS comprises the following components: 60-70 parts of poly(3,4-ethylenedioxythiophene) PEDOT and 30-40 parts of polystyrene sulfonate PSS.

3. The method for preparing the energy-level tunable composite conductive carbon paste according to claim 1, characterized in that, The mass ratio of dipropylene glycol methyl ether to conductive polymer composite material PEDOT:PSS is 1-10:

10.

4. The method for preparing the energy level tunable composite conductive carbon paste according to claim 1, characterized in that, The Lewis acid dopant is scandium trifluoromethanesulfonate Sc(OTf)3 or zinc bis(trifluoromethanesulfonylimide)Zn(TFSI)2.

5. The method for preparing the energy level tunable composite conductive carbon paste according to claim 1, characterized in that, The mass ratio of the Lewis acid dopant to the conductive polymer composite material PEDOT:PSS is 1-20:

100.

6. The method for preparing the energy level tunable composite conductive carbon paste according to claim 1, characterized in that, The film-forming polymer binder is acrylic resin, epoxy resin, phenolic resin, ethyl cellulose, or hydroxypropyl cellulose.

7. The method for preparing the energy level tunable composite conductive carbon paste according to claim 1, characterized in that, The mass ratio of the two-dimensional graphite, conductive carbon black and one-dimensional nanotubes is 5~10:1~5:0~0.

1.

8. A composite conductive carbon paste with tunable energy levels prepared by any one of claims 1-7, characterized in that, It includes the following components: conductive polymer composite material PEDOT:PSS: 100 parts; dipropylene glycol methyl ether: 10–100 parts; Lewis acid dopant: 0.01–0.2 parts; film-forming polymer binder: 1–10 parts; multi-scale composite conductive carbon filler: 5–15 parts.

9. An application of a composite conductive carbon paste according to any one of claims 1-8, characterized in that, Application of composite conductive carbon paste in perovskite solar cells; A carbon electrode is formed by coating a composite conductive carbon paste onto the surface of a perovskite thin film, followed by drying and curing.

10. The application of the composite conductive carbon paste according to claim 9, characterized in that, The perovskite solar cell has a photoelectric conversion efficiency of ≥14.05%.

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