Perovskite solar cell and preparation method and application thereof

Abstract

The invention discloses a perovskite solar cell and a preparation method and application thereof, and the perovskite solar cell, the perovskite solar cell is characterized in that the perovskite solar cell comprises a hole transport layer and a perovskite light absorption layer, a hole transport interface modification layer is arranged between the hole transport layer and the perovskite light absorption layer, the hole transport interface modification layer is an amine-rich layer, and the hole transport interface modification layer is an amine-rich layer. The perovskite light absorption layer is a formamidino perovskite layer or a formamidino phase-based formamidino / methylamine mixed perovskite layer. According to the method, through formation of the amine-rich interface, control of the temperature in the spin-coating process and confinement space annealing, the phenomenon of nucleus aggregation during formamidino perovskite nucleation is effectively inhibited, and the phenomenon of solute depletion caused by rapid volatilization of a wet film is avoided, so that the formamidino perovskite film forming quality is improved, and the efficiency of a perovskite photovoltaic device is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cells, and in particular to a perovskite solar cell and a preparation method and application thereof. Background Art

[0002] In recent years, perovskite solar cells have developed rapidly, but further improvement of device efficiency and stability remains an important research direction in this field. Formamidinium-based perovskites (FAPbX3) or formamidinium / methylamine mixed perovskites (FA / MA) have attracted widespread attention from researchers due to their high efficiency, good stability and process repeatability. For formamidinium-based perovskites, the crystallization process is mainly divided into four stages: nucleation, transformation from α phase to δ phase, transformation from δ phase to α phase, and bulk crystal formation. However, nuclear aggregation is very likely to occur during the nucleation process, which can cause solute depletion of the wet film, leading to cracking of the film, greatly affecting the crystallinity and morphology of the film, and ultimately resulting in a decrease in the efficiency of perovskite photovoltaic devices. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0004] To this end, an embodiment of the present invention provides a perovskite solar cell and a preparation method and application thereof.

[0005] In a first aspect, the present invention proposes a perovskite solar cell, comprising a hole transport layer and a perovskite light absorbing layer, wherein a hole transport interface modification layer is arranged between the hole transport layer and the perovskite light absorbing layer, the hole transport interface modification layer is an amine-rich layer, and the perovskite light absorbing layer is a formamidine-based perovskite layer or a formamidine / methylamine mixed perovskite layer mainly composed of a formamidine-based phase.

[0006] Furthermore, the perovskite solar cell also includes transparent conductive glass, an electron transport layer, an electrode, and encapsulation glass, and the transparent conductive glass, the hole transport layer, the hole transport interface modification layer, the perovskite light absorption layer, the electron transport layer, the electrode, and the encapsulation glass are arranged in sequence.

[0007] Furthermore, the transparent conductive glass includes one of ITO glass, FTO glass and AZO glass.

[0008] Furthermore, the electron transport layer includes one of C60, PCBM and BCP.

[0009] Furthermore, the electrode includes one of Au, Ag, Cu, IWO, and AZO.

[0010] Furthermore, the hole transport layer includes one of NiO, PTAA, P3HT, 2PACz, and Me-4PACz.

[0011] Furthermore, the encapsulation glass includes ultra-white glass.

[0012] In a second aspect, the present invention provides a method for preparing a perovskite solar cell, which is used to prepare the perovskite solar cell provided in the first aspect, comprising the following steps:

[0013] (a) Preparing a hole transport layer on a transparent conductive glass;

[0014] (b) preparing a hole transport interface modification layer on the surface of the hole transport layer;

[0015] (c) preparing a perovskite light absorbing layer on the surface of the hole transport interface modification layer.

[0016] Furthermore, in the step (b), the hole transport interface modification layer is prepared by introducing an amine-containing material onto the surface of the hole transport layer or by subjecting the hole transport layer to oxygen plasma treatment and then immersing the layer in a silane solution for annealing.

[0017] Furthermore, the thickness of the hole transport interface modification layer is 5 to 15 nm.

[0018] Furthermore, the amine-containing material includes one of N-(2-aminoethyl)acetamide, thioacetamide, and aniline.

[0019] Furthermore, the oxygen flow rate of the oxygen plasma treatment is 100 to 300 mL / min, and the treatment time is 15 to 60 s.

[0020] Furthermore, the step (c) comprises:

[0021] Applying a perovskite solution on the surface of the hole transport interface modification layer by a solution method at 10-20° C.;

[0022] The perovskite light-absorbing layer is obtained by annealing at 100-160° C. for 15-30 min in a closed space.

[0023] Furthermore, the thickness of the perovskite light-absorbing layer is 400-800 nm.

[0024] In a third aspect, the present invention proposes the application of the perovskite solar cell proposed in the first aspect or the perovskite solar cell prepared by the preparation method proposed in the second aspect in the photovoltaic field.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] The present invention forms an amine-rich interface, controls the temperature of the spin-coating process and the confined space annealing, effectively inhibits the nuclear aggregation phenomenon during the nucleation of the formamidinium-based perovskite, avoids the solute depletion phenomenon caused by the rapid volatilization of the wet film, thereby improving the film formation quality of the formamidinium-based perovskite film and improving the efficiency of the perovskite photovoltaic device. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0028] Figure 1 This is a schematic diagram of the structure of a perovskite solar cell according to the present invention. DETAILED DESCRIPTION

[0029] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0030] The perovskite solar cell of the present invention and its preparation method and application are described below in conjunction with the accompanying drawings.

[0031] like Figure 1 As shown, the perovskite solar cell of the present invention comprises a transparent conductive glass, a hole transport layer, a hole transport interface modification layer, a perovskite light absorption layer, an electron transport layer, an electrode and an encapsulation glass which are arranged in sequence.

[0032] The transparent conductive glass includes one of ITO glass, FTO glass and AZO glass, and is generally prepared by using a magnetron sputtering method on glass.

[0033] The hole transport layer includes one of NiO, PTAA, P3HT, 2PACz, and Me-4PACz, and can be prepared by spin coating, blade coating, wire rod coating, slit coating, spray deposition, magnetron sputtering, etc.

[0034] A hole transport interface modification layer is arranged between the hole transport layer and the perovskite light absorbing layer, and the hole transport interface modification layer is an amine-rich layer.

[0035] The perovskite light-absorbing layer is a formamidite perovskite layer or a formamidite / methylamine mixed perovskite layer mainly composed of a formamidite phase, and its general chemical formula is ABX3, wherein A is FA or a mixture of FA / MA, and the FA phase is mainly present in the mixture of FA / MA, B is Pb, and X is I, Br, Cl, etc.

[0036] The electron transport layer includes one of C60, PCBM, and BCP, and can be prepared by spin coating, blade coating, wire rod coating, slit coating, thermal evaporation, and the like.

[0037] The electrode is a top metal electrode or a metal oxide transparent electrode, and the main materials are Au, Ag, Cu, IWO, AZO, etc., which can be prepared by thermal evaporation, magnetron sputtering, reactive plasma deposition, etc.

[0038] The encapsulation glass includes ultra-white glass, which is used to protect perovskite solar cells from corrosion such as water vapor and improve their stability.

[0039] A method for preparing a perovskite solar cell comprises the following steps:

[0040] (a) Preparing a hole transport layer on a transparent conductive glass;

[0041] (b) preparing a hole transport interface modification layer on the surface of the hole transport layer;

[0042] (c) Preparation of a perovskite light-absorbing layer on the surface of the hole transport interface modification layer.

[0043] Wherein, in step (a), a hole transport layer is prepared on the transparent conductive glass, and it is used as a substrate for the subsequent preparation of the perovskite film.

[0044] In step (b), a hole transport interface modification layer is prepared on the surface of the hole transport layer, and the thickness of the hole transport interface modification layer is 5 to 15 nm.

[0045] In some embodiments, an amine-rich layer is formed by introducing an amine-containing material on the surface of the substrate by spin coating or solution dipping, that is, a material rich in NH2 groups is introduced on the surface of the hole transport layer to form a hole transport interface modification layer. The amine-containing material includes one of N-(2-aminoethyl)acetamide, thioacetamide, and aniline.

[0046] In some embodiments, the hole transport interface modification layer is prepared by subjecting the hole transport layer to oxygen plasma treatment and then immersing it in a silane solution for annealing. When performing oxygen plasma treatment, a plasma treatment machine is used, oxygen is used as a process gas, and the treatment is performed for 15 to 60 seconds at a radio frequency of 40 KHz, a plasma power of 300 to 400 W, and an oxygen flow rate of 100 to 300 mL / min, and then immersed in a silane solution and annealed at 75 to 85° C. to form an amine-rich interface layer.

[0047] Step (c) comprises: applying a perovskite solution on the surface of the hole transport interface modification layer by a solution method at 10-20° C.; and annealing at 100-160° C. for 15-30 minutes in a closed space to obtain a perovskite light absorbing layer.

[0048] The perovskite precursor solvent is one or more of DMF, DMSO, NMP, IPA, etc., the solute is formamidinium perovskite or formamidinium / methylamine perovskite, and the solute concentration is 1.0-1.5 mol / L. The perovskite film is prepared by spin coating, scraper coating, wire rod coating, slit coating, etc., and the substrate temperature is controlled to be 10-20°C during the preparation process by PID temperature control through semiconductor cold stage or water cooling, the temperature stability is ±0.1-0.5°C, the temperature resolution is 0.1°C, and the film thickness is 400-800nm.

[0049] After coating, annealing is performed at 100-160° C. for 15-30 min in a confined space to obtain a perovskite light-absorbing layer. In some embodiments, the glass cover is inverted on a hot plate to form a confined space, so that the perovskite film prepared by the solution method is placed in a confined space for annealing.

[0050] The present invention first forms an amine-rich layer on the substrate, and then prepares a perovskite film layer on the amine-rich layer. The NH2 group can form coordination with the formamidinium-based perovskite or the formamidinium / methylamine-based perovskite, so that the formamidinium-based perovskite or the formamidinium / methylamine-based perovskite nucleates along the amine-rich template. At the same time, by reducing the substrate temperature, the nucleation efficiency of the formamidinium-based perovskite or the formamidinium / methylamine-based perovskite and the solvent volatilization rate are reduced, effectively avoiding the nuclear aggregation phenomenon in the nucleation stage. Confined space annealing can effectively avoid the rapid volatilization of solutes in the wet film with the solvent, further improving the crystallization quality of the perovskite film.

[0051] The present invention is described below with reference to specific embodiments.

[0052] Example 1

[0053] On the transparent conductive glass ITO glass, a PTAA layer with a hole transport layer thickness of 50 nm was prepared by spin coating, and an ethanol solution of thioacetamide was spin coated on the PTAA layer to prepare a rich amine layer with a thickness of 5 nm. A 1.0 mol / L DMF solution of FAPbI3 was scraped on the surface of the rich amine layer at 12.0±0.5°C, and annealed at 120°C in a closed space for 20 min to obtain a perovskite film layer with a thickness of 500 nm.

[0054] A PCBM electron transport layer with a thickness of 100 nm was prepared by spin coating on the perovskite thin film layer, and a Ag electrode with a thickness of 60 nm was obtained by thermal evaporation on the electron transport layer, and finally it was encapsulated with ultra-white glass.

[0055] Example 2

[0056] On the transparent conductive glass ITO glass, a PTAA layer with a hole transport layer thickness of 50 nm was prepared by spin coating, and an ethanol solution of thioacetamide was spin coated on the PTAA layer to prepare a rich amine layer with a thickness of 15 nm. A 1.0 mol / L DMF solution of FAPbI3 was scraped on the surface of the rich amine layer at 15.0±0.5°C, and annealed at 150°C for 15 min in a closed space to obtain a perovskite film layer with a thickness of 500 nm.

[0057] A PCBM electron transport layer with a thickness of 100 nm was prepared by spin coating on the perovskite thin film layer, and a Ag electrode with a thickness of 60 nm was obtained by thermal evaporation on the electron transport layer, and finally it was encapsulated with ultra-white glass.

[0058] Example 3

[0059] On the transparent conductive glass ITO glass, a PTAA layer with a hole transport layer thickness of 50 nm was prepared by spin coating, and an ethanol solution of thioacetamide was spin coated on the PTAA layer to prepare a rich amine layer with a thickness of 10 nm. A 1.5 mol / L DMF solution of FAPbI3 was scraped on the surface of the rich amine layer at 12.0±0.5°C, and annealed at 120°C in a closed space for 20 min to obtain a perovskite film layer with a thickness of 800 nm.

[0060] A PCBM electron transport layer with a thickness of 100 nm was prepared by spin coating on the perovskite thin film layer, and a Ag electrode with a thickness of 60 nm was obtained by thermal evaporation on the electron transport layer, and finally it was encapsulated with ultra-white glass.

[0061] Example 4

[0062] On the transparent conductive glass FTO glass, a PTAA layer with a hole transport layer thickness of 50 nm was prepared by spin coating. The FTO / PTAA substrate was treated at a radio frequency power of 40 kHz, a plasma power of 300 W, and an oxygen flow rate of 100 mL / min for 60 s, then immersed in a silane solution and annealed at 80°C to form a rich amine interface layer with a thickness of 10 nm. A 1.0 mol / L DMF solution of FAPbI3 was scraped on the surface of the rich amine layer at 12.0±0.5°C, and annealed at 120°C in a closed space for 20 min to obtain a perovskite film layer with a thickness of 500 nm.

[0063] A PCBM electron transport layer with a thickness of 100 nm was prepared by spin coating on the perovskite thin film layer, and a Ag electrode with a thickness of 60 nm was obtained by thermal evaporation on the electron transport layer, and finally it was encapsulated with ultra-white glass.

[0064] Comparative Example 1

[0065] On the transparent conductive glass ITO glass, a PTAA layer with a hole transport layer thickness of 50 nm was prepared by spin coating, and a 1.0 mol / L DMF solution of FAPbI3 was scraped on the surface of the hole transport layer at 12.0±0.5°C, and annealed at 120°C in a closed space for 20 min to obtain a perovskite film layer with a thickness of 500 nm.

[0066] A PCBM electron transport layer with a thickness of 100 nm was prepared by spin coating on the perovskite thin film layer, and a Ag electrode with a thickness of 60 nm was obtained by thermal evaporation on the electron transport layer, and finally it was encapsulated with ultra-white glass.

[0067] Test example

[0068] The perovskite solar cells prepared in Examples 1 to 4 and Comparative Example 1 were tested by a solar light simulator to test the photoelectric conversion efficiency of the perovskite solar cells. The test results are shown in Table 1 below.

[0069] Table 1

[0070]

[0071]

[0072] According to Table 1, the photoelectric conversion efficiency of the perovskite solar cells of Examples 1 to 4 is greater than that of Comparative Example 1. When a hole transport interface modification layer is provided between the hole transport layer and the perovskite light absorbing layer, the photoelectric conversion efficiency of the perovskite solar cell can be improved.

[0073] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms may be for different embodiments or examples. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0074] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0075] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A perovskite solar cell, characterized in that: It comprises a hole transport layer and a perovskite light absorbing layer, wherein a hole transport interface modification layer is arranged between the hole transport layer and the perovskite light absorbing layer, the hole transport interface modification layer is an amine-rich layer, and the perovskite light absorbing layer is a formamidine-based perovskite layer or a formamidine / methylamine mixed perovskite layer mainly containing a formamidine-based perovskite phase.

2. The perovskite solar cell according to claim 1, characterized in that The perovskite solar cell also includes transparent conductive glass, an electron transport layer, an electrode, and encapsulation glass. The transparent conductive glass, the hole transport layer, the hole transport interface modification layer, the perovskite light absorption layer, the electron transport layer, the electrode, and the encapsulation glass are arranged in sequence.

3. The perovskite solar cell according to claim 2, characterized in that The transparent conductive glass includes one of ITO glass, FTO glass and AZO glass; And / or, the electron transport layer comprises one of C60, PCBM, and BCP; And / or, the electrode comprises one of Au, Ag, Cu, IWO, and AZO; And / or, the hole transport layer comprises one of NiO, PTAA, P3HT, 2PACz, and Me-4PACz; And / or, the encapsulation glass includes ultra-white glass.

4. A method for preparing a perovskite solar cell, characterized in that: The method for preparing the perovskite solar cell according to any one of claims 1 to 3 comprises the following steps: (a) Preparing a hole transport layer on a transparent conductive glass; (b) preparing a hole transport interface modification layer on the surface of the hole transport layer; (c) preparing a perovskite light absorbing layer on the surface of the hole transport interface modification layer.

5. The preparation method according to claim 4, characterized in that: In the step (b), the hole transport interface modification layer is prepared by introducing an amine-containing material on the surface of the hole transport layer or by subjecting the hole transport layer to an oxygen plasma treatment and then immersing the layer in a silane solution for annealing; And / or, the thickness of the hole transport interface modification layer is 5 to 15 nm.

6. The preparation method according to claim 5, characterized in that: The amine-containing material includes one of N-(2-aminoethyl)acetamide, thioacetamide and aniline.

7. The preparation method according to claim 5, characterized in that: The oxygen flow rate of the oxygen plasma treatment is 100 to 300 mL / min, and the treatment time is 15 to 60 s.

8. The preparation method according to claim 4, characterized in that: The step (c) comprises: Applying a perovskite solution on the surface of the hole transport interface modification layer by a solution method at 10-20° C.; The perovskite light-absorbing layer is obtained by annealing at 100-160° C. for 15-30 min in a closed space.

9. The preparation method according to claim 8, characterized in that: The thickness of the perovskite light-absorbing layer is 400-800 nm.

10. Application of the perovskite solar cell according to any one of claims 1 to 3 or the perovskite solar cell prepared by the preparation method according to any one of claims 4 to 9 in the photovoltaic field.

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