Perovskite solar cell based on field effect passivation and preparation method thereof

Abstract

The invention belongs to the field of solar cells, and particularly discloses a perovskite solar cell based on field effect passivation and a preparation method thereof. The structure comprises transparent conductive glass, a hole transport layer, an organic molecule passivation layer, a field effect passivation layer, a perovskite absorption layer, an electron transport layer and a metal electrode. The preparation method of the field effect passivation layer comprises the following steps: dispersing Al2O3 nanoparticles in a solvent, and obtaining an Al2O3 film through a spin-coating annealing method. On the basis of organic molecule passivation, an Al2O3 interface passivation layer is introduced to a hole transport layer / perovskite interface, and the cell performance is improved through field effect passivation. The passivation method is suitable for all types of perovskite unijunction cells and perovskite laminated cells, is low in cost and simple to operate, and is expected to be commercially popularized.

Description

Technical Field

[0001] The invention belongs to the field of solar cells, and in particular relates to a perovskite solar cell based on field effect passivation and a preparation method thereof. Background Art

[0002] Perovskite solar cells are considered to be the most promising photovoltaic technology in the future due to their high carrier mobility, adjustable bandgap, high conversion efficiency and simple preparation process. Compared with traditional formal perovskite solar cells, inverted perovskite solar cells have attracted much attention due to their higher stability, negligible hysteresis effect and lower defect state density. Since the first perovskite solar cell appeared in 2013, the photoelectric conversion efficiency of single-junction perovskite solar cells has increased from 3.8% to 26.7%, and has developed very rapidly.

[0003] In inverse perovskite solar cells with nickel oxide as the hole transport layer, organic molecules with specific functional groups are usually used as buried bottom interface passivation materials to further eliminate defects on the surface and grain boundaries of the perovskite film. However, specific organic passivation materials may only be applicable to specific perovskite films, which has certain limitations and the passivation effect needs to be improved. In crystalline silicon cells, Al 2 O 3 The / Si contact surface has a high fixed negative charge density and exhibits significant field effect passivation characteristics by shielding minority carriers on the p-type silicon surface, thereby improving the hole transport efficiency. At the same time, the Al2O3 porous insulator contact is introduced at the hole transport layer / perovskite interface. 2 O 3 The dielectric layer can improve the hydrophilicity and hydrophobicity of the hole transport layer and improve the quality of the perovskite film. Therefore, we developed a perovskite solar cell based on field effect passivation and its preparation method to effectively improve the battery performance. Summary of the invention

[0004] The purpose of the present invention is to solve the limitation of the application of organic molecules with specific functional groups and the problem that the passivation performance needs to be improved, and to propose a perovskite solar cell based on field effect passivation and a preparation method thereof. On the basis of organic molecule passivation, Al is introduced at the hole transport layer / perovskite interface 2 O 3 Interface passivation layer improves battery performance through field effect passivation. This passivation method is applicable to all types of perovskite single-junction cells and perovskite stacked cells.

[0005] In order to achieve the above technical objectives, the present invention adopts the following technical solutions: A perovskite solar cell based on field effect passivation, the structure of which includes: transparent conductive glass, a hole transport layer, an organic molecule passivation layer, a field effect passivation layer, a perovskite absorption layer, an electron transport layer, and a metal electrode.

[0006] Furthermore, the transparent conductive glass is one or more transparent conductive oxide films such as tin-doped indium oxide (ITO), cerium-doped indium oxide (ICO), tungsten-doped indium oxide (IWO), zinc-doped indium oxide (IZO), hafnium-doped indium oxide (IHfO), zirconium-doped indium oxide (IZrO), aluminum-doped zinc oxide (AZO), tin-doped zinc oxide (ZTO), and fluorine-doped tin oxide (FTO).

[0007] Furthermore, the hole transport layer is nickel oxide, and the electron transport layer is fullerene and its derivatives.

[0008] Further, the organic molecular passivation layer material is one or more of [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (2PACz), [2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphonic acid (Me-2PACz), [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACz), [4-(9H-carbazole-9-yl)butyl]phosphonic acid (4PACz), [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid (Me-4PACz), and [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid (MeO-4PACz).

[0009] Furthermore, the field effect passivation layer is Al 2 O 3 Thin films formed by nanoparticles.

[0010] Furthermore, the perovskite absorption layer is a perovskite material of ABX3 structure, wherein A is one or more organic cations such as amines and amidines or inorganic cations such as cesium and rubidium; B is one or more metal cations such as lead, tin, and germanium; and X is one or more halogen anions such as fluorine, chlorine, bromine, and iodine.

[0011] Furthermore, the metal electrode is one or more of gold, silver, copper, platinum and the like.

[0012] A method for preparing a perovskite solar cell based on field effect passivation, further, the preparation method of the hole transport layer is one of magnetron sputtering and solution method. The preparation method of the organic molecular passivation layer is solution method. The preparation method of the field effect passivation layer is to prepare Al 2 O 3 The nanoparticles were dispersed in a solvent and Al2 O 3 The preparation method of the perovskite absorption layer is one of the solution method, the thermal evaporation-solution method, and the full vacuum method. The preparation method of the electron transport layer is one of the solution method and the thermal evaporation method. The preparation method of the metal electrode is one of the thermal evaporation method and the screen printing method.

[0013] Further, the Al 2 O 3 The nanoparticle dispersion includes one or more solvents such as water, ethanol, isopropanol, benzene, etc. 2 O 3 The concentration of the nanoparticle dispersion is 0.5-3.0 mg / mL. The spin coating method is a rotation speed of 3000-6000 rpm and a time of 10-50 s. The annealing method is an annealing temperature of 80-150°C and a time of 5-30 min.

[0014] Furthermore, the field effect passivation layer preparation method is applicable to all types of perovskite single junction cells and perovskite stacked cells.

[0015] Beneficial effects of the invention: The invention provides a perovskite solar cell based on field effect passivation and a preparation method thereof. In an inverse perovskite solar cell, an organic molecule with a specific functional group is usually used as a buried interface passivation material to further eliminate defects on the surface and grain boundaries of the perovskite film. However, a specific organic passivation material may only be applicable to a specific perovskite film, has certain limitations, and the passivation effect needs to be improved. Based on the passivation of organic molecules, we use Al 2 O 3 The fixed negative charge forms a field effect passivation at the hole transport layer / perovskite interface, improving the battery performance. This passivation method is applicable to all types of perovskite single-junction cells and perovskite stacked cells. It is low-cost and simple to operate, and is expected to be commercialized. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the structure of a perovskite solar cell based on field effect passivation according to the present invention; Figure 2 This is a flow chart of the preparation of a perovskite solar cell based on field effect passivation according to the present invention; Figure 3 JV curves of the perovskite solar cells obtained in Examples 1-5 and Comparative Example 1; Figure 4 The short-circuit current density of the perovskite solar cell obtained in Examples 1-5 and Comparative Example 1 ( J sc )、Open circuit voltage(V oc )、fill factor( FF ) and conversion efficiency ( PCE ). DETAILED DESCRIPTION

[0017] To make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings. However, the described embodiments are only a part of all possible embodiments of the present invention and are not limited thereto.

[0018] The present invention provides a field effect passivation-based perovskite solar cell and a preparation method thereof, wherein the cell structure is as follows: Figure 1 As shown, it includes transparent conductive glass, hole transport layer, organic molecule passivation layer, field effect passivation layer, perovskite absorption layer, electron transport layer, and metal electrode. The preparation process of the perovskite solar cell based on field effect passivation is as follows: Figure 2 shown. Example 1

[0019] (1) ITO conductive glass cleaning: wipe the ITO conductive glass with a dust-free cloth moistened with ethanol, then ultrasonicate it in acetone and ethanol for 10 min respectively, then rinse it with deionized water, blow dry it with nitrogen, and treat it with UV for 30 min before use.

[0020] (2) Preparation of hole transport layer: nickel oxide was dissolved in deionized water and ultrasonically dispersed, and then deposited on the above-mentioned ITO conductive glass by spin coating, and then annealed to obtain the hole transport layer. The concentration of nickel oxide was 20 mg / mL, the spin coating speed was 2000 rpm, and the spin coating time was 30 s. The annealing temperature in air was 200 °C, and the annealing time was 10 min.

[0021] (3) Preparation of organic molecular passivation layer: ethanol solutions of MeO-2PACz and Me-4PACz were mixed, deposited on the hole transport layer by spin coating, and annealed to obtain the organic molecular passivation layer. The spin coating speed was 3000 rpm, the spin coating time was 30 s, and the annealing temperature in air was 100 °C, and the annealing time was 10 min.

[0022] (4) Preparation of field effect passivation layer: Al 2 O 3 The nanoparticles are ultrasonically dispersed in an isopropanol solvent, deposited on the substrate by spin coating, and annealed to obtain a field effect passivation layer. 2 O 3The concentration of nanoparticles was 0.5 mg / mL, the spin coating speed was 4000 rpm, the spin coating time was 30 s, and the annealing temperature in the glove box was 100 °C for 15 min.

[0023] (5) Preparation of perovskite absorption layer: obtain an inorganic salt skeleton by thermal evaporation process, cover the inorganic salt skeleton with organic salt, and finally obtain a perovskite film by annealing. The inorganic salt skeleton is PbI 2 The organic salts are MABr and FAI. Two-step annealing is carried out in air with a humidity of 30%-40%, with the first annealing temperature at 150 °C and the annealing time at 10 min; the second annealing temperature at 100 °C and the annealing time at 10 min.

[0024] (6) Preparation of electron transport layer: an electron transport layer with a thickness of 20 nm is prepared on the perovskite absorption layer by a solution method.

[0025] (7) Preparation of metal electrode: a 120 nm copper electrode is deposited on the electron transport layer by thermal evaporation process. Example 2

[0026] (1) ITO conductive glass cleaning: wipe the ITO conductive glass with a dust-free cloth moistened with ethanol, then ultrasonicate it in acetone and ethanol for 10 min respectively, then rinse it with deionized water, blow dry it with nitrogen, and treat it with UV for 30 min before use.

[0027] (2) Preparation of hole transport layer: nickel oxide was dissolved in deionized water and ultrasonically dispersed, and then deposited on the above-mentioned ITO conductive glass by spin coating, and then annealed to obtain the hole transport layer. The concentration of nickel oxide was 20 mg / mL, the spin coating speed was 2000 rpm, and the spin coating time was 30 s. The annealing temperature in air was 200 °C, and the annealing time was 10 min.

[0028] (3) Preparation of organic molecular passivation layer: ethanol solutions of MeO-2PACz and Me-4PACz were mixed, deposited on the hole transport layer by spin coating, and annealed to obtain the organic molecular passivation layer. The spin coating speed was 3000 rpm, the spin coating time was 30 s, and the annealing temperature in air was 100 °C, and the annealing time was 10 min.

[0029] (4) Preparation of field effect passivation layer: Al 2 O 3 The nanoparticles are ultrasonically dispersed in an isopropanol solvent, deposited on the substrate by spin coating, and annealed to obtain a field effect passivation layer. 2 O 3The concentration of nanoparticles was 1.0 mg / mL, the spin coating speed was 4000 rpm, the spin coating time was 30 s, and the annealing temperature in the glove box was 100 °C for 15 min.

[0030] (5) Preparation of perovskite absorption layer: obtain an inorganic salt skeleton by thermal evaporation process, cover the inorganic salt skeleton with organic salt, and finally obtain a perovskite film by annealing. The inorganic salt skeleton is PbI 2 The organic salts are MABr and FAI. Two-step annealing is carried out in air with a humidity of 30%-40%, with the first annealing temperature at 150 °C and the annealing time at 10 min; the second annealing temperature at 100 °C and the annealing time at 10 min.

[0031] (6) Preparation of electron transport layer: an electron transport layer with a thickness of 20 nm is prepared on the perovskite absorption layer by a solution method.

[0032] (7) Preparation of metal electrode: a 120 nm copper electrode is deposited on the electron transport layer by thermal evaporation process. Example 3

[0033] (1) ITO conductive glass cleaning: wipe the ITO conductive glass with a dust-free cloth moistened with ethanol, then ultrasonicate it in acetone and ethanol for 10 min respectively, then rinse it with deionized water, blow dry it with nitrogen, and treat it with UV for 30 min before use.

[0034] (2) Preparation of hole transport layer: nickel oxide was dissolved in deionized water and ultrasonically dispersed, and then deposited on the above-mentioned ITO conductive glass by spin coating, and then annealed to obtain the hole transport layer. The concentration of nickel oxide was 20 mg / mL, the spin coating speed was 2000 rpm, and the spin coating time was 30 s. The annealing temperature in air was 200 °C, and the annealing time was 10 min.

[0035] (3) Preparation of organic molecular passivation layer: ethanol solutions of MeO-2PACz and Me-4PACz were mixed, deposited on the hole transport layer by spin coating, and annealed to obtain the organic molecular passivation layer. The spin coating speed was 3000 rpm, the spin coating time was 30 s, and the annealing temperature in air was 100 °C, and the annealing time was 10 min.

[0036] (4) Preparation of field effect passivation layer: Al 2 O 3 The nanoparticles are ultrasonically dispersed in an isopropanol solvent, deposited on the substrate by spin coating, and annealed to obtain a field effect passivation layer. 2 O 3The concentration of nanoparticles was 2.0 mg / mL, the spin coating speed was 4000 rpm, the spin coating time was 30 s, and the annealing temperature in the glove box was 100 °C for 15 min.

[0037] (5) Preparation of perovskite absorption layer: obtain an inorganic salt skeleton by thermal evaporation process, cover the inorganic salt skeleton with organic salt, and finally obtain a perovskite film by annealing. The inorganic salt skeleton is PbI 2 The organic salts are MABr and FAI. Two-step annealing is carried out in air with a humidity of 30%-40%, with the first annealing temperature at 150 °C and the annealing time at 10 min; the second annealing temperature at 100 °C and the annealing time at 10 min.

[0038] (6) Preparation of electron transport layer: an electron transport layer with a thickness of 20 nm is prepared on the perovskite absorption layer by a solution method.

[0039] (7) Preparation of metal electrode: a 120 nm copper electrode is deposited on the electron transport layer by thermal evaporation process. Example 4

[0040] (1) ITO conductive glass cleaning: wipe the ITO conductive glass with a dust-free cloth moistened with ethanol, then ultrasonicate it in acetone and ethanol for 10 min respectively, then rinse it with deionized water, blow dry it with nitrogen, and treat it with UV for 30 min before use.

[0041] (2) Preparation of hole transport layer: nickel oxide was dissolved in deionized water and ultrasonically dispersed, and then deposited on the above-mentioned ITO conductive glass by spin coating, and then annealed to obtain the hole transport layer. The concentration of nickel oxide was 20 mg / mL, the spin coating speed was 2000 rpm, and the spin coating time was 30 s. The annealing temperature in air was 200 °C, and the annealing time was 10 min.

[0042] (3) Preparation of organic molecular passivation layer: ethanol solutions of MeO-2PACz and Me-4PACz were mixed, deposited on the hole transport layer by spin coating, and annealed to obtain the organic molecular passivation layer. The spin coating speed was 3000 rpm, the spin coating time was 30 s, and the annealing temperature in air was 100 °C, and the annealing time was 10 min.

[0043] (4) Preparation of field effect passivation layer: Al 2 O 3 The nanoparticles are ultrasonically dispersed in an isopropanol solvent, deposited on the substrate by spin coating, and annealed to obtain a field effect passivation layer. 2 O 3The concentration of nanoparticles was 2.5 mg / mL, the spin coating speed was 4000 rpm, the spin coating time was 30 s, and the annealing temperature in the glove box was 100 °C for 15 min.

[0044] (5) Preparation of perovskite absorption layer: obtain an inorganic salt skeleton by thermal evaporation process, cover the inorganic salt skeleton with organic salt, and finally obtain a perovskite film by annealing. The inorganic salt skeleton is PbI 2 The organic salts are MABr and FAI. Two-step annealing is carried out in air with a humidity of 30%-40%, with the first annealing temperature at 150 °C and the annealing time at 10 min; the second annealing temperature at 100 °C and the annealing time at 10 min.

[0045] (6) Preparation of electron transport layer: an electron transport layer with a thickness of 20 nm is prepared on the perovskite absorption layer by a solution method.

[0046] (7) Preparation of metal electrode: a 120 nm copper electrode is deposited on the electron transport layer by thermal evaporation process. Example 5

[0047] (1) ITO conductive glass cleaning: wipe the ITO conductive glass with a dust-free cloth moistened with ethanol, then ultrasonicate it in acetone and ethanol for 10 min respectively, then rinse it with deionized water, blow dry it with nitrogen, and treat it with UV for 30 min before use.

[0048] (2) Preparation of hole transport layer: nickel oxide was dissolved in deionized water and ultrasonically dispersed, and then deposited on the above-mentioned ITO conductive glass by spin coating, and then annealed to obtain the hole transport layer. The concentration of nickel oxide was 20 mg / mL, the spin coating speed was 2000 rpm, and the spin coating time was 30 s. The annealing temperature in air was 200 °C, and the annealing time was 10 min.

[0049] (3) Preparation of organic molecular passivation layer: ethanol solutions of MeO-2PACz and Me-4PACz were mixed, deposited on the hole transport layer by spin coating, and annealed to obtain the organic molecular passivation layer. The spin coating speed was 3000 rpm, the spin coating time was 30 s, and the annealing temperature in air was 100 °C, and the annealing time was 10 min.

[0050] (4) Preparation of field effect passivation layer: Al 2 O 3 The nanoparticles are ultrasonically dispersed in an isopropanol solvent, deposited on the substrate by spin coating, and annealed to obtain a field effect passivation layer. 2 O 3The concentration of nanoparticles was 3.0 mg / mL, the spin coating speed was 4000 rpm, the spin coating time was 30 s, and the annealing temperature in the glove box was 100 °C for 15 min.

[0051] (5) Preparation of perovskite absorption layer: obtain an inorganic salt skeleton by thermal evaporation process, cover the inorganic salt skeleton with organic salt, and finally obtain a perovskite film by annealing. The inorganic salt skeleton is PbI 2 The organic salts are MABr and FAI. Two-step annealing is carried out in air with a humidity of 30%-40%, with the first annealing temperature at 150 °C and the annealing time at 10 min; the second annealing temperature at 100 °C and the annealing time at 10 min.

[0052] (6) Preparation of electron transport layer: an electron transport layer with a thickness of 20 nm is prepared on the perovskite absorption layer by a solution method.

[0053] (7) Preparation of metal electrode: a 120 nm copper electrode is deposited on the electron transport layer by thermal evaporation process.

[0054] The preparation method of the battery in Comparative Example 1 is similar to that in Example 1, the only difference being that the preparation of the field effect passivation layer is omitted. The perovskite solar cells obtained in Examples 1-5 and Comparative Example 1 were subjected to JV tests, and the results are shown in FIG. Figure 3 and Figure 4 We found that the introduction of Al at the hole transport layer / perovskite interface 2 O 3 Nanoparticles have a good field effect passivation effect, and the average V oc Increased from 1.068 V to 1.082 V, average FF From 65.81% to 70.65%, the average PCE From 18.44% to 20.05%. PCE The field effect passivation method proposed by the present invention is applicable to all types of perovskite single-junction cells and perovskite stacked cells. It is low in cost and simple to operate, and is expected to be commercially promoted.

[0055] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A perovskite solar cell based on field effect passivation, characterized in that: The structure includes: Transparent conductive glass, hole transport layer, organic molecule passivation layer, field effect passivation layer, perovskite absorption layer, electron transport layer, metal electrode.

2. A perovskite solar cell based on field effect passivation according to claim 1, characterized in that: The transparent conductive glass is one or more transparent conductive oxide films such as tin-doped indium oxide (ITO), cerium-doped indium oxide (ICO), tungsten-doped indium oxide (IWO), zinc-doped indium oxide (IZO), hafnium-doped indium oxide (IHfO), zirconium-doped indium oxide (IZrO), aluminum-doped zinc oxide (AZO), tin-doped zinc oxide (ZTO), and fluorine-doped tin oxide (FTO).

3. A perovskite solar cell based on field effect passivation according to claim 1, characterized in that: The hole transport layer is nickel oxide, and the electron transport layer is fullerene and its derivatives.

4. A perovskite solar cell based on field effect passivation according to claim 1, characterized in that: The organic molecular passivation layer material is one or more of [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (2PACz), [2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphonic acid (Me-2PACz), [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACz), [4-(9H-carbazole-9-yl)butyl]phosphonic acid (4PACz), [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid (Me-4PACz), and [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid (MeO-4PACz).

5. A perovskite solar cell based on field effect passivation according to claim 1, characterized in that: The field effect passivation layer is a thin film formed by Al2O3 nanoparticles.

6. A perovskite solar cell based on field effect passivation according to claim 1, characterized in that: The perovskite absorption layer is a perovskite material of ABX3 structure, wherein A is one or more organic cations such as amine and amidine or inorganic cations such as cesium and rubidium; B is one or more metal cations such as lead, tin, and germanium; and X is one or more halogen anions such as fluorine, chlorine, bromine, and iodine.

7. A perovskite solar cell based on field effect passivation according to claim 1, characterized in that: The metal electrode is one or more of gold, silver, copper, platinum and the like.

8. A method for preparing a perovskite solar cell based on field effect passivation, characterized in that: The hole transport layer is prepared by magnetron sputtering or solution method. The organic molecular passivation layer is prepared by solution method. The field effect passivation layer is prepared by dispersing Al2O3 nanoparticles in a solvent and obtaining an Al2O3 film by spin coating annealing. The perovskite absorption layer is prepared by solution method, thermal evaporation-solution method, and full vacuum method. The electron transport layer is prepared by solution method or thermal evaporation method. The metal electrode is prepared by thermal evaporation or screen printing method.

9. The method for preparing a perovskite solar cell based on field effect passivation according to claim 8, characterized in that: The Al2O3 nanoparticle dispersion includes one or more solvents such as water, ethanol, isopropanol, benzene, etc. The concentration of the Al2O3 nanoparticle dispersion is 0.5-3.0 mg / mL. The spin coating method is a rotation speed of 3000-6000 rpm and a time of 10-50 s. The annealing method is an annealing temperature of 80-150 ° C and a time of 5-30 min.

10. The method for preparing a field effect passivation layer according to claim 9, characterized in that: This method is applicable to all types of perovskite single-junction cells as well as perovskite tandem cells.

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