A kind of translucent perovskite solar cell and its preparation method

Abstract

The application discloses a kind of translucent perovskite solar cells and its preparation method;Translucent perovskite solar cells from bottom to top include: ITO indium tin oxide conductive glass layer, hole transport layer, anode modification layer, perovskite active layer, cathode modification layer, electron transport layer, cathode buffer layer, transparent cathode, silver grid line.The translucent perovskite solar cells prepared in the application reach 14% or more under the condition that the average light transmittance reaches 38%, and are very suitable for commercial application of building integrated photovoltaics.

Description

A semi-transparent perovskite solar cell and its fabrication method Technical Field

[0001] This invention belongs to the field of thin-film solar cells and relates to a semi-transparent perovskite solar cell for building-integrated photovoltaics and its preparation method. Background Technology

[0002] Today, buildings consume a massive amount of electricity, accounting for nearly one-third of global energy demand. A low-cost and sustainable solution to this problem is to integrate photovoltaics (PV) into buildings, forming Building Integrated Photovoltaics (BIPV), transforming any urban infrastructure into a green and self-powered asset. Due to a lack of transparency and design flexibility, crystalline silicon solar cell modules in current BIPV systems are typically attached to the limited rooftop space of buildings. This system is attached to the exterior rather than integrated into the building's materials, thus requiring additional space and incurring relatively high costs. To integrate PV into buildings more sustainably and effectively, PV modules need to be organically integrated into all available surfaces of the building structure, including roofs, facades, windows, skylights, balconies, and shading systems. Therefore, these PV modules can serve not only as sustainable power generators but also as functional covering materials. Most importantly, PV modules in BIPV can offer more possibilities for building functionality and aesthetics than just energy production. For this purpose, appropriate transparency within the visible spectrum, as well as color tunability and simplicity of manufacturing processes, are highly desirable characteristics for future BIPV. Transparency has become a key issue encouraging further investment in BIPV. By simultaneously achieving superior performance and transparency, and ultimately enabling color tunability, semi-transparent perovskite solar cells (ST-PSCs) will be the most promising third-generation solar energy for realizing this application.

[0003] At the technical level, the main challenge in BIPV design lies in the manufacturing of solar cell modules. These modules must meet specific aesthetic requirements in terms of size, shape, texture, transparency, and color while remaining competitive. ST-PSC photoelectric conversion efficiencies of 5-10% can be used for integrated photovoltaic facades and building photovoltaic glass applications, while efficiencies of 2-5% can provide self-powered smart windows. Since conversion efficiency varies with transmittance, another important parameter to consider when comparing ST-PSC efficiencies is the average visible light transmittance (AVT), which is typically defined as the average transmittance within the 380-780 nm wavelength range visible to the human eye. Because ST-PSC efficiency and transparency are often interdependent—as cell efficiency increases, module transparency decreases—optimal ST-PSC performance is determined by the balance between cell efficiency and AVT. Currently, the best-performing ST-PSC for BIPV has a photoelectric conversion efficiency of 13.61% and an AVT of 24.7% (Nano Energy 82(2021)105703).

[0004] Compared to traditional opaque perovskite solar cells, ST-PSCs must replace the traditional high-reflectivity metal top electrode with a suitable transparent conductive electrode; that is, both the front and back electrodes of an ST-PSC must be transparent. An ideal transparent top electrode (TTE) should simultaneously possess good conductivity and maximum transparency, along with low cost, good chemical stability, and an appropriate work function. Currently, transparent conductive oxides (TCOs) offer the best trade-off between conductivity and transparency, holding a dominant position in transparent electrode applications in the optoelectronic industry. However, TCOs are difficult to use as TTEs because they typically require high-energy deposition processes (e.g., magnetron sputtering), which can damage the underlying perovskite active layer and charge transport layer due to high-energy ion bombardment (such as plasma in magnetron sputtering). Currently, to protect the underlying active material beneath the TTE, a buffer layer (such as tin oxide) is grown on the underlying material using atomic layer deposition methods prior to TCO sputtering. Summary of the Invention

[0005] The purpose of this invention is to provide a semi-transparent perovskite solar cell that has higher photoelectric conversion efficiency and visible light transmittance.

[0006] Another object of the present invention is to provide a method for preparing the above-mentioned battery.

[0007] The design concept of this invention is to adjust the bandgap of the perovskite by regulating the ratio of iodine (I) and bromine (Br) in the perovskite active layer, thereby adjusting the transmittance and efficiency of the battery. Simultaneously, this invention employs a low-cost thermal evaporation process to prepare a BCP / ultra-thin metallic silver (Ag) / MoO3 cathode buffer layer.

[0008] Specifically, the technical solution adopted to achieve the first inventive objective is as follows:

[0009] A semi-transparent perovskite solar cell comprises, from bottom to top: an ITO indium tin oxide conductive glass layer, a hole transport layer, an anode modification layer, a perovskite active layer, a cathode modification layer, an electron transport layer, a cathode buffer layer, a transparent cathode, and silver grid lines.

[0010] The hole transport layer is nickel oxide (NiO); the anode modification layer is [2-(9H-carbazole-9-yl)ethyl]phosphonic acid; and the perovskite active layer is Cs. x FA 1-x Pb(I y Br 1-y 3, where FA is formamidin, 0≤x≤1, 0≤y≤1; the cathode modification layer is PEAI. 1- z Br z In the formula, PEAI is phenylethyl iodide, PEABr is phenylethyl bromide, 0≤z≤1; the electron transport layer is fullerene C60; the cathode buffer layer is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline / Ag silver / MoO3 molybdenum oxide; and the transparent cathode is an ITO thin film.

[0011] To achieve the second objective of the invention, the technical solution adopted is as follows:

[0012] A method for fabricating a semi-transparent perovskite solar cell includes the following steps:

[0013] 1) Cleaning ITO glass substrate: ultrasonically clean it in glass detergent, deionized water, acetone and isopropanol solutions for 10 minutes each, then dry it with nitrogen gas and treat it in a UV ozone cleaner for 15 minutes.

[0014] 2) Preparation of hole transport layer—nickel oxide layer: Nickel oxide solution was spin-coated onto the cleaned ITO glass substrate using a spin coater at a speed of 4000 rpm for 30 s, followed by thermal annealing for 15 min at a temperature of 120℃; The nickel oxide solution was prepared by dissolving nickel oxide nanoparticles in deionized water and sonicating for 1 h.

[0015] 3) Preparation of anodic modification layer: spin-coating 2PACz solution at 3000 rpm for 30 s, followed by thermal annealing for 10 min at 100℃;

[0016] 4) Preparation of perovskite active layer—Cs x FA 1-x Pb(I y Br 1-y3) Transfer the substrate to a nitrogen glove box and spin-coat the perovskite solution using a spin coater at 1000 rpm followed by 6000 rpm for 30 seconds. Immediately afterward, extract the perovskite solution by spin-coating at 6000 rpm for 30 seconds. Then, anneal at 100°C for 10 minutes. The perovskite solution used is Cs. x FA 1-x Pb(I y Br 1-y The solution has a concentration of 0.2M to 2M and is a mixture of DMF (N,N-dimethylformamide) and DMSO (dimethyl sulfoxide) in a 4:1 ratio.

[0017] 5) Preparation of cathode modification layer: spin-coating PEAI 1-z Br z Solution, speed 6000 rpm, time 30 s;

[0018] 6) Preparation of the electron transport layer C60 and the cathode buffer layer: The substrate was transferred to a vacuum deposition machine, and a 20 nm thick C60 layer was first deposited at room temperature using thermal evaporation. Then, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (5–8 nm), Ag (0.5–1.5 nm), and MoO3 (3–5 nm) were deposited sequentially. The background vacuum of the thermal evaporation chamber was better than 1 × 10⁻⁶. -3 Pa, the evaporation rates of C60, BCP, Ag, and MoO3 were 0.4 nm, 0.1 nm, 0.04 nm, and 0.1 nm per second, respectively;

[0019] 7) Fabrication of a transparent cathode-ITO thin film: ITO was sputtered using magnetron sputtering to a thickness of 70 nm. The specific growth process is as follows: the sputtering target was a high-purity metallic silver target, and the base vacuum of the sputtering cavity was better than 5 × 10⁻⁶. -4 Pa, RF sputtering power of 20-30W, RF frequency of 13.56MHz, sputtering gas pressure of 0.5-2.0Pa, sputtering working gas of argon, argon flow rate of 30sccm, substrate room temperature, and film thickness monitored by a quartz crystal oscillator thickness gauge.

[0020] 8) Preparation of silver grid lines: Silver grid lines are deposited using a thermal evaporation method.

[0021] The main functions of the buffer layer in this invention are: (1) to block the bombardment of the perovskite active layer by high-energy ions during the subsequent magnetron sputtering deposition of Ag electrodes; (2) to shield the perovskite material from water vapor penetration and damage; and (3) to prevent the perovskite reactants from corroding the metal electrode under illumination. In the buffer layer structure, the thickness of the ultrathin silver is 0.5–1.5 nm, and its main function is to increase the conductivity between BCP and MoO3 and the adhesion of MoO3 to BCP. The semi-transparent perovskite solar cell prepared in this invention achieves a photoelectric conversion efficiency of over 14% with an average transmittance of 38%, making it very suitable for the commercial application of building-integrated photovoltaics. Attached Figure Description

[0022] Figure 1 is a schematic diagram of the battery in this invention.

[0023] Figure 2 shows the transmittance curve of a semi-transparent perovskite solar cell according to an embodiment of the present invention.

[0024] Figure 3 shows the JV test curve of the semi-transparent perovskite solar cell according to an embodiment of the present invention. Detailed Implementation

[0025] Example 1 Battery Structure

[0026] In this embodiment, the schematic diagram of the semi-transparent perovskite solar cell device structure is shown in Figure 1. From bottom to top, it includes ITO (indium tin oxide) conductive glass, a hole transport layer, an anode modification layer, a perovskite active layer, a cathode modification layer, a cathode buffer layer, a transparent cathode, and silver grid lines. The hole transport layer is nickel oxide (NiO), the anode modification layer is 2PACz ([2-(9H-carbazole-9-yl)ethyl]phosphonic acid), and the perovskite active layer is Cs. x FA 1-x Pb(I y Br 1-y )3 (FA is formamidin, x = 0.2, y = 0.6), the cathode modification layer is PEAI 1-z Br z (PEAI is phenylethyl iodide, PEABr is phenylethyl bromine, z = 0.4), the electron transport layer is C60 (fullerene C60), the cathode buffer layer is BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) / Ag (silver) / MoO3 (molybdenum oxide), and the transparent cathode is an ITO thin film.

[0027] Preparation method of Example 2

[0028] 1.1 Cleaning ITO glass substrate: ultrasonically cleaned in glass detergent, deionized water, acetone and isopropanol solutions for 10 min each, then dried with nitrogen and treated in a UV ozone cleaner for 15 min.

[0029] 1.2 Preparation of hole transport layer—nickel oxide layer: Nickel oxide solution was spin-coated onto the cleaned ITO glass substrate using a spin coater at a speed of 4000 rpm for 30 s, followed by thermal annealing for 15 min at a temperature of 120 ℃; The nickel oxide solution was prepared by dissolving nickel oxide nanoparticles in deionized water and sonicating for 1 h.

[0030] 1.3 Preparation of anodic modification layer: spin-coating 2PACz solution at 3000 rpm for 30 s, followed by thermal annealing for 10 min at 100 ℃;

[0031] 1.4 Preparation of perovskite active layer—Cs x FA 1-x Pb(I y Br 1-y 3 (x = 0.2, y = 0.6): The substrate was transferred to a nitrogen glove box, and a perovskite solution was spin-coated using a spin coater at 1000 rpm followed by 6000 rpm for 30 s. Immediately afterwards, a chlorobenzene solution was added for extraction, spin-coating the chlorobenzene solution at 6000 rpm for 30 s. The substrate was then annealed at 100°C for 10 min. The perovskite solution was Cs... x FA 1-x Pb(I y Br 1-y The solution has a concentration of 0.2–2.0 M and is a mixture of DMF (N,N-dimethylformamide) and DMSO (dimethyl sulfoxide) in a 4:1 ratio.

[0032] 1.5 Preparation of cathode modification layer: spin-coating PEAI 1-z Br z (z=0.4) solution, speed 6000rpm, time 30s;

[0033] 1.6 Fabrication of the electron transport layer (C60) and cathode buffer layer (BCP / Ag / MoO3): The substrate was transferred to a vacuum deposition machine, and a 20 nm thick C60 layer was first deposited at room temperature using thermal evaporation. Then, BCP (5–8 nm), Ag (0.5–1.5 nm), and MoO3 (3–5 nm) were deposited sequentially. The background vacuum of the thermal evaporation chamber was better than 1 × 10⁻⁶. -3 Pa, the evaporation rates of C60, BCP, Ag, and MoO3 were 0.4 nm, 0.1 nm, 0.04 nm, and 0.1 nm per second, respectively.

[0034] 1.7 Preparation of a transparent cathode-ITO thin film: ITO was sputtered using magnetron sputtering to a thickness of 70 nm. The specific growth process is as follows. The sputtering target was a high-purity metallic silver target, and the base vacuum of the sputtering cavity was better than 5 × 10⁻⁶. -4The sputtering conditions were as follows: Pa, RF sputtering power 20–30 W, RF frequency 13.56 MHz, sputtering gas pressure 0.5–2.0 Pa, sputtering working gas argon with a flow rate of 30 sccm, substrate room temperature, and film thickness monitored by a quartz crystal oscillator thickness gauge. Electrical measurements showed that the resistivity of the ITO film was 2–6 mΩ·cm.

[0035] 1.8 Preparation of silver grid lines: Silver grid lines were deposited using a thermal evaporation method.

[0036] Example 3: Photoelectric performance testing of a semi-transparent perovskite solar cell:

[0037] Figure 2 shows the average transmittance (AVT) of semi-transparent solar cells prepared with perovskite precursors of different concentrations in the visible light range (380-780 nm). The results indicate that the device obtained by this structure has excellent light transmittance. At AM1.5 and 100 mW / cm², the transmittance is significantly higher than that of the solar cells prepared with perovskite precursors of different concentrations. 2 Under standard test conditions of 25°C, with an average visible light transmittance of 38%, the cell efficiency reached 14.4%. Its optimal performance in both transmittance and photoelectric conversion efficiency is higher than the currently reported conversion efficiency of 13.61% and transmittance of 24.7% (Nano Energy 82(2021)105703). This demonstrates that the performance of the semi-transparent perovskite solar cell proposed in this invention surpasses the best reported internationally, exhibiting significant cost and performance advantages in the commercial application of building-integrated photovoltaics.

Claims

1. A semi-transparent perovskite solar cell, comprising, from bottom to top: The structure comprises an ITO indium tin oxide conductive glass layer, a hole transport layer, an anode modification layer, a perovskite active layer, a cathode modification layer, an electron transport layer, a cathode buffer layer, a transparent cathode, and silver grid lines; the hole transport layer is nickel oxide (NiO); the anode modification layer is [2-(9H-carbazole-9-yl)ethyl]phosphonic acid; and the perovskite active layer is Cs. x FA 1-x Pb(I y Br 1-y 3, where FA is formamidin, 0≤x≤1, 0≤y≤1; the cathode modification layer is PEAI. 1- z Br z In the formula, PEAI is phenylethyl iodide, PEABr is phenylethyl bromide, 0≤z≤1; the electron transport layer is fullerene C60; the cathode buffer layer is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline / Ag silver / MoO3 molybdenum oxide, wherein the thickness of the silver layer is 0.5~1.5nm; and the transparent cathode is an ITO thin film.

2. The method for preparing a semi-transparent perovskite solar cell as described in claim 1, comprising the following steps: 1) Cleaning the ITO glass substrate: The substrate was sequentially ultrasonically cleaned in glass detergent, deionized water, acetone, and isopropanol solutions for 10 min each, then dried with nitrogen and treated with a UV ozone cleaner for 15 min. 2) Preparation of the hole transport layer—nickel oxide layer: Nickel oxide solution was spin-coated onto the cleaned ITO glass substrate at 4000 rpm for 30 s, followed by thermal annealing for 15 min at 120℃. The nickel oxide solution was prepared by dissolving nickel oxide nanoparticles in deionized water and ultrasonicating for 1 h. 3) Preparation of the anodic modification layer: 2PACz solution was spin-coated at 3000 rpm for 30 s, followed by thermal annealing for 10 min at 100℃. 4) Preparation of the perovskite active layer—Cs x FA 1-x Pb(I y Br 1-y 3) Transfer the substrate to a nitrogen glove box and spin-coat the perovskite solution using a spin coater at 1000 rpm followed by 6000 rpm for 30 seconds. Immediately afterward, extract the perovskite solution by spin-coating at 6000 rpm for 30 seconds. Then, anneal at 100°C for 10 minutes. The perovskite solution used is Cs. x FA 1-x Pb(I y Br 1-y 3) Solution, concentration from 0.2M to 2M, solvent is DMF (N,N-dimethylformamide) and DMSO (dimethyl sulfoxide) mixed in a 4:1 ratio; 5) Preparation of cathode modification layer: spin-coating PEAI 1-z Br z 6) Preparation of electron transport layer C60 and cathode buffer layer: The substrate was transferred to a vacuum coating machine, and C60 with a thickness of 20 nm was deposited first at room temperature by thermal evaporation, followed by the sequential deposition of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (5~8 nm), Ag (0.5~1.5 nm), and MoO3 (3~5 nm); the background vacuum of the thermal evaporation chamber was better than 1×10 -3 Pa, the evaporation rates of C60, BCP, Ag, and MoO3 were 0.4 nm, 0.1 nm, 0.04 nm, and 0.1 nm per second, respectively; 7) Preparation of transparent cathode-ITO thin film: ITO was sputtered using magnetron sputtering to a thickness of 70 nm. The specific growth process is as follows: the sputtering target was a high-purity metallic silver target, and the base vacuum of the sputtering cavity was better than 5 × 10⁻⁶. -4 Pa, RF sputtering power is 20~30 W, RF frequency is 13.56 MHz, sputtering gas pressure is 0.5~2.0 Pa, sputtering working gas is argon, argon flow rate is 30 sccm, substrate is at room temperature, and film thickness is monitored by a quartz crystal oscillator thickness gauge; 8) Preparation of silver grid lines: Silver grid lines are deposited by thermal evaporation.

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