A color semi-transparent organic solar cell and a preparation method thereof

Abstract

The application provides a kind of color translucent organic solar cell and its preparation method, the color translucent organic solar cell includes metal bottom electrode, electron transport layer, active layer and metal top electrode which are stacked in sequence;Microcavity structure is formed between the metal bottom electrode and the metal top electrode.The color translucent organic solar cell of the application can realize yellow, cyan, blue, purple and orange reflectance chroma and has translucent appearance when reflecting light, meets public aesthetic, and can be used for decorating building;At the same time, the color translucent organic solar cell has similar current density to ITO solar cell under weak interference condition.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of organic solar cells, and particularly relates to a color semi-transparent organic solar cell and a preparation method thereof. BACKGROUND

[0002] In order to cope with the energy crisis, the field of solar cells has developed rapidly. Among them, organic solar cells have attracted widespread attention due to their advantages such as solution processing, printable preparation of large-area devices, low cost, light weight, and easy adjustment of the band gap of the light absorption layer. Each component of the organic solar cell has a significant impact on its working process. Due to its high electrical conductivity, metal materials have been used as the light reflecting electrode for preparing organic solar cells. On the transparent electrode side, the most widely used in the field is doped indium tin oxide (ITO) due to the need for good transmittance in the visible light region and high electrical conductivity. However, ITO is expensive and the material is scarce. Compared with traditional solar cells such as Si, the extinction coefficient of the active layer of the organic solar cell is suitable, and it has great application potential and can replace high-rise building glass to realize the concept of building green power generation in the future. The existing technology for adjusting the color of the device is usually based on the traditional device structure of ITO plus additional light coupling structures (Bragg grating, dielectric mirror, microcavity electrode, etc.). However, these structures are difficult to simultaneously consider the light transmittance and reflectance of the device, and the multi-layer structure also leads to a complex process, which is difficult to apply in practice.

[0003] CN108321221A discloses a graphene solar cell with a microcavity structure, which comprises an n-type monocrystalline silicon, one side of the n-type monocrystalline silicon is provided with a silicon dioxide layer, the silicon dioxide layer is an annular structure with a through hole, the surface of the silicon dioxide layer and the surface of the n-type monocrystalline silicon exposed by the through hole of the silicon dioxide layer are provided with a first graphene film layer, a silicon nitride film is arranged on the surface of the first graphene film layer in the area of the through hole of the silicon dioxide layer, a second graphene film layer is arranged on the surface of the silicon nitride film, a front electrode is arranged on the surface of the first graphene film layer in the peripheral area of the through hole of the silicon dioxide layer, and the other side of the n-type monocrystalline silicon is provided with a metal film back electrode. However, the extinction coefficient of the graphene solar cell with a microcavity structure is large.

[0004] CN111929755A discloses a photonic crystal composite structure and a semi-transparent organic solar cell. The photonic crystal composite structure comprises: a first photonic crystal, a second photonic crystal and a microcavity structure; the lower surface of the second photonic crystal is arranged on the upper surface of the first photonic crystal, and the lower surface of the microcavity structure is arranged on the upper surface of the second photonic crystal; the material of the first photonic crystal is the same as that of the second photonic crystal, the thickness of the material of the first photonic crystal is different from that of the material of the second photonic crystal, and the center wavelength of the first photonic crystal is complementary to that of the second photonic crystal; the first photonic crystal and the second photonic crystal are both used for reflecting photons; the material of the microcavity structure is different from that of the first photonic crystal, and the material of the microcavity structure has a complex refractive index; and the microcavity structure is used to realize the constructive interference of light. However, the structure of the photonic crystal composite structure and the semi-transparent organic solar cell is complex, and the preparation cost is high.

[0005] CN104241428A discloses a two-dimensional silicon-based micro-nano photonic crystal solar cell, a periodic array of front electrodes is arranged on the lower side of a front contact layer; a two-dimensional silicon-based micro-nano photonic crystal solar cell structure is arranged between the front electrodes and a back electrode, an upper layer of the two-dimensional silicon-based micro-nano photonic crystal solar cell structure is an n-type silicon semiconductor layer, and a lower layer of the two-dimensional silicon-based micro-nano photonic crystal solar cell structure is a p-type silicon semiconductor layer, the n-type silicon semiconductor layer and the p-type silicon semiconductor layer form a PN junction; a back contact layer is arranged at the bottom of the back electrode, and the material of the back contact layer is the same as that of the front contact layer; and the back electrode with an aluminum thin layer structure is arranged in a slow light region or a forbidden band region of the p-type silicon semiconductor layer. However, the light transmission chroma and the light reflection chroma of the two-dimensional silicon-based micro-nano photonic crystal solar cell are poor, and the diversity of the transmitted light color cannot be realized.

[0006] The currently disclosed organic solar cells and preparation methods thereof have certain defects, and have problems of poor light transmission chroma, poor light reflection chroma, high cost, high extinction coefficient, poor transparency and complex preparation process. Therefore, it is crucial to develop a new type of colored semi-transparent organic solar cell and a preparation method thereof. SUMMARY

[0007] In view of the deficiencies of the prior art, the purpose of the present application is to provide a colored semi-transparent organic solar cell and a preparation method thereof. The colored semi-transparent organic solar cell can realize yellow, cyan, blue, purple or orange light reflection chroma and has a semi-transparent appearance when reflecting light, meets the aesthetic needs of the public, and can be used for decorating buildings. At the same time, the colored semi-transparent organic solar cell has a low cost and a current density similar to that of an ITO solar cell under weak interference.

[0008] To achieve the purpose of the present application, the following technical solutions are adopted:

[0009] In a first aspect, the present application provides a color semi-transparent organic solar cell, which comprises a metal bottom electrode, an electron transport layer, an active layer and a metal top electrode which are stacked in sequence.

[0010] A microcavity structure is formed between the metal bottom electrode and the metal top electrode.

[0011] The metal top electrode and the metal bottom electrode can be reasonably selected according to actual needs. The metal top electrode and the metal bottom electrode have a light reflecting property. The microcavity structure formed by the metal top electrode and the metal bottom electrode is used to strengthen the light field distribution of a specific wavelength. The resonant wavelength is controlled by adjusting the spacing between the metal top electrode and the metal bottom electrode, thereby controlling the light field distribution.

[0012] The microcavity structure is formed between the metal bottom electrode and the metal top electrode. The color semi-transparent organic solar cell can realize yellow, cyan, blue, purple or orange light reflecting chroma. The color semi-transparent organic solar cell has a semi-transparent appearance, meets the aesthetic needs of the public, and can be used to decorate buildings. At the same time, the color semi-transparent organic solar cell has a low cost and a current density similar to that of an ITO solar cell under weak interference.

[0013] Preferably, the thickness of the metal bottom electrode is 4-100 nm, for example, it can be 4 nm, 6 nm, 8 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm or 100 nm, but is not limited to the listed values. Other values not listed in this range are also applicable, and preferably 5-18 nm.

[0014] Preferably, the thickness of the metal top electrode is 4-100 nm, for example, it can be 4 nm, 6 nm, 8 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm or 100 nm, but is not limited to the listed values. Other values not listed in this range are also applicable, and preferably 11-20 nm.

[0015] Preferably, the thickness of the electron transport layer is 3-8 nm, for example, it can be 3 nm, 3.5 nm, 4 nm, 4.5 nm, 5 nm, 5.5 nm, 6 nm, 6.5 nm, 7 nm, 7.5 nm or 8 nm, but is not limited to the listed values. Other values not listed in this range are also applicable.

[0016] Preferably, the thickness of the active layer is 50-200 nm, for example, it can be 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, 150 nm, 160 nm, 170 nm, 180 nm, 190 nm or 200 nm, but is not limited to the listed values, and other values not listed in the range are also applicable, preferably 100-130 nm; when the thickness of the active layer is too low, the short-circuit current density and the open-circuit voltage decrease, and the transparency increases, because the light absorption of the active layer is weakened, and the resonance wavelength is blue-shifted to outside the optimal absorption wavelength, resulting in a weak light field in the active layer, which reduces the short-circuit current and the open-circuit voltage, and a weak active layer results in a greater average light transmittance; when the thickness of the active layer is too high, the short-circuit current density and the open-circuit voltage decrease, and the transparency decreases, because the excessive thickness of the active layer leads to additional carrier recombination, and the resonance wavelength is excessively red-shifted, which is not conducive to the generation of excitons.

[0017] Preferably, the color semi-transparent organic solar cell further comprises a substrate, which is connected to the metal bottom electrode.

[0018] Preferably, the metal bottom electrode comprises a light coupling layer, a first seed layer and a first metal thin film which are stacked in sequence; the light coupling layer is connected to the substrate, and the first metal thin film is connected to the electron transport layer.

[0019] Preferably, the thickness of the light coupling layer is 2-10 nm, for example, it can be 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm or 10 nm, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0020] Preferably, the thickness of the first seed layer is 0.5-2 nm, for example, it can be 0.5 nm, 0.6 nm, 0.7 nm, 0.8 nm, 0.9 nm, 1 nm, 1.1 nm, 1.2 nm, 1.3 nm, 1.4 nm, 1.5 nm, 1.6 nm, 1.7 nm, 1.8 nm, 1.9 nm or 2 nm, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0021] Preferably, the thickness of the first metal thin film is 4-30 nm, for example, 4 nm, 6 nm, 8 nm, 10 nm, 12 nm, 15 nm, 18 nm, 20 nm, 22 nm, 25 nm, 28 nm or 30 nm, but not limited to the listed values, and other values not listed within the range are also applicable. When the thickness of the first metal thin film is too low, the short-circuit current density and open-circuit voltage decrease, because the metal grows mainly in island form, thus not forming a continuous film and not reaching the threshold film thickness for conduction, and thus the device has too high a series resistance. When the thickness of the first metal thin film is too high, the short-circuit current density and open-circuit voltage decrease, because the metal is too thick and reduces the light transmittance, thus weakening the absorption of the active layer.

[0022] Preferably, the metal top electrode comprises, in sequence, a hole transport layer, a second seed layer and a second metal thin film, and the hole transport layer is connected to the active layer.

[0023] Preferably, the thickness of the hole transport layer is 2-10 nm, for example, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm or 10 nm, but not limited to the listed values, and other values not listed within the range are also applicable.

[0024] Preferably, the thickness of the second seed layer is 0.5-2 nm, for example, 0.5 nm, 0.6 nm, 0.7 nm, 0.8 nm, 0.9 nm, 1 nm, 1.1 nm, 1.2 nm, 1.3 nm, 1.4 nm, 1.5 nm, 1.6 nm, 1.7 nm, 1.8 nm, 1.9 nm or 2 nm, but not limited to the listed values, and other values not listed within the range are also applicable.

[0025] Preferably, the thickness of the second metal thin film is 4-30 nm, for example, 4 nm, 6 nm, 8 nm, 10 nm, 12 nm, 15 nm, 18 nm, 20 nm, 22 nm, 25 nm, 28 nm or 30 nm, but not limited to the listed values, and other values not listed within the range are also applicable.

[0026] In a second aspect, the present application provides a preparation method of the color semi-transparent organic solar cell according to the first aspect, and the preparation method comprises the following steps:

[0027] (1) first evaporation to obtain a metal bottom electrode;

[0028] (2) first coating of an electron transport material solution on the metal bottom electrode obtained in step (1) to obtain an electron transport layer;

[0029] (3) coating a solution of an active material on the electron transport layer obtained in step (2) to obtain an active layer;

[0030] (4) performing a second evaporation on the active layer obtained in step (3) to obtain the color semi-transparent organic solar cell.

[0031] The preparation method of the color semi-transparent organic solar cell has simple steps, low raw material cost and strong controllability.

[0032] Preferably, the first evaporation in step (1) comprises sequentially evaporating a first metal oxide, a first metal and a second metal on the substrate.

[0033] The preparation method further comprises a pretreatment of the substrate, wherein the pretreatment comprises ultrasonic cleaning the substrate in water, a ketone and an alcohol in sequence, and the pretreatment further comprises treating the substrate after the ultrasonic cleaning by using ultraviolet ozone.

[0034] Preferably, the evaporation rate of the first metal oxide is 0.1-0.5 nm / s. For example, it can be 0.1-0.5 nm / s. or but not limited to the listed values, other values not listed in the value range are also applicable.

[0035] Preferably, the evaporation rate of the first metal is 0.1-0.5 nm / s. For example, it can be 0.1-0.5 nm / s. or but not limited to the listed values, other values not listed in the value range are also applicable.

[0036] Preferably, the evaporation rate of the second metal is 0.1-0.5 nm / s. For example, it can be 0.1-0.5 nm / s. or but not limited to the listed values, other values not listed in the value range are also applicable; when the evaporation rate of the second metal is too low, the short-circuit current density and the open-circuit voltage will decrease, because the ultra-thin metal prepared at too low a rate cannot form a continuous thin film, resulting in an increase in the series resistance of the device and a decrease in the short-circuit current density and the open-circuit voltage; when the evaporation rate of the second metal is too high, the short-circuit current density and the open-circuit voltage will decrease, because the roughness of the electrode increases, which is not conducive to the realization of ohmic contact.

[0037] Preferably, the second evaporation in step (4) comprises sequentially evaporating a second metal oxide, a third metal and a fourth metal on the active layer.

[0038] Preferably, the evaporation rate of the second metal oxide is 0.1-0.5 nm / s. For example, can be or but not limited to the listed numerical values, other unlisted numerical values within the numerical range are also applicable.

[0039] Preferably, the evaporation rate of the third metal is For example, can be or but not limited to the listed numerical values, other unlisted numerical values within the numerical range are also applicable.

[0040] Preferably, the evaporation rate of the fourth metal is For example, can be or but not limited to the listed numerical values, other unlisted numerical values within the numerical range are also applicable.

[0041] Preferably, the second evaporation of step (4) includes covering a mask on 10% to 70% of the area of the surface of the active layer obtained in step (3), for example, can be 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65% or 70%, but not limited to the listed numerical values, other unlisted numerical values within the numerical range are also applicable.

[0042] The first evaporation and the second evaporation of the present application are carried out in a vacuum evaporation chamber, and both are carried out in an environment with a vacuum degree less than 2x10 - 4 Pa.

[0043] Preferably, the material of the substrate includes any one or a combination of at least two of glass, single crystal silicon, metal, plastic or ceramic, typical but non-limiting combinations include a combination of glass and single crystal silicon, a combination of single crystal silicon and metal, a combination of metal and plastic, a combination of plastic and ceramic, a combination of glass, single crystal silicon and metal, or a combination of glass, single crystal silicon, metal and ceramic.

[0044] Preferably, the first metal oxide includes any one or a combination of at least two of MoO3, WO3 or V2O5, typical but non-limiting combinations include a combination of MoO3 and WO3, a combination of WO3 and V2O5, or a combination of MoO3, WO3 and V2O5.

[0045] Preferably, the second metal oxide includes any one or a combination of at least two of MoO3, WO3 or V2O5, typical but non-limiting combinations include a combination of MoO3 and WO3, a combination of WO3 and V2O5, or a combination of MoO3, WO3 and V2O5.

[0046] Preferably, the first metal comprises any one or a combination of at least two of Ca, Al or Au, typically but not exclusively a combination of Ca and Al, Al and Au, or Ca, Al and Au.

[0047] Preferably, the second metal comprises any one or a combination of at least two of Au, Ag, Al or Cu, typically but not exclusively a combination of Au and Ag, Ag and Al, Al and Cu, Au, Ag and Al, or Au, Ag, Al and Cu.

[0048] Preferably, the third metal comprises any one or a combination of at least two of Ca, Al or Au, typically but not exclusively a combination of Ca and Al, Al and Au, or Ca, Al and Au.

[0049] Preferably, the fourth metal comprises any one or a combination of at least two of Au, Ag, Al or Cu, typically but not exclusively a combination of Au and Ag, Ag and Al, Al and Cu, Au, Ag and Al, or Au, Ag, Al and Cu.

[0050] Preferably, the first coating of step (2) is performed by spin coating at a speed of 1500 to 5500 rpm, for example, it can be 1500 rpm, 1700 rpm, 200 rpm, 2200 rpm, 2500 rpm, 2700 rpm, 3000 rpm, 3200 rpm, 3500 rpm, 3700 rpm, 4000 rpm, 4200 rpm, 1500 rpm, 4700 rpm or 5000 rpm, but not limited to the listed values, other values not listed in this range are also applicable.

[0051] Preferably, the solute of the electron transport material solution of step (2) comprises PFN-Br, and the solvent comprises alcohol.

[0052] The alcohol of the present application comprises methanol.

[0053] Preferably, the concentration of the solute in the electron transport material solution of step (2) is 0.5 to 2 mg / ml, for example, it can be 0.5 mg / ml, 0.7 mg / ml, 0.9 mg / ml, 1 mg / ml, 1.2 mg / ml, 1.4 mg / ml, 1.6 mg / ml, 1.8 mg / ml or 2 mg / ml, but not limited to the listed values, other values not listed in this range are also applicable.

[0054] Preferably, the second coating of step (3) comprises spin coating at a rotation speed of 1300-7000 rpm in an inert atmosphere, for example, it can be 1300 rpm, 1500 rpm, 1800 rpm, 2000 rpm, 2500 rpm, 3000 rpm, 3500 rpm, 4000 rpm, 4500 rpm, 5000 rpm, 5500 rpm, 6000 rpm, 6500 rpm or 7000 rpm, but not only limited to the listed values, other values not listed in the range are also applicable.

[0055] The inert atmosphere described in the present application includes nitrogen and / or inert gas.

[0056] Preferably, the solute of the active material solution of step (3) comprises an active donor material and an active acceptor material.

[0057] Preferably, the mass ratio of the active donor material and the active acceptor material is (1-4):3, for example, it can be 1:3, 1.2:3, 1.5:3, 1.8:3, 2:3, 2.2:3, 2.5:3, 2.8:3, 3.1:3, 3.4:3, 3.7:3 or 4:3, but not only limited to the listed values, other values not listed in the range are also applicable.

[0058] Preferably, the concentration of the solute in the active material solution of step (3) is 20-40 mg / ml, for example, it can be 20 mg / ml, 22 mg / ml, 25 mg / ml, 28 mg / ml, 30 mg / ml, 32 mg / ml, 35 mg / ml, 38 mg / ml or 40 mg / ml, but not only limited to the listed values, other values not listed in the range are also applicable.

[0059] Preferably, the active donor material comprises PTB7-Th.

[0060] Preferably, the active acceptor material comprises PC71BM and / or IEICO-4F.

[0061] Preferably, the solvent of the active material solution comprises halogenated hydrocarbon.

[0062] Preferably, as a preferred technical solution of the preparation method of the first aspect, the preparation method comprises the following steps:

[0063] (1) sequentially evaporating a first metal oxide on a substrate at a rate of evaporating a first metal at a rate of evaporating a second metal at a rate of to obtain a metal bottom electrode;

[0064] (2) in the inert atmosphere, spin-coating PFN-Br alcohol solution with a concentration of 0.5-2 mg / ml on the metal bottom electrode obtained in step (1) at a speed of 1500-5500 rpm to obtain an electron transport layer;

[0065] (3) in the inert atmosphere, spin-coating halogenated hydrocarbon solution with a solute concentration of 20-40 mg / ml on the electron transport layer obtained in step (2) at a speed of 1300-7000 rpm, wherein the solute in the halogenated hydrocarbon solution is a combination of active donor material and active acceptor material with a mass ratio of (1-4):3 to obtain an active layer;

[0066] (4) after covering the mask on 10%-70% of the area of the active layer obtained in step (3), sequentially evaporating the second metal oxide at a speed of , evaporating the third metal at a speed of , and evaporating the fourth metal at a speed of to obtain a color semi-transparent organic solar cell.

[0067] Compared with the prior art, the present application has the following beneficial effects:

[0068] The color semi-transparent organic solar cell can realize the reflection chroma of yellow, cyan, blue, purple or orange, has a semi-transparent appearance, meets the aesthetic needs of the public, and can be used for decorating buildings; meanwhile, the color semi-transparent organic solar cell has a low cost and a current density similar to that of an ITO solar cell in the case of weak interference; the preparation method of the color semi-transparent organic solar cell has simple steps, low raw material cost and strong controllability. BRIEF DESCRIPTION OF DRAWINGS

[0069] Figure 1 It is a structural schematic diagram of the color semi-transparent organic solar cell in Example 1.

[0070] 1-glass substrate; 2-MoO3 light coupling layer; 3-first Au seed layer; 4-first Ag thin film; 5-PFN-Br electron transport layer; 6-active layer; 7-MoO3 hole transport layer; 8-second Au seed layer; 9-second Ag thin film. DETAILED DESCRIPTION

[0071] The technical solutions of the present application will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only used to help understand the present application and should not be regarded as specific limitations on the present application.

[0072] Example 1

[0073] The embodiment provides a kind of color translucent organic solar cell, such as Figure 1 As shown in the figure, the color translucent organic solar cell includes the metal bottom electrode with the thickness of 30nm, the PFN-Br electron transport layer 5 with the thickness of 5nm, the active layer 6 with the thickness of 125nm and the metal top electrode with the thickness of 30nm, which are sequentially stacked;

[0074] Microcavity structure is formed between the metal bottom electrode and the metal top electrode;The color translucent organic solar cell further includes the glass substrate 1 connected with the metal bottom electrode;

[0075] The metal bottom electrode includes the MoO3 light coupling layer 2 with the thickness of 6nm, the first Au seed layer 3 with the thickness of 1.2nm and the first Ag film 4 with the thickness of 22.8nm, which are sequentially stacked;The MoO3 light coupling layer 2 is connected with the glass substrate 1, and the first Ag film 4 is connected with the PFN-Br electron transport layer 5;

[0076] The metal top electrode includes the MoO3 hole transport layer 7 with the thickness of 6nm, the second Au seed layer 8 with the thickness of 0.8nm and the second Ag film 9 with the thickness of 23.2nm, which are sequentially stacked, and the MoO3 hole transport layer 7 is connected with the active layer 6.

[0077] The preparation method of the color translucent organic solar cell includes the following steps:

[0078] (1) sequentially evaporate MoO3 on the glass substrate 1 at a rate of , evaporate Au at a rate of , and evaporate Ag at a rate of , to obtain the metal bottom electrode;

[0079] (2) spin-coat the PFN-Br methanol solution with a concentration of 1.6mg / ml on the metal bottom electrode obtained in step (1) at a speed of 3500rpm in a nitrogen atmosphere, to obtain the PFN-Br electron transport layer 5;

[0080] (3) spin-coat the chlorobenzene solution with a solute concentration of 30mg / ml on the PFN-Br electron transport layer 5 obtained in step (2) at a speed of 2500rpm in a nitrogen atmosphere, and the solute in the chlorobenzene solution is a combination of PTB7-Th and PC71BM with a mass ratio of 3.2:3, to obtain the active layer 6;

[0081] (4) after covering the mask on 45% of the area on the surface of the active layer 6 obtained in step (3), sequentially evaporate MoO3 at a rate of , evaporate Au at a rate of , and evaporate Ag at a rate of , to obtain the color translucent organic solar cell.

[0082] Example 2

[0083] This embodiment provides a colored semi-transparent organic solar cell, which includes a metal bottom electrode with a thickness of 20 nm, a PFN-Br electron transport layer with a thickness of 3 nm, an active layer with a thickness of 180 nm, and a metal top electrode with a thickness of 12 nm, stacked sequentially.

[0084] A microcavity structure is formed between the metal bottom electrode and the metal top electrode; the colored semi-transparent organic solar cell also includes a monocrystalline silicon substrate connected to the metal bottom electrode;

[0085] The metal bottom electrode comprises a V2O5 optical coupling layer with a thickness of 8 nm, a first Al seed layer with a thickness of 0.8 nm, and a first Au thin film with a thickness of 11.2 nm, which are stacked sequentially; the V2O5 optical coupling layer is connected to a single-crystal silicon substrate, and the first Au thin film is connected to a PFN-Br electron transport layer.

[0086] The metal top electrode comprises a WO3 hole transport layer with a thickness of 8 nm, a second Ca seed layer with a thickness of 1.2 nm, and a second Cu thin film with a thickness of 2.8 nm stacked sequentially, wherein the WO3 hole transport layer is connected to the active layer.

[0087] The method for preparing the colored semi-transparent organic solar cell includes the following steps:

[0088] (1) Sequentially on a single-crystal silicon substrate using WO3 was deposited at a rate of [missing information - likely a specific rate or speed]. Al was deposited at a rate of [missing information], at [missing information] Au is deposited at a rate that yields a metal bottom electrode;

[0089] (2) In a nitrogen atmosphere, a methanol solution with a PFN-Br concentration of 0.8 mg / ml is spin-coated onto the metal bottom electrode obtained in step (1) at a speed of 4500 rpm to obtain a PFN-Br electron transport layer.

[0090] (3) In a nitrogen atmosphere, a chlorobenzene solution with a solute concentration of 35 mg / ml was spin-coated onto the PFN-Br electron transport layer obtained in step (2) at a speed of 4000 rpm. The solute in the chlorobenzene solution was a combination of PTB7-Th and IEICO-4F with a mass ratio of 1.7:3, to obtain an active layer.

[0091] (4) After covering 70% of the surface of the active layer obtained in step (3) with a mask, sequentially... V2O5 was deposited at a rate of [missing information - likely a rate or speed]. Ca is evaporated at a rate of [missing information], at [missing information] Cu was deposited at a high rate to obtain a colored semi-transparent organic solar cell.

[0092] Embodiment 3

[0093] The embodiment provides a colored semi-transparent organic solar cell, which comprises a metal bottom electrode with a thickness of 42 nm, a PFN-Br electron transport layer with a thickness of 8 nm, an active layer with a thickness of 50 nm and a metal top electrode with a thickness of 20 nm which are sequentially stacked;

[0094] A microcavity structure is formed between the metal bottom electrode and the metal top electrode; the colored semi-transparent organic solar cell further comprises a glass substrate connected with the metal bottom electrode;

[0095] The metal bottom electrode comprises a MoO3 light coupling layer with a thickness of 10 nm, a first Al seed layer with a thickness of 2 nm and a first Ag thin film with a thickness of 30 nm which are sequentially stacked; the MoO3 light coupling layer is connected with the glass substrate, and the first Ag thin film is connected with the PFN-Br electron transport layer;

[0096] The metal top electrode comprises a WO3 hole transport layer with a thickness of 2 nm, a second Ag seed layer with a thickness of 1.6 nm and a second Au thin film with a thickness of 16.4 nm which are sequentially stacked, and the WO3 hole transport layer is connected with the active layer.

[0097] The preparation method of the colored semi-transparent organic solar cell comprises the following steps:

[0098] (1) sequentially evaporating MoO3 on the glass substrate at a rate of 0.1 A / s, evaporating Al at a rate of 0.1 A / s and evaporating Ag at a rate of 0.1 A / s to obtain the metal bottom electrode;

[0099] (2) in an argon atmosphere, spin-coating a PFN-Br ethanol solution with a concentration of 1.2 mg / ml on the metal bottom electrode obtained in step (1) at a rotation speed of 2500 rpm to obtain the PFN-Br electron transport layer;

[0100] (3) in an argon atmosphere, spin-coating a chlorobenzene solution with a solute concentration of 40 mg / ml on the PFN-Br electron transport layer obtained in step (2) at a rotation speed of 7000 rpm, wherein the solute in the chlorobenzene solution is a combination of PTB7-Th and PC71BM with a mass ratio of 1:3 to obtain the active layer;

[0101] (4) after covering the mask on 10% of the surface of the active layer obtained in step (3), sequentially evaporating WO3 at a rate of 0.1 A / s, evaporating Ag at a rate of 0.1 A / s and evaporating Au at a rate of 0.1 A / s to obtain the colored semi-transparent organic solar cell. ​​​​​​

[0102] Embodiment 4

[0103] The embodiment provides a colored semi-transparent organic solar cell, which comprises a metal bottom electrode with a thickness of 12 nm, a PFN-Br electron transport layer with a thickness of 4 nm, an active layer with a thickness of 90 nm and a metal top electrode with a thickness of 42 nm which are sequentially stacked;

[0104] A microcavity structure is formed between the metal bottom electrode and the metal top electrode; the colored semi-transparent organic solar cell further comprises a monocrystalline silicon substrate connected with the metal bottom electrode;

[0105] The metal bottom electrode comprises a V2O5 light coupling layer with a thickness of 2 nm, a first Au seed layer with a thickness of 0.5 nm and a first Ag thin film with a thickness of 9.5 nm which are sequentially stacked; the V2O5 light coupling layer is connected with the monocrystalline silicon substrate, and the first Ag thin film is connected with the PFN-Br electron transport layer;

[0106] The metal top electrode comprises a V2O5 hole transport layer with a thickness of 10 nm, a second Au seed layer with a thickness of 2 nm and a second Ag thin film with a thickness of 30 nm which are sequentially stacked, and the V2O5 hole transport layer is connected with the active layer.

[0107] The preparation method of the colored semi-transparent organic solar cell comprises the following steps:

[0108] (1) sequentially evaporating V2O5 on a substrate at a rate of 0.1 nm / s, evaporating Au at a rate of 0.1 nm / s and evaporating Ag at a rate of 0.1 nm / s to obtain a metal bottom electrode; (2) in an argon atmosphere, spin-coating a 2 mg / ml PFN-Br propanol solution on the metal bottom electrode obtained in step (1) at a rotation speed of 5500 rpm to obtain a PFN-Br electron transport layer; (3) in an argon atmosphere, spin-coating a 25 mg / ml chlorobenzene solution of a combination of PTB7-Th and IEICO-4F with a mass ratio of 2.5:3 on the PFN-Br electron transport layer obtained in step (2) at a rotation speed of 1300 rpm to obtain an active layer;

[0109] (4) after covering a mask on 25% of the surface of the active layer obtained in step (3), sequentially evaporating V2O5 at a rate of 0.1 nm / s, evaporating Au at a rate of 0.1 nm / s and evaporating Ag at a rate of 0.1 nm / s to obtain a metal top electrode;

[0110]

[0111] ​​​​​The color semi-transparent organic solar cell is prepared by evaporating Ag at a rate of 0.5 nm / min.

[0112] Embodiment 5

[0113] The color semi-transparent organic solar cell comprises a metal bottom electrode with a thickness of 7.6 nm, a PFN-Br electron transport layer with a thickness of 6 nm, an active layer with a thickness of 200 nm and a metal top electrode with a thickness of 8.5 nm which are sequentially stacked;

[0114] A microcavity structure is formed between the metal bottom electrode and the metal top electrode; the color semi-transparent organic solar cell further comprises a glass substrate connected with the metal bottom electrode;

[0115] The metal bottom electrode comprises a WO3 light coupling layer with a thickness of 2 nm, a first Al seed layer with a thickness of 1.6 nm and a first Ag thin film with a thickness of 4 nm which are sequentially stacked; the WO3 light coupling layer is connected with the glass substrate, and the first Ag thin film is connected with the PFN-Br electron transport layer;

[0116] The metal top electrode comprises a MoO3 hole transport layer with a thickness of 4 nm, a second Au seed layer with a thickness of 0.5 nm and a second Ag thin film with a thickness of 4 nm which are sequentially stacked, and the MoO3 hole transport layer is connected with the active layer.

[0117] The preparation method of the color semi-transparent organic solar cell comprises the following steps:

[0118] (1) sequentially evaporating WO3 at a rate of 0.5 nm / min, evaporating Al at a rate of 0.5 nm / min and evaporating Ag at a rate of 0.5 nm / min on a glass substrate to obtain a metal bottom electrode; (2) in a nitrogen atmosphere, spin-coating a PFN-Br methanol solution with a concentration of 0.5 mg / ml on the metal bottom electrode obtained in step (1) at a speed of 1500 rpm to obtain a PFN-Br electron transport layer; (3) in a nitrogen atmosphere, spin-coating a chlorobenzene solution with a solute concentration of 20 mg / ml on the PFN-Br electron transport layer obtained in step (2) at a speed of 5500 rpm, wherein the solute in the chlorobenzene solution is a combination of PTB7-Th and PC71BM with a mass ratio of 4:3 to obtain an active layer;

[0119] (4) after covering a mask on 60% of the area of the surface of the active layer obtained in step (3), sequentially evaporating MoO3 at a rate of 0.5 nm / min, evaporating Au at a rate of 0.5 nm / min and evaporating Ag at a rate of 0.5 nm / min to obtain a metal top electrode;

[0120]

[0121] ​​​​​The Ag is evaporated at a rate of 0.2 nm / s to obtain a color semi-transparent organic solar cell.

[0122] Example 6

[0123] This example provides a color semi-transparent organic solar cell, which is the same as example 1 except that the thickness of the active layer is 30 nm.

[0124] Example 7

[0125] This example provides a color semi-transparent organic solar cell, which is the same as example 1 except that the thickness of the active layer is 230 nm.

[0126] Example 8

[0127] This example provides a color semi-transparent organic solar cell, which is the same as example 1 except that the thickness of the first Ag thin film is 2 nm and the thickness of the metal bottom electrode is 9.2 nm.

[0128] Example 9

[0129] This example provides a color semi-transparent organic solar cell, which is the same as example 1 except that the thickness of the first Ag thin film is 35 nm and the thickness of the metal bottom electrode is 42.2 nm.

[0130] Example 10

[0131] This example provides a color semi-transparent organic solar cell, which is the same as example 1 except that the Ag is evaporated at a rate of 0.2 nm / s in step (1).

[0132] Example 11

[0133] This example provides a color semi-transparent organic solar cell, which is the same as example 1 except that the Ag is evaporated at a rate of 0.2 nm / s in step (1).

[0134] Comparative Example 1

[0135] This comparative example provides a color semi-transparent organic solar cell, which is the same as example 1 except that the metal bottom electrode is replaced by an ITO bottom electrode.

[0136] Comparative Example 2

[0137] This comparative example provides a color semi-transparent organic solar cell, which is the same as example 2 except that the metal bottom electrode is replaced by an ITO bottom electrode.

[0138] ​​The color semi-transparent organic solar cells described in Examples 1-11 and Comparative Examples 1 and 2 were tested for voltammetry characteristic curves, and the test method was as follows: a Keithley SourceMeter (2400) was combined with a solar simulator (SS-F5-3A, Enlitech) and a standard Si cell light (SRC-2020, Enlitech) was used, and the short-circuit current density (Jsc) and open-circuit voltage (Voc) of the color semi-transparent organic solar cells were tested, as shown in Table 1.

[0139] The color semi-transparent organic solar cells described in Examples 1-7 and Comparative Examples 1 and 2 were tested for light transmission and reflection, and the test method was as follows: a spectrophotometer (Lambda-950) was used for testing, and the test results are shown in Table 2.

[0140] Table 1

[0141] Jsc(mA / cm 2 )]]> Voc (V) Example 1 12.52 0.777 Example 2 13.24 0.790 Example 3 12.70 0.785 Example 4 11.54 0.783 Example 5 11.11 0.762 Example 6 9.68 0.752 Example 7 10.46 0.754 Example 8 10.09 0.759 Example 9 10.23 0.761 Example 10 9.12 0.743 Example 11 9.87 0.748 Comparative Example 1 13.85 0.770 Comparative Example 2 13.38 0.774

[0142] Table 2

[0143]

[0144]

[0145] From Tables 1 and 2:

[0146] (1) The color semi-transparent organic solar cells in Examples 1-5 have high current density, the microcavity structure is formed between the metal bottom electrode and the metal top electrode, the color semi-transparent organic solar cells can realize yellow, cyan, blue, purple or orange reflection chroma, the color semi-transparent organic solar cells have a semi-transparent appearance, meet the aesthetic needs of the public, and can be used for decorating buildings; at the same time, the color semi-transparent organic solar cells have low cost and similar current density to ITO solar cells under weak interference.

[0147] (2) From the comparison of Example 1 and Examples 6 and 7, it can be seen that the thickness of the active layer will affect the short-circuit current density, the open-circuit voltage and the transparency; when the thickness of the active layer is low, it will cause the Jsc to decrease, the Voc to decrease, and the transparency to increase, which is because the light absorption of the active layer is weakened, and at the same time the resonance wavelength is blue-shifted to outside the optimal absorption wavelength, resulting in a weak light field in the active layer, and the weak light intensity will simultaneously reduce the short-circuit current and the open-circuit voltage, and the weak active layer will result in a larger average light transmittance; when the thickness of the active layer is too high, it will cause the Jsc to decrease, the Voc to decrease, and the transparency to decrease, which is because the active layer is too thick, which will cause additional carrier recombination, and at the same time the resonance wavelength is too red-shifted, which is not conducive to the generation of excitons.

[0148] (3) By comparing Example 1 with Examples 8 and 9, it is found that the thickness of the first metal thin film affects the short-circuit current density, open-circuit voltage, reflective color and transparency; when the thickness of the first metal thin film is too low, it will result in the decrease of Jsc and Voc, because the too thin metal is mainly in island growth, thus a continuous thin film is not formed and the threshold film thickness for conduction is not reached, so the series resistance of the device is too high; when the thickness of the first metal thin film is too high, it will result in the decrease of Jsc and Voc, because the too thick metal will reduce the light transmittance and thus weaken the absorption of the active layer.

[0149] (4) By comparing Example 1 with Examples 10 and 11, it is found that the evaporation rate of the second metal affects the short-circuit current density, open-circuit voltage, reflective color and transparency; when the evaporation rate of the second metal is too low, it will result in the decrease of Jsc and Voc, because the too low rate for preparing ultra-thin metal cannot form a continuous thin film, resulting in the increase of the series resistance of the device and thus the decrease of Jsc and Voc; when the evaporation rate of the second metal is too high, it will result in the decrease of Jsc and Voc, because the increased roughness of the electrode is not conducive to the realization of ohmic contact.

[0150] (5) By comparing Example 1 with Comparative Examples 1 and 2, it is found that the color semi-transparent organic solar cell of the present application has low cost and similar current density to ITO solar cell, and the color semi-transparent organic solar cell can realize yellow, yellow, cyan, blue, purple or orange reflective color, and has a semi-transparent appearance.

[0151] In summary, the color semi-transparent organic solar cell of the present application can realize yellow, cyan, blue, purple or orange reflective color, and has a semi-transparent appearance, which meets the aesthetic needs of the public and can be used for decorating buildings; at the same time, the color semi-transparent organic solar cell has low cost and similar current density to ITO solar cell under weak interference; the preparation method of the color semi-transparent organic solar cell of the present application has simple steps, low cost of raw materials and strong controllability of process.

[0152] The above merely illustrates the specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and those skilled in the art should understand that any changes or replacements within the technical scope disclosed by the present application can be easily thought of by those skilled in the art, and all fall within the protection scope and disclosure scope of the present application.

Claims

1. A color semi-transparent organic solar cell, characterized by, The color semi-transparent organic solar cell comprises a metal bottom electrode, an electron transport layer, an active layer and a metal top electrode which are sequentially stacked; The metal bottom electrode comprises a light coupling layer, a first seed layer and a first metal thin film which are sequentially stacked; the light coupling layer is connected with a substrate, and the first metal thin film is connected with the electron transport layer; The light coupling layer is a MoO3 light coupling layer, a WO3 light coupling layer or a V2O5 light coupling layer; A microcavity structure is formed between the metal bottom electrode and the metal top electrode.

2. The colored semi-transparent organic solar cell according to claim 1, characterized in that, The thickness of the metal bottom electrode is 4-100 nm.

3. The colored semi-transparent organic solar cell according to claim 2, characterized in that, The thickness of the metal bottom electrode is 5-18 nm.

4. The colored semi-transparent organic solar cell according to claim 1, characterized in that, The thickness of the metal top electrode is 4-100 nm.

5. The colored semi-transparent organic solar cell according to claim 4, characterized in that, The thickness of the metal top electrode is 11-20 nm.

6. The colored semi-transparent organic solar cell according to claim 1, characterized in that, The thickness of the electron transport layer is 3-8 nm.

7. The colored semi-transparent organic solar cell according to claim 1, characterized in that, The thickness of the active layer is 50-200 nm.

8. The colored semi-transparent organic solar cell according to claim 7, characterized in that, The thickness of the active layer is 100-130 nm.

9. The colored semi-transparent organic solar cell according to claim 1, characterized in that, The color semi-transparent organic solar cell further comprises a substrate which is connected with the metal bottom electrode.

10. The colored semi-transparent organic solar cell according to claim 1, characterized in that, The thickness of the light coupling layer is 2-10 nm.

11. The colored semi-transparent organic solar cell according to claim 1, characterized in that, The thickness of the first seed layer is 0.5-2 nm.

12. The colored semi-transparent organic solar cell according to claim 1, characterized in that, The thickness of the first metal thin film is 4-30 nm.

13. The colored semi-transparent organic solar cell according to claim 1, characterized in that, The metal top electrode comprises a hole transport layer, a second seed layer and a second metal thin film which are sequentially stacked; the hole transport layer is connected with the active layer.

14. The colored semi-transparent organic solar cell according to claim 13, characterized in that, The thickness of the hole transport layer is 2-10 nm.

15. The colored semi-transparent organic solar cell according to claim 13, characterized in that, The thickness of the second seed layer is 0.5-2 nm.

16. The colored semi-transparent organic solar cell according to any one of claims 13-15, characterized in that, The thickness of the second metal thin film is 4-30 nm.

17. A method of producing a color semi-transparent organic solar cell according to any one of claims 1 to 16, characterized by, The preparation method comprises the following steps: (1) first evaporation to obtain a metal bottom electrode; (2) first coating of an electron transport material solution on the metal bottom electrode obtained in step (1) to obtain an electron transport layer; (3) second coating of an active material solution on the electron transport layer obtained in step (2) to obtain an active layer; (4) second evaporation on the active layer obtained in step (3) to obtain the color semi-transparent organic solar cell.

18. The method of claim 17, wherein, The first evaporation in step (1) comprises sequentially evaporating a first metal oxide, a first metal and a second metal on a substrate.

19. The method of claim 18, wherein, The evaporation rate of the first metal oxide is 20. The method of claim 18, wherein, The evaporation rate of the first metal is 21. The method of claim 18, wherein, The evaporation rate of the second metal is 22. The method of claim 17, wherein, The second evaporation in step (4) comprises sequentially evaporating a second metal oxide, a third metal and a fourth metal on the active layer.

23. The method of claim 22, wherein, The evaporation rate of the second metal oxide is 24. The method of claim 22, wherein, The evaporation rate of the third metal is 25. The preparation method according to claim 22, characterized in that, The evaporation rate of the fourth metal is 26. The method of claim 17, wherein, The second evaporation in step (4) comprises covering a mask on 10%-70% of the area of the surface of the active layer obtained in step (3).

27. The method of any one of claims 18-21, wherein, The material of the substrate comprises any one or a combination of at least two of glass, monocrystalline silicon, metal, plastic or ceramic.

28. The method of any one of claims 18-21, wherein, The first metal oxide comprises any one or a combination of at least two of MoO3, WO3 or V2O5.

29. The method of any one of claims 22-25, wherein, The second metal oxide comprises any one or a combination of at least two of MoO3, WO3 or V2O5.

30. The method of any one of claims 18-21, wherein, The first metal comprises any one or a combination of at least two of Ca, Al or Au.

31. The method of any one of claims 18-21, wherein, The second metal comprises any one or a combination of at least two of Au, Ag, Al or Cu.

32. The method of any one of claims 22-25, wherein, The third metal comprises any one or a combination of at least two of Ca, Al or Au.

33. The method of any one of claims 22-25, wherein, The fourth metal comprises any one or a combination of at least two of Au, Ag, Al or Cu.

34. The method of claim 17, wherein, The first coating in step (2) comprises spin coating in an inert atmosphere at a rotation speed of 1500-5500 rpm.

35. The method of claim 17, wherein the method is carried out at a temperature of about 20°C to about 30°C. The solute of the electron transport material solution in step (2) comprises PFN-Br, and the solvent comprises alcohol.

36. The method of claim 17, wherein the method is carried out at a temperature of about 20°C to about 30°C. The concentration of the solute in the electron transport material solution in step (2) is 0.5-2 mg / ml.

37. The method of claim 17, wherein the method is carried out at a temperature of about 20°C to about 30°C. The second coating in step (3) comprises spin coating in an inert atmosphere at a rotation speed of 1300-7000 rpm.

38. The method of claim 17, wherein the method is carried out at a temperature of about 20°C to about 30°C. The solute of the active material solution in step (3) comprises an active donor material and an active acceptor material.

39. The method of claim 38, wherein the method is performed in a single step. The mass ratio of the active donor material to the active acceptor material is (1-4):

3.

40. The method of claim 17, wherein, The concentration of the solute in the active material solution in step (3) is 20-40 mg / ml.

41. The method of claim 38 or 39, wherein, The active donor material comprises PTB7-Th.

42. The method of claim 38 or 39, wherein, The active acceptor material comprises PC71BM and / or IEICO-4F.

43. The method of claim 17, wherein the method is carried out at a temperature of about 20°C to about 30°C. The solvent of the active material solution comprises halogenated hydrocarbon.

44. The method of claim 17, wherein the method is carried out at a temperature of about 20°C to about 30°C. The preparation method comprises the following steps: (1) sequentially evaporating a first metal oxide on a substrate at a rate of , evaporating a first metal at a rate of , and evaporating a second metal at a rate of to obtain a metal bottom electrode; (2) in an inert atmosphere, spin coating an alcohol solution with a PFN-Br concentration of 0.5-2 mg / ml on the metal bottom electrode obtained in step (1) at a rotation speed of 1500-5500 rpm, to obtain an electron transport layer; (3) in an inert atmosphere, spin coating a halogenated hydrocarbon solution with a solute concentration of 20-40 mg / ml on the electron transport layer obtained in step (2) at a rotation speed of 1300-7000 rpm, wherein the solute in the halogenated hydrocarbon solution is a combination of an active donor material and an active acceptor material with a mass ratio of (1-4):3, to obtain an active layer; (4) covering the active layer surface with a mask on 10% to 70% of the area, and then evaporating a second metal oxide at a rate of , evaporating a third metal at a rate of , and evaporating a fourth metal at a rate of , to obtain a color semi-transparent organic solar cell.

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