Preparation method of single crystal perovskite battery

Abstract

The invention discloses a preparation method of a single crystal perovskite cell, which belongs to the technical field of solar cells, and comprises the following steps: S1, spin-coating a perovskite hole transport layer on a transparent conductive glass substrate; s2, coating the perovskite hole transport layer in the S1 with a perovskite solution, and growing a single crystal perovskite layer through inverse temperature crystallization by a space confinement method; and S3, spin-coating a bifunctional molecular layer on the single crystal perovskite layer in the step S2. According to the invention, high stability of the single crystal perovskite thin film is realized through surface modification; and surface defect passivation and stability improvement of the single crystal perovskite thin film are realized by using the bifunctional molecular layer. S atoms in the bifunctional molecular layer can be coordinated with Pb < 2 + > of the single-crystal perovskite thin film, so that the surface defect density and non-radiative recombination are reduced; besides, surface ion migration is reduced through modification of the bifunctional molecular layer, and finally, silane molecules and single crystal perovskite are cross-linked to form a protective layer on the surface of the crystal, so that the environmental stability of the material and the device is enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cells, and more specifically, to a method for preparing a single crystal perovskite cell. Background Art

[0002] In the past decade, metal halide perovskites have made rapid progress in various optoelectronic applications, and single-junction perovskite solar cells have achieved high certified power conversion efficiencies;

[0003] Currently, most of the work is conducted on polycrystalline perovskite films. The existence of grain boundaries in polycrystalline perovskite leads to a large number of defects in the perovskite film, and these defects will affect the stability of the entire battery due to the entry of moisture and oxygen. In order to solve this problem of polycrystalline perovskite films, single crystal perovskite has gradually attracted the attention of researchers. Compared with polycrystalline perovskite films, single crystal perovskite films have long-range ordered crystal orientation, smaller defect density and longer diffusion length.

[0004] However, the current preparation process of single crystal perovskite has defects on the surface of its film, and the non-radiative recombination caused by interface defects between the transport layer will affect the efficiency of single crystal perovskite cells.

[0005] To this end, a method for preparing a single crystal perovskite battery is proposed. Summary of the invention

[0006] In view of the problems existing in the prior art, the object of the present invention is to provide a method for preparing a single crystal perovskite battery, which can achieve high stability of the single crystal perovskite film through surface modification.

[0007] To solve the above problems, the present invention adopts the following technical solutions.

[0008] A method for preparing a single crystal perovskite battery comprises the following steps:

[0009] S1, spin coating a perovskite hole transport layer on a transparent conductive glass substrate;

[0010] S2, coating a perovskite solution on the perovskite hole transport layer in S1, and growing a single crystal perovskite layer by inversion crystallization using a spatial confinement method;

[0011] S3, spin coating a bifunctional molecular layer on the single crystal perovskite layer in S2;

[0012] S4, evaporating an electron transport layer on the bifunctional molecular layer in S3;

[0013] S5, atomic layer deposition of an interface modification layer on the electron transport layer in S4;

[0014] S6, evaporating a metal electrode on the interface modification layer in S5.

[0015] Furthermore, the perovskite hole transport layer is a SAM material with a thickness of 5nm-30nm.

[0016] Further, the thickness of the single crystal perovskite layer is 1 μm-30 μm;

[0017] The thickness of the bifunctional molecular layer is 1-10 nm;

[0018] The thickness of the electron transport layer is 5-30 nm;

[0019] The thickness of the interface modification layer is 5-20 nm.

[0020] Furthermore, the metal electrode is a silver electrode.

[0021] Furthermore, the interface modification layer is a SnO2 and BCP interface modification layer; SnO2 has a wider bandgap and is less damaged by ultraviolet light, thereby inhibiting photochemical reactions related to ultraviolet light and improving the stability of the device; BCP is often used as an exciton barrier layer, which can effectively separate and block excitons from reaching the metal electrode, thereby reducing non-radiative energy loss and improving the open circuit voltage and overall efficiency of the battery.

[0022] The electron transport layer is C 60 , PCBM electron transport layer; C 60 The electron transport layer can effectively passivate the defects on the perovskite surface, reduce trap-induced recombination, prolong the life of carriers, and help improve the photoelectric conversion efficiency; C 60 The application of PCBM as electron transport layer in perovskite solar cells brings the convenience of low-temperature preparation, optimized energy level matching, improved interface quality, and enhanced electron transport performance and stability.

[0023] Further, the bifunctional molecular layer is a bifunctional molecular layer of trimethoxysilane, 3-mercaptopropyltriethoxysilane or mercaptopropylmethyldimethoxysilane;

[0024] Furthermore, Meo-2PACz or Me-4PAC containing phosphoric acid groups is used as the perovskite hole transport layer.

[0025] Further, in step S1: when preparing a single crystal perovskite layer on the perovskite hole transport layer, the following steps are included:

[0026] S1.1, dropwise adding the perovskite solution onto the perovskite hole transport layer coated substrate at room temperature and enclosing with another SAM hole transport layer material for spatially confined inversion crystallization;

[0027] S1.2. Rapidly increase the heating temperature to 100°C within 1 hour, and then slowly increase it to 120°C at a rate of 1°C / h to induce nucleation and growth to obtain a single crystal perovskite layer.

[0028] Furthermore, the concentration of the perovskite solution is 1.5M, and the composition of the perovskite solution is Cs 0.05 FA 0.95 PbI3.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The present invention achieves high stability of single crystal perovskite film through surface modification; and uses a bifunctional molecular layer to achieve surface defect passivation and stability improvement of single crystal perovskite film. The S atoms in the bifunctional molecular layer can coordinate with the Pb2+ of the single crystal perovskite film to reduce the surface defect density and non-radiative recombination; in addition, the modification of the bifunctional molecular layer reduces the surface ion migration, thereby enhancing the operational stability of the device; finally, the silane molecules cross-link with the single crystal perovskite and form a protective layer on the crystal surface, thereby enhancing the environmental stability of the material and the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a structural diagram of a single crystal perovskite battery according to the present invention.

[0032] Figure 2 It is the structural formula of trimethoxysilane, the bifunctional molecular layer material of the present invention.

[0033] Figure 3 It is the structural formula of 3-mercaptopropyltriethoxysilane, the bifunctional molecular layer material of the present invention.

[0034] Figure 4 It is the structural formula of the bifunctional molecular layer material mercaptopropylmethyldimethoxysilane of the present invention. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making creative work are within the scope of protection of the present invention.

[0036] Embodiment 1:

[0037] See also Figures 1 to 4 , a method for preparing a single crystal perovskite battery, the single crystal perovskite battery comprising, from top to bottom, a metal electrode, an interface modification layer, an electron transport layer, a bifunctional molecular layer, a single crystal perovskite layer, a hole transport layer, and a transparent conductive glass substrate;

[0038] The steps include:

[0039] S1. Spin-coating a SAM material on a transparent conductive glass substrate to form a perovskite hole transport layer with a thickness of 5nm-30nm; and using Meo-2PACz or Me-4PAC containing a phosphoric acid group as the perovskite hole transport layer;

[0040] S2, coating a 1.5M perovskite solution on the perovskite hole transport layer in S1, wherein the composition of the perovskite solution is Cs 0.05 FA 0.95 PbI3; a single crystal perovskite layer with a thickness of 1 μm-30 μm is grown by inversion crystallization using a spatial confinement method;

[0041] S3, spin coating a bifunctional molecular layer with a thickness of 1-10 nm on the single crystal perovskite layer in S2; the bifunctional molecular layer is a bifunctional molecular layer of trimethoxysilane, 3-mercaptopropyltriethoxysilane or mercaptopropylmethyldimethoxysilane;

[0042] S4, evaporating an electron transport layer with a thickness of 5-30 nm on the bifunctional molecular layer in S3; the electron transport layer is C 60 , PCBM electron transport layer; C 60 The electron transport layer can effectively passivate the defects on the perovskite surface, reduce trap-induced recombination, prolong the life of carriers, and help improve the photoelectric conversion efficiency; C 60 The application of PCBM as electron transport layer in perovskite solar cells brings the convenience of low-temperature preparation, optimized energy level matching, improved interface quality, and enhanced electron transport performance and stability;

[0043] S5, depositing SnO2 and BCP interface modification layers with a thickness of 5-20 nm on the electron transport layer in S4 by atomic layer deposition; SnO2 has a wide bandgap and is less damaged by ultraviolet light, thus inhibiting photochemical reactions related to ultraviolet light and improving the stability of the device; BCP is often used as an exciton blocking layer, which can effectively separate and block excitons from reaching the metal electrode, thereby reducing non-radiative energy loss and improving the open circuit voltage and overall efficiency of the battery;

[0044] S6. Vapor-depositing a metal electrode on the interface modification layer in S5, wherein the metal electrode is a silver electrode.

[0045] In a specific embodiment of the present invention, in step S1: when preparing a single crystal perovskite layer on the perovskite hole transport layer, the following steps are included:

[0046] S1.1, dropwise adding the perovskite solution onto the perovskite hole transport layer coated substrate at room temperature and enclosing with another SAM hole transport layer material for spatially confined inversion crystallization;

[0047] S1.2. Rapidly increase the heating temperature to 100°C within 1 hour, and then slowly increase it to 120°C at a rate of 1°C / h to induce nucleation and growth to obtain a single crystal perovskite layer.

[0048] Usage method: spin coating a perovskite hole transport layer on a transparent conductive glass substrate, and the perovskite hole transport layer is a SAM material with a thickness of 5nm-30nm; then coating a perovskite solution on the perovskite hole transport layer, and growing a single crystal perovskite layer by inversion crystallization through a spatial confinement method; the thickness of the single crystal perovskite layer is 1μm-30μm; spin coating a bifunctional molecular layer on the single crystal perovskite layer; the thickness of the bifunctional molecular layer is 1-10nm; the bifunctional molecular layer is a trimethoxysilane, 3-mercaptopropyltriethoxysilane or mercaptopropylmethyldimethoxysilane bifunctional molecular layer; evaporating an electron transport layer on the bifunctional molecular layer; the thickness of the electron transport layer is 5-30nm; the electron transport layer is C 60 , PCBM electron transport layer; C 60 The electron transport layer can effectively passivate the defects on the perovskite surface, reduce trap-induced recombination, prolong the life of carriers, and help improve the photoelectric conversion efficiency; C 60 The application of PCBM as an electron transport layer in perovskite solar cells brings the convenience of low-temperature preparation, optimized energy level matching, improved interface quality, and enhanced electron transport performance and stability; an atomic layer deposition interface modification layer is formed on the electron transport layer; the thickness of the interface modification layer is 5-20nm, and the interface modification layer is a SnO2, BCP interface modification layer; SnO2 has a wider bandgap width and is less damaged by ultraviolet light, which inhibits photochemical reactions related to ultraviolet light and improves the stability of the device; BCP is often used as an exciton blocking layer, which can effectively separate and block excitons from reaching the metal electrode, thereby reducing non-radiative energy loss and improving the open circuit voltage and overall efficiency of the battery; a metal electrode is evaporated on the interface modification layer to eventually form a perovskite solar cell with a band gap of 1.5eV-1.6eV.

[0049] The above is only a preferred specific implementation of the present invention; however, the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solution and its improved conception within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing a single crystal perovskite battery, characterized in that: The steps include: S1, spin coating a perovskite hole transport layer on a transparent conductive glass substrate; S2, coating a perovskite solution on the perovskite hole transport layer in S1, and growing a single crystal perovskite layer by inversion crystallization using a spatial confinement method; S3, spin coating a bifunctional molecular layer on the single crystal perovskite layer in S2; S4, evaporating an electron transport layer on the bifunctional molecular layer in S3; S5, atomic layer deposition of an interface modification layer on the electron transport layer in S4; S6, evaporating a metal electrode on the interface modification layer in S5.

2. The method for preparing a single crystal perovskite battery according to claim 1, characterized in that: The perovskite hole transport layer is a SAM material with a thickness of 5nm-30nm.

3. The method for preparing a single crystal perovskite battery according to claim 2, characterized in that: The thickness of the single crystal perovskite layer is 1 μm-30 μm; The thickness of the bifunctional molecular layer is 1-10 nm; The thickness of the electron transport layer is 5-30 nm; The thickness of the interface modification layer is 5-20 nm.

4. The method for preparing a single crystal perovskite battery according to claim 3, characterized in that: The metal electrode is a silver electrode.

5. The method for preparing a single crystal perovskite battery according to claim 4, characterized in that: The interface modification layer is SnO2 or BCP interface modification layer; The electron transport layer is C 60 , PCBM electron transport layer; The bifunctional molecular layer is a trimethoxysilane, 3-mercaptopropyltriethoxysilane or mercaptopropylmethyldimethoxysilane bifunctional molecular layer; The perovskite hole transport layer is Meo-2PACz.

6. The method for preparing a single crystal perovskite battery according to claim 5, characterized in that: in, In step S1: when preparing a single crystal perovskite layer on the perovskite hole transport layer, the following steps are included: S1.1, dropwise adding the perovskite solution onto the perovskite hole transport layer coated substrate at room temperature and enclosing with another SAM hole transport layer material for spatially confined inversion crystallization; S1.

2. Rapidly increase the heating temperature to 100°C within 1 hour, and then slowly increase it to 120°C at a rate of 1°C / h to induce nucleation and growth to obtain a single crystal perovskite layer.

7. The method for preparing a single crystal perovskite battery according to claim 6, characterized in that: The concentration of the perovskite solution is 1.5M, and the composition of the perovskite solution is Cs 0.05 FA 0.95 PbI3.

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