Printable mesoscale perovskite solar cell and method of making the same

Abstract

The application provides a printable mesoscopic perovskite solar cell and a preparation method thereof, and the solar cell has a layered structure framework. By adding an alcohol ether to a precursor solution, the permeability of the precursor solution is effectively improved, and the fill factor, short-circuit current and stability of the solar cell are significantly improved, so that the technical problem that the existing perovskite precursor is not filled sufficiently in the porous membrane framework, resulting in poor photoelectric performance, is solved.

Description

Technical Field

[0001] This invention relates to the field of perovskite solar cells, and more specifically to a novel printable mesoscopic perovskite solar cell based on a perovskite thin film and its fabrication method. Background Technology

[0002] Perovskite solar cells have attracted widespread attention due to their numerous advantages, including high absorption coefficient, tunable bandgap, low exciton binding energy, long carrier diffusion radius, and solution-processability. To date, the power conversion efficiency of single-junction perovskite solar cells has rapidly increased from an initial 3.8% to the current 25.8%. However, the instability of perovskite materials and other materials used in fabrication to water and oxygen necessitates that most perovskite solar cells be prepared in an inert gas environment. Furthermore, the complex and variable crystallization process of perovskite leads to relatively complex perovskite thin-film fabrication processes with numerous limiting factors, hindering the large-scale fabrication and industrialization of perovskite solar cells.

[0003] CN103441217A discloses a carbon-based fully printed perovskite solar cell. Using conductive glass as a substrate, a hole-blocking layer is first deposited, followed by the sequential fabrication of a mesoporous nanocrystalline layer, an insulating spacer layer, and a mesoporous hole-collecting layer from bottom to top using a screen printing process. All three layers are filled with perovskite semiconductor materials. This carbon-based mesoporous perovskite solar cell fabricated using screen printing technology can largely solve the problems of complex fabrication processes, high costs, and poor stability associated with traditional planar heterojunction perovskite solar cells. However, the tens of micrometers-thick three-layer mesoporous structure (mesoporous nanocrystalline layer, insulating spacer layer, and mesoporous hole-collecting layer) poses a challenge to the uniform filling of perovskite materials within it. Furthermore, the crystallization process of perovskite materials is difficult to control, leading to numerous defects. This, in turn, causes an irreversible increase in defects in the precursor solution dispersed in the mesopores during annealing.

[0004] CN112510155A discloses a printable mesoscopic perovskite solar cell using a low-boiling-point reagent as a solvent and its preparation method. The method involves preparing a perovskite precursor solution using a low-boiling-point reagent as a solvent, then depositing the perovskite precursor solution into a mesoporous layer to obtain a high-quality perovskite thin film at room temperature, thus fabricating a printable mesoscopic perovskite solar cell device. This significantly improves the fill factor, open-circuit voltage, and stability of the solar cell. Furthermore, the preparation process is simple, requires no annealing, and is low-cost. However, the selected low-boiling-point solvent evaporates too quickly, preventing further penetration of the precursor solution; therefore, the process needs further improvement. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention provides a method for fabricating printable mesoscopic perovskite solar cells. The solar cells have a layered structural framework similar to that described in CN103441217A. This layered structural framework includes: a conductive substrate and, sequentially disposed on the conductive substrate, a hole-blocking layer, a mesoporous electron transport layer, a mesoporous insulating layer, and a mesoporous electrode layer. The method is characterized by:

[0006] Step 1: Mix the perovskite material with a solvent and stir to prepare a perovskite precursor solution. The perovskite material is ABX3 type perovskite material, wherein A is a monovalent organic or inorganic cation, B is a divalent metal cation, and X is a monovalent anion. The solvent includes alcohols, ethers, and other organic solvents.

[0007] Step 2: Deposit the perovskite precursor solution into the layered structure framework, allowing the precursor solution to permeate and fill the mesoporous electron transport layer, mesoporous insulating layer, and mesoporous electrode layer;

[0008] Step 3: Allow to stand at room temperature or anneal at high temperature to obtain the printable mesoscopic perovskite solar cell.

[0009] This invention discovers that adding alcohol ethers to the precursor solution can effectively improve the permeability of the precursor solution while maintaining a certain level of volatility, thereby significantly improving the fill factor, short-circuit current, and stability of the solar cell. This solves the technical problem of insufficient filling of porous membrane frameworks by existing perovskite precursors, which leads to poor photoelectric performance.

[0010] Preferably, the proportion of alcohol ether in the solvent is not less than 50% by volume, and preferably not less than 70%.

[0011] Preferably, the concentration of the perovskite precursor solution is 0.1-2 mol / L.

[0012] Preferably, in the ABX3 type perovskite material, A is one or more of methylamine group, formamidinium group, acetamdinium group, cesium ion, lithium ion, potassium ion, sodium ion, and rubidium ion; B is one or more of lead ion, tin ion, copper ion, germanium ion, manganese ion, ferrous ion, cobalt ion, nickel ion, zinc ion, and magnesium ion; and X is one or more of fluorine ion, chloride ion, bromide ion, iodide ion, boron tetrafluoride anion, and thiocyanate anion.

[0013] Preferably, the alcohol ether solvent is selected from one or more of the following: ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, diethylene glycol monoethyl ether, diethylene glycol propyl ether, diethylene glycol butyl ether, diethylene glycol pentyl ether, and diethylene glycol hexyl ether.

[0014] Preferably, the other organic solution is one or more of N,N-dimethylformamide, N-methylformamide, N-methylpyrrolidone, dimethyl sulfoxide, methanol, ethanol, isopropanol, methylamine, ethylamine, triethylamine, propylamine, acetonitrile, and tetrahydrofuran.

[0015] Preferably, the conductive substrate includes a substrate and a conductive substrate layer.

[0016] The substrate is selected from one of the following: glass, polyethylene terephthalate, polyimide, polyethylene, polypropylene, polystyrene, and polyethylene terephthalate.

[0017] The conductive substrate is selected from ITO and FTO; preferably, the thickness of the conductive substrate is 10-1000 nm.

[0018] The hole blocking layer is one or more of dense TiO2, SnO2, and ZnO. Preferably, the thickness of the hole blocking layer is 1-100 nm.

[0019] The mesoporous electron transport layer is one or more of mesoporous TiO2, SnO2, and ZnO. Preferably, the thickness of the mesoporous electron transport layer is 10-2000 nm.

[0020] The mesoporous insulating layer is one or more of Al2O3, ZrO2, and MgO. Preferably, the thickness of the mesoporous insulating layer is 0.01-10 μm.

[0021] The mesoporous electrode layer is a carbon electrode, and preferably, the thickness of the mesoporous electrode layer is 0.1-30 μm.

[0022] Preferably, the layered structure skeleton can be prepared by one or more of the following methods: spin coating, spray coating, scraping coating, slot coating, screen printing, gravure printing, letterpress printing, flexographic printing, and offset printing.

[0023] Preferably, the method for depositing perovskite precursor solution is one or more of the following: drop coating, spin coating, spray coating, blade coating, slot coating, screen printing, gravure printing, letterpress printing, flexographic printing, and offset printing.

[0024] Preferably, the high-temperature annealing temperature is 50-150℃.

[0025] In step three, as the solvent in the perovskite precursor solution evaporates, the perovskite material crystallizes in the mesoporous layer. The morphology of the crystals directly determines the performance of the resulting perovskite solar cell. Room temperature crystallization is preferred, but high-temperature annealing is also an option, depending on the choice of solvent.

[0026] Another aspect of the present invention provides a printable mesoscopic perovskite solar cell, which is prepared by the method described above.

[0027] The beneficial effects of this invention are as follows: This invention adds alcohol ethers to the solvent used to prepare the precursor, particularly using alcohol ether solvents as the main component to prepare the perovskite precursor solution. Utilizing the easy flow and certain volatility of alcohol ether solvents, the perovskite precursor solution is better deposited into the mesoporous layer. During this process, the crystallization quality of the perovskite film in the mesopores is improved by controlling the crystallization process of the perovskite, ultimately obtaining a high-quality perovskite film and fabricating a printable mesoscopic perovskite solar cell. This method can significantly improve the fill factor, short-circuit current, and stability of solar cells. Furthermore, the fabrication process is simple, low-cost, and highly reproducible, solving the technical problem of poor photoelectric performance in existing mesoscopic perovskite solar cells. Attached Figure Description

[0028] Figure 1 This is a cross-sectional view of the perovskite solar cell described in this invention;

[0029] Figure 2 The IV test diagrams are for Example 1 and Comparative Example 1;

[0030] Figure 3 The IV test results are for Example 2 and Comparative Example 2.

[0031] Figure 4 The IV test results are for Example 3 and Comparative Example 3.

[0032] Figure 5 The images show IV test results for Example 4 and Comparative Example 4. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. Specific examples herein are merely illustrative and do not limit the scope of the invention.

[0034] like Figure 1The perovskite solar cell shown comprises, from bottom to top, a conductive substrate layer 1, a hole-blocking layer 2, a mesoporous electron transport layer 3, a mesoporous insulating layer 4, and a mesoporous electrode layer 5, sequentially stacked on a glass substrate. The conductive substrate layer is selected from ITO and FTO, and its thickness is 10-1000 nm. The hole-blocking layer is one or more of dense TiO2, SnO2, and ZnO, and its thickness is 1-100 nm. The mesoporous electron transport layer is one or more of mesoporous TiO2, SnO2, and ZnO, and its thickness is 10-2000 nm. The mesoporous insulating layer is one or more of Al2O3, ZrO2, and MgO, and its thickness is 0.01-10 μm. The mesoporous electrode layer is a carbon electrode, and its thickness is 0.1-30 μm.

[0035] In the following embodiments and comparative examples, the thickness of the conductive substrate layer is 200 nm; the hole blocking layer is one or more of dense TiO2, SnO2, and ZnO, preferably TiO2, and the thickness of the hole blocking layer is 30 nm; the mesoporous electron transport layer is one or more of mesoporous TiO2, SnO2, and ZnO, preferably TiO2, and the thickness of the mesoporous electron transport layer is 300 nm; the mesoporous insulating layer is one or more of Al2O3, ZrO2, and MgO, preferably ZrO2, and the thickness of the mesoporous insulating layer is 1.5 μm; and the mesoporous electrode layer is a carbon electrode, and the thickness of the mesoporous electrode layer is 15 μm.

[0036] The various indicator parameters involved in the following embodiments are explained as follows:

[0037] Power conversion efficiency (PCE): This refers to the maximum power output (P) of a solar cell. m Solar irradiance P reaching the ground in The ratio:

[0038]

[0039] Power conversion efficiency (PCE) and open-circuit voltage (V) OC ), short-circuit current density (J SC The relationship between the fill factor (FF) and the fill factor (FF) is as follows:

[0040]

[0041] Under standard solar cell test conditions (AM 1.5G, solar irradiance P...) S =1000W / m 2(Ambient temperature T = 25 ± 1℃), battery area is 0.1 cm². 2 At this time P in =100mW / cm 2 J SC The unit is mA / cm -2 V OC The unit is V.

[0042] Example 1:

[0043] In this embodiment, the solvent is a mixture of ethylene glycol monomethyl ether and γ-butyrolactone (volume ratio 4:1), and A is CH3NH3. + B is Pb 2+ X is I - The specific steps for preparing this material are as follows:

[0044] Weigh out 0.3842 g of PbI2 and 0.128 g of CH3NH3I and completely dissolve them in 1 mL of ethylene glycol monomethyl ether and γ-butyrolactone (in a volume ratio of 3:2) to obtain solution A;

[0045] 8 μL of perovskite precursor solution A was deposited into a printable mesoscopic perovskite solar cell.

[0046] Printable mesoscopic perovskite solar cell devices can be finally obtained by annealing at 53℃ for 4 hours.

[0047] The obtained battery was subjected to IV testing, and the short-circuit current of the device was 21.10 mA / cm². 2 The open-circuit voltage is 0.91V, the fill factor is 66.95%, and the energy conversion efficiency is 12.85%.

[0048] Comparative Example 1:

[0049] Unlike Example 1 below, the solvent used is γ-butyrolactone, and A is CH3NH3. + B is Pb 2+ X is I - The specific steps for preparing this material are as follows:

[0050] 1. Weigh out 0.3842g of PbI2 and 0.128g of CH3NH3I and dissolve them completely in 1ml of γ-butyrolactone to obtain solution A;

[0051] 2. Take 8 μL of perovskite precursor solution A and deposit it into a printable mesoscopic perovskite solar cell;

[0052] Printable mesoscopic perovskite solar cell devices can be finally obtained by annealing at 3.53℃ for 4 hours.

[0053] The obtained battery was subjected to IV testing, and the short-circuit current of the device was 22.82 mA / cm². 2 The open-circuit voltage is 0.82V, the fill factor is 44.14%, and the energy conversion efficiency is 8.26%.

[0054] Example 2:

[0055] In this embodiment, the preferred solvent is a mixture of ethylene glycol monomethyl ether and dimethyl sulfoxide (volume ratio 10:1), and A is CH4N2. + B is Pb 2+ X is I - The specific steps for preparing this material are as follows:

[0056] 1. Weigh 0.5071g PbI2 and 0.1749g CH4N2I and completely dissolve them in 1mL of ethylene glycol monomethyl ether and dimethyl sulfoxide (in a volume ratio of 4:1) to obtain solution A;

[0057] 2. Take 8 μL of perovskite precursor solution A and deposit it into a printable mesoscopic perovskite solar cell;

[0058] 3. The printable mesoscopic perovskite solar cell device can be finally obtained by placing it in an air environment at room temperature for 24 hours.

[0059] The obtained battery was subjected to IV testing, and the short-circuit current of the device was 23.99 mA / cm². 2 The open-circuit voltage is 0.90V, the fill factor is 70.05%, and the energy conversion efficiency is 15.12%.

[0060] Comparative Example 2:

[0061] Unlike Example 2 below, the solvent used is N,N-dimethylformamide and dimethyl sulfoxide (volume ratio 10:1), and A is CH3NH3. + B is Pb 2+ X is I - The specific steps for preparing this material are as follows:

[0062] 1. Weigh 0.461g PbI2 and 0.156g CH3NH3I and completely dissolve them in 1ml of a mixture of N,N-dimethylformamide and dimethyl sulfoxide (by volume ratio 4:1) to obtain solution A;

[0063] 2. Take 3.5 μL of perovskite precursor solution A and deposit it into a printable mesoscopic perovskite solar cell;

[0064] 3. Annealing at 100℃ for 20 minutes will finally produce printable mesoscopic perovskite solar cell devices.

[0065] The obtained battery was subjected to IV testing, and the short-circuit current of the device was 16.90 mA / cm². 2 The open-circuit voltage is 0.92V, the fill factor is 66.01%, and the energy conversion efficiency is 10.26%.

[0066] Example 3:

[0067] In this embodiment, the preferred solvent is a mixture of ethylene glycol monomethyl ether and acetonitrile (volume ratio 3:2), and A is CH3NH3. + B is Pb 2+ X is I - The specific steps for preparing this material are as follows:

[0068] 1. Weigh 0.461g PbI2 and 0.156g CH3NH3I and completely dissolve them in 1mL of ethylene glycol monomethyl ether and acetonitrile (in a volume ratio of 1:1) to obtain solution A;

[0069] 2. Take 8 μL of perovskite precursor solution A and deposit it into a printable mesoscopic perovskite solar cell;

[0070] 3. Printable mesoscopic perovskite solar cell devices can be finally obtained by placing them in a methylamine gas environment for 24 hours.

[0071] The obtained battery was subjected to IV testing, and the short-circuit current of the device was 22.47 mA / cm². 2 The open-circuit voltage is 0.97V, the fill factor is 77.14%, and the energy conversion efficiency is 16.82%.

[0072] Comparative Example 3:

[0073] Unlike Example 3 below, the solvent used is a mixture of methylamine-ethanol and acetonitrile (volume ratio 1:1), and A is CH3NH3. + B is Pb 2+ X is I - The specific steps for preparing this material are as follows:

[0074] 1. Weigh 0.461g PbI2 and 0.156g CH3NH3I and completely dissolve them in 1ml of a mixture of methylamine-ethanol and acetonitrile (by volume ratio 1:1) to obtain solution A;

[0075] 2. Take 8 μL of perovskite precursor solution A and deposit it into a printable mesoscopic perovskite solar cell;

[0076] 3. The printable mesoscopic perovskite solar cell device can be finally obtained by letting it stand at room temperature for 24 hours.

[0077] The obtained battery was subjected to IV testing, and the short-circuit current of the device was 16.99 mA / cm². 2 The open-circuit voltage is 0.96V, the fill factor is 73.94%, and the energy conversion efficiency is 12.06%.

[0078] Example 4:

[0079] In this embodiment, the preferred solvent is a mixture of ethylene glycol monomethyl ether and N-methylpyrrolidone (volume ratio 10:1), and A is CH4N2. + B is Pb 2+ X is I - The specific steps for preparing this material are as follows:

[0080] 1. Weigh 0.5071g PbI2 and 0.1749g CH4N2I and completely dissolve them in 1mL of ethylene glycol monomethyl ether and N-methylpyrrolidone (in a volume ratio of 4:1) to obtain solution A;

[0081] 2. Take 6 μL of perovskite precursor solution A and deposit it into a printable mesoscopic perovskite solar cell;

[0082] 3. Printable mesoscopic perovskite solar cell devices can be finally obtained by placing them in a methylamine gas environment for 24 hours.

[0083] The short-circuit current (J) of printable mesoscopic perovskite solar cells prepared using the above solvent SC The fill factor (FF) and power conversion efficiency (PCE) have all been significantly improved.

[0084] The obtained battery was subjected to IV testing, and the short-circuit current of the device was 22.66 mA / cm². 2 The open-circuit voltage is 0.98V, the fill factor is 77.01%, and the energy conversion efficiency is 17.10%.

[0085] Comparative Example 4:

[0086] Unlike Example 4 below, the solvent used is N-methylpyrrolidone, and A is CH3NH3. + B is Pb 2+ X is I - The specific steps for preparing this material are as follows:

[0087] 1. Weigh 0.5071g PbI2 and 0.1749g CH4N2I and completely dissolve them in 1ml N-methylpyrrolidone to obtain solution A;

[0088] 2. Take 6 μL of perovskite precursor solution A and deposit it into a printable mesoscopic perovskite solar cell;

[0089] 3. The printable mesoscopic perovskite solar cell device can be finally obtained by letting it stand at room temperature for 24 hours.

[0090] The obtained battery was subjected to IV testing, and the short-circuit current of the device was 16.79 mA / cm². 2 The open-circuit voltage is 0.96V, the fill factor is 69.92%, and the energy conversion efficiency is 11.27%.

[0091] As can be seen from the above experiments, the printable mesoscopic perovskite solar cells prepared using the embodiments of this patent have significantly improved power conversion efficiency (PCE) compared with existing solar cells without added alcohol ether solvents.

Claims

1. A method for fabricating a printable mesoscopic perovskite solar cell, wherein the solar cell has a layered structural framework, the layered structural framework comprising: A conductive substrate and a hole-blocking layer, a mesoporous electron transport layer, a mesoporous insulating layer, and a mesoporous electrode layer sequentially disposed on the conductive substrate, characterized in that: Step 1: A perovskite precursor solution is prepared by mixing and stirring the perovskite material with a solvent. The perovskite material is ABX3 type perovskite, where A is a monovalent organic or inorganic cation, B is a divalent metal cation, and X is a monovalent anion. The solvent includes alcohols, ethers, and other organic solvents. In the solvent, the proportion of alcohol ether is not less than 50% by volume. The other organic solvents are one or more selected from N,N-dimethylformamide, N-methylformamide, N-methylpyrrolidone, dimethyl sulfoxide, methanol, ethanol, isopropanol, methylamine, ethylamine, triethylamine, propylamine, acetonitrile, and tetrahydrofuran; Step 2: Deposit the perovskite precursor solution into the layered structure framework of the solar cell, allowing the precursor solution to permeate and fill the mesoporous electron transport layer, mesoporous insulating layer, and mesoporous electrode layer. Step 3: Allow to stand at room temperature to obtain the printable mesoscopic perovskite solar cell.

2. The preparation method according to claim 1, characterized in that, The proportion of alcohol ether in the solvent is not less than 70%.

3. The preparation method according to claim 1, characterized in that, The concentration of the perovskite precursor solution is 0.1-2 mol / L.

4. The preparation method according to claim 1, characterized in that, In the ABX3 type perovskite material, A is one or more of the following: methylamine group, formamidinium group, acetamidine group, cesium ion, lithium ion, potassium ion, sodium ion, and rubidium ion; B is one or more of the following: lead ion, tin ion, copper ion, germanium ion, manganese ion, ferrous ion, cobalt ion, nickel ion, zinc ion, and magnesium ion; and X is one or more of the following: fluoride ion, chloride ion, bromide ion, iodide ion, boron tetrafluoride anion, and thiocyanate anion.

5. The preparation method according to claim 1, characterized in that, The alcohol ether solvent is selected from one or more of the following: ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, diethylene glycol monoethyl ether, diethylene glycol propyl ether, diethylene glycol butyl ether, diethylene glycol pentyl ether, and diethylene glycol hexyl ether.

6. The preparation method according to claim 1, characterized in that, The conductive substrate includes a substrate and a conductive substrate layer.

7. The preparation method according to claim 6, characterized in that, The substrate is selected from one of the following: glass, polyethylene terephthalate, polyimide, polyethylene, polypropylene, polystyrene, and polyethylene terephthalate.

8. The preparation method according to claim 6, characterized in that, The conductive substrate layer is selected from ITO and FTO; the hole blocking layer is one or more of dense TiO2, SnO2, and ZnO; the mesoporous electron transport layer is one or more of mesoporous TiO2, SnO2, and ZnO; the mesoporous insulating layer is one or more of Al2O3, ZrO2, and MgO; and the mesoporous electrode layer is a carbon electrode.

9. The preparation method according to claim 8, characterized in that, The thickness of the conductive substrate layer is 10-1000 nm; the thickness of the hole blocking layer is 1-100 nm; the thickness of the mesoporous electron transport layer is 10-2000 nm; the thickness of the mesoporous insulating layer is 0.01-10 μm; and the thickness of the mesoporous electrode layer is 0.1-30 μm.

10. The preparation method according to claim 1, characterized in that, The layered structure skeleton can be prepared by one or more of the following methods: spin coating, spray coating, scraping coating, slot coating, screen printing, gravure printing, letterpress printing, flexographic printing, and offset printing.

11. The preparation method according to claim 1, characterized in that, The method for depositing the perovskite precursor solution is one or more of the following: drop coating, spin coating, spray coating, blade coating, slot coating, screen printing, gravure printing, letterpress printing, flexographic printing, and offset printing.

12. A printable mesoscopic perovskite solar cell, which is prepared by the method according to any one of claims 1-11.

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