An easily scalable process for passivating perovskite surfaces

Abstract

The present invention proposes a perovskite surface passivation process that is easy to scale up, comprising the following steps: S1: taking a first substrate glass, and sequentially preparing a first electrode, an electron transport layer and a perovskite layer on the first substrate glass; S2: taking a second substrate glass, sequentially preparing a second electrode and a hole transport layer on the second substrate glass, and then preparing a passivation layer on the hole transport layer; S3: using a hot pressing method to press the semi-finished perovskite devices prepared in steps S1 and S2 together at high temperature, and the perovskite layer and the passivation layer are bonded to each other to form a final complete perovskite device. This process can successfully scale up the perovskite surface passivation process used in small devices to the preparation of large components, reduce the damage of the solution of the passivation layer to the perovskite, and improve the efficiency and stability of the device; and the solvent used in the passivation process is not subject to too many restrictions, thereby expanding its selection range.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic technology, and in particular to a perovskite surface passivation process that is easily scalable. Background Art

[0002] In recent years, with the continuous deepening of research, perovskite batteries have made rapid progress, with the efficiency increasing from the initial 3.8% to more than 25%, and are hailed as "the new hope in the photovoltaic field."

[0003] Common perovskite cell structures are divided into mesoscopic structures, mesoscopic superstructures, planar nip-type and planar pin-type structures. In order to improve the efficiency of perovskite devices, perovskite doping or interface passivation processes are commonly used. Perovskite doping is easy to industrially scale up, but the perovskite surface passivation process is not easy, because the commonly used process for perovskite surface passivation is solution spin coating, dissolving the passivation material in solvents such as isopropanol, ethanol, ethyl acetate, and then spin coating the solution on the perovskite surface to achieve the passivation effect. The specific steps are shown in Figure 4 This method is mainly used for the preparation of small devices. If it is used for industrial amplification, coating or scraping is generally used. However, unlike spin coating of small devices, the solvent in the solution can evaporate quickly during spin coating and will not damage the perovskite. During coating or scraping, the solution stays on the perovskite surface for a long time. Many solvents used will damage the perovskite, resulting in reduced device efficiency, and the effect of passivation to improve device efficiency cannot be achieved. Or only solvents such as chlorobenzene that have less destructive effect on perovskite can be used. In addition, the solubility of the passivation material must be considered, which makes the passivation process very limited in terms of solvent selection. Summary of the invention

[0004] In order to solve the above technical problems, the present invention proposes a perovskite surface passivation process that is easy to scale up, comprising the following steps:

[0005] S1: taking a first substrate glass, and sequentially preparing a first electrode, an electron transport layer and a perovskite layer on the first substrate glass;

[0006] S2: taking a second substrate glass, sequentially preparing a second electrode and a hole transport layer on the second substrate glass, and then preparing a passivation layer on the hole transport layer;

[0007] S3: The semi-finished perovskite devices prepared in steps S1 and S2 are pressed together at high temperature by hot pressing, and the perovskite layer and the passivation layer are bonded to each other to form a final complete perovskite device.

[0008] Preferably, the first electrode and the second electrode are prepared by vacuum evaporation or vacuum sputtering.

[0009] Preferably, the substrate is prepared by physical vapor deposition, evaporation or sputtering.

[0010] Preferably, the electron transport layer is sequentially provided with TiO2 and SnO2, the thickness of the TiO2 is about 10 to 50 nm; the thickness of the SnO2 is about 40 to 80 nm, and is prepared by any one of spin coating, spray coating or scraping coating methods.

[0011] Preferably, the passivation layer is prepared on the hole transport layer by coating, doctor blade coating or spray coating.

[0012] Preferably, the passivation layer is made of Lewis acid-base coordination materials dissolved in solvents such as isopropanol, ethanol, ethyl acetate, etc., with a concentration of 0.1-2 mg / ml.

[0013] Preferably, the Lewis acid-base coordination material is pyridine or thiophene.

[0014] Preferably, the pressing temperature in S3 is 100° C.-200° C., and the pressure is 0.1 MPa-10 MPa.

[0015] Preferably, the perovskite device may be a forward structure device or an inverted structure device, and the structure comprises: a conductive substrate, a buffer layer, a perovskite layer, a passivation layer, a buffer layer, an electrode and a glass substrate.

[0016] The easily scalable perovskite surface passivation process proposed in the present invention has the following beneficial effects: the process can successfully scale up the perovskite surface passivation process used in small devices to the preparation of large components, reduce the damage of the solution of the passivation layer to the perovskite, and improve the efficiency and stability of the device; and the solvent used in the passivation process is not subject to too many restrictions, thereby expanding its selection range. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for describing the embodiments are briefly introduced below.

[0018] Figure 1 is a schematic diagram of step 1 of the present invention;

[0019] Figure 2 is a schematic diagram of step 2 of the present invention;

[0020] Figure 3 is a schematic diagram of step 3 of the present invention;

[0021] Figure 4 The process method is the prior art; DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0023] The present invention proposes a perovskite surface passivation process that is easily scalable, comprising the following steps:

[0024] S1: Take the first substrate glass, and prepare the first electrode, electron transport layer and perovskite layer on the first substrate glass in sequence; specifically, remove the substrate glass, select FTO conductive glass for the substrate glass, clean it in ethanol or deionized water by ultrasonic cleaning machine, then sputter any one of Ag, Al or Au on the first substrate glass by vacuum sputtering machine, prepare the electron transport layer on the upper part of the electrode by any one of spin coating, spray coating or scraping, and prepare the electron transport layer on the surface by spraying or scraping, the specific electron transport layer is TiO2 and SnO2 arranged in sequence, the thickness of TiO2 is about 10-50nm; the thickness of SnO2 is about 40-80nm, and it is prepared by any one of spin coating, spray coating or scraping. The preparation method is detailed in the spraying liquid, perovskite layer and its preparation method, and perovskite battery disclosed in the invention with patent number: 201711136970.4, which is the technology previously disclosed by the applicant and will not be repeated in this application.

[0025] S2: Take a second substrate glass. Similarly, after the second substrate glass is ultrasonically cleaned in an ultrasonic device, a second electrode and a hole transport layer are prepared on the second substrate glass in sequence, and then a passivation layer is prepared on the hole transport layer; the specific method for the hole transport layer is the technical method disclosed in 202010991860.1, and its specific steps are no longer repeated in this application, and then a passivation layer is coated on the hole transport layer by coating. Specifically: the passivation layer uses a Lewis acid-base coordination material dissolved in a solvent such as isopropanol, ethanol, or ethyl acetate. Preferably, the Lewis acid-base coordination material is pyridine or thiophene, thereby reducing the defect state density of the film, promoting the extraction and transport of carriers, and inhibiting the non-radiative recombination induced by defects, so as to achieve a more efficient perovskite solar cell with a concentration of 0.1-2 mg / ml. The passivation solution is coated on the hole transport layer by coating, and the passivation layer is formed by drying with hot air. The hole transport layer is not easily destroyed by the passivation solution relative to the perovskite layer, and most of the solvents used in the preparation of the passivation layer will not have a destructive effect on it.

[0026] S3: The semi-finished perovskite devices prepared in steps S1 and S2 are pressed together at high temperature by hot pressing, and the perovskite layer and the passivation layer are bonded to each other to form a final complete perovskite device. When both groups of components are set up, the perovskite layer and the passivation layer of the above two groups of components are hot pressed into shape by a hot press, and the hot pressing temperature is controlled at 100℃-200℃, and the pressure is 0.1Mpa-10Mpa. The high temperature and high pressure make the perovskite layer and the passivation layer compound together, and the perovskite layer will not be affected by the passivation solution in the above manner.

[0027] In addition, it should be noted that the perovskite device can be a forward structure device or an inverted structure device, and the structure is: glass substrate, electron transport layer, perovskite layer, passivation layer, hole transport layer, electrode and glass substrate. The final product is formed in two groups of glass substrates, and through this method, the passivation solution does not contact the perovskite layer, does not damage the perovskite layer, and does not affect the performance of the entire component when preparing large components. In addition, the selectivity of the passivation solution is increased. The glass substrate is one of FTO conductive glass, ITO conductive glass, FTO conductive plastic, and ITO conductive plastic, wherein the thickness of FTO is about 500nm and the thickness of ITO is about 300-400nm; the three-stage electron transport layer is TiO2 with a thickness of about 10 to 50nm; the thickness of SnO2 is about 40 to 80nm; the structural formula of perovskite MAPbI3 (MA is CH3NH3 + ), with a thickness of 300 to 1000 nm; the hole transport layer is any one of Spiro-OMeTAD (2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene), PEDOT:PSS, P3HT, PTAA or PCDTBT, with a thickness of 300-600 nm; the electrode is any one of Ag, Al, Au or TCO, with a thickness of about 100 to 300 nm.

[0028] Various modifications to the embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An easily scalable perovskite surface passivation process, characterized in that: The following steps are involved: S1: taking a first substrate glass, and sequentially preparing a first electrode, an electron transport layer and a perovskite layer on the first substrate glass; S2: taking a second substrate glass, preparing a second electrode and a hole transport layer on the second substrate glass in sequence, and then coating a passivation layer on the hole transport layer by coating, wherein the passivation layer is made of a Lewis acid-base coordination material dissolved in isopropanol, ethanol or ethyl acetate solvent, wherein the Lewis acid-base coordination material is pyridine or thiophene, thereby reducing the defect state density of the film and promoting the extraction and transportation of carriers; S3: The semi-finished perovskite devices prepared in steps S1 and S2 are pressed together at high temperature by hot pressing, and the perovskite layer and the passivation layer are bonded to each other to form a final complete perovskite device. The pressing temperature is 100°C-200°C and the pressure is 0.1Mpa-10Mpa.

2. The easily scalable perovskite surface passivation process according to claim 1, characterized in that: The first electrode and the second electrode are prepared by vacuum evaporation or vacuum sputtering.

3. The easily scalable perovskite surface passivation process according to claim 1, characterized in that: The electron transport layer is TiO2 and SnO2 arranged in sequence, the thickness of the TiO2 is 10-50nm; the thickness of the SnO2 is 40-80nm, and is prepared by any one of spin coating, spray coating or scraping coating methods.

4. The easily scalable perovskite surface passivation process according to claim 1, characterized in that: The passivation layer is prepared on the hole transport layer by coating, blade coating or spraying.

5. The easily scalable perovskite surface passivation process according to claim 1, characterized in that: The perovskite device is a forward structure device or an inverted structure device, and the structure comprises: a conductive substrate, a buffer layer, a perovskite layer, a passivation layer, a buffer layer, an electrode and a glass substrate.

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