CN111244210A - Flexible perovskite/microcrystalline silicon laminated solar cell and manufacturing method thereof - Google Patents

Abstract

A flexible perovskite/microcrystalline silicon stacked solar cell and a manufacturing method thereof, relate to the technical field of solar cell production, and include a sputtering unit (1) and an evaporation unit (2), the sputtering unit (1), evaporation The unit (2) is provided with a flexible deposition track system, and the flexible substrate is driven to move between chambers by the flexible deposition track system; the sputtering unit (1) is mainly used for transparent conductive films, electron transport layers, The sputtering deposition of the hole transport layer and the metal electrode, the evaporation unit (2) is used for the perovskite absorber layer, the electron transport layer, the hole transport layer, and the evaporation source is reserved for the adjustment of other processes and the performance of the film. Improve. According to the basic structure of the perovskite, the present invention divides the system into a sputtering unit and an evaporation unit, which can operate independently or work together.

Description

A flexible perovskite/microcrystalline silicon tandem solar cell and its manufacturing method

technical field

The invention relates to a flexible semiconductor device for converting light energy into electric energy, in particular to a flexible perovskite/microcrystalline silicon stacked solar cell and a preparation method thereof.

Background technique

With the increasingly prominent problem of energy crisis, the development of new energy is related to the future of mankind. As an inexhaustible and inexhaustible energy source, solar energy has entered the human field of vision very early. How to convert solar energy into available and storable energy such as electricity is the focus of research in various countries.

Microcrystalline silicon thin-film battery is an extremely mature technology in the field of thin-film batteries. It has great advantages such as abundant raw materials, simple preparation process, low cost, wide spectral response, and adjustable band gap. Efficiency restricts its further development. Organolead halide-based perovskite solar cells have developed rapidly in recent years, with device efficiencies jumping from 3.8% a few years ago to more than 22%. The raw materials of perovskite cells are abundant and cheap, and they do not require high-temperature and high-energy-consuming processes, and have huge commercial potential. However, the spectral response of this cell is narrow, and the spectral response is usually 300-800 nm. Flexible thin-film batteries have the special advantages of being flexible and bendable, and have great application prospects in wearable, portable electronic products, and near-space vehicles. However, flexible batteries are a challenge to both the fabrication process and technology. Based on the above problems, the present invention combines the advantages of a flexible substrate with a perovskite cell and a microcrystalline silicon cell, and realizes a combined stacking of the two cells to fully absorb sunlight and improve the conversion efficiency.

SUMMARY OF THE INVENTION

The key technical problem to be solved by the present invention is: combining the advantages of wide spectral absorption of microcrystalline silicon cells and high efficiency of perovskite cells, by placing perovskite thin film cells on the top and microcrystalline silicon cells on the bottom, a flexible stack is prepared. The layered battery combination can fully absorb sunlight and improve the light conversion efficiency of battery devices.

The present invention realizes through the following technical solutions:

The flexible perovskite/microcrystalline silicon tandem solar cell is prepared by using a flexible substrate, and the perovskite thin film cell is used as the top cell and the microcrystalline silicon cell is used as the bottom cell. The structure of the stacked battery is from bottom to top: flexible substrate/metal back electrode/transparent conductive (TCO) film/n-type microcrystalline silicon/intrinsic microcrystalline silicon/p-type microcrystalline silicon/TCO film/electron transport layer/ Perovskite absorber layer/hole transport layer/TCO film/metal gate electrode.

The flexible substrate is a flexible metal substrate such as stainless steel, aluminum, or a polymer substrate such as polyimide. In order to improve the electrical conductivity of the substrate, the substrate needs to be modified, and the methods that can be used are: vacuum methods such as magnetron sputtering, electron beam evaporation or resistance thermal evaporation. In order to increase the light trapping characteristics and effectively protect the battery and prevent the diffusion of metal ions, a transparent conductive film is deposited on the modified substrate. The methods that can be used are: magnetron sputtering, electron beam evaporation, resistive thermal evaporation, electroplating method Wait.

The microcrystalline silicon thin film battery is used as a bottom battery and is prepared by plasma enhanced chemical vapor deposition (PECVD). The prepared flexible substrate is introduced into PECVD equipment for preheating, and after preheating, an n-layer is deposited. The n-layer can adopt different structures, such as microcrystalline silicon oxygen or microcrystalline silicon/microcrystalline silicon oxygen composite structure. After completion, the preparation of the intrinsic microcrystalline silicon thin film is carried out. Then, a p-layer is prepared, and the p-layer can also adopt different structures, such as microcrystalline silicon oxygen or microcrystalline silicon/microcrystalline silicon oxygen composite structure.

After the preparation of the microcrystalline silicon cell, the tunnel junction preparation of the top cell and the bottom cell is carried out. This preparation is a very critical step, and the surface of the prepared film is required to be sufficiently flat and free of short-circuit points. The technical solutions adopted are as follows:

1. The preparation method is a vacuum method such as resistance type or electron beam evaporation, magnetron sputtering, etc.

2. The tunnel junction structure can be a TCO/Au/TCO composite structure or a TCO single-layer structure. Equal magnetron sputtering TCO conductive film.

3. Passivate the microcrystalline silicon battery with TCO conductive film to remove short-circuit points.

The perovskite thin film battery is used as a top battery and is prepared on a tunnel junction TCO conductive thin film. The preparation sequence is electron transport layer, perovskite absorber layer, hole transport layer, TCO conductive film and metal gate.

The electron transport layer can be inorganic substances such as titanium oxide, tin oxide, indium sulfide, etc., or organic substances such as PCBM, C60 and the like. The preparation method of the electron transport layer can be a vacuum method, a blade coating method, a spin coating method, and the like.

The perovskite absorption layer can be an organic or inorganic material, and the preparation method can be a vacuum method, a blade coating method, a spin coating method, or the like.

The hole transport layer can be an inorganic material such as nickel oxide, copper oxide, copper thiocyanate, etc., or an organic hole layer such as sprio, PTAA, PEDOT, and the like. The preparation method can be vacuum method, blade coating method, spin coating method and the like.

The top cell TCO thin film needs to ensure no damage to the perovskite hole transport layer, so it is prepared by processes such as electron beam evaporation and LPCVD.

The metal gate can be Au, Ag, etc., and is prepared by methods such as vacuum evaporation or sputtering.

The advantages and positive effects of the present invention are:

1. The present invention provides a preparation method, which combines a traditional microcrystalline silicon battery and a perovskite battery to prepare a laminated battery, combines the advantages of the two batteries with each other, broadens the spectral absorption of the battery, and effectively improves the photoelectricity of the battery. conversion efficiency.

2. The present invention is prepared based on a flexible substrate, and based on the advantages of a flexible battery, it will be beneficial to the application of the photovoltaic device in special fields such as wearable, portable equipment and near-space vehicles.

Mechanism analysis of the present invention:

The invention mainly combines the spectral responses of different battery materials to achieve the full spectrum absorption of sunlight as much as possible, thereby improving the photoelectric conversion efficiency of the battery, and combining the characteristics of the flexible substrate to improve the applicability of photovoltaic devices. The stacked battery is connected through the middle TCO conductive film.

Description of drawings

1 is a schematic diagram of the overall structure of the laminated battery of the present invention,

Figure 2 is a schematic diagram of the structure of a microcrystalline silicon single junction cell with a stainless steel substrate,

Figure 3 is a schematic diagram of the structure of the top cell perovskite thin film battery,

Wherein, 103 in FIG. 1 is a metal or polymer flexible substrate. C1 is a single-junction microcrystalline silicon thin-film battery, and C2 is a single-junction perovskite thin-film battery. In Figure 2, C101 is the metal back electrode layer of the microcrystalline silicon battery, C102 is the back electrode TCO layer of the microcrystalline silicon battery, C103 is the n layer of the microcrystalline silicon battery, C104 is the i layer of the microcrystalline silicon battery, and C105 is the The p-layer of microcrystalline silicon cells, C106 is the TCO tunneling layer of microcrystalline silicon cells and perovskite cells. In Figure 3, C201 is the electron transport layer of the perovskite cell, C202 is the absorption layer of the perovskite cell, C203 is the hole transport layer of the perovskite cell, and C204 is the front electrode of the TCO thin film of the perovskite cell.

FIG. 4 is a schematic diagram of the specific structure of the laminated battery of the present invention.

Detailed ways

Based on the diversity of the preparation methods of perovskite thin film batteries, the present invention is described from three embodiments respectively by vacuum method, blade coating method and spin coating method.

Example 1

Microcrystalline silicon thin-film batteries were fabricated using metal or stainless steel substrates. The microcrystalline silicon thin film battery in this embodiment is prepared by the following method:

1. Clean the flexible substrate (such as stainless steel substrate, polymer PET, PI substrate) in (neutral cleaning solution) to remove surface contaminants. Air dry or dry the cleaned substrate;

2. Modification of flexible substrates. The prepared flexible substrate is placed in a vacuum equipment to prepare metal thin films (like Au, Al, Ag, etc.) electrodes and TCO thin films (like ITO, IWO, ITIO, AZO, etc.);

3. PECVD film deposition. The samples prepared in the second step are placed in a PECVD chamber to preheat and deposit microcrystalline silicon films. The thin film process is a microcrystalline silicon thin film preparation process.

4. Preparation of the tunnel junction of the tandem battery. The cells in the third step are placed in a vacuum equipment for the preparation of TCO thin films (like ITO, IWO, ITIO, AZO, etc.).

5. After the preparation of the samples, the microcrystalline silicon cells are subjected to passivation treatment.

After completing the above steps, the preparation of the perovskite thin film battery is carried out. The preparation method of the battery is a vacuum method, and the preparation method is as follows:

1. The surface of the microcrystalline silicon film sample is subjected to UV treatment.

2. Place the processed flexible sample in a vacuum device, which can be a flexible roll-to-roll device or a rigid substrate device (using a flexible substrate fixture to place the sample).

3. Introduce the sample in the second step into a vacuum device to prepare an electron transport layer. The electron transport layer can be inorganic substances such as titanium oxide, tin oxide, indium sulfide, etc., or organic substances such as PCBM, C60 and the like. The inorganic electron transport layer is realized by sputtering, electron beam or resistive thermal evaporation deposition, and the organic electron transport layer is realized by organic source evaporation.

4. The samples of the third step were introduced into the perovskite vacuum deposition chamber to prepare the absorber layer. Deposition by evaporation from organic sources. The deposition components of the perovskite absorption layer are adjusted according to requirements, including organic perovskite and inorganic perovskite materials, and the deposition parameters are adjusted by adjusting the temperature of the evaporation source.

5. Introduce the sample of the fourth step into the hole transport layer chamber deposition. The hole transport layer can be an organic substance such as Spiro, which is deposited by evaporation from an organic source; it can also be an inorganic substance such as nickel oxide, copper oxide, copper thiocyanate, etc., which can be deposited by sputtering, electron beam or resistive thermal evaporation. deposition.

6. Finally, the preparation of TCO (like ITO, IWO, ITIO, AZO, etc.) front electrodes and metal (like Au, Al, Ag, etc.) gate lines is performed.

Example 1 is all prepared by vacuum method, which conforms to the mode of industrial production, and the perovskite prepared by vacuum method has better stability.

Example 2

The preparation of the microcrystalline silicon thin film battery is equivalent to that of Example 1, as follows:

1. Clean the flexible substrate (such as stainless steel substrate, polymer PET, PI substrate) in (neutral cleaning solution) to remove surface contaminants. Air dry or dry the cleaned substrate;

2. Modification of flexible substrates. The prepared flexible substrate is placed in a vacuum equipment to prepare metal thin films (like Au, Al, Ag, etc.) electrodes and TCO thin films (like ITO, IWO, ITIO, AZO, etc.);

3. PECVD film deposition. The samples prepared in the second step are placed in a PECVD chamber to preheat and deposit microcrystalline silicon films. The thin film process is a microcrystalline silicon thin film preparation process.

4. Preparation of the tunnel junction of the tandem battery. The cells in the third step are placed in a vacuum equipment for the preparation of TCO thin films (like ITO, IWO, ITIO, AZO, etc.).

5. After the preparation of the samples, the microcrystalline silicon cells are subjected to passivation treatment.

After the above steps are completed, the preparation of the perovskite thin film battery is carried out. The preparation method of the battery is the blade coating method, and the preparation method is as follows:

1. The surface of the microcrystalline silicon film sample is subjected to UV treatment.

2. Place the treated flexible sample in a blade coating device, which can be a flexible roll-to-roll blade coating device or a flat blade coating device.

3. Preparation of blade coating of electron transport layer. The electron transport layer can be inorganic substances such as titanium oxide, tin oxide, indium sulfide, etc., or organic substances such as PCBM, C60 and the like. After selecting the preparation material of the electron transport layer, adjust the ratio to prepare the blade coating solution. The prepared solution is placed in the reagent propelling device of the scraping coating equipment for scraping coating. Adjust the temperature of the heating table, control the coating speed, and adjust the film performance.

4. Preparation of perovskite absorber layer. After selecting the preparation material of the perovskite absorbing layer, adjust the ratio to prepare the blade coating solution. The prepared solution is placed in the reagent propelling device of the scraping coating equipment for scraping coating. Adjust the temperature of the heating table, control the coating speed, and adjust the film performance.

5. Preparation of hole transport layer cavity. The hole transport layer can be an organic substance such as Spiro; it can also be an inorganic substance such as nickel oxide, copper oxide, copper thiocyanate and the like. After selecting the preparation material of the hole transport layer, adjust the ratio to prepare the blade coating solution. The prepared solution is placed in the reagent propelling device of the scraping coating equipment for scraping coating. Adjust the temperature of the heating table, control the coating speed, and adjust the film performance.

6. Finally, the preparation of TCO (like ITO, IWO, ITIO, AZO, etc.) front electrodes and metal (like Au, Al, Ag, etc.) gate lines is performed.

Example 3

The preparation of the microcrystalline silicon thin film battery is the same as that of Example 1 and Example 2, and will not be described in detail.

The preparation method of the perovskite thin film battery is a spin coating method, and the preparation method is as follows:

1. The surface of the microcrystalline silicon film sample is subjected to UV treatment.

2. Place the sample on a spinner for electron transport layer preparation. The electron transport layer can be inorganic substances such as titanium oxide, tin oxide, indium sulfide, etc., or organic substances such as PCBM, C60 and the like. After selecting the preparation material of the electron transport layer, adjust the ratio to prepare the spin coating solution. Use a pipette to drop the prepared solution on the surface of the sample for spin coating.

3. Spin-coating of the perovskite absorber layer. After selecting the preparation material of the perovskite absorbing layer, weigh the medicine according to the required ratio, and select the appropriate solvent to prepare the spin-coating solution. Use a pipette to drop the prepared solution onto the sample on the spin coater for spin coating.

4. Preparation of hole transport layer. The hole transport layer can be an organic substance such as Spiro; it can also be an inorganic substance such as nickel oxide, copper oxide, copper thiocyanate and the like. After selecting the preparation material of the hole transport layer, adjust the ratio to prepare the spin coating solution. Use a pipette to drop the prepared solution onto the sample on the spin coater for spin coating.

5. Finally, the preparation of TCO (like ITO, IWO, ITIO, AZO, etc.) front electrodes and metal (like Au, Al, Ag, etc.) gate lines is performed.

The present invention is a laminated battery in its structural form, and the several embodiments described are better embodiments of the present invention. Several substitutions or modifications can be made without departing from the concept of the present invention, and have similar performance or the same use. , should be regarded as belonging to the protection scope of the present invention. Therefore, the protection scope of the present invention is subject to the claims.

Claims (10)

1. A flexible perovskite/microcrystalline silicon laminated solar cell, characterized in that: the laminated cell is prepared by using a flexible substrate; the laminated cell is made of a perovskite thin film cell as a top cell, and battery as bottom battery; From bottom to top: flexible substrate, microcrystalline silicon battery, perovskite thin film battery. 2. The flexible perovskite/microcrystalline silicon laminated solar cell according to claim 1, characterized in that: the laminated cell structure from bottom to top is: flexible substrate, metal back electrode, transparent conductive ( TCO) thin film, n-type microcrystalline silicon, intrinsic microcrystalline silicon, p-type microcrystalline silicon, TCO thin film, electron transport layer, perovskite absorption layer, hole transport layer, TCO thin film, metal gate electrode. 3 . The flexible perovskite/microcrystalline silicon tandem solar cell according to claim 1 or 2 , wherein the tunnel junction of the top cell and the bottom cell adopts a TCO conductive film. 4 . 4. The flexible perovskite/microcrystalline silicon tandem solar cell according to claim 2, wherein the perovskite absorption layer can be one or more of organic or inorganic materials. 5. The flexible perovskite solar cell vacuum deposition system according to claim 2, wherein the electron transport layer can be inorganic: titanium oxide, tin oxide, indium sulfide, or organic: One or more of PCBM and C60. 6. The flexible perovskite solar cell vacuum deposition system according to claim 2, wherein the hole transport layer can be one of nickel oxide, copper oxide, and copper thiocyanate in inorganic materials Or two or more, organic hole layers such as one or more of Sprio, PTAA, PEDOT. 7. The flexible perovskite solar cell vacuum deposition system according to claim 2, wherein the TCO front electrode material of the top cell can be one or two of ITO, ITIO, BZO, graphene, etc. above. 8. A manufacturing method of the flexible perovskite/microcrystalline silicon stacked solar cell according to any one of claims 1-7, wherein the flexible substrate is a metal substrate or a polymer substrate, The substrate is modified by vacuum deposition of materials with high electrical conductivity, and a TCO film with light trapping properties is prepared on the modified surface. 9. The method for manufacturing a flexible perovskite/microcrystalline silicon tandem solar cell according to claim 8, wherein the bottom cell is a microcrystalline silicon cell, using plasma enhanced chemical vapor deposition, an n-layer Phosphorus-doped hydrogenated microcrystalline silicon oxygen material is used, microcrystalline silicon material is used for the intrinsic layer, and boron-doped hydrogenated microcrystalline silicon oxygen material is used for the p layer. 10. The flexible perovskite/microcrystalline silicon laminated solar cell according to claim 8 or 9, wherein the top cell is a perovskite thin film cell, and the preparation method can be a vacuum method, a blade coating method Or more than one type of work in the spin coating method; The TCO front electrode of the top cell can be prepared by a vacuum method.

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