Solar cell and preparation method thereof, power generation device and power utilization device

Abstract

The invention provides a solar cell and a preparation method thereof, a power generation device and a power utilization device. The solar cell comprises a transparent substrate; the light absorption layer is arranged on one side of the transparent substrate; the electrode layer is arranged on the side, away from the transparent substrate, of the light absorption layer, the electrode layer comprises a composite transparent conductive film, and the composite transparent conductive film comprises a first transparent conductive film and a second transparent conductive film which are arranged in an overlapped mode; the carrier concentration of the first transparent conductive film is greater than that of the second transparent conductive film; the carrier mobility of the first transparent conductive film is lower than the carrier mobility of the second transparent conductive film. The composite transparent conductive film has high conductivity, high carrier mobility and high light transmittance, so that the obtained solar cell has high light absorptivity and high photoelectric conversion efficiency, and the overall performance is excellent.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to solar cells and methods for preparing the same, power generation devices, and power consumption devices. Background Art

[0002] Transparent conductive films (TCO) play a key role in many optoelectronic devices, including solar energy and display technology. However, transparent conductive films cannot achieve high conductivity, high mobility and high visible light transmittance at the same time, which still needs to be studied. Summary of the invention

[0003] In view of the technical problems existing in the background technology, the present application provides a solar cell and a preparation method thereof, a power generation device and a power consumption device, aiming to solve how to obtain a solar cell comprising a transparent conductive film having high electrical conductivity, high carrier mobility and high light transmittance.

[0004] In order to achieve the above-mentioned object, the first aspect of the present application provides a solar cell, the solar cell comprising: a transparent substrate;

[0005] A light absorbing layer, wherein the light absorbing layer is disposed on one side of the transparent substrate;

[0006] An electrode layer, the electrode layer is arranged on a side of the light absorbing layer away from the transparent substrate, the electrode layer comprises a composite transparent conductive film, and the composite transparent conductive film comprises a first transparent conductive film and a second transparent conductive film which are overlapped;

[0007] The carrier concentration of the first transparent conductive film is greater than the carrier concentration of the second transparent conductive film;

[0008] The carrier mobility of the first transparent conductive film is lower than the carrier mobility of the second transparent conductive film.

[0009] In the solar cell of the present application, a first transparent conductive film with high carrier concentration and low carrier mobility is overlapped with a second transparent conductive film with low carrier concentration and high carrier mobility, and the formed composite transparent conductive film has high electrical conductivity, high carrier mobility and high light transmittance. Thus, the obtained solar cell has high light absorption and high photoelectric conversion efficiency, and the overall performance is excellent.

[0010] In some embodiments, the composite transparent conductive film satisfies at least one of the following conditions:

[0011] Square resistance is 50Ω / sq~200Ω / sq;

[0012] Carrier mobility is 30V·S / cm 2 ~75V·S / cm 2 ;

[0013] Visible light transmittance is not less than 92%;

[0014] The infrared light transmittance is not less than 90%.

[0015] In some embodiments, the outermost layer of the composite transparent conductive film on the side facing the light absorbing layer is the second transparent conductive film;

[0016] The oxygen vacancies of the first transparent conductive film are higher than those of the second transparent conductive film.

[0017] In some embodiments, the carrier concentration of the first transparent conductive film is 2E20 / cm 3 ~5E20 / cm 3 ;

[0018] And / or, the carrier mobility of the first transparent conductive film is 10cm 2 V -1 s -1 ~30cm 2 V -1 s -1 .

[0019] In some embodiments, the carrier concentration of the second transparent conductive film is 1E20 / cm 3 ~2E20 / cm 3 ;

[0020] And / or, the carrier mobility of the second transparent conductive film is 30cm 2 V -1 s -1 ~70cm 2 V -1 s -1 .

[0021] In some embodiments, the thickness of the first transparent conductive film is 1 nm to 10 nm;

[0022] And / or, the thickness of the second transparent conductive film is 1 nm to 10 nm;

[0023] And / or, the total thickness of the adjacent first transparent conductive film and the second transparent conductive film is no more than 20 nm.

[0024] In some embodiments, the first transparent conductive film and / or the second transparent conductive film includes doped indium oxide.

[0025] In some embodiments, the doping element of the doped indium oxide includes one or more of zinc, gallium, tungsten, molybdenum, cerium, titanium, zirconium and hafnium;

[0026] The doping amount of the doped indium oxide is 0.5 mass % to 30 mass %;

[0027] The first transparent conductive film and the second transparent conductive film are made of the same material and have different oxygen vacancies.

[0028] In some embodiments, a first carrier transport layer is further included between the transparent substrate and the light absorbing layer, and a second carrier transport layer is further included between the light absorbing layer and the electrode layer;

[0029] One of the first carrier transport layer and the second carrier transport layer is an electron transport layer, and the other is a hole transport layer.

[0030] In the second aspect of the present application, the present application proposes a method for preparing the solar cell described in the first aspect, the method comprising: overlapping a light-absorbing layer arranged on one side of a transparent substrate away from a side of the transparent substrate to form a first transparent conductive film and a second transparent conductive film to obtain the composite transparent conductive film.

[0031] In some embodiments, the first transparent conductive film and the second transparent conductive film are formed by magnetron sputtering, nanoparticle solution method, reactive plasma deposition method or pulsed laser deposition method.

[0032] In some embodiments, the magnetron sputtering method satisfies at least one of the following conditions:

[0033] The oxygen content in the sputtering gas flow is 0 volume % to 20 volume %, and the hydrogen content is 0 volume % to 10 volume %;

[0034] In the sputtering gas flow for forming the first transparent conductive film, the oxygen content is 0 volume % to 5 volume % and the hydrogen content is 0 volume % to 3 volume %;

[0035] In the sputtering gas flow for forming the second transparent conductive film, the oxygen content is 1 volume % to 10 volume % and the hydrogen content is 0 volume % to 10 volume %;

[0036] The temperature of the transparent substrate is no more than 150°C;

[0037] The sputtering time is 10 minutes to 30 minutes.

[0038] In a third aspect of the present application, the present application proposes a power generation device, which includes: the solar cell described in the first aspect of the present application.

[0039] In a fourth aspect of the present application, the present application proposes an electrical device, which includes: the solar cell described in the first aspect of the present application.

[0040] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0042] Figure 1 A schematic diagram of the structure of a solar cell according to an embodiment of the present application is shown;

[0043] Figure 2 A schematic diagram of the structure of a single-junction perovskite solar cell according to an embodiment of the present application is shown;

[0044] Figure 3 A schematic diagram of the structure of a HJT crystalline silicon bottom cell-perovskite tandem solar cell according to an embodiment of the present application is shown.

[0045] Description of reference numerals:

[0046] 10: solar cell; 100: transparent substrate; 200: light absorbing layer; 300: electrode layer; A: first transparent conductive film; B: second transparent conductive film. DETAILED DESCRIPTION

[0047] The following is a detailed description of the embodiments of the technical solution of the present application. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0048] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0049] "Scope" disclosed in the present application is limited in the form of lower limit and upper limit, and a given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a special range. The scope limited in this way can be including end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a scope. For example, if the scope of 60-120 and 80-110 is listed for a specific parameter, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range values ​​1 and 2 listed, and if the maximum range values ​​3,4 and 5 are listed, the following scope can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present application, unless otherwise specified, the numerical range "ab" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers, and the scope limited in this way can be including end values ​​a and b. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0050] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0051] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0052] If there is no special explanation, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0053] There is an intrinsic limit to the electrical conductivity of TCOs; since the electrical conductivity σ can be expressed as: Where n is the carrier concentration, e is the charge, μ is the electron mobility, which is a function of the electron scattering time τ, and m* is the electron effective mass. There are two main reasons for the intrinsic electrical performance limitations of TCOs: first, for practical TCOs with relatively high carrier concentrations, the values ​​of n and μ cannot usually be increased independently, and the two are interrelated. Both Brooks and Dingle's theories point out that electron transport is mainly limited by ionized impurity scattering caused by Coulomb interactions between electrons and dopant ions; the degree of scattering increases with increasing carrier concentration, so the value of τ decreases. In addition, the reflection model of free electrons for light, as described by the Drude model, has been successfully used to characterize the transparency of TCO films. In optoelectronic devices, the requirement for visible transparency limits the actual carrier concentration in the TCO to preferably not exceed 2×10 21 cm -3 .

[0054] High mobility, high transmittance and high conductivity are necessary conditions for an ideal TCO, but they are often contradictory. As shown in the above conductivity σ calculation formula, if you want to obtain high conductivity, you must increase the mobility and carrier concentration. However, the increase in carrier concentration will lead to the resonance of electrons in the near-infrared and even visible light regions, thereby greatly increasing the TCO's absorption of light and reducing light transmittance. At the same time, increasing the carrier concentration will also increase the scattering caused by ion defects and reduce mobility.

[0055] In view of this, the present application alternately arranges two transparent conductive films to form a composite transparent conductive film, wherein one transparent conductive film A has a high carrier concentration and a low carrier mobility, and the other transparent conductive film B has a low carrier concentration and a high carrier mobility. Transparent conductive film A has a high carrier concentration to provide a large number of carriers; transparent conductive film B has a high carrier mobility so that the aforementioned large number of carriers can be efficiently migrated. At the same time, due to its low carrier concentration, it can weaken the scattering of ionized impurities and reduce light absorption, which helps to improve light transmittance. In addition, due to the band gap difference between the two layers of transparent conductive films, the potential generated by the carriers according to the band gap difference enters from low mobility to high mobility, which is more conducive to carrier migration. Thus, the obtained composite transparent conductive film has high conductivity, high mobility and light transmittance, thereby giving the solar cell high light absorption and high photoelectric conversion efficiency, and excellent overall performance.

[0056] To this end, in the first aspect of the present application, the present application proposes a solar cell. According to an embodiment of the present application, see Figure 1The solar cell 10 includes: a transparent substrate 100, a light absorbing layer 200 and an electrode layer 300, wherein the light absorbing layer 200 is arranged on one side of the transparent substrate 100; the electrode layer 300 is arranged on the side of the light absorbing layer 200 away from the transparent substrate 100, and the electrode layer 300 includes a composite transparent conductive film, and the composite transparent conductive film includes a first transparent conductive film A and a second transparent conductive film B which are overlapped.

[0057] In the present application, two transparent conductive films are alternately arranged to form a composite transparent conductive film, wherein one transparent conductive film A has a high carrier concentration and a low carrier mobility, and the other transparent conductive film B has a low carrier concentration and a high carrier mobility. Transparent conductive film A has a high carrier concentration to provide a large number of carriers; transparent conductive film B has a high carrier mobility so that the aforementioned large number of carriers can be efficiently migrated. At the same time, due to its low carrier concentration, it can weaken the scattering of ionized impurities and reduce light absorption, which helps to improve light transmittance. In addition, due to the band gap difference between the two layers of transparent conductive films, the potential generated by the carriers according to the band gap difference enters from low mobility to high mobility, which is more conducive to carrier migration. Thus, the obtained composite transparent conductive film has high conductivity, high mobility and light transmittance, thereby giving the solar cell high light absorption and high photoelectric conversion efficiency, and excellent overall performance.

[0058] According to an embodiment of the present application, the composite transparent conductive film satisfies at least one of the following conditions:

[0059] The square resistance is 50Ω / sq~200Ω / sq, such as 50Ω / sq, 60Ω / sq, 80Ω / sq, 100Ω / sq, 120Ω / sq, 140Ω / sq, 150Ω / sq, 160Ω / sq, 180Ω / sq, 200Ω / sq;

[0060] Carrier mobility is 30V·S / cm 2 ~75V·S / cm 2 , for example 30V·S / cm 2 、35V·S / cm 2 、40V·S / cm 2 、45V·S / cm 2 、50V·S / cm 2 、55V·S / cm 2 、60V·S / cm 2 、65V·S / cm 2 、70V·S / cm 2 、75V·S / cm 2 ;

[0061] Visible light transmittance is not less than 92%, for example, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%;

[0062] The infrared light transmittance is not less than 90%, for example 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%.

[0063] Therefore, the composite transparent conductive film of the present application has high conductivity, high mobility and light transmittance, thereby giving the solar cell high light absorption and high photoelectric conversion efficiency, and the overall performance is excellent.

[0064] According to an embodiment of the present application, the outermost layer on the side of the composite transparent conductive film facing the light absorbing layer 200 is the second transparent conductive film B. Thus, the carrier concentration gradient enables the carriers to better move toward the B layer with a low carrier concentration, and the B layer has a high mobility and is more suitable for carrier extraction, thereby reducing the recombination loss of carriers during transmission.

[0065] According to an embodiment of the present application, the oxygen vacancies of the first transparent conductive film are higher than the oxygen vacancies of the second transparent conductive film. Thus, a first transparent conductive film with high carrier concentration and low resistivity and a second transparent conductive film with low carrier concentration and high mobility can be obtained respectively. Then, by adjusting different parameters such as oxygen partial pressure, hydrogen partial pressure, sputtering power, etc. during the preparation process, a multilayer periodic film composed of a combination of staggered donor-rich and high mobility units under the same material system can be obtained. In this case, intermediate resistivity, transmittance and relatively high carrier mobility can be obtained.

[0066] According to an embodiment of the present application, the first transparent conductive film and the second transparent conductive film are made of the same material. The conductivity of the composite transparent conductive film structure of the present application is highly sensitive to the thickness of a single sub-layer and the quality of the interlayer interface, so the structure is designed using the same material technology, and there is no problem of heterojunction interface.

[0067] According to an embodiment of the present application, the carrier concentration of the first transparent conductive film is 2E20 / cm 3 ~5E20 / cm 3 , for example, it can be 2E20 / cm 3 , 2.5E20 / cm 3 、3E20 / cm 3 、3.5E20 / cm 3 , 4E20 / cm 3 , 4.5E20 / cm 3 , 5E20 / cm 3 The carrier mobility of the first transparent conductive film is 10cm 2 V-1 s -1 ~30cm 2 V -1 s -1 , for example, it can be 10cm 2 V -1 s -1 、15cm 2 V -1 s -1 , 20cm 2 V -1 s -1 、25cm 2 V -1 s -1 、30cm 2 V -1 s -1 . The first transparent conductive film has the above-mentioned high carrier concentration and can provide a large amount of carrier concentration. The use of the first transparent conductive film in combination with the second transparent conductive film with low carrier concentration and high mobility is conducive to the migration of a large number of carriers under the action of high mobility. In addition, due to the presence of a large number of carriers, the scattering caused by ion defects will increase, hindering the free movement of carriers and resulting in low carrier mobility. Furthermore, the carrier concentration is proportional to the absorptivity in the infrared band. By adopting the above-mentioned carrier concentration, it is possible to avoid a decrease in the transmittance of the film due to an excessively high carrier concentration, thereby reducing the current of the battery.

[0068] According to an embodiment of the present application, the carrier concentration of the second transparent conductive film is 1E20 / cm 3 ~2E20 / cm 3 , for example, 1E20 / cm 3 , 1.2E20 / cm 3 , 1.4E20 / cm 3 , 1.5E20 / cm 3 , 1.6E20 / cm 3 , 1.8E20 / cm 3 , 2E20 / cm 3 The carrier mobility of the second transparent conductive film is 30cm 2 V -1 s -1 ~70cm 2 V -1 s -1 , for example, it can be 30cm 2 V - 1 s -1 、35cm 2 V -1 s -1 、40cm 2V -1 s -1 、45cm 2 V -1 s -1 , 50cm 2 V -1 s -1 、55cm 2 V -1 s -1 、60cm 2 V -1 s -1 、65cm 2 V -1 s -1 、70cm 2 V -1 s -1 Therefore, the second transparent conductive film, due to its low carrier concentration, will weaken the scattering caused by ion defects, so that the carriers have high mobility, and when used in conjunction with the first transparent conductive film with high carrier concentration, it is conducive to the efficient migration of a large number of carriers. In addition, the low carrier concentration is conducive to reducing light absorption, thereby improving light transmittance.

[0069] The first transparent conductive film and the second transparent conductive film have the above-mentioned carrier concentration and mobility. The combination of the two can make the composite transparent conductive film have high conductivity, high carrier mobility and high light transmittance.

[0070] According to an embodiment of the present application, the thickness of the first transparent conductive film A is 1 nm to 10 nm, for example, 1 nm, 2 nm, 4 nm, 5 nm, 6 nm, 8 nm, 10 nm. Thus, it is possible to have both low resistivity and high light transmittance, so as to have good carrier transfer efficiency and light transmittance, thereby improving the overall performance of the solar cell. At the same time, the first transparent conductive film has good mechanical strength and durability, which is conducive to stable operation under various environmental conditions.

[0071] According to an embodiment of the present application, the thickness of the second transparent conductive film is 1 nm to 10 nm. Thus, it can have both low resistivity and high transmittance, so as to have good carrier transmission efficiency and light transmittance, thereby improving the overall performance of the solar cell. At the same time, the second transparent conductive film has good mechanical strength and durability, which is conducive to stable operation under various environmental conditions.

[0072] According to an embodiment of the present application, the total thickness of the adjacent first transparent conductive film and the second transparent conductive film is no more than 20nm, for example, 2cm, 5cm, 8cm, 10cm, 12cm, 15cm, 18cm, 20cm. Thus, it is possible to have both low resistivity and high transmittance, so as to have good carrier transfer efficiency and light transmittance, thereby improving the overall performance of the solar cell. At the same time, the transparent conductive film has good mechanical strength and durability, which is conducive to stable operation under various environmental conditions.

[0073] According to an embodiment of the present application, the first transparent conductive film and / or the second transparent conductive film comprises doped indium oxide. Doping indium oxide with other elements can optimize its electrical and optical properties, improve its electrical conductivity and light transmittance, and enhance its mechanical properties and chemical stability.

[0074] According to an embodiment of the present application, the doping element of the doped indium oxide includes one or more of zinc, gallium, tungsten, molybdenum, cerium, titanium, zirconium and hafnium; the doping amount of the doped indium oxide is 0.5 mass% to 30 mass%, for example, 0.5 mass%, 1 mass%, 5 mass%, 10 mass%, 15 mass%, 20 mass%, 25 mass%, 30 mass%. Thus, its conductivity, light transmittance, mechanical strength and chemical stability can be further improved.

[0075] According to an embodiment of the present application, a first carrier transport layer is further included between the transparent substrate and the light absorbing layer, and a second carrier transport layer is further included between the light absorbing layer and the electrode layer; one of the first carrier transport layer and the second carrier transport layer is an electron transport layer, and the other is a hole transport layer ( Figure 2 ).

[0076] In some embodiments, the hole transport layer includes: [2-(9H-carbazole-9-yl)ethyl]phosphonic acid, [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid, benzoic acid, 4-[bis(2,4-dimethoxybiphenyl-4-yl)amino]-biphenyl-4-carboxylic acid, [4-(7H-dibenzocarbazole-7-yl)butyl]phosphonic acid, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], 4,4'-cyclohexylbis[N,N-bis(4-methylphenyl)aniline, 2,2",7,7"-tetrakis[N,N-bis(4-methoxyphenyl) one or more of]-9,9'-spirobifluorene, [bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly(3-hexylthiophene-2,5-diyl), poly(3,4-ethylenedioxythiophene): poly(4-styrenesulfonic acid), 2,2',7,7'-tetrakis(N,N-di-p-tolyl)amino-9,9'-spirobifluorene, 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-benzoquinone, hexafluoro-2,3,5,6-tetracyano-4-benzothiazoline, 4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline], NiOx, CuSCN, CuAlO2, V2O5, CdS and CdSe;

[0077] And / or, the electron transport layer includes: one or more of fullerene and its derivatives, cyanide-containing polyphenylene vinylene, boron-containing polymer, 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline, 4,7-diphenyl-1,10-phenanthroline, hydroxyquinoline aluminum, oxadiazole compounds, benzimidazole compounds, naphthalenetetracarboxylic acid compounds, perylene derivatives, phosphine oxide compounds, phosphine sulfide compounds, fluorinated phthalocyanine, titanium oxide, zinc oxide, indium oxide, tin oxide, gallium oxide, tin sulfide, indium sulfide, lithium fluoride, sodium fluoride, magnesium fluoride, calcium fluoride and zinc sulfide.

[0078] In some embodiments, the material of the light absorbing layer includes ABX3, A includes one or more of cesium ions, copper ions, zinc ions, gallium ions, tin ions and calcium ions; B includes one or more of methylamine ions and formamidine ions; X includes one or more of iodine ions, bromide ions, chloride ions, fluoride ions and thiocyanate ions.

[0079] In some embodiments, the transparent substrate can be a silicon wafer, conductive glass, an oxide silicon wafer coated with electrodes, a ceramic wafer coated with electrodes, or a polymer transparent substrate coated with electrodes. A first conductive layer is disposed on the side of the transparent substrate facing the light absorbing layer, and the first conductive layer includes ITO.

[0080] In some embodiments, a buffer layer is further included between the light absorbing layer and the second carrier transport layer, and the buffer layer includes one or more of lithium fluoride, molybdenum oxide, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, magnesium fluoride, tin dioxide, titanium dioxide and silicon dioxide.

[0081] According to an embodiment of the present application, the solar cell further comprises: a bottom cell, the bottom cell is arranged on a side of the transparent substrate away from the light absorbing layer, and the bottom cell comprises: one or more of a crystalline silicon bottom cell, a perovskite bottom cell, a CdTe bottom cell, a CIGS bottom cell and a GaAs bottom cell. Exemplarily, the crystalline silicon bottom cell comprises a HJT crystalline silicon bottom cell ( Figure 3 , where the composite layer is a tunneling composite layer).

[0082] The third aspect of the present application provides a method for preparing the solar cell described in the first aspect, the method comprising: overlapping a light absorbing layer disposed on one side of the transparent substrate away from the side of the transparent substrate to form a first transparent conductive film and a second transparent conductive film, to obtain the composite transparent conductive film. The features and advantages described above for the solar cell are also applicable to the method for preparing the solar cell, and will not be repeated here.

[0083] The method of forming the first transparent conductive film and the second transparent conductive film may include: a nanoparticle solution method, a reactive plasma deposition (RPD) method, a pulsed laser deposition (PLD) method or a magnetron sputtering method. According to an embodiment of the present application, the first transparent conductive film and the second transparent conductive film are formed by a magnetron sputtering method.

[0084] In the magnetron sputtering process, the carrier concentration in the film can be regulated by controlling the oxygen content and hydrogen content in the sputtering gas flow. Specifically, hydrogen atoms act as interstitial impurities. When the hydrogen atom content in the film is higher, the carrier concentration is higher; when there are more oxygen atoms in the film, more oxygen vacancies will be filled, making the carrier concentration lower. When the oxygen content in the sputtering gas flow is 0 volume%-20 volume% (0 volume%, 5 volume%, 10 volume%, 15 volume%, 20 volume%) and the hydrogen content is 0 volume% to 10 volume% (0 volume%, 2 volume%, 4 volume%, 5 volume%, 6 volume%, 8 volume%, 10 volume%), the first transparent conductive film has a high carrier concentration and the second transparent conductive film has a low carrier concentration. In some embodiments, in the sputtering gas flow for forming the first transparent conductive film, the oxygen content is 0 volume % to 5 volume %, and the hydrogen content is 0 volume % to 3 volume % (0 volume %, 0.3 volume %, 0.5 volume %, 0.8 volume %, 1 volume %, 1.3 volume %, 1.5 volume %, 1.8 volume %, 2 volume %, 2.3 volume %, 2.5 volume %, 2.8 volume %, 3 volume %); in the sputtering gas flow for forming the second transparent conductive film, the oxygen content is 1 volume % to 10 volume % (1 volume %, 2 volume %, 4 volume %, 5 volume %, 6 volume %, 8 volume %, 10 volume %), and the hydrogen content is 0 volume % to 10 volume % (0 volume %, 1 volume %, 2 volume %, 4 volume %, 5 volume %, 6 volume %, 8 volume %, 10 volume %). Thus, both the first transparent conductive film and the second transparent conductive film have better carrier concentration and mobility. For example, the sputtering gas flow may also contain inert gases such as argon and nitrogen.

[0085] According to an embodiment of the present application, the temperature of the transparent substrate is no more than 150° C., for example, it may be 100° C., 110° C., 120° C., 130° C., 140° C., or 150° C. This is conducive to forming a stable and uniform transparent conductive film.

[0086] According to an embodiment of the present application, the sputtering time is 10 minutes to 30 minutes, for example, 10 minutes, 15 minutes, 20 minutes, 25 minutes, or 30 minutes, which is conducive to forming a stable and uniform transparent conductive film.

[0087] The third aspect of the present application provides a power generation device, the power generation device comprising: the solar cell described in the second aspect of the present application. Therefore, the light emitting device of the present application has excellent photoelectric performance, repeatability and stability.

[0088] In this application, the power generation device refers to a power generation system that uses the photovoltaic effect to directly convert solar radiation energy into electrical energy, which is divided into a stand-alone photovoltaic power generation system (Stand-alone PV System) and a grid-connected photovoltaic power generation system (Grid-connected PV System). The stand-alone photovoltaic power generation system consists of a solar photovoltaic array composed of photovoltaic components, a battery pack, a charge controller, a power electronic converter (inverter), a load, etc. The grid-connected photovoltaic power generation system consists of a photovoltaic array, a high-frequency DC / DC boost circuit, a power electronic converter (inverter) and a system monitoring part.

[0089] The fourth aspect of the present application provides an electrical device, the electrical device comprising: the solar cell according to the second aspect of the present application. Therefore, the electrical device of the present application has excellent photoelectric performance, repeatability and stability.

[0090] In the present application, electrical devices may include lighting elements, display elements, mobile devices, etc., and may specifically include street lights, signal indicators, insect killer lamps, electric fans, electric toys, electric tools, battery vehicles, electric vehicles, ships, spacecraft, etc., among which electric toys may include fixed or mobile electric toys, for example, game consoles, electric car toys, electric ship toys and electric airplane toys, etc., and spacecraft may include airplanes, rockets, space shuttles and spacecraft, etc.; photovoltaic power generation systems may include large-scale ground photovoltaic power generation systems, distributed photovoltaic power generation and building integrated photovoltaic power generation systems, etc.

[0091] It should be noted that the features and advantages described above for the solar cell in the first aspect and the method for preparing the solar cell in the second aspect of the present application are also applicable to the power generation device in the third aspect and the power consumption device in the fourth aspect of the present application, and will not be repeated here.

[0092] The scheme of the present application will be explained below in conjunction with the embodiments. It will be appreciated by those skilled in the art that the following embodiments are only used to illustrate the present application and should not be considered as limiting the scope of the present application. If no specific technology or conditions are indicated in the embodiments, the technology or conditions described in the literature in this area or the product specification are carried out. The reagents used or the instruments that do not indicate the manufacturer are all conventional products that can be obtained commercially.

[0093] Example 1

[0094] 1. A transparent conductive oxide ITO layer is formed as a composite layer on the HJT crystalline silicon bottom cell by PVD magnetron sputtering with a thickness of 10 nm.

[0095] 2. A hole transport layer (2PACz layer) is formed by coating and evaporating on the side of the ITO layer away from the HJT crystalline silicon bottom cell. The thickness of the hole transport layer is 2 nm.

[0096] 3. Deposit the perovskite light absorbing layer Cs on the hole transport layer by a one-step spin coating method 0.25 FA 0.75 Pb(I 0.8 Br 0.2 )3, the band gap is about 1.68ev and the thickness is 500nm.

[0097] 4. A LiF layer and a C60 layer are formed in sequence by thermal evaporation, with a total thickness of 10 nm.

[0098] 5. Atomic layer deposition was used to prepare the SnO2 layer with a thickness of 150 nm.

[0099] 6. The top electrode is a TCO layer (layer A and layer B overlap), both of which are prepared by PVD, and the material is doped indium oxide; the preparation parameters of layer A are: sputtering current is 160A, oxygen content in the sputtering gas flow is 0%, and hydrogen content is 0%; the preparation parameters of layer B are: sputtering current is 160A, oxygen content in the sputtering gas flow is 6%, and hydrogen content is 0%. The temperature of the transparent substrate is 60°C, and the sputtering time is 15 minutes. On the surface of the SnO2 layer, layer B is first sputtered to form layer A, and then layer A is sputtered. The thickness of layer A is 2nm, the thickness of layer B is 2nm, and 12 groups of AB layers are co-deposited, that is, the total thickness of the top electrode TCO layer is 48nm.

[0100] Example 2

[0101] The difference from Example 1 is that step 1 is not included, and in step 2, a hole transport layer (2PACz layer) is formed by coating and evaporating the TCO glass.

[0102] Example 3

[0103] The difference from Example 1 is that in step 6, the oxygen content in the sputtering gas flow of layer A is 1%, and the hydrogen content is 0.5%, and the oxygen content in the sputtering gas flow of layer B is 10%, and the hydrogen content is 1%.

[0104] Example 4

[0105] The difference from Example 1 is that in step 6, the oxygen content in the sputtering gas flow of layer A is 15%, and the hydrogen content is 0.5%, and the oxygen content in the sputtering gas flow of layer B is 10%, and the hydrogen content is 1%.

[0106] Example 5

[0107] The difference from Example 1 is that in step 6, the oxygen content in the sputtering gas flow of layer A is 1%, and the hydrogen content is 0.5%, and the oxygen content in the sputtering gas flow of layer B is 25%, and the hydrogen content is 15%.

[0108] Example 6

[0109] The difference from Example 1 is that in step 6, the A layer is first sputtered to form the surface of the SnO2 layer and then the B layer is sputtered to form the surface of the SnO2 layer.

[0110] Comparative Example 1

[0111] The difference from Example 1 is that in step 6, only the A layer is sputtered.

[0112] Comparative Example 2

[0113] The difference from Example 1 is that in step 6, only the B layer is sputtered.

[0114] Test Case

[0115] 1. The carrier concentration and carrier mobility of the A layer and the B layer prepared in Examples 1 to 6, the conductivity, carrier mobility, visible light transmittance and infrared light transmittance of the top electrode TCO layer were tested respectively, and the conductivity, carrier mobility, visible light transmittance and infrared light transmittance of the top electrode TCO layer of the comparative example were tested. The conductivity, carrier mobility and concentration can all be measured by the Hall test method, and the visible light transmittance and infrared transmittance can all be measured by the spectrophotometer method.

[0116] The results are shown in Table 1. Compared with Comparative Examples 1 and 2 which only use one transparent conductive layer as the top electrode, Examples 1 to 6 use alternating layers A and B as the top electrode, which have high conductivity, high carrier mobility and high light transmittance.

[0117] Table 1

[0118]

[0119] 2. The performance of the solar cells prepared in the above-mentioned Examples 1 to 6 and Comparative Examples 1 to 2 was tested respectively.

[0120] The specific test method is: place the prepared battery device under a light source with an intensity P of 100mW / cm 2 The AM1.5G standard simulates sunlight. By changing the bias voltage of the load on the battery device, the current value of the battery device is obtained, thereby drawing the current density (J)-voltage (V) curve of the battery device, and thus obtaining the open circuit voltage Voc, short circuit current density Jsc, fill factor FF, and photoelectric conversion efficiency of the battery device, that is, battery efficiency PCE: V and J of the battery device change with the change of external load. When the external load is short-circuited, V=0, and J at this time is called short-circuit current density Jsc; when the external load is disconnected, J=0, and V at this time is called open circuit voltage Voc; the output power of the battery device has a maximum value, which is called the maximum power point Pmax, Pmax divided by the effective light-receiving area of ​​the battery device, that is, the battery efficiency PCE; the fill factor FF of the battery device is PCE×P / (Jsc×Voc).

[0121] The results are shown in Table 2. Compared with Comparative Examples 1 and 2 which use only one transparent conductive layer as the top electrode, Examples 1 to 6 use alternately arranged layers A and B as the top electrodes, and the prepared solar cells have excellent overall performance.

[0122] Table 2 Performance parameters of different solar cells

[0123] Examples <![CDATA[Jsc(mA / cm 2 )]]> Voc(V) PCE(%) FF(%) Example 1 20.21 1.997 33.09 82 Example 2 20.43 1.52 25.77 83 Example 3 20.22 1.985 33.31 83 Example 4 19.22 1.976 30.76 81 Example 5 19.3 1.984 30.63 80 Example 6 19.25 1.982 30.14 79 Comparative Example 1 19.02 1.923 28.53 78 Comparative Example 2 18.99 1.974 28.86 77

[0124] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A solar cell, characterized in that: include: Transparent substrate; A light absorbing layer, wherein the light absorbing layer is disposed on one side of the transparent substrate; An electrode layer, the electrode layer is arranged on a side of the light absorbing layer away from the transparent substrate, the electrode layer comprises a composite transparent conductive film, and the composite transparent conductive film comprises a first transparent conductive film and a second transparent conductive film which are overlapped; The carrier concentration of the first transparent conductive film is greater than the carrier concentration of the second transparent conductive film; The carrier mobility of the first transparent conductive film is lower than the carrier mobility of the second transparent conductive film.

2. The solar cell according to claim 1, characterized in that The composite transparent conductive film satisfies at least one of the following conditions: Square resistance is 50Ω / sq~200Ω / sq; Carrier mobility is 30V·S / cm 2 ~75V·S / cm 2 ; Visible light transmittance is not less than 92%; The infrared light transmittance is not less than 90%.

3. The solar cell according to claim 1, characterized in that The outermost layer on the side of the composite transparent conductive film facing the light absorbing layer is the second transparent conductive film; The oxygen vacancies of the first transparent conductive film are higher than those of the second transparent conductive film.

4. The solar cell according to claim 1, characterized in that The carrier concentration of the first transparent conductive film is 2E20 / cm 3 ~5E20 / cm 3 ; The carrier mobility of the first transparent conductive film is 10 cm 2 V -1 s -1 ~30cm 2 V -1 s -1 .

5. The solar cell according to claim 1, characterized in that: The carrier concentration of the second transparent conductive film is 1E20 / cm 3 ~2E20 / cm 3 ; The carrier mobility of the second transparent conductive film is 30 cm 2 V -1 s -1 ~70cm 2 V -1 s -1 .

6. The solar cell according to claim 1, characterized in that The thickness of the first transparent conductive film is 1 nm to 10 nm; And / or, the thickness of the second transparent conductive film is 1 nm to 10 nm; And / or, the total thickness of the adjacent first transparent conductive film and the second transparent conductive film is no more than 20 nm.

7. The solar cell according to claim 1, characterized in that The first transparent conductive film and / or the second transparent conductive film includes doped indium oxide.

8. The solar cell according to claim 7, characterized in that: The first transparent conductive film and the second transparent conductive film are made of the same material and have different oxygen vacancies.

9. The solar cell according to claim 1, characterized in that: A first carrier transport layer is further included between the transparent substrate and the light absorbing layer, and a second carrier transport layer is further included between the light absorbing layer and the electrode layer; One of the first carrier transport layer and the second carrier transport layer is an electron transport layer, and the other is a hole transport layer.

10. A method for preparing the solar cell according to any one of claims 1 to 9, characterized in that: include: The light absorbing layer disposed on one side of the transparent substrate overlaps with the side away from the transparent substrate to form a first transparent conductive film and a second transparent conductive film, thereby obtaining the composite transparent conductive film.

11. The method according to claim 10, characterized in that The first transparent conductive film and the second transparent conductive film are formed by magnetron sputtering, nanoparticle solution method, reactive plasma deposition method or pulsed laser deposition method.

12. The method according to claim 11, characterized in that The magnetron sputtering method satisfies at least one of the following conditions: The oxygen content in the sputtering gas flow is 0 volume % to 20 volume %, and the hydrogen content is 0 volume % to 10 volume %; In the sputtering gas flow for forming the first transparent conductive film, the oxygen content is 0 volume % to 5 volume % and the hydrogen content is 0 volume % to 3 volume %; In the sputtering gas flow for forming the second transparent conductive film, the oxygen content is 1 volume % to 10 volume % and the hydrogen content is 0 volume % to 10 volume %; The temperature of the transparent substrate is no more than 150°C; The sputtering time is 10min to 30min.

13. A power generation device, characterized in that: include: The solar cell according to any one of claims 1 to 9 or the method for preparing a solar cell according to any one of claims 10 to 12 is obtained.

14. An electrical device, characterized in that: include: The solar cell according to any one of claims 1 to 9 or the method for preparing a solar cell according to any one of claims 10 to 12 is obtained.

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