Solar cell module

Abstract

The utility model provides a solar cell module. A solar cell module is provided with a composite electron transport layer and comprises a light scattering layer, a first electron transport layer and a second electron transport layer which are arranged in a stacked mode, and the light scattering layer is provided with gaps and used for receiving first light rays and forming scattering; the first electron transport layer is used for filling and leveling up at least part of gaps in the light scattering layer; a conduction band price difference exists between the first electron transport layer and the second electron transport layer. The light scattering layer in the composite electron transport layer can increase light scattering, the first electron transport layer can fill and level up at least part of gaps in the light scattering layer, and conduction band price difference exists between the first electron transport layer and the second electron transport layer, so that electron transport can be accelerated. The three layers cooperate to effectively passivate interface defects, inhibit interface carrier recombination and improve device efficiency and stability.

Description

TECHNICAL FIELD

[0001] The utility model belongs to photovoltaic technical field, concretely relates to a solar cell module. BACKGROUND

[0002] In recent years, with the continuous deepening of research, perovskite battery has made rapid development, and the theoretical value and laboratory efficiency of perovskite single layer and laminated layer are all more than crystalline silicon battery.The theoretical efficiency of perovskite single layer is more than 30%, and the theoretical conversion efficiency of laminated layer can reach 45%.

[0003] Perovskite battery can be divided into two structures of positive type (n-i-p type) and inverted type (p-i-n type),

[0004] In the inverted structure, the electron transport layer is placed on the perovskite layer, and the hole transport layer is placed at the bottom of the perovskite layer, which is opposite to the position of the electron transport layer and the hole transport layer of the positive structure (n-i-p). Compared with the positive structure, the air stability of the inverted structure is better, because the hole transport layer at the bottom can play a certain protective role, which can reduce the contact of the perovskite layer with water and oxygen, and its structure and preparation process are compatible with some other types of optoelectronic devices, which is convenient for integration with other devices to build a laminated structure. However, there are defects in the interface between perovskite and electron transport layer in the inverted structure, and the interface carrier recombination is serious, which leads to large energy loss and restricts the improvement of photoelectric conversion efficiency. Secondly, although the long-term stability of perovskite battery of inverted structure is poor, it is easily affected by environmental factors such as light, humidity and temperature.

[0005] Therefore, how to further passivate the interface defects between perovskite and electron transport layer in the inverted structure, inhibit the interface carrier recombination, improve the electron transport efficiency of the electron transport layer, and further improve the efficiency and stability of the device, is a technical problem to be solved. UTILITY MODEL CONTENT

[0006] In view of the defects of the prior art, the utility model aims at providing a solar cell module. In the composite electron transport layer designed by the utility model, the light scattering particle layer has gaps, can receive first light and form scattering, the first electron transport layer can fill at least part of the gaps formed by the agglomeration of nano particles in the light scattering layer, reduce the surface roughness, and there is a conduction band price difference between the first electron transport layer and the second electron transport layer, which can accelerate electron transport. Therefore, the three layers cooperate with each other, can effectively passivate the interface defects between perovskite and composite electron transport layer, inhibit the interface carrier recombination, significantly improve the electron transport efficiency and stability of the composite electron transport layer, and further improve the efficiency and stability of the device, which has good development prospect.

[0007] To achieve the utility model purpose, the utility model adopts the following technical scheme:

[0008] The utility model provides a solar cell module has the composite electron transmission layer, the composite electron transmission layer includes the light scattering layer, first electron transmission layer and second electron transmission layer of laminated arrangement:

[0009] Among them, the light scattering layer has gap for receiving first light and forms scattering, the first electron transmission layer is used for filling at least part of gap in the light scattering layer, and the first electron transmission layer has conduction band value difference with the second electron transmission layer.

[0010] The light scattering particle layer has gap in the composite electron transmission layer designed by the utility model, can receive first light and form scattering, the first electron transmission layer can fill at least part of gap formed due to the agglomeration of nanometer particles in the light scattering layer, reduce surface roughness, and the first electron transmission layer has conduction band value difference with the second electron transmission layer, can accelerate electron transmission, so three layers cooperate, can effectively passivate the interface defect of perovskite and composite electron transmission layer, inhibit the interface carrier recombination, significantly improve the electron transport efficiency and stability of composite electron transmission layer, and further improve the efficiency and stability of the device, and have good development prospect.

[0011] It should be noted that the conduction band value difference in the utility model refers to the difference of conduction band bottom energy between the first electron transmission layer and the second electron transmission layer. In semiconductor physics, the conduction band is an energy region where electrons can move freely, and the energy position of the bottom plays a key role in the electrical properties of materials, especially in the transmission of electrons and related physical processes. The size and sign of this difference determine the trend of electron transfer between the two materials and many other electrical properties. From the perspective of electron transport, the conduction band value difference determines the direction of electron transfer and also affects the mobility of electrons near the interface of the two materials. From the perspective of the battery, the conduction band value difference allows photo-generated electrons and holes to move in different directions, reducing the probability of electron-hole recombination and thus improving the photoelectric conversion efficiency of the battery.

[0012] It should be noted that the light scattering layer has a wide band gap and the layer is very thin, so electrons can directly tunnel through it.

[0013] It should be noted that the first light refers to sunlight that shines on the surface of the light scattering layer.

[0014] Preferably, the LUMO energy level (lowest unoccupied molecular orbital) of the first electron transmission layer is greater than the LUMO energy level of the second electron transmission layer.

[0015] In the utility model, the lowest unoccupied molecular orbital energy level of the first electron transport layer is relatively high, which makes the first electron transport layer more easily accept electrons; in comparison, the LUMO energy level of the second electron transport layer is lower, similar to a "deep pit", and the electron is more inclined to fill the first electron transport layer first, and this layered electron transport mode is helpful to better control the flow of electrons in the device and improve the electron transport efficiency, which has a positive effect on the performance of the device. In addition, the stability of the device during long-time operation can also be improved, such as reducing the phenomena of material aging or performance degradation caused by excessive electron injection.

[0016] Preferably, the light scattering layer comprises an aluminum oxide layer and / or a silicon oxide layer.

[0017] Preferably, the thickness of the light scattering layer is 1-10 nm, for example, it can be 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm or 10 nm, etc., preferably 5-10 nm.

[0018] In the utility model, if the light scattering layer is too thin, it cannot play the role of light scattering; if the light scattering layer is too thick, it will affect the electron transport due to poor conductivity.

[0019] Preferably, in the light scattering layer, the average particle size of the light scattering particles is 5-30 nm, for example, it can be 5 nm, 10 nm, 15 nm, 20 nm, 25 nm or 30 nm, etc.

[0020] It should be noted that the particle size of the light scattering particles in the 20wt% nanodispersion mother liquor used in the experiment is between 5-30 nm, and after diluting it to a nanodispersion liquid with a concentration of 0.1-1wt%, film formation is carried out, at this time, the compactness of the formed film is low, not so dense and continuous, that is, the light scattering particles are scattered in the light scattering layer.

[0021] Preferably, the light scattering layer also has a modified material distributed therein, and the modified material comprises a nitrogen-containing heterocyclic compound.

[0022] In the utility model, the introduction of the nitrogen-containing heterocyclic compound into the light scattering layer helps to improve the electron transport rate of the composite electron transport layer.

[0023] Preferably, the nitrogen-containing heterocyclic compound comprises 1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]imidazole.

[0024] Preferably, the first electron transport layer comprises a fullerene derivative layer.

[0025] Preferably, the fullerene derivative layer comprises a PCBM layer ([6,6]-phenyl-C61-butyric acid methyl ester layer) and / or an ICBA layer (indene-C60 bisadduct layer).

[0026] Preferably, the first electron transport layer fills all gaps in the light scattering layer.

[0027] Preferably, the thickness of the first electron transport layer is 1-10 nm, for example, it can be 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm or 10 nm, etc., preferably 5-10 nm.

[0028] In the utility model, if the first electron transport layer is too thin, it cannot play the role of filling the gaps of the light scattering layer, slowing down the unevenness of the upper surface and reducing the surface roughness; if the first electron transport layer is too thick, it will introduce too much series resistance, affecting the device efficiency.

[0029] Preferably, the surface roughness of the surface of the first electron transport layer close to the surface of the second electron transport layer is 5-15 nm, for example, it can be 5 nm, 8 nm, 10 nm, 12 nm or 15 nm, etc.

[0030] In the utility model, the first electron transport layer with low surface roughness helps to reduce the interface roughness and defect density, and build a more solid heterojunction, thereby improving the charge transport efficiency and further improving the performance and stability of the device.

[0031] Preferably, the second electron transport layer comprises C 60 layer.

[0032] Preferably, the thickness of the second electron transport layer is 20-40 nm, for example, it can be 20 nm, 25 nm, 30 nm, 35 nm or 40 nm, etc., preferably 25-30 nm.

[0033] Preferably, the thickness ratio of the light scattering layer, the first electron transport layer and the second electron transport layer is 1:(1-1.5):(2-6).

[0034] In the utility model, the thickness ratio of the light scattering layer, the first electron transport layer and the second electron transport layer is 1:(1-1.5):(2-6), wherein the selection range of the first electron transport layer "1-1.5" can be 1, 1.1, 1.2, 1.3, 1.4 or 1.5, etc., and the selection range of the second electron transport layer "2-6" can be 2, 3, 4, 5 or 6, etc.

[0035] If the thickness ratio of the first electron transport layer and the light scattering layer is too small, the first electron transport layer cannot fill the gaps of the light scattering layer well, reducing the surface roughness; if the thickness ratio of the first electron transport layer and the light scattering layer is too large, a too thick first electron transport layer is introduced, resulting in an increase in the series resistance of the device, affecting the efficiency of the device. If the thickness ratio of the second electron transport layer and the first electron transport layer is too small, the electron transport ability becomes weak, resulting in an increase in electron-hole recombination, affecting the efficiency of the battery; if the thickness ratio of the second electron transport layer and the first electron transport layer is too large, a large series resistance is introduced, affecting the efficiency of the device.

[0036] Preferably, the battery assembly further comprises an electrically conductive substrate, a hole transport layer, a perovskite absorption layer and an electrode arranged in a stack, the composite electron transport layer is located between the perovskite absorption layer and the electrode, and the light scattering layer is close to the perovskite absorption layer.

[0037] Preferably, the electrically conductive substrate comprises electrically conductive glass or electrically conductive plastic. For example, the electrically conductive glass can be FTO (fluorine-doped tin oxide) electrically conductive glass or ITO (indium tin oxide) electrically conductive glass, and the electrically conductive plastic can be FTO (fluorine-doped tin oxide) electrically conductive plastic or ITO (indium tin oxide) electrically conductive plastic. Among them, the thickness of the FTO layer can be 500 nm, and the thickness of the ITO layer can be 300-400 nm, whether it is electrically conductive glass or electrically conductive plastic.

[0038] Preferably, the material of the hole transport layer comprises nickel oxide and / or self-assembled small molecules.

[0039] Preferably, the thickness of the hole transport layer is 10-20 nm, for example, it can be 10 nm, 12 nm, 14 nm, 16 nm, 18 nm or 20 nm, etc.

[0040] Preferably, the chemical formula of the perovskite absorption layer is ABX3, wherein A comprises any one or a combination of at least two of methylamine ions, formamidinium ions or cesium ions, B comprises lead ions and / or tin ions, and X comprises any one or a combination of at least two of chloride ions, bromide ions or iodide ions.

[0041] Preferably, the thickness of the perovskite absorption layer is 300-1000 nm, for example, it can be 300 nm, 500 nm, 700 nm or 900 nm, etc.

[0042] Preferably, the thickness of the composite electron transport layer is 30-60 nm, for example, it can be 30 nm, 40 nm, 50 nm or 60 nm, etc.

[0043] The composite electronic transmission layer with the suitable thickness can form a good interface energy level arrangement in the battery assembly, promotes the effective transmission of electrons from the perovskite layer to the electrode, helps to reduce the interface resistance, and improves the overall performance of the battery.

[0044] Preferably, the material of the electrode comprises any one of Ag, Al, Au or TCO (transparent conductive oxide). Exemplarily, the TCO can be ITO or FTO, etc.

[0045] Preferably, the layer thickness of the electrode is 100-300 nm, for example, can be 100 nm, 200 nm or 300 nm, etc.

[0046] In the second aspect, the utility model provides a kind of preparation method of the solar cell module as described in the first aspect, and the preparation method comprises the following steps:

[0047] Providing a substrate, the surface of the substrate is stacked to prepare light scattering layer, first electron transmission layer and second electron transmission layer, to obtain the solar cell module.

[0048] Preferably, the substrate comprises the electrically conductive substrate, hole transport layer and perovskite absorption layer of stacked arrangement, and the light scattering layer is close to the perovskite absorption layer.

[0049] Preferably, the forming method of the light scattering layer comprises:

[0050] Nanodispersion is coated on the substrate, and the light scattering layer is obtained after annealing.

[0051] Preferably, the nanodispersion comprises alumina nanodispersion and / or silicon oxide nanodispersion.

[0052] Preferably, the concentration of the nanodispersion is 0.1-1wt%, for example, can be 0.1wt%, 0.5wt% or 1wt%, etc.

[0053] Preferably, the nanodispersion solution is doped with a modified material, and the doping amount of the modified material is 0.2-0.5mg / mL, for example, can be 0.2mg / mL, 0.35mg / mL or 0.5mg / mL, etc.

[0054] In the utility model, the suitable doping amount of the modified material helps the regular arrangement of subsequent PCBM layer and improves the electron transmission capacity.

[0055] Preferably, the forming method of the first electron transmission layer comprises any one or combination of at least two of spin coating method, spraying method or blade coating method.

[0056] Preferably, the forming method of the second electron transmission layer comprises thermal evaporation method.

[0057] Preferably, the preparation method comprises the following steps:

[0058] (1) sequentially forming a hole transport layer and a perovskite absorption layer on an electrically conductive substrate.

[0059] (2) forming a light scattering layer on the perovskite absorption layer, and the specific steps comprise: coating a nano-dispersion liquid with a concentration of 0.1-1wt% on the perovskite absorption layer, and obtaining the light scattering layer after annealing; the nano-dispersion liquid is doped with a modification material, and the doping concentration of the modification material is 0.2-0.5mg / mL.

[0060] (3) sequentially forming a first electron transport layer, a second electron transport layer and an electrode on a side surface of the light scattering layer away from the perovskite absorption layer.

[0061] Preferably, the preparation method of the electrically conductive substrate comprises a physical vapor deposition method, and examples are, for example, evaporation or sputtering.

[0062] Preferably, the formation method of the hole transport layer comprises any one of a sputtering method, a spin coating method, a spray coating method or a doctor blade coating method.

[0063] Preferably, the formation method of the perovskite absorption layer comprises any one of an anti-solvent method, an air suction method, an air blowing method or a doctor blade coating method.

[0064] Preferably, the formation method of the electrode comprises a vacuum evaporation method or a vacuum sputtering method.

[0065] The numerical range of the utility model not only includes the point values listed above, but also includes any point values between the above numerical ranges that are not listed, and due to the length and for the sake of simplicity, the utility model will not exhaustively list the specific point values included in the range.

[0066] Compared with the prior art, the utility model has the following beneficial effects:

[0067] In the composite electron transport layer designed by the utility model, the light scattering layer has gaps, can receive first light and form scattering, the first electron transport layer not only can fill at least part of the gaps formed by the agglomeration of the nano-particles in the light scattering layer and reduce the surface roughness, but also can accelerate electron transport due to the existence of the conduction band price difference between the first electron transport layer and the second electron transport layer, so that the three layers can effectively passivate the interface defects of the perovskite and the composite electron transport layer, inhibit the interface carrier recombination, significantly improve the electron transport efficiency and stability of the composite electron transport layer, and further improve the efficiency and stability of the device, and has a good development prospect. BRIEF DESCRIPTION OF DRAWINGS

[0068] Figure 1 A structural schematic diagram of a solar cell module provided for Embodiment 1 in the utility model.

[0069] Figure 2 An energy level schematic diagram of part of a functional layer in the solar cell module provided for Embodiment 1 in the utility model.

[0070] Wherein, 1-ITO conductive glass; 2-nickel oxide layer; 3-perovskite absorption layer; 41-light scattering layer; 42-first electron transport layer; 43-second electron transport layer; 4-composite electron transport layer; 5-electrode. DETAILED DESCRIPTION

[0071] The technical scheme of the utility model will be further explained by specific embodiments. Those skilled in the art should understand that the embodiments are only to help understand the utility model and should not be regarded as the specific limitation of the utility model.

[0072] Embodiment 1

[0073] This embodiment provides a kind of solar cell module, its structural schematic diagram as shown in Figure 1 The solar cell module includes ITO conductive glass 1, nickel oxide layer 2, perovskite absorption layer 3, composite electron transport layer 4 and electrode 5 which are stacked, and the composite electron transport layer 4 includes light scattering layer 41, first electron transport layer 42 and second electron transport layer 43 which are sequentially stacked along the direction away from perovskite absorption layer 3.

[0074] Wherein, the ITO layer thickness of ITO conductive glass 1 is 350nm; The thickness of nickel oxide layer 2 is 15nm; The chemical formula of perovskite absorption layer 3 is FA 0.9 Cs 0.1 Pb I3 , thickness is 600nm; The thickness of composite electron transport layer 4 is 40nm, the light scattering layer 41 is aluminum oxide layer, and the thickness is 5nm; The first electron transport layer 42 is PCBM layer, and the thickness is 5nm; The PCBM is filled in the gap between all particles of the aluminum oxide layer 41; The second electron transport layer 43 is C 60 Layer, and the thickness is 30nm; The first electron transport layer 42 and the second electron transport layer 43 have conduction band price difference, and the LUMO energy level (lowest unoccupied molecular orbital) of the first electron transport layer 42 is greater than the LUMO energy level of the second electron transport layer 43; The surface roughness of the side surface of the first electron transport layer 42 close to the second electron transport layer 43 is about 10nm; The thickness ratio of the light scattering layer 41, first electron transport layer 42 and second electron transport layer 43 is 1:1:6; Electrode 5 is Ag electrode, and the thickness is 200nm.

[0075] The embodiment also provides a preparation method of the solar cell module.

[0076] (1) A layer of nickel oxide is deposited on the ITO conductive glass by a magnetron sputtering method, and then a perovskite absorption layer is prepared by a reverse solvent method.

[0077] (2) A 0.25wt% aluminum oxide nanodispersion liquid is spin-coated on the perovskite absorption layer at 3000rpm for 30s, and then annealed at 100℃ for 10min to remove the solvent, so as to form an aluminum oxide layer.

[0078] The solvent of the aluminum oxide nanodispersion liquid is isopropanol.

[0079] (3) Then, a 5mg / mL PCBM solution is spin-coated on the aluminum oxide layer at 3000rpm for 30s, and then annealed at 100℃ for 10min to remove the solvent, so as to form a first electron transport layer.

[0080] (4) Then, a layer of C 60 is evaporated on the first electron transport layer by an evaporation method to form a second electron transport layer, and the evaporation rate is

[0081] (5) Then, a layer of Ag electrode is deposited by a vacuum evaporation method, so as to obtain the solar cell module.

[0082] Figure 2 The energy level diagram of part of the functional layers in the solar cell module provided by the embodiment is shown. The energy level relationship between the perovskite absorption layer 3, the light scattering layer 41, the first electron transport layer 42 and the second electron transport layer 43 in the solar cell module is shown, and it can be known from the diagram that the thin light scattering layer 41 has a wide band gap, and the electrons can directly tunnel through it. The conduction band positions of the perovskite absorption layer 3, the first electron transport layer 42 and the second electron transport layer 43 are arranged in turn in a decreasing manner, which is helpful to promote the effective transmission of electrons from the perovskite absorption layer 3 to the electrode.

[0083] Embodiment 2

[0084] The embodiment provides a solar cell module, which comprises an ITO conductive glass, a nickel oxide layer, a perovskite absorption layer, a composite electron transport layer and an electrode which are arranged in a stack, and the composite electron transport layer comprises a light scattering layer, a first electron transport layer and a second electron transport layer which are arranged in a stack in a direction away from the perovskite absorption layer.

[0085] The ITO layer of the ITO conductive glass has a thickness of 350nm; the nickel oxide layer has a thickness of 15nm; the perovskite absorption layer has a chemical formula of FA 0.95Cs 0.05 PbI3, thickness of 650 nm; the light scattering layer is a silicon oxide layer, thickness of 10 nm; the first electron transport layer is a PCBM layer, thickness of 5 nm; the silicon oxide layer is filled with PCBM in all the inter-particle gaps; the second electron transport layer is a C 60 layer, thickness of 35 nm; the first electron transport layer has a conduction band valence difference with the second electron transport layer, and the LUMO energy level of the first electron transport layer is greater than the LUMO energy level of the second electron transport layer; the surface roughness of the surface of the first electron transport layer close to the second electron transport layer is 8 nm; the thickness ratio of the light scattering layer, the first electron transport layer and the second electron transport layer is 1:1:7; the electrode is an Ag electrode, thickness of 200 nm.

[0086] The embodiment also provides a preparation method of the solar cell module, and the preparation method comprises the following steps:

[0087] (1) depositing a nickel oxide layer on ITO conductive glass by using a magnetron sputtering method, and then preparing a perovskite absorption layer by using an anti-solvent method.

[0088] (2) spin coating a silicon oxide nanodispersion liquid with a concentration of 0.5wt% on the perovskite absorption layer at 3000 rpm for 30 s, and then performing annealing at 100℃ for 10 min to remove the solvent, so as to form a silicon oxide layer.

[0089] The solvent of the silicon oxide nanodispersion liquid is isopropyl alcohol.

[0090] (3) then spin coating a PCBM solution with a concentration of 5mg / mL on the silicon oxide layer at 3000 rpm for 30 s, and then performing annealing at 100℃ for 10 min to remove the solvent, so as to form a first electron transport layer.

[0091] (4) then evaporating a C 60 layer on the first electron transport layer by using an evaporation method, so as to form a second electron transport layer, and the evaporation rate is

[0092] (5) then depositing an Ag electrode by using a vacuum evaporation method, so as to obtain the solar cell module.

[0093] Example 3

[0094] The embodiment provides a solar cell assembly, which comprises ITO conductive glass, a nickel oxide layer, a perovskite absorption layer, a composite electron transport layer and an electrode, and the composite electron transport layer comprises a light scattering layer, a first electron transport layer and a second electron transport layer which are sequentially stacked in the direction away from the perovskite absorption layer.

[0095] The ITO layer of the ITO conductive glass has a thickness of 350 nm; the nickel oxide layer has a thickness of 15 nm; the perovskite absorption layer has a chemical formula of MAPbI3 and a thickness of 600 nm; the composite electron transport layer has a thickness of 48 nm; the light scattering layer is an aluminum oxide layer and has a thickness of 3 nm; the first electron transport layer is a PCBM layer and has a thickness of 5 nm; the aluminum oxide layer is filled with PCBM in part of the particle gaps; the second electron transport layer is a C 60 The first electron transport layer has a LUMO energy level greater than that of the second electron transport layer; the surface roughness of the side surface of the first electron transport layer close to the second electron transport layer is 5 nm; the thickness ratio of the light scattering layer, the first electron transport layer and the second electron transport layer is 1:1:4; and the electrode is an Ag electrode and has a thickness of 200 nm.

[0096] The embodiment further provides a preparation method of the solar cell assembly, and the preparation method comprises the following steps:

[0097] (1) depositing a nickel oxide layer on the ITO conductive glass by using a magnetron sputtering method, and then preparing a perovskite absorption layer by using an anti-solvent method.

[0098] (2) applying an aluminum oxide nano-dispersion liquid with a concentration of 0.25wt% on the perovskite absorption layer by using a spin coating method at 5000rpm for 30s, and then performing annealing at 100℃ for 10min to remove the solvent, so as to form an aluminum oxide layer.

[0099] The solvent of the aluminum oxide nano-dispersion liquid is isopropyl alcohol.

[0100] (3) then applying a PCBM solution with a concentration of 5mg / mL on the aluminum oxide layer by using a spin coating method at 3000rpm for 30s, and then performing annealing at 100℃ for 10min to remove the solvent, so as to form a first electron transport layer.

[0101] (4) then evaporating a C 60 70A layer on the first electron transport layer by using an evaporation method, so as to form a second electron transport layer, and the evaporation rate is 0.1A / s.

[0102] (5) Then a layer of Ag electrode is deposited by vacuum evaporation method to obtain the solar cell module.

[0103] Example 4

[0104] The difference between this example and Example 1 is that a modified material, 1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]imidazole, is also distributed in the light scattering layer, and the doping concentration of 1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]imidazole in the alumina nanodispersion is 0.2 mg / mL.

[0105] The rest of the preparation method and parameters remain the same as in Example 1.

[0106] Example 5

[0107] The difference between this example and Example 4 is that the doping concentration of 1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]imidazole in the alumina nanodispersion is 0.35 mg / mL.

[0108] The rest of the preparation method and parameters remain the same as in Example 4.

[0109] Example 6

[0110] The difference between this example and Example 4 is that the doping concentration of 1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]imidazole in the alumina nanodispersion is 0.5 mg / mL.

[0111] The rest of the preparation method and parameters remain the same as in Example 4.

[0112] Example 7

[0113] The difference between this example and Example 4 is that the doping concentration of 1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]imidazole in the alumina nanodispersion is 1 mg / mL.

[0114] The rest of the preparation method and parameters remain the same as in Example 4.

[0115] Example 8

[0116] The difference between this example and Example 1 is that the thickness of the light scattering layer is 0.5 nm by adjusting the spin coating speed of the alumina nanodispersion in step (1).

[0117] The rest of the preparation method and parameters remain the same as in Example 1.

[0118] Example 9

[0119] The difference between this example and Example 1 is that the thickness of the light scattering layer is 20 nm by adjusting the spin coating rate of the alumina nanodispersion in step (1).

[0120] The rest of the preparation method and parameters are consistent with Example 1.

[0121] Example 10

[0122] The difference between this example and Example 1 is that the thickness of the first electron transport layer is 0.5 nm by adjusting the spin coating rate of the PCBM solution in step (2).

[0123] The rest of the preparation method and parameters are consistent with Example 1.

[0124] Example 11

[0125] The difference between this example and Example 1 is that the thickness of the first electron transport layer is 20 nm by adjusting the spin coating rate of the PCBM solution in step (2).

[0126] The rest of the preparation method and parameters are consistent with Example 1.

[0127] Example 12

[0128] The difference between this example and Example 1 is that the thickness ratio of the light scattering layer and the first electron transport layer is 1:0.5.

[0129] The rest of the preparation method and parameters are consistent with Example 1.

[0130] Example 13

[0131] The difference between this example and Example 1 is that the thickness ratio of the light scattering layer and the first electron transport layer is 1:2.

[0132] The rest of the preparation method and parameters are consistent with Example 1.

[0133] Example 14

[0134] The difference between this example and Example 1 is that the thickness ratio of the first electron transport layer and the second electron transport layer is 1:10.

[0135] The rest of the preparation method and parameters are consistent with Example 1.

[0136] Example 15

[0137] The difference between this example and Example 1 is that the thickness ratio of the first electron transport layer and the second electron transport layer is 2:2.

[0138] The rest of the preparation method and parameters are consistent with Example 1.

[0139] Comparative Example 1

[0140] The difference between this comparative example and Example 1 is that no light scattering layer is provided, i.e. step (1) is not performed.

[0141] The rest of the preparation method and parameters are consistent with Example 1.

[0142] Comparative Example 2

[0143] The difference between this comparative example and Example 1 is that no first electron transport layer is provided, i.e. step (2) is not performed.

[0144] The rest of the preparation method and parameters are consistent with Example 1.

[0145] Comparative Example 3

[0146] The difference between this comparative example and Example 1 is that no second electron transport layer is provided, i.e. step (3) is not performed.

[0147] The rest of the preparation method and parameters are consistent with Example 1.

[0148] Comparative Example 4

[0149] The difference between this comparative example and Example 1 is that the composite electron transport layer comprises a light scattering layer, a second electron transport layer and a first electron transport layer which are stacked, i.e. after step (1), step (3) is performed first, and then step (2) is performed.

[0150] The rest of the preparation method and parameters are consistent with Example 1.

[0151] Performance Test

[0152] The transverse perovskite solar cells provided by the above examples and comparative examples were tested for photoelectric performance, and the test conditions were: test area 1 cm 2 , AM1.5, 1000 W / m 2 , 25±2℃.

[0153] The test results are shown in Table 1.

[0154] Table 1

[0155]

[0156]

[0157] Analysis:

[0158] From the above table, the light scattering layer has a gap, which can receive the first light and form scattering, the first electron transport layer not only can fill the at least part of the gap gap formed by the agglomeration of nanoparticles in the light scattering layer, reduce the surface roughness, and the first electron transport layer and the second electron transport layer exist the band gap, which can accelerate the electron transport, so the three layers cooperate, which can effectively passivate the interface defects of the perovskite and the electron transport layer, inhibit the interface carrier recombination, significantly improve the electron transport efficiency and stability of the composite electron transport layer, and further improve the efficiency and stability of the device.

[0159] From example 1 and example 4, if 1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]imidazole is introduced as a modified material in the light scattering layer, it is beneficial to help the regular arrangement of the PCBM layer and improve the electron transport capacity.

[0160] From example 4 and example 7, if the doping concentration of the modified material is too much, the conductivity of the material will decrease, which will affect the electrochemical properties.

[0161] From example 1 and example 8-9, if the thickness of the light scattering layer is too thin, it cannot play a role in light scattering, which will lead to poor device performance; if the thickness of the light scattering layer is too thick, the conductivity is poor, which will affect the electron transport and make the device performance worse.

[0162] From example 1 and example 10-11, if the thickness of the first electron transport layer is too thin, it cannot play a role in filling the gap of the light scattering layer, reducing the unevenness of the upper surface and reducing the surface roughness, which will lead to a decrease in the efficiency of the prepared device; if the thickness of the first electron transport layer is too thick, it will introduce too much series resistance, which will affect the efficiency of the device.

[0163] From example 1 and example 12-13, if the thickness ratio of the light scattering layer and the first electron transport layer is too small, the light scattering layer is too thin, and the first electron transport layer is too thick, which will reduce the scattered light and introduce too much internal resistance, so the short-circuit current of the device will decrease significantly; if the thickness ratio of the light scattering layer and the first electron transport layer is too large, the light scattering layer is too thick, and the electron cannot pass through, which will also seriously reduce the short-circuit current.

[0164] From example 1 and example 14-15, if the thickness ratio of the first electron transport layer and the second electron transport layer is too small, the thickness of the first electron transport layer is too thin, the thickness of the second electron transport layer is large, the interface roughness increases, which will affect the interface electron transport and lead to a decrease in the short-circuit current and the fill factor; if the thickness ratio of the first electron transport layer and the second electron transport layer is too large, the thickness of the first electron transport layer is too large, the thickness of the second electron transport layer is too thin, which will increase the interface defects and weaken the transport capacity of the second electron transport layer, leading to a decrease in the short-circuit current and the fill factor.

[0165] From Example 1 and Comparative Examples 1-3, if the light scattering layer is not provided, part of the light scattering will be lost, resulting in a decrease in the device current; if the first electron transport layer is not provided, the interface electron transport will be affected, resulting in a significant decrease in the fill factor of the device; if the second electron transport layer is not provided, the electrons cannot be quickly separated from the perovskite layer and injected into the electrode layer, which will seriously recombine with holes, resulting in a serious decrease in efficiency.

[0166] From Example 1 and Comparative Example 4, if the composite electron transport layer includes the light scattering layer, the second electron transport layer and the first electron transport layer which are stacked, it will cause the energy level arrangement to be mismatched, a potential barrier is formed in the middle, the interface electron transport is affected, and the fill factor of the device is seriously affected.

[0167] The applicant declares that the process method of the utility model is illustrated by the above examples, but the utility model is not limited to the above process steps, that is, it does not mean that the utility model must rely on the above process steps to be implemented. The skilled in the art should understand that any improvement of the utility model, equivalent replacement of the raw materials selected by the utility model and addition of auxiliary ingredients, selection of specific modes, etc. fall within the protection scope and disclosure scope of the utility model.

Claims

1. A solar cell module having a composite electron transport layer, characterized by, The composite electron transport layer comprises a light scattering layer, a first electron transport layer and a second electron transport layer arranged in a stack: The light scattering layer has gaps for receiving first light and forming scattering; the first electron transport layer is used for filling at least part of the gaps in the light scattering layer; and the first electron transport layer and the second electron transport layer have a conduction band energy difference.

2. The solar cell module according to claim 1, characterized by The LUMO energy level of the first electron transport layer is greater than the LUMO energy level of the second electron transport layer.

3. The solar cell module according to claim 1, characterized by, The light scattering layer comprises an aluminum oxide layer and / or a silicon oxide layer.

4. The solar cell module according to claim 3, characterized by The thickness of the light scattering layer is 1-10 nm. In the light scattering layer, the average particle size of the light scattering particles is 5-30 nm.

5. The solar cell module according to claim 1, characterized by The first electron transport layer comprises a fullerene derivative layer. The fullerene derivative layer comprises a PCBM layer and / or an ICBA layer.

6. The solar cell module according to claim 1, wherein The thickness of the first electron transport layer is 1-10 nm.

7. The solar cell module according to claim 1, wherein The surface roughness of the surface of the first electron transport layer close to the surface of the second electron transport layer is 5-15 nm.

8. The solar cell module according to claim 1, characterized by, The second electron transport layer includes C 60 layer.

9. The solar cell module according to claim 1, characterized by, The thickness of the second electron transport layer is 20-40 nm. The thickness ratio of the light scattering layer, the first electron transport layer and the second electron transport layer is 1:(1-1.5):(2-6).

10. The solar cell module according to claim 1, characterized by, The battery assembly further comprises a conductive substrate, a hole transport layer, a perovskite absorption layer and an electrode arranged in a stack, the composite electron transport layer is located between the perovskite absorption layer and the electrode, and the light scattering layer is close to the perovskite absorption layer.

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