Patent Description:
With poor stability, perovskite materials are easy to decompose under actions of light, heat, water, and oxygen, reducing photoelectric conversion efficiency of perovskite solar cells. Therefore, it is necessary to ensure that a perovskite solar cell device is prepared with good sealing performance.

However, the perovskite battery device with only good sealing performance ensured during packaging has a limited effect on prolonging service life of a perovskite solar cell.

Embodiments of this application are intended to provide a perovskite solar cell, a preparation method thereof, and an electric device, so as to prolong service life of the perovskite solar cell.

A first aspect of this application provides a perovskite solar cell, including:.

In this application, the <NUM>%-<NUM>% ammonia gas and the residual inert gas are contained in a structure of the perovskite solar cell containing the organic amine cation, which can effectively inhibit migration and decomposition of organic amine cations in the perovskite material and improves thermal stability of the perovskite solar cell device, thereby improving light conversion efficiency and service life of the perovskite solar cell.

In some embodiments of the first aspect of this application, A includes at least one of CH<NUM>NH<NUM>+ and HC(NH<NUM>)<NUM>+.

Optionally, in ABX<NUM>, B is at least one of Pb<NUM>+, Sn<NUM>+, and Ge<NUM>+.

In some embodiments of the first aspect of this application, in ABX<NUM>, A further includes at least one of Cs+, Rb+, and K+.

In some embodiments of the first aspect of this application, the inert gas includes at least one of nitrogen, argon, helium, and neon.

Optionally, the volume fraction of the ammonia gas in the sealed cavity is <NUM>%-<NUM>%.

In this application, the volume fraction of the ammonia gas being controlled within the above ranges in the sealed cavity can ensure various advantages such as low production costs, high light conversion efficiency of the solar cell, and operation safety.

In some embodiments of the first aspect of this application, the perovskite solar cell further includes a sealing element, where the sealing element connects the transparent substrate and the back plate to form the sealed cavity.

Optionally, the sealing element is a sealant.

Optionally, the sealant is around a periphery of the perovskite solar cell device, and the back plate is fastened to the perovskite solar cell device using the sealant.

Optionally, the sealant is further located on at least part of a surface or the entire surface on a side of the back plate facing toward the perovskite solar cell device.

In some embodiments of the first aspect of this application, a material of the transparent substrate is glass or polyethylene terephthalate.

Optionally, a material of the back plate is glass or polyethylene terephthalate.

A second aspect of this application provides a preparation method of perovskite solar cell, including:.

The perovskite solar cell device is packaged in the preset atmosphere containing the ammonia gas having the volume fraction of <NUM>%-<NUM>% and the residual inert gas, so that the perovskite solar cell device is located in the above preset atmosphere; and the present atmosphere can inhibit migration and decomposition of organic amine cations in the perovskite material containing the organic amine cation.

In some embodiments of the second aspect of this application, in ABX<NUM>, A includes at least one of CH<NUM>NH<NUM>+ and HC(NH<NUM>)<NUM>+.

Optionally, in ABX<NUM>, A further includes at least one of Cs+, Rb+, and K+.

In some embodiments of the second aspect of this application, the inert gas includes at least one of nitrogen, argon, helium, and neon.

Optionally, the volume fraction of the ammonia gas in the preset atmosphere is <NUM>%-<NUM>%.

Packaging in the above preset atmosphere can allow the preset atmosphere to be packaged inside the perovskite solar cell device, which reduces costs in a manufacturing process when the efficiency and service life of the battery are increased.

In some embodiments of the second aspect of this application, in the process of packaging a perovskite solar cell device between the transparent substrate and the back plate, a sealing element is used for packaging.

Optionally, the sealant is applied at a periphery of the perovskite solar cell device, and the back plate is fastened to the perovskite solar cell device using the sealant.

Optionally, the sealant is further applied on at least part of a surface or the entire surface on a side of the back plate facing toward the perovskite solar cell device.

A third aspect of this application provides an electric device, where the electric device includes the perovskite solar cell according to the first aspect, and the perovskite solar cell serves as a power source or an energy storage unit of the electric device.

To describe the technical solutions in the embodiments of this application more clearly, the following briefly describes the accompanying drawings required for describing the embodiments of this application. Apparently, the accompanying drawings in the following description show merely some embodiments of this application, and persons of ordinary skill in the art may still derive other drawings from the accompanying drawings without creative efforts.

Reference signs: <NUM>. perovskite solar cell; <NUM>. sealed cavity; <NUM>. back plate; <NUM>. transparent substrate; <NUM>. positive electrode leading-out terminal; <NUM>. negative electrode leading-out terminal; <NUM>. perovskite solar cell device; <NUM>. transparent conductive electrode; <NUM>. hole transport layer; <NUM>. perovskite layer; <NUM>. electron transmission layer; <NUM>. metal conductive layer; and <NUM>. sealing element.

To make the objectives, technical solutions, and advantages of this application clearer, the following clearly and completely describes the technical solutions of the embodiments of this application. Embodiments, where specific conditions are not specified, are implemented in accordance with general conditions or those recommended by a manufacturer. The reagents or instruments used are all conventional products that can be purchased on the market if no manufacturer is indicated.

<FIG> is a schematic cross-sectional diagram of a perovskite solar cell <NUM>. Referring to <FIG>, this embodiment provides a perovskite solar cell <NUM>, where the perovskite solar cell <NUM> mainly includes a back plate <NUM>, a transparent substrate <NUM>, and a perovskite solar cell device <NUM>.

A sealed cavity <NUM> is formed between the back plate <NUM> and the transparent substrate <NUM>, and the perovskite solar cell device <NUM> is located in the sealed cavity <NUM>.

In some embodiments of this application, the perovskite solar cell <NUM> further includes a sealing element <NUM>, where the sealing element <NUM> is located between the back plate <NUM> and the transparent substrate <NUM>, and the back plate <NUM>, the transparent substrate <NUM>, and the sealing element jointly enclose the sealed cavity <NUM>.

For example, a side of the transparent substrate <NUM> is provided with a positive electrode leading-out terminal <NUM> and a negative electrode leading-out terminal <NUM>; a front face of the perovskite solar cell device <NUM> is connected to the transparent substrate <NUM>; a positive electrode of the perovskite solar cell device <NUM> is electrically connected to the positive electrode leading-out terminal <NUM> and a negative electrode of the perovskite solar cell device <NUM> is connected to the negative electrode leading-out terminal <NUM>; and a back face of the perovskite solar cell device <NUM> is connected to the back plate <NUM>, the sealing element <NUM> is located between the back face of the perovskite solar cell device <NUM> and the back plate <NUM>, and the sealing element <NUM> seals the perovskite solar cell device <NUM>.

For example, in this embodiment, a material of the transparent substrate <NUM> is glass. In another embodiment, a material of the transparent substrate <NUM> may be another transparent material such as polyethylene terephthalate.

For example, in this embodiment, a material of the back plate <NUM> is polyethylene terephthalate. In another embodiment, a material of the back plate <NUM> may alternatively be glass or another material.

In this embodiment, the sealing element <NUM> is a sealant; and for example, the sealant may seal the perovskite solar cell device <NUM> through the following implementations.

Referring to <FIG>, the sealant is applied on an entire surface of the perovskite solar cell device <NUM> facing away from the transparent substrate <NUM> and at a periphery of the perovskite solar cell device <NUM>, and the back plate <NUM> is attached to the sealant to seal the perovskite solar cell device <NUM>; or alternatively, the sealant is applied on a surface of the back plate <NUM> facing toward the perovskite solar cell device <NUM>, and the back plate <NUM> is attached to the sealant to seal the perovskite solar cell device <NUM>; and the sealed cavity <NUM> is present between the sealant and the perovskite solar cell device <NUM>.

It should be noted that the sealed cavity <NUM> is provided in a quantity of one or more, and a plurality of sealed cavities <NUM> may communicate with each other or not.

The sealant being applied on the entire surface of the perovskite solar cell device <NUM> facing away from the transparent substrate <NUM> helps improve mechanical property of the perovskite solar cell <NUM>, increasing firmness and stability of a packaging structure of the perovskite solar cell <NUM>.

<FIG> is a schematic cross-sectional diagram of a perovskite solar cell <NUM>. Referring to <FIG>, in <FIG>, the sealant is around a periphery of the perovskite solar cell device <NUM> and on a partial surface of the perovskite solar cell device <NUM> facing away from the transparent substrate <NUM>. The sealant may seal the perovskite solar cell device <NUM> in the following manners.

The sealant is applied at the periphery of the perovskite solar cell device <NUM>, and the back plate <NUM> is attached to the sealant to seal the perovskite solar cell device <NUM>. Alternatively, the sealant is applied at a periphery of the back plate <NUM> facing toward the perovskite solar cell device <NUM>, and the back plate <NUM> is attached to the sealant to seal the perovskite solar cell device <NUM>.

The sealed cavity <NUM> is present between the perovskite solar cell device <NUM> and the back plate <NUM>; or in some embodiments, due to an uneven surface of the perovskite solar cell device <NUM> or other reasons, there may alternatively be at least one sealed cavity <NUM> between the perovskite solar cell device <NUM> and the sealant.

The above two examples are made with respect to sealing of the perovskite solar cell device <NUM> using the sealant. It should be noted that, in another embodiment of this application, the sealant may seal the perovskite solar cell device <NUM> in another manner. For example, the sealant is applied at the periphery of the back plate <NUM> facing toward the perovskite solar cell device <NUM> and on an entire surface of the back plate <NUM>, and the back plate <NUM> is attached to the sealant to seal the perovskite solar cell device <NUM>.

Correspondingly, the sealed cavity <NUM> formed is located between the sealant and the perovskite solar cell device <NUM>, or is alternatively located between the perovskite solar cell device <NUM> and the back plate <NUM>; or the sealed cavity <NUM> is provided at both the above positions. A shape and a quantity of the sealed cavity <NUM> and whether a plurality of sealed cavities <NUM> communicate with each other are not limited in this application.

In addition, in <FIG>, the sealed cavity <NUM> accounting for a large volume of the entire perovskite solar cell <NUM> is merely intended for better identifying the sealed cavity <NUM> in the figure. This does not mean that the volume accounted by the sealed cavity <NUM> of the entire perovskite solar cell <NUM> is as shown in <FIG>. It should be noted that the volume occupied by the sealed cavity <NUM> of the entire perovskite solar cell <NUM> is not limited in the embodiments of this application. During actual production, the sealed cavity <NUM> may be a cavity deliberately formed during packaging, or may alternatively be a cavity inevitably formed during packaging; or may include both the above cases.

For example, the sealant is selected from at least one of an epoxy packaging sealant, an organic silicon packaging sealant, a polyurethane packaging sealant, a UV-light curing packaging sealant, ethylene-vinyl acetate copolymer, polyvinyl butyral, ethylene-octene copolymer, polyisobutylene, and a polyolefin packaging sealant.

For example, the sealant is an epoxy packaging sealant, for example, an epoxy AB sealant including sealant A and sealant B of which a mass ratio is <NUM>:(<NUM>-<NUM>), and the mass ratio of sealant A to sealant B may be, for example, <NUM>:<NUM>, <NUM>:<NUM>, <NUM>:<NUM>, <NUM>:<NUM> or <NUM>:<NUM>.

The sealing element <NUM> may not be limited to the sealant. For example, another sealing part is used to seal the perovskite solar cell device <NUM>; or no sealing element <NUM> is used to seal the perovskite solar cell device <NUM>, and the perovskite solar cell device <NUM> is directly sealed by the transparent substrate <NUM> and the back plate <NUM>.

In the inventive perovskite solar cell, the sealed cavity <NUM> contains ammonia gas having a volume fraction of <NUM>%-<NUM>% and residual inert gas. In other words, gases in the sealed cavity <NUM> include the ammonia gas having the volume fraction of <NUM>%-<NUM>% and the residual inert gas.

For example, the volume fraction of the ammonia gas in the sealed cavity <NUM> may be <NUM>%-<NUM>%, <NUM>%-<NUM>%, <NUM>%-<NUM>%, or the like.

For example, the volume fraction of the ammonia gas in the sealed cavity <NUM> may be <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, or the like.

For example, the inert gas may be at least one of nitrogen, argon, helium, and neon. For example, in this embodiment, the inert gas is nitrogen.

It should be noted that the <NUM>%-<NUM>% ammonia gas and the residual inert gas do not mean only the above two types of components in an absolute sense. The sealed cavity <NUM> may further include inevitable trace impurity gas during actual production (generally, a volume fraction of the trace impurity gas is less than <NUM>%).

<FIG> is a schematic diagram of an internal structure of a perovskite solar cell device <NUM>. Referring to <FIG>, the perovskite solar cell device <NUM> includes a transparent conductive electrode <NUM>, a hole transport layer <NUM>, a perovskite layer <NUM>, an electron transmission layer <NUM>, and a metal conductive layer <NUM> that are stacked in sequence.

It should be understood that, the hole transport layer <NUM> shown in <FIG> may be located at the electron transmission layer <NUM>, and the electron transmission layer <NUM> is located at the hole transport layer <NUM>.

For example, a material of the transparent conductive electrode <NUM> is selected from at least one of indium tin oxide and fluorine doped with tin dioxide.

A material of the hole transport layer <NUM> is selected from at least one of poly(<NUM>,<NUM>-ethylenedioxythiophene), polystyrene sulfonate, poly[bis(<NUM>-phenyl)(<NUM>,<NUM>,<NUM>-trimethylphenyl)amine], CuSCN, NiOx, CuI, MoOx, <NUM>,<NUM>',<NUM>,<NUM>'-tetrakis[N,N-bis(<NUM>-methoxyphenyl)amino]-<NUM>,<NUM>'-spirobifluorene, WO<NUM>, polyethoxyethyleneimine, polyethyleneimine, ZnO, TiO<NUM>, [<NUM>,<NUM>]-phenyl-C61-isobutyl butyrate, and SnO<NUM>.

A material of the electron transmission layer <NUM> is selected from at least one of poly(<NUM>,<NUM>-ethylenedioxythiophene), polystyrene sulfonate, polytriarylamine , CuSCN, NiOx, CuI, MoOx, <NUM>,<NUM>',<NUM>,<NUM>'-tetrakis[N,N-bis(<NUM>-methoxyphenyl)amino]-<NUM>,<NUM>'-spirobifluorene, WO<NUM>, polyethoxyethyleneimine, polyethyleneimine, ZnO, TiO<NUM>, [<NUM>,<NUM>]-phenyl-C61-isobutylbutyrate, and SnO<NUM>.

A material of the metal conductive layer <NUM> is selected from at least one of Au, Ag, Cu, Al, Ni, Cr, Bi, Pt, Mg, and alloys thereof.

A chemical formula of a perovskite material in the perovskite layer <NUM> is ABX<NUM>, where A includes an organic amine cation, B is a metal cation, and X is a halogen anion or SCN-.

For example, in ABX<NUM>, A may include at least one of CH<NUM>NH<NUM>+ and HC(NH<NUM>)<NUM>+. In other words, A may be CH<NUM>NH<NUM>+, HC(NH<NUM>)<NUM>+ or a mixture of the two in any ratio. It should be understood that A may further include a metal ion, for example, at least one of Cs+, Rb+, and K+.

For example, in ABX<NUM>, B may be at least one of Pb<NUM>+, Sn<NUM>+, and Ge<NUM>+.

For example, ABX<NUM> may be CH<NUM>NH<NUM>PbI<NUM>, CH<NUM>NH<NUM>SnI<NUM>, CH<NUM>NH<NUM>PbI<NUM>Cl, CH<NUM>NH<NUM>PbI<NUM>Br, or CH<NUM>NH<NUM>Pb(I<NUM>-xBrx)<NUM> (where <NUM><x<<NUM>), where
CH<NUM>NH<NUM>+is abbreviated as MA+, and HC(NH<NUM>)<NUM>+ is abbreviated as FA+; and ABX<NUM> may further be:.

In this application, the inventors have found through research that the ammonia gas having the volume fraction of <NUM>%-<NUM>% and the residual inert gas being contained in the sealed cavity <NUM> can effectively inhibit migration and decomposition of organic amine cations in the perovskite material, improve structural stability of the perovskite material, and improve thermal stability of the perovskite solar cell <NUM>, thereby improving light conversion efficiency and service life of the perovskite solar cell.

The volume fraction of the ammonia gas in the sealed cavity <NUM> is closely related to an effect of improving the structural stability of the perovskite material. On a condition that decomposition is inhibited to some extent, considering cost and safety, the volume fraction of the ammonia gas in the sealed cavity <NUM> may be within an appropriate range, such as <NUM>%-<NUM>%.

For example, this application further shows a preparation method of the perovskite solar cell.

The preparation method mainly includes the following steps.

S1: Prepare a perovskite solar cell device on a transparent substrate. For example, the preparation method mainly includes:
preparing in sequence a transparent conductive electrode, one of a hole transport layer and an electron transmission layer, a perovskite layer, the other of the hole transport layer and the electron transmission layer, and a metal conductive layer on the transparent substrate.

As mentioned above, in a process of preparing the transparent conductive electrode, a material of the transparent conductive electrode is selected from at least one of indium tin oxide and fluorine doped with tin dioxide.

In a process of preparing the hole transport layer or the electron transmission layer, a material of the hole transport layer and a material of the electron transmission layer are each independently selected from at least one of poly(<NUM>,<NUM>-ethylenedioxythiophene), polystyrene sulfonate, poly[bis(<NUM>-phenyl)(<NUM>,<NUM>,<NUM>-trimethylphenyl)amine], CuSCN, NiOx, CuI, MoOx, <NUM>,<NUM>',<NUM>,<NUM>'-tetrakis[N,N-bis(<NUM>-methoxyphenyl)amino]-<NUM>,<NUM>'-spirobifluorene, WO<NUM>, polyethoxyethylene imine, polyethyleneimine, ZnO, TiO<NUM>, [<NUM>,<NUM>]-phenyl -C61- isobutyl butyrate, and SnO<NUM>.

In a process of preparing the perovskite layer, an optional formula of a material in the perovskite layer is ABX<NUM>, where A includes an organic amine cation, B is a metal cation, and X is a halogen anion or SCN-. For example, ABX<NUM> may be CH<NUM>NH<NUM>PbI<NUM>, CH<NUM>NH<NUM>SnI<NUM>, CH<NUM>NH<NUM>PbI<NUM>Cl, or CH<NUM>NH<NUM>PbI<NUM>Br, where CH<NUM>NH<NUM>+ is abbreviated as MA+, and HC(NH<NUM>)<NUM>+ is abbreviated as FA+; and ABX<NUM> may further be:.

In a process of preparing the metal conductive layer, a material of the metal conductive layer is selected from at least one of Au, Ag, Cu, Al, Ni, Cr, Bi, Pt, Mg, and alloys thereof.

For example, process parameters of step S1 may be as follows.

Part of the transparent substrate is etched with Zn powder and 1mol/L-<NUM> mol/L hydrochloric acid, and then dried after washing. In a N<NUM> atmosphere, the transparent substrate is spin-coated with a TiO<NUM> precursor solution at a rate of 4000rpm-6500rpm, and kept at <NUM>-<NUM> for <NUM>-<NUM>; then the temperature is increased to <NUM>-<NUM> and maintained at the temperature for <NUM>-<NUM>; and then the transparent substrate is annealed at <NUM>-<NUM>.

In a N<NUM> atmosphere, the transparent substrate is spin-coated with a perovskite layer (which, for example, may be CH<NUM>NH<NUM>PnI<NUM>) at a rate of 3000rpm-4500rpm, cured for <NUM>-<NUM>, and then oxidized for <NUM>-<NUM> in a low humidity drying tower.

Then the transparent substrate is vapor-deposited with a layer of electrode, such that a perovskite solar cell device is prepared.

The inventive preparation method of the perovskite solar cell comprises the following step S2. S2: In a preset atmosphere, package the perovskite solar cell device using a back plate, where the preset atmosphere contains ammonia gas having a volume fraction of <NUM>%-<NUM>% and residual inert gas.

For example, the packaging includes that the perovskite solar cell device is packaged using a sealing material and the back plate.

Still referring to <FIG>, a method for packaging the perovskite solar cell device may be: The sealing material is applied at a periphery of the perovskite solar cell device and an entire back face of the perovskite solar cell device, and the back plate is attached to the back face of the perovskite solar cell device to implement sealing. Correspondingly, the sealing material may alternatively be applied on the back plate before the back plate is attached to the back face of the perovskite solar cell device so that the sealing material is applied on the entire back face of the perovskite solar cell device.

Alternatively, still referring to <FIG>, a method for packaging the perovskite solar cell device may be: The sealing material is applied at a periphery of the perovskite solar cell device, and the back plate is attached to the back face of the perovskite solar cell device to implement sealing. Alternatively, the sealing material may be applied on the back plate before the back plate is attached to the back face of the perovskite solar cell device.

For example, the sealing material may be a sealant, and the sealant may be an epoxy packaging sealant, for example, an epoxy AB sealant. It should be understood that the sealant may also be selected from at least one of an organic silicon packaging sealant, a polyurethane packaging sealant, a UV-light curing packaging sealant, ethylene-vinyl acetate copolymer, polyvinyl butyral, ethylene-octene copolymer, polyisobutylene, and a polyolefin packaging sealant.

It should be noted that, in another embodiment of this application, the sealing material may alternatively be another material that can seal the perovskite solar cell device. Alternatively, in some embodiments, on the premise that the back plate can seal the perovskite solar cell device, the sealing material may not be used to seal the perovskite solar cell device.

In the inventive perovskite solar cell and in the inventive preparation method of the perovskite solar cell, the preset atmosphere includes the ammonia gas having the volume fraction of <NUM>%-<NUM>%, the residual inert gas, and inevitable trace impurity gas.

For example, the volume fraction of the ammonia gas in the preset atmosphere may be <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, or the like. The inert gas may be at least one of nitrogen, argon, helium, and neon. For example, in this embodiment, the inert gas is nitrogen.

For example, a process of step S2 may be as follows.

In the preset atmosphere, a layer of a packaging sealant is applied at a periphery of the perovskite solar cell device and on a surface of the perovskite solar cell device, and the back plate is pressed onto the packaging sealant before the packaging sealant is cured.

The preparation method of perovskite solar cell provided in this embodiment of this application has at least the following advantages.

In the inventive preparation method of a perovskite solar cell, packaging is performed in the preset atmosphere composed of the ammonia gas having the volume fraction of <NUM>%-<NUM>% and the residual inert gas, so that the sealed cavity after packaging contains the ammonia gas having the volume fraction of <NUM>%-<NUM>%. The foregoing configuration can effectively inhibit migration and decomposition of organic amine cations in the perovskite material and improve thermal stability of the perovskite solar cell device, thereby improving light conversion efficiency and service life of the perovskite solar cell.

An inventive electric device includes the foregoing inventive perovskite solar cell <NUM>, and the perovskite solar cell <NUM> serves as a power source of the foregoing electric device for supplying power, or the perovskite solar cell <NUM> can be used as an energy storage unit of the foregoing electric device. For example, the electric device may be a lighting element, a display element, an automobile, or the like.

The following further describes features and performance of this application in detail with reference to examples.

In this example, a perovskite solar cell was provided and mainly prepared through the following steps.

The packaging sealant was a colorless transparent epoxy resin AB sealant that was prepared at a mass ratio of A:B=<NUM>: <NUM>, where A was an epoxy resin main agent, and B was a curing agent.

In this way, a perovskite solar cell was obtained.

Examples <NUM>-<NUM> and Comparative Examples <NUM>-<NUM> each provide a perovskite solar cell. For a preparation method thereof, refer to Example <NUM>. These examples differ from Example <NUM> in an active substance at the perovskite layer in step (<NUM>) or the atmosphere in the glove box in step (<NUM>). Details are given in Table <NUM>.

Light conversion efficiency of the perovskite solar cell provided in the examples and comparative examples after storage in a high-temperature and highhumidity environment was tested using a specific test method as follows.

After the perovskite solar cells were stored at <NUM> and <NUM>% relative humidity for different days, light conversion efficiency of the cell was tested using an I-V test system under standard simulated sunlight (AM <NUM>,<NUM> mW/cm<NUM>). A test voltage range was -<NUM>. 2V and a scanning rate was 50mV/s. Normalized efficiency of the cell on day n=efficiency tested after n days/efficiency tested after <NUM> days×<NUM>%. Test results are shown in Table <NUM>.

It can be learned from Table <NUM> that, as compared with <NUM>% nitrogen contained in the sealed cavity, in a case that ammonia gas having a volume fraction of <NUM>% or more is contained in the sealed cavity of the perovskite solar cell, an attenuation rate of light conversion efficiency of the cell after storage in a high temperature and high humidity environment is reduced, effectively enhancing thermal stability of the cell. Even a small amount of dry air (for example, 2vol%) contained in the sealed cavity of the perovskite solar cell causes a significant decrease in the thermal stability of the cell. It can be found through the above experiments that, for an embodiment in which the sealed cavity contains 10vol% or more ammonia gas and the residual gas is inert gas, thermal stability of the perovskite solar cell is improved. Although an action mechanism is not clear, the inventors speculate a possible reason may be that, in an environment with the temperature of <NUM> and <NUM>% relative humidity, a perovskite active material experiences thermal decomposition due to migration of organic cations, and when a specified amount of ammonia gas is present in the high temperature and high humidity environment, the thermal decomposition of the perovskite material is effectively inhibited, so that the thermal stability is improved.

Claim 1:
A perovskite solar cell (<NUM>), comprising:
a back plate (<NUM>);
a transparent substrate (<NUM>), wherein a sealed cavity (<NUM>) is formed between the transparent substrate (<NUM>) and the back plate (<NUM>); and
a perovskite solar cell device (<NUM>), wherein the perovskite solar cell device (<NUM>) is located in the sealed cavity (<NUM>); wherein
a chemical formula of a perovskite material of the perovskite solar cell device (<NUM>) is ABX<NUM>, wherein A comprises an organic amine cation, B is a metal cation, and X is a halogen anion or SCN-,
characterized in that the sealed cavity contains ammonia gas having a volume fraction of <NUM>% -<NUM>% and residual inert gas.