CN214505521U

CN214505521U - Laminated solar cell

Info

Publication number: CN214505521U
Application number: CN202120858345.6U
Authority: CN
Inventors: 夏锐; 陈艺绮; 王尧; 刘成法; 邹杨; 陈达明; 陈奕峰
Original assignee: Trina Solar Co Ltd
Current assignee: Trina Solar Changzhou Technology Co ltd; Trina Solar Co Ltd
Priority date: 2021-04-25
Filing date: 2021-04-25
Publication date: 2021-10-26
Anticipated expiration: 2031-04-25

Abstract

The utility model provides a laminated solar cell, which comprises a TOPCon cell and a perovskite solar cell which are arranged in a laminated way; the TOPCon battery comprises a silicon wafer layer, wherein a diffusion silicon layer and a passivation layer are arranged on one side surface of the silicon wafer layer in a laminated mode, and a tunneling layer and a polycrystalline silicon layer are arranged on the other side surface of the silicon wafer layer in a laminated mode; and the surface of the polycrystalline silicon layer, which is far away from the tunneling layer, is attached to one side, which is far away from the electrode, of the perovskite solar cell. The utility model discloses invert as the end battery with the TOPCon battery to grow perovskite solar cell at the back of TOPCon battery, have simple structure, convenient preparation, with low costs and characteristics such as photoelectricity photoelectric conversion high efficiency.

Description

Laminated solar cell

Technical Field

The utility model belongs to the technical field of solar cell, especially, relate to a stromatolite solar cell.

Background

Improving the energy conversion efficiency and reducing the cost of the device are the key points of the solar cell technology towards large-scale application. At present, the research and practical application of the solar cell mainly uses a single device, and takes a crystalline silicon solar cell as an example, the laboratory efficiency of the solar cell reaches 27.6 percent and is close to the limit theoretical efficiency of 30 percent, but the efficiency is further improved with great difficulty. The band gap of the crystalline silicon material is 1.12eV, short-wavelength light in the solar spectrum cannot be reasonably utilized, and if the crystalline silicon solar cell is used as a substrate and a top cell with a wider band gap is continuously deposited to form a laminated cell, solar energy can be utilized to the maximum extent, spectral response is widened, and the efficiency of a device is improved.

The organic metal halide perovskite material has excellent light absorption and electric conduction performance, and has the advantages of low cost, simple and convenient preparation, diversity and the like, and the perovskite solar cell prepared by taking the material as the absorption layer has great commercial application prospect. In addition, the controllable adjustment of the band gap of the perovskite material within the range of 1.5-2.3 eV can be realized by changing the components of the perovskite material, if a perovskite solar top cell with a wider band gap is prepared by taking a crystalline silicon bottom cell as a substrate, good spectrum matching is formed, the perovskite/crystalline silicon two-end laminated solar cell is obtained, the remarkable improvement of the photoelectric conversion efficiency can be realized on the premise of slight increase of the cost, the theoretical efficiency of the laminated cell can reach 44%, and the perovskite/crystalline silicon two-end laminated solar cell has great research potential and rising space.

The crystalline silicon cell type used by most of the perovskite/crystalline silicon two-end laminated cell technologies reported at present is a heterojunction solar cell (HIT), and the perovskite/HIT laminated cell certification efficiency prepared by OXFORD PV corporation in the uk has reached 29.5%. The HIT bottom cell has the advantages of high open-circuit voltage and high conversion efficiency, however, the material and equipment cost is expensive, the process condition requirement is strict, and a certain distance is provided for large-scale mass production. A tunnel oxide layer passivation contact solar cell (TOPCon) with a homojunction structure is characterized in that an ultrathin tunnel oxide layer and a highly doped polycrystalline silicon thin layer are prepared on the back of a device and form a passivation contact structure together, so that minority carrier hole recombination can be effectively prevented, and the open-circuit voltage and the short-circuit current of the cell are improved. Compared with PERC, TOPCon currently has higher device efficiency and efficiency improvement space, and the battery preparation thereof is compatible with the existing mass production process.

CN111987184A discloses a stacked cell structure comprising a top cell unit, a bottom cell unit and an intermediate layer between the top cell unit and the bottom cell unit; the middle layer is constructed as a tunneling junction consisting of a p +/n + double-layer crystalline silicon thin film; the top battery unit comprises an electron transport layer, a perovskite photosensitive layer, a hole transport layer and a front electrode, wherein the electron transport layer, the perovskite photosensitive layer and the hole transport layer are sequentially stacked in the direction from far away to near the intermediate layer; the bottom battery unit is a PERC solar battery; the utility model discloses a through adopting nanometer silicon tunnel junction structure can obtain good perovskite battery performance, have characteristics such as photoelectric conversion efficiency height.

CN110649111A discloses a stacked solar cell, which comprises an antireflection layer, an upper cell, an interface layer, a lower cell and a lower electrode, which are stacked in sequence from top to bottom, wherein at least 3 slots are formed in the upper surface of the antireflection layer at equal intervals, a front electrode is electrically connected to each slot, and the upper cell contains a titanium ore structural material. The utility model discloses a because its range upon range of formula structural design can obtain higher open circuit voltage to upper and lower battery absorbs different wavelength range's sunlight respectively, can improve the utilization ratio of sunlight by at utmost, promotes the short-circuit cell, consequently can obtain higher photoelectric conversion efficiency.

The existing solar cells all have the problems of complex structure, high cost and low photoelectric conversion efficiency, so that the problems which need to be solved at present are solved by ensuring that the solar cells have the characteristics of high photoelectric conversion efficiency, simple preparation process and the like under the conditions of simple structure and low cost.

SUMMERY OF THE UTILITY MODEL

Not enough to prior art exist, the utility model aims to provide a stromatolite solar cell to TOPCon battery is end battery, guarantees that TOPCon battery front part's process is complete, grows perovskite top solar cell in proper order at the back, makes the utility model has the characteristics of simple structure, the cost is lower and conversion efficiency is high.

To achieve the purpose, the utility model adopts the following technical proposal:

the utility model provides a laminated solar cell, which comprises a TOPCon cell and a perovskite solar cell which are arranged in a laminated way; the TOPCon battery comprises a silicon wafer layer, wherein a diffusion silicon layer and a passivation layer are arranged on one side surface of the silicon wafer layer in a laminated mode, and a tunneling layer and a polycrystalline silicon layer are arranged on the other side surface of the silicon wafer layer in a laminated mode; and the surface of the polycrystalline silicon layer, which is far away from the tunneling layer, is attached to one side, which is far away from the electrode, of the perovskite solar cell.

The utility model discloses a TOPCon battery and perovskite solar cell of range upon range of setting, the process of guaranteeing the front part is complete, gets rid of passivation layer and metal electrode on the back preparation technology, invert as the bottom cell with the TOPCon battery to grow perovskite solar cell at the back of TOPCon battery, wherein, the effect of composite bed can be realized to the polycrystalline silicon layer, thereby save the preparation of composite bed, simplify the preparation technology, make simple structure and reduce material cost; in addition, compare in the structure of growing perovskite solar cell in TOPCon battery's positive, it directly gets rid of positive passivation layer structure, leads to the passivation effect to weaken to reduced the performance of battery, and the utility model discloses well polycrystalline silicon layer also can play certain passivation effect, can improve photoelectric conversion rate. The utility model discloses well polycrystalline silicon layer can play the effect of passivation layer, can also regard as the composite bed of being connected with perovskite solar cell, has simple structure, convenient preparation, characteristics such as with low costs and photoelectric conversion efficient height.

It should be noted that the TOPCon cell is a tunnel oxide passivated contact solar cell.

As a preferred technical solution of the present invention, at least one first metal electrode is inserted on the diffusion silicon layer.

And heavily doped silicon is arranged at the contact part of the first metal electrode and the diffusion silicon layer.

As a preferred technical solution of the present invention, the TOPCon cell is an n-type TOPCon cell, the material of the silicon wafer layer is n-type silicon, the material of the diffusion silicon layer is p-type diffusion silicon, and the polysilicon layer is n-type polysilicon.

The perovskite solar cell comprises a perovskite layer, an electron transmission layer, a buffer layer, a conducting layer, a metal electrode layer and an antireflection layer which are arranged in a stacked mode, wherein the polycrystalline silicon layer is far away from the tunneling layer, and the perovskite layer is attached to the polycrystalline silicon layer.

It should be noted that the perovskite layer of the present invention is made of a material having a chemical structural formula of ABX₃Wherein a comprises one or a combination of monovalent cations of potassium, cesium, rubidium, methylamino or amidino; b comprises one or more divalent cations of lead or tin; x comprises one or more monovalent anions of iodine, bromine or chlorine.

And a composite layer is also arranged between the perovskite layer and the polycrystalline silicon layer.

And a hole transport layer is also arranged between the composite layer and the perovskite layer.

As a preferred technical solution of the present invention, the TOPCon cell is a p-type TOPCon cell, the material of the silicon wafer layer is p-type silicon, the material of the diffusion silicon layer is n-type diffusion silicon, and the polysilicon layer is p-type polysilicon.

The perovskite solar cell comprises an electron transmission layer, a perovskite layer, a buffer layer, a conducting layer, a metal electrode layer and an antireflection layer which are arranged in a stacked mode, wherein the polycrystalline silicon layer is far away from the tunneling layer, and the electron transmission layer is attached to the polycrystalline silicon layer.

And a composite layer is arranged between the electron transmission layer and the polycrystalline silicon layer.

And a hole transport layer is also arranged between the buffer layer and the perovskite layer.

As a preferred technical solution of the present invention, in the n-type TOPCon battery, the heavily doped silicon is p-type heavily doped silicon.

As a preferred technical solution of the present invention, in the p-type TOPCon battery, the heavily doped silicon is n-type heavily doped silicon.

At least one second metal electrode is connected to the metal electrode layer.

It should be noted that the electrode of the present invention is not limited to specific requirements and specific limitations, and those skilled in the art can reasonably select the electrode arrangement form according to the design requirement, for example, by printing with metal paste.

As a preferred embodiment of the present invention, the thickness of the tunneling layer is 0.5 to 3nm, for example, 0.5nm, 0.7nm, 0.9nm, 1.1nm, 1.3nm, 1.5nm, 1.7nm, 1.9nm, 2.1nm, 2.3nm, 2.5nm, 2.7nm, 2.9nm or 3.0 nm.

The thickness of the polysilicon layer is 10-200 nm, for example, 10nm, 20nm, 40nm, 60nm, 80nm, 100nm, 120nm, 140nm, 160nm, 180nm or 200 nm.

The thickness of the diffusion silicon layer is more than or equal to 30nm, for example, the thickness is 30nm, 50nm, 70nm, 90nm, 100nm, 150nm or 200 nm.

As a preferred embodiment of the present invention, the thickness of the composite layer is 0 to 200nm, excluding 0, for example, 5nm, 10nm, 30nm, 50nm, 100nm, 120nm, 150nm, 180nm, or 200 nm.

The perovskite layer has a thickness of 100 to 1000nm, for example, a thickness of 100nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm or 1000 nm.

The buffer layer has a thickness of 0 to 100nm, excluding 0, for example, a thickness of 5nm, 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, or 100 nm.

The conductive layer has a thickness of 0 to 500nm, excluding 0, for example, a thickness of 5nm, 10nm, 30nm, 50nm, 100nm, 150nm, 200nm, 250nm, 300nm, 350nm, 400nm, 450nm, or 500 nm.

The thickness of the metal electrode layer is 0 to 500nm, but not 0, for example, the thickness is 5nm, 10nm, 30nm, 50nm, 100nm, 150nm, 200nm, 250nm, 300nm, 350nm, 400nm, 450nm or 500 nm.

The antireflection layer has a thickness of 0 to 5mm excluding 0, for example, a thickness of 0.5mm, 1.0mm, 1.5mm, 2.0mm, 2.5mm, 3.0mm, 3.5mm, 4.0mm, 4.5mm, or 5.0 mm.

The hole transport layer has a thickness of 0 to 500nm excluding 0, for example, a thickness of 5nm, 10nm, 30nm, 50nm, 100nm, 150nm, 200nm, 250nm, 300nm, 350nm, 400nm, 450nm or 500 nm.

The electron transport layer has a thickness of 0 to 500nm excluding 0, for example, a thickness of 5nm, 10nm, 30nm, 50nm, 100nm, 150nm, 200nm, 250nm, 300nm, 350nm, 400nm, 450nm or 500 nm.

As an optimized technical scheme of the utility model, the material of passivation layer is SiO₂Silicon nitride, aluminum oxide, or silicon oxynitride.

The composite layer is made of nanocrystalline silicon, polycrystalline silicon and SnO₂、TiO₂、ZnO₂Any one of ITO, FTO, IZO and AZO.

The hole transport layer is made of Spiro-OMeTAD, PTAA, nickel oxide, P3HT, PEDOT PSS, CuSCN, CuAlO₂Or any of Spiro-TTB.

The electron transport layer is made of SnO₂、TiO₂、ZnO₂、ITO、FTO、IZO, fullerene derivative, BaSnO₃Or AZO.

The fullerene derivative is any one of C60, C70 or PCBM.

The buffer layer is made of molybdenum oxide, LiF and SnO₂、TiO₂、SiO₂Or amorphous silicon.

The conducting layer is made of SnO₂、TiO₂Any one of IZO, AZO, graphene or nano silver.

The metal electrode layer is made of any one of Au, Ag, Al and Cu.

The material of the anti-reflection layer is LiF and MgF₂、Si₃N₄、SiO₂Or a suede flexible film material.

The suede flexible film material is dimethyl siloxane polymer.

Illustratively, the present invention provides a method for manufacturing the above-mentioned tandem solar cell, the method comprising the following steps:

and arranging a diffusion silicon layer and a passivation layer on one side of the silicon chip layer in sequence, arranging a tunneling layer and a polycrystalline silicon layer on the surface of the other side of the silicon chip layer in sequence to form a TOPCon battery, inverting the TOPCom battery, arranging a perovskite solar battery on the polycrystalline silicon layer, and attaching one side of the perovskite solar battery, which is far away from the electrode, to the polycrystalline silicon layer to prepare the laminated solar battery.

As a preferred technical solution of the present invention, the TOPCon cell is an n-type TOPCon cell, and the perovskite solar cell is prepared by the steps of: and sequentially forming a perovskite layer, an electron transmission layer, a buffer layer, a conductive layer, a metal electrode layer and an antireflection layer on the surface of the polycrystalline silicon layer.

And a composite layer is also formed between the polycrystalline silicon layer and the perovskite layer.

And a hole transport layer is also formed between the composite layer and one side of the perovskite layer.

The TOPCon battery is a p-type TOPCon battery, and the perovskite solar battery is prepared by the following steps: and sequentially forming an electron transmission layer, a perovskite layer, a buffer layer, a conductive layer, a metal electrode layer and an antireflection layer on the surface of the polycrystalline silicon layer.

And a composite layer is also formed between the polycrystalline silicon layer and the electron transmission layer.

And a hole transport layer is also formed between the perovskite layer and the buffer layer.

The diffusion silicon layer is formed by chemical vapor deposition or selective etching.

The diffused silicon layer is formed by chemical vapor deposition and has a sheet resistance of 80-250 ohm/sq, for example, 80ohm/sq, 90ohm/sq, 100ohm/sq, 110ohm/sq, 120ohm/sq, 130ohm/sq, 140ohm/sq, 150ohm/sq, 160ohm/sq, 170ohm/sq, 180ohm/sq, 190ohm/sq, 200ohm/sq, 210ohm/sq, 220ohm/sq, 230ohm/sq, 240ohm/sq or 250 ohm/sq.

The diffused silicon layer is formed by selective etching, and the sheet resistance of the diffused silicon layer is 50-150 ohm/sq, for example, the sheet resistance is 50ohm/sq, 60ohm/sq, 70ohm/sq, 80ohm/sq, 90ohm/sq, 100ohm/sq, 110ohm/sq, 120ohm/sq, 130ohm/sq, 140ohm/sq or 150 ohm/sq.

The formation mode of the tunneling layer comprises a high-temperature thermal oxidation method, a nitric acid oxidation method and an ozone oxidation method.

The forming mode of the polycrystalline silicon layer comprises a chemical vapor growth method.

The temperature of the chemical vapor deposition is 550 to 650 ℃, for example, 550 ℃, 560 ℃, 570 ℃, 580 ℃, 590 ℃, 600 ℃, 610 ℃, 620 ℃, 630 ℃, 640 ℃ or 650 ℃.

The formation mode of the diffusion silicon layer comprises an in-situ doping method or a high-temperature activation method.

The activation temperature of the high-temperature activation method is not less than 800 deg.C, for example, 800 deg.C, 900 deg.C, 1000 deg.C, 1100 deg.C, 1200 deg.C, 1300 deg.C, 1400 deg.C, 1500 deg.C, 2000 deg.C or 2500 deg.C.

The diffusion silicon layer is an n-type silicon wafer layer, the high-temperature activation method is a phosphorus diffusion high-temperature activation method, or the in-situ doping method is a boron doping in-situ doping method.

The passivation layer is formed by PECVD and/or PEALD.

PECVD is a plasma-enhanced chemical vapor deposition method, and PEALD is a plasma-enhanced atomic layer deposition method.

As a preferred embodiment of the present invention, the formation mode of the composite layer includes one or a combination of at least two of a vapor deposition method, an atomic layer deposition method, a magnetron sputtering method, a solution method, and a thermal evaporation method of plasma enhanced chemistry.

The forming mode of the hole transport layer comprises one or the combination of at least two of a spin coating method, a thermal evaporation method, a blade coating method, a coating method and a printing method.

The electron transport layer is formed by a solution method, a magnetron sputtering method, a spray pyrolysis method, a thermal evaporation method, an atomic layer deposition method, a blade coating method, a coating method or a printing method.

The buffer layer is formed by ALD, PECVD, spin-coating, sputtering or thermal evaporation.

ALD is an atomic layer deposition method.

The conductive layer is formed by ALD, PECVD, spin-coating, sputtering or thermal evaporation.

The metal electrode layer is formed by a thermal evaporation method and/or a screen printing method.

The formation mode of the anti-reflection layer comprises an evaporation method, a sputtering method or an ALD method.

The numerical range of the present invention includes not only the point values listed above, but also any point values between the above numerical ranges not listed, which is limited to space and for the sake of brevity, the present invention does not exhaust the specific point values included in the range.

Compared with the prior art, the beneficial effects of the utility model are that:

Drawings

Fig. 1 is a schematic structural diagram of a tandem solar cell of an n-type TOPCon cell provided in embodiments 2-4 of the present invention;

fig. 2 is a schematic structural diagram of a tandem solar cell of a p-type TOPCon cell provided in embodiment 4 of the present invention;

fig. 3 is a schematic structural view of a tandem solar cell provided in comparative example 1 of the present invention;

fig. 4 is a J-V graph of the tandem solar cell provided in example 2, example 4 and comparative example 1 of the present invention.

Wherein, 1-antireflection layer; 2-a conductive layer; 3-a buffer layer; 4-a hole transport layer; 5-a perovskite layer; 6-electron transport layer; 7-a composite layer; 8-a polysilicon layer; 9-a tunneling layer; 10-a silicon wafer layer; 11-a diffused silicon layer; 12-a passivation layer; 13-a first metal electrode; 14-second metal electrode.

Detailed Description

It is to be understood that in the description of the present invention, the terms "central," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in the orientation or positional relationship indicated in the drawings for the purpose of convenience and simplicity of description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be construed as limiting the present invention. Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

It should be noted that, unless explicitly stated or limited otherwise, the terms "disposed," "connected" and "connected" in the description of the present invention are to be construed broadly, and may for example be fixedly connected, detachably connected or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.

The technical solution of the present invention will be further explained by the following embodiments.

In one embodiment, the present invention provides a tandem solar cell, the solar cell comprising a TOPCon cell and a perovskite solar cell stacked together; the TOPCon battery comprises a silicon wafer layer 10, wherein a diffusion silicon layer 11 and a passivation layer 12 are arranged on one side surface of the silicon wafer layer 10 in a laminated mode, and a tunneling layer 9 and a polycrystalline silicon layer 8 are arranged on the other side surface of the silicon wafer layer 10 in a laminated mode; the surface of the polycrystalline silicon layer 8 far away from the tunneling layer 9 is attached to one side of the perovskite solar cell far away from the electrode.

Furthermore, the TOPCon cell is an n-type TOPCon cell, the silicon wafer layer 10 is made of n-type silicon, the diffused silicon layer 11 is made of p-type diffused silicon, and the polysilicon layer 8 is n-type polysilicon; the perovskite solar cell comprises a perovskite layer 5, an electron transmission layer 6, a buffer layer 3, a conducting layer 2, a metal electrode layer (not shown in the figure) and an antireflection layer 1 which are arranged in a laminated mode from the direction of a polycrystalline silicon layer 8 far away from a tunneling layer 9; further, a composite layer 7 is provided between the perovskite layer 5 and the polycrystalline silicon layer 8, and a hole transport layer 4 is provided between the composite layer 7 and the perovskite layer 5.

Furthermore, the TOPCon cell is a p-type TOPCon cell, the silicon wafer layer 10 is made of p-type silicon, the diffused silicon layer 11 is made of n-type diffused silicon, and the polysilicon layer 8 is p-type polysilicon; the perovskite solar cell comprises an electron transmission layer 6, a perovskite layer 5, a buffer layer 3, a conducting layer 2, a metal electrode layer and an antireflection layer 1 which are arranged in a laminated mode from the direction of a polycrystalline silicon layer 8 far away from a tunneling layer 9; further, a composite layer 7 is provided between the electron transport layer 6 and the polycrystalline silicon layer 8, and a hole transport layer 4 is provided between the buffer layer 3 and the perovskite layer 5.

Further, at least one first metal electrode 13 is interposed on the diffused silicon layer 11; heavily doped silicon is arranged at the contact part of the first metal electrode 13 and the diffusion silicon layer 11, wherein in the n-type TOPCon battery, the heavily doped silicon is p-type heavily doped silicon; in the p-type TOPCon battery, heavily doped silicon is n-type heavily doped silicon; at least one second metal electrode 14 is connected to the metal electrode layer.

Further, the thickness of the tunneling layer 9 is 0.5-3 nm, the thickness of the polycrystalline silicon layer 8 is 10-200 nm, the thickness of the diffusion silicon layer 11 is not less than 30nm, the thickness of the composite layer 7 is 0-200 nm but not 0, the thickness of the perovskite layer 5 is 100-1000 nm, the thickness of the buffer layer 3 is 0-100 nm but not 0, the thickness of the conductive layer 2 is 0-500 nm but not 0, the thickness of the metal electrode layer is 0-500 nm but not 0, the thickness of the anti-reflection layer 1 is 0-5 mm but not 0, the thickness of the hole transmission layer 4 is 0-500 nm but not 0, and the thickness of the electron transmission layer 6 is 0-500 nm but not 0.

Further, the passivation layer 12 is made of SiO₂Silicon nitride, aluminum oxide or silicon oxynitride, the composite layer 7 is made of nanocrystalline silicon, polycrystalline silicon or SnO₂、TiO₂、ZnO₂ITO, FTO, IZO or AZO, the hole transport layer 4 is made of Spiro-OMeTAD, PTAA, nickel oxide, P3HT, PEDOT PSS, CuSCN or CuAlO₂Or Spiro-TTB, the material of the electron transport layer 6 is SnO₂、TiO₂、ZnO₂ITO, FTO, IZO, fullerene derivative, BaSnO₃Or AZO, the fullerene derivative is C60, C70 or PCBM, and the buffer layer 3 is made of molybdenum oxide, LiF or SnO₂、TiO₂、SiO₂Or amorphous silicon, the conductive layer 2 is made of SnO₂、TiO₂IZO, AZO, graphene or nano silver, the metal electrode layer is made of Au, Ag, Al or Cu, and the anti-reflection layer 1 is made of LiF or MgF₂、Si₃N₄、SiO₂Or a dimethylsiloxane polymer.

and arranging a diffusion silicon layer 11 and a passivation layer 12 on one side of a silicon wafer layer 10 in sequence, arranging a tunneling layer 9 and a polycrystalline silicon layer 8 on the other side surface of the silicon wafer layer 10 in sequence to form a TOPCon battery, inverting the TOPCom battery, arranging a perovskite solar battery on the polycrystalline silicon layer 8, and attaching one side of the perovskite solar battery, which is far away from an electrode, to the polycrystalline silicon layer 8 to prepare the laminated solar battery.

Further, the TOPCon cell is an n-type TOPCon cell, and the perovskite solar cell is prepared by the following steps: sequentially forming a perovskite layer 5, an electron transport layer 6, a buffer layer 3, a conducting layer 2, a metal electrode layer and an antireflection layer 1 on the surface of the polycrystalline silicon layer 8; further, a composite layer 7 is formed between the polycrystalline silicon layer 8 and the perovskite layer 5, and a hole transport layer 4 is formed between the composite layer 7 and the perovskite layer 5.

Further, the TOPCon cell is a p-type TOPCon cell, and the perovskite solar cell is prepared by the following steps: an electron transport layer 6, a perovskite layer 5, a buffer layer 3, a conductive layer 2, a metal electrode layer and an antireflection layer 1 are sequentially formed on the surface of the polycrystalline silicon layer 8. Further, a composite layer 7 is formed between the polycrystalline silicon layer 8 and the electron transport layer 6, and a hole transport layer 4 is formed between the perovskite layer 5 and the buffer layer 3.

Further, the formation method of the diffusion silicon layer 11 includes a chemical vapor deposition method or a selective etching method, the formation method of the diffusion silicon layer 11 is the chemical vapor deposition method, the sheet resistance of the diffusion silicon layer 11 is 80-250 ohm/sq, the formation method of the diffusion silicon layer 11 is the selective etching method, and the sheet resistance of the diffusion silicon layer 11 is 50-150 ohm/sq.

Further, the formation mode of the tunneling layer 9 includes a high temperature thermal oxidation method, a nitric acid oxidation method and an ozone oxidation method, the formation mode of the polycrystalline silicon layer 8 includes a chemical vapor growth method, the temperature of the chemical vapor growth method is 550-650 ℃, the formation mode of the diffused silicon layer 11 includes an in-situ doping method or a high temperature activation method, the activation temperature of the high temperature activation method is not less than 800 ℃, the diffused silicon layer 11 is an n-type diffused silicon layer 11, the high temperature activation method is a phosphorus diffusion high temperature activation method, or the in-situ doping method is a boron doping in-situ doping method.

Further, the passivation layer 12 is formed by PECVD and/or PEALD, the composite layer 7 is formed by PECVD, atomic layer deposition, magnetron sputtering, solution method and thermal evaporation, the hole transport layer 4 is formed by spin coating, thermal evaporation, blade coating, coating or printing, the electron transport layer 6 is formed by solution method, magnetron sputtering, spray pyrolysis method and thermal evaporation, the buffer layer 3 is formed by an ALD, PECVD, spin coating, sputtering or thermal evaporation method, the conductive layer 2 is formed by an ALD, PECVD, spin coating, sputtering or thermal evaporation method, the metal electrode layer is formed by a thermal evaporation method and/or screen printing method, and the antireflective layer 1 is formed by an evaporation method, sputtering or ALD.

Example 1

The present embodiment provides a tandem solar cell, which is based on the tandem solar cell provided in one embodiment, wherein the TOPCon cell is an n-type TOPCon cell, and the thickness of the hole transport layer 4 is 30 nm; the thickness of the electron transport layer 6 was 0 nm; two first metal electrodes 13 are inserted on the diffused silicon layer 11, and two second metal electrodes 14 are connected to the metal electrode layers.

The thickness of the tunneling layer 9 is 1.5 nm; the thickness of the polysilicon layer 8 is 120 nm; the thickness of the diffused silicon layer 11 is 50 nm; the thickness of the composite layer 7 is 100 nm; the thickness of the perovskite layer 5 is 500 nm; the thickness of the buffer layer 3 is 2 nm; the thickness of the conductive layer 2 is 100 nm; the thickness of the metal electrode layer is 60 nm; the thickness of the antireflective layer 1 was 150 nm.

The embodiment also provides a preparation method of the laminated solar cell, which specifically comprises the following steps:

preparation of TOPCon battery: cleaning and texturing a silicon wafer layer 10, carrying out boron doping on the surface of the silicon wafer layer 10 by adopting a chemical vapor deposition method to form a diffusion silicon layer 11 with uniform sheet resistance of the whole surface, wherein the sheet resistance is 70ohm/sq, printing a barrier type slurry with a grid line structure above the diffusion silicon layer 11, carrying out selective etching, and preparing an emitter with selective contact;

performing single-side cleaning and etching on the other side surface of the silicon wafer layer 10 to remove BSG (borosilicate glass), wherein the BSG layer on the front side and the silicon diffusion layer 11 cannot be damaged; growing a tunneling layer 9 on the other side surface of the silicon wafer layer 10 by a high-temperature thermal oxidation method; a polysilicon layer 8 is continuously grown on the tunneling oxide layer by adopting low-pressure chemical vapor deposition, and the temperature is about 600 ℃;

then, the silicon wafer layer 10 is cleaned by HF to remove BSG on the front surface and PSG (phosphosilicate glass) on the back surface; preparing a passivation layer 12 made of aluminum oxide and silicon nitride by adopting a PECVD method; the first metal electrode 13 is printed by silver paste slurry, and the main grid line and the auxiliary grid line are aligned with the selective emitter;

(II) preparation of perovskite solar cell: the composite layer 7 made of nanocrystalline silicon is prepared by a very high frequency PECVD method, and the process gas is H₂And SiH₄Volume flow ratio of 95:1, power density of 65mW/cm²；

Preparing a hole transport layer 4 by an evaporation method, weighing 100mg of Spiro-TTB into an evaporation boat, wherein the vacuum degree in the evaporation process is 5 multiplied by 10^-4Pa, heating current of 30A, evaporation rate maintained at

The perovskite layer 5 was prepared by first preparing a perovskite precursor solution, and mixing 232.16mg of FAI, 31.92mg of CsBr, 414.9mg of PbI₂And 220.2mg of PbBr₂Dissolved inIn a mixed solvent of 800. mu.l of DMF and 200. mu.l of DMSO, the mixture was stirred for 2 hours until the mixture was completely dissolved. Before preparation, the substrate was treated for 10 minutes by an ultraviolet light cleaner and then transferred to a glove box for spin coating preparation of the perovskite layer 5. Dripping 80 microliters of chlorobenzene on a substrate, carrying out spin coating at the speed of 1000rpm for 10 seconds, accelerating to 3000rpm, carrying out spin coating for 30 seconds, quickly dripping 110 microliters of chlorobenzene when the spin coating is carried out at the speed for 10 seconds, after the spin coating is finished, putting a sample on a heating table at 100 ℃, and carrying out heating treatment for 30 minutes;

preparing a buffer layer 3 in a thermal evaporator, weighing 100mg LiF, and controlling the vacuum degree in the evaporation process to be 5 multiplied by 10^- ⁴Pa, heating current of 30A, evaporation rate maintained at

The conductive layer 2 made of ITO is prepared by adopting a magnetron sputtering method, the distance between an ITO target and a substrate is 6cm, and a mechanical pump and a molecular pump are sequentially used for pumping the vacuum degree of a cavity to 5 multiplied by 10 in the working process^-4Introducing argon again, keeping the flow rate at 35mL/min, adjusting the working pressure to 0.5Pa after introducing for 10 minutes, beginning to deposit an ITO film on the substrate after pre-sputtering for 15 minutes, wherein the deposition time is 5 minutes, and taking out after the deposition is finished;

covering the mask plate, sending to a thermal evaporator for preparing a metal electrode layer, weighing 1g of gold, and controlling the vacuum degree in the evaporation process to be 5 multiplied by 10^-4Pa, heating current of 55A, evaporation rate maintained at

Replacing the mask plate, and sending the mask plate to a thermal evaporator for MgF₂Preparation of antireflection layer 1, 100mg of MgF was weighed₂Vacuum degree in evaporation process of 5X 10^-4Pa, heating current 50A, evaporation rate maintained at

After evaporation, the anti-reflection layer 1 is formed.

Example 2

The present embodiment provides a tandem solar cell, as shown in fig. 1, based on the tandem solar cell provided in embodiment 1, which is different in that the thickness of the hole transport layer 4 is 200 nm; the thickness of the electron transport layer 6 was 50 nm; two first metal electrodes 13 are inserted on the diffused silicon layer 11, and two second metal electrodes 14 are connected to the metal electrode layers.

The thickness of the tunneling layer 9 is 3 nm; the thickness of the polysilicon layer 8 is 10 nm; the thickness of the diffused silicon layer 11 is 80 nm; the thickness of the composite layer 7 is 150 nm; the thickness of the perovskite layer 5 is 550 nm; the thickness of the buffer layer 3 is 5 nm; the thickness of the conductive layer 2 is 300 nm; the thickness of the metal electrode layer is 100 nm; the thickness of the antireflective layer 1 was 1mm, and the sheet resistance of the diffused silicon layer 11 was 50 ohm/sq.

The electron transport layer 6 is formed by a solution method.

Example 3

The present embodiment provides a tandem solar cell, as shown in fig. 1, based on the tandem solar cell provided in embodiment 1, which is different in that the thickness of the hole transport layer 4 is 500 nm; the thickness of the electron transport layer 6 was 125 nm; two first metal electrodes 13 are inserted on the diffused silicon layer 11, and two second metal electrodes 14 are connected to the metal electrode layers.

The thickness of the tunneling layer 9 is 0.5 nm; the thickness of the polysilicon layer 8 is 100 nm; the thickness of the diffused silicon layer 11 is 60 nm; the thickness of the composite layer 7 is 500 nm; the thickness of the perovskite layer 5 is 400 nm; the thickness of the buffer layer 3 is 50 nm; the thickness of the conductive layer 2 is 500 nm; the thickness of the metal electrode layer is 400 nm; the thickness of the antireflection layer 1 was 5 mm. The sheet resistance of the diffused silicon layer 11 was 100 ohm/sq.

The electron transport layer 6 is formed by magnetron sputtering.

Example 4

This embodiment provides a tandem solar cell, as shown in fig. 2, based on the tandem solar cell provided in embodiment 2, the difference is that the TOPCon cell is a p-type TOPCon cell, the silicon wafer layer 10 is made of p-type silicon, the diffused silicon layer 11 is made of n-type diffused silicon, and the polysilicon layer 8 is p-type polysilicon; the perovskite solar cell comprises a composite layer 7, an electron transport layer 6, a perovskite layer 5, a hole transport layer 4, a buffer layer 3, a conductive layer 2, a metal electrode layer and an antireflection layer 1 which are arranged in a stacked mode from the direction of a polycrystalline silicon layer 8 far away from a tunneling layer 9. The remaining dimensional parameters and preparation were exactly the same as in example 2.

Example 5

This example provides a tandem solar cell, based on the tandem solar cell provided in example 2, which is different in that the thickness of the composite layer is 0nm, and the rest of the structure and parameters are identical to those of example 2.

Comparative example 1

This comparative example provides a conventional tandem solar cell, as shown in fig. 3, which is different from example 2 in that the solar cell is composed of an anti-reflection layer 1, a metal electrode layer, a conductive layer 2, a buffer layer 3, a hole transport layer 4, a perovskite layer 5, a recombination layer 7, a diffused silicon layer 11, a silicon wafer layer 10, a tunneling layer 9, a polysilicon layer 8, and a passivation layer 12, which are sequentially stacked, and the remaining dimensional parameters and materials are completely the same as those of example 2.

The solar cells prepared in the above examples and comparative examples were subjected to a photoelectric conversion rate performance test, the test method comprising:

the prepared solar cell is placed under an AM1.5 simulated light source (model of a light source simulator is Newport Oriel 94043A), and the energy density of the light source is 100mW/cm²The light source was calibrated using a standard crystalline silicon cell and the J-V curve of the solar cell was tested using a keithley 2420 source table. The light directly irradiates the surface of the solar cell, and the effective area of the solar cell is 0.5cm²。

The test results are shown in table 1, and the J-V curves of example 2, example 4 and comparative example 1 are shown in fig. 4.

TABLE 1

(1) Compared with the embodiment 5 and the comparative example 1, the photoelectric conversion efficiency of the embodiment 2 is superior to that of the embodiment 5 and the comparative example 1, so that the utility model discloses a TOPCon battery and a perovskite solar battery which are arranged in a stacked manner, the process of the front part is ensured to be complete, the passivation layer and the metal electrode are removed in the back preparation process, the TOPCon battery is inverted to be used as a bottom battery, and the perovskite solar battery is grown on the back of the TOPCon battery, wherein, the polycrystalline silicon layer 8 can realize the function of the composite layer 7, thereby omitting the preparation of the composite layer 7, simplifying the preparation process, simplifying the structure and reducing the material cost; in addition, compare in the structure of growing perovskite solar cell in TOPCon battery's positive, it directly gets rid of positive passivation layer structure, leads to the passivation effect to weaken to reduced the performance of battery, and the utility model discloses well polycrystalline silicon layer 8 also can play certain passivation effect, can improve photoelectric conversion rate. The utility model discloses well polycrystalline silicon layer 8 can play the effect of passivation layer, can also regard as the composite bed 7 of being connected with perovskite solar cell, has simple structure, convenient preparation, characteristics such as with low costs and photoelectric conversion are efficient.

The applicant states that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto, and those skilled in the art should understand that any changes or substitutions easily conceivable by those skilled in the art within the technical scope of the present invention are within the protection scope and the disclosure scope of the present invention.

Claims

1. The laminated solar cell is characterized by comprising a TOPCon cell and a perovskite solar cell which are arranged in a laminated mode; the TOPCon battery comprises a silicon wafer layer, wherein a diffusion silicon layer and a passivation layer are arranged on one side surface of the silicon wafer layer in a laminated mode, and a tunneling layer and a polycrystalline silicon layer are arranged on the other side surface of the silicon wafer layer in a laminated mode;

and the surface of the polycrystalline silicon layer, which is far away from the tunneling layer, is attached to one side, which is far away from the electrode, of the perovskite solar cell.

2. The solar cell according to claim 1, wherein at least one first metal electrode is interposed on the diffused silicon layer;

3. The solar cell of claim 2, wherein the TOPCon cell is an n-type TOPCon cell, the silicon wafer layer is made of n-type silicon, the diffusion silicon layer is made of p-type diffusion silicon, and the polysilicon layer is n-type polysilicon;

4. The solar cell according to claim 3, wherein a composite layer is further disposed between the perovskite layer and the polycrystalline silicon layer;

5. The solar cell of claim 2, wherein the TOPCon cell is a p-type TOPCon cell, the silicon wafer layer is made of p-type silicon, the diffusion silicon layer is made of n-type diffusion silicon, and the polysilicon layer is p-type polysilicon;

6. The solar cell according to claim 5, wherein a composite layer is further disposed between the electron transport layer and the polysilicon layer;

7. The solar cell of claim 3, wherein the heavily doped silicon in the n-type TOPCon cell is p-type heavily doped silicon.

8. The solar cell of claim 5, wherein in the p-type TOPCon cell, the heavily doped silicon is n-type heavily doped silicon;

at least one second metal electrode is connected to the metal electrode layer;

the thickness of the tunneling layer is 0.5-3 nm;

the thickness of the polycrystalline silicon layer is 10-200 nm;

the thickness of the diffusion silicon layer is more than or equal to 30 nm.

9. The solar cell according to claim 4 or 6, wherein the composite layer has a thickness of 0 to 200nm excluding 0;

the thickness of the perovskite layer is 100-1000 nm;

the thickness of the buffer layer is 0-100 nm but 0 is not included;

the thickness of the conductive layer is 0-500 nm but 0 is not included;

the thickness of the metal electrode layer is 0-500 nm but not 0;

the thickness of the anti-reflection layer is 0-5 mm but 0 is not included;

the thickness of the hole transport layer is 0-500 nm but 0 is not included;

the thickness of the electron transport layer is 0-500 nm but not 0.

10. The solar cell of claim 9, wherein the passivation layer is made of SiO₂Any one of silicon nitride, aluminum oxide, and silicon oxynitride;

the composite layer is made of nanocrystalline silicon, polycrystalline silicon and SnO₂、TiO₂、ZnO₂Any one of ITO, FTO, IZO and AZO;

the hole transport layer is made of Spiro-OMeTAD, PTAA, nickel oxide, P3HT, PEDOT PSS, CuSCN, CuAlO₂Or any of Spiro-TTB;

the electron transport layer is made of SnO₂、TiO₂、ZnO₂ITO, FTO, IZO, fullerene derivative, BaSnO₃Or AZO;

the fullerene derivative is any one of C60, C70 or PCBM;

the buffer layer is made of molybdenum oxide, LiF and SnO₂、TiO₂、SiO₂Or amorphous silicon;

the conducting layer is made of SnO₂、TiO₂Any one of IZO, AZO, graphene or nano silver;

the metal electrode layer is made of any one of Au, Ag, Al or Cu;

the material of the anti-reflection layer is LiF and MgF₂、Si₃N₄、SiO₂Or any one of suede flexible film pasting materials;

the suede flexible film material is dimethyl siloxane polymer.