Semitransparent color-changeable solar cell and preparation method thereof

Abstract

The invention relates to a semitransparent color-changeable solar cell and a preparation method thereof. The cell comprises the following modules which are stacked in sequence: a substrate; one or more photovoltaic modules, and one or more color changing modules. According to the technical scheme of the invention, the semitransparent solar cell can convert light energy into electric energy, and change of an absorption spectrum, namely photochromism, can be realized at the same time. In the embodiment of taking glass / ITO / PEDOT: PSS / PM6: Y6 / ZnO / BTE-CN / AgNWs: HPMC / ZnO as a device structure, 56.6% of average visible light transmittance can be maintained on the premise of realizing more than 5% of energy conversion efficiency, and the transmittance change exceeds 6% after complete color change. Meanwhile, compared with a standard device without a photochromic layer, the device with the structure can keep better anti-ultraviolet stability in the coloring-fading circulation process.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic cells, and in particular to a semi-transparent color-variable solar cell and a preparation method thereof. Background Art

[0002] Semi-transparent solar cells (ST-PV), including semi-transparent organic solar cells, semi-transparent perovskite solar cells, semi-transparent quantum dot solar cells, etc., have become strong competitors for building integrated photovoltaic applications due to their relatively excellent average visible light transmittance, energy conversion efficiency, solution processing and flexibility. In order to further reduce the energy consumption of building integrated photovoltaics, the emergence of smart windows provides a promising solution. For the development of smart windows, the color-changing and adaptive optical functions of the device are particularly important. Compared with the existing electrochromic integrated photovoltaic windows, color-changing photovoltaics integrate the two major features of color change and energy supply, reduce the manufacturing steps, simplify the component structure, and are the future development trend of photovoltaic building integration (BIPV). Since 2015, a few literatures have reported that diarylethenes and spiropyran derivatives have begun to be used as light-absorbing layers in dye-sensitized solar cells (DSSCs), achieving a PCE of nearly 4%, and the modulation threshold of semi-transparent devices for AVT is close to 30%. Compared with DSSCs, ST-PV is easier to make into all-solid-state planar batteries, achieving 100% active area coverage; secondly, the color-changing molecules have more options for different functional layers in the ST-PV device structure, while the materials of DSSCs except for the sensitizing layer are basically fixed, making research and development more difficult.

[0003] Recently, Demadrille et al. used photochromic dye molecules as sensitizing layer materials to combine color change and photovoltaics. The cell can adaptively adjust transparency according to changes in external light intensity while generating electricity, and has relatively excellent performance (Huaulmé Q, Mwalukuku VM, Joly D, et al. Photochromic dye-sensitized solar cells with light-driven adjustable optical transmission and power conversion efficiency. Nat. Energy, 2020, 5, 468-477; Joly D, Kervella Y, Demadrille R. Organic photochromic dye and uses thereof for dye sensitized solar cells. EP2018063208W, 2018).

[0004] However, since high-efficiency DSSCs usually require the use of liquid electrolytes, they are less stable and have higher maintenance costs than solid-state batteries. In addition, the structure of DSSCs devices is relatively simple, and the types of color-changing units are relatively small, which is limited to the research and development of electrodes and sensitizing layer materials. For high-efficiency sensitizing layer materials, the synthesis process is complicated; for electrode modification, the thickness of the mesoporous electrode and the position and thickness of the color-changing coating attached to the electrode need to be reasonably controlled. The manufacturing process is relatively complicated and is not suitable for large-scale application of color-changing photovoltaic technology, such as integration on glass curtain walls or agricultural greenhouses. Summary of the invention

[0005] In view of the above problems of the prior art, in order to produce a high-efficiency, all-solid-state, color-changing semi-transparent solar cell, the applicant has conducted repeated experiments and obtained a semi-transparent color-changing solar cell with high efficiency and stability, and completed the present invention on this basis.

[0006] According to one aspect of the present invention, there is provided

[0007] A semi-transparent color-changing solar cell, characterized in that the cell comprises the following modules stacked in sequence:

[0008] a substrate, transparent and insulating, configured as a support material on one side of which the solar cell is deposited;

[0009] One or more photovoltaic modules, each photovoltaic module comprising a transparent electrode layer 1, a photovoltaic functional layer and a transparent electrode layer 2, located on one side of the substrate, wherein the photovoltaic functional layer is configured to absorb light energy to generate carriers 1 and carriers 2 with different electrical properties, and to make the carriers 1 and the carriers 2 migrate to the transparent electrode layer 1 and the transparent electrode layer 2 respectively;

[0010] One or more color-changing modules, each composed of a photochromic layer, are located between photovoltaic modules, on one side of a photovoltaic module, or in a photovoltaic module, and are configured to absorb light energy to cause a change in a spectral absorption peak position or peak intensity.

[0011] By using the organic solar cell with the above structure, it is possible to achieve a change in the absorption spectrum while converting light energy into electrical energy, i.e., photochromism occurs. For example, in an embodiment with glass / ITO / PEDOT:PSS / PM6:Y6 / ZnO / BTE-CN / AgNWs:HPMC / ZnO as the device structure, an average visible light transmittance of 56.6% can be maintained while achieving an energy conversion efficiency of more than 5%, thereby meeting the needs of various smart windows and still achieving photovoltaic applications.

[0012] According to one embodiment of the present invention, when the color-changing module is located in a photovoltaic module, the photochromic layer is located between the transparent electrode layer 1 and the photovoltaic functional layer, or between the transparent electrode layer 2 and the photovoltaic functional layer, and the photochromic layer is configured to absorb light energy to cause a change in the position or peak intensity of the spectral absorption peak, and at the same time be able to transmit carriers from the photovoltaic functional layer.

[0013] According to one embodiment of the present invention, the photovoltaic functional layer comprises a photoactive layer and an optional transport layer, wherein the photoactive layer is configured to absorb light energy to generate carriers, and in the case where a transport layer is present, the transport layer comprises only the transport layer 1, or only the transport layer 2, or both the transport layer 1 and the transport layer 2.

[0014] The transmission layer 1 and the transmission layer 2 are respectively located on both sides of the photoactive layer and are configured to transfer carriers 1 and carriers 2 respectively.

[0015] According to one embodiment of the present invention, the photoactive layer includes or is selected from an organic semiconductor photoactive layer, a perovskite photoactive layer, a quantum dot photoactive layer, and a dye-sensitized cell sensitizing layer.

[0016] According to one embodiment of the present invention, when a plurality of photovoltaic modules are included, the plurality of photovoltaic modules are stacked.

[0017] According to one embodiment of the present invention, the solar cell is a flexible solar cell, wherein the flexible solar cell is made by stacking a flexible substrate, a photovoltaic module and a color-changing module in sequence.

[0018] According to one embodiment of the present invention, after the photochromic layer absorbs ultraviolet or visible light, the absorption peak position or peak intensity in the spectrum changes, resulting in a change in the CIE value of its color coordinates.

[0019] According to the present invention, based on an embodiment of a device structure of glass / ITO / PEDOT:PSS / PM6:Y6 / ZnO / BTE-CN / AgNWs:HPMC / ZnO, the semi-transparent color-changing organic solar cell can achieve an energy conversion efficiency of more than 5% when the color change degree ΔT>6%, wherein the color change degree is calculated by the following method:

[0020] (1) Coloring: UV light source with a wavelength less than 400 nm and an irradiation intensity higher than 10 mW cm -2 The light is irradiated for more than 200 seconds in a nitrogen or air atmosphere to illuminate the translucent device so that the device reaches the maximum degree of coloring;

[0021] (2) Fading: a) anneal the device on a hot plate at 30-80°C for 0.5-60 min, or b) use a wavelength of 550-780 nm and an irradiation intensity of 10-100 mW cm -2 The device will fade if the light is irradiated for more than 3 minutes; c) Place it at night without natural lighting conditions;

[0022] The transmittance T1 of the device colored according to the method (1) and the transmittance T2 of the device faded according to the method (2) are measured, and the difference between the transmittance T1 and the transmittance T2 is taken as ΔT, and ΔT max This means that ΔT reaches its maximum value in the visible light region.

[0023] The energy conversion efficiency is calculated by the following method:

[0024] The energy conversion efficiency was measured using a AAA-level solar simulator in conjunction with a Keithley 2400 digital source meter according to the JB / T9478.3-1999 test method.

[0025] According to one embodiment of the present invention, the semi-transparent color-changing organic solar cell can maintain more than 60% of the energy conversion efficiency and color change degree ΔT before the cycle after 10 coloring / fading cycles.

[0026] According to one embodiment of the present invention,

[0027] The material of the transparent electrode layer 1 is selected from indium tin oxide, fluorine-doped tin oxide, aluminum-doped zinc oxide and a combination thereof;

[0028] The material of the transmission layer 1 is selected from poly (3,4-ethylenedioxythiophene:polystyrene sulfonate) (PEDOT:PSS), nickel oxide, tungsten oxide, molybdenum trioxide, titanium dioxide, vanadium pentoxide and combinations thereof;

[0029] The photoactive layer material is selected from PM6:ITIC, PM6:Y6, PM6:BTP-eC9, PCE10:IEICO-4F, D18:L8-BO and other donors and combinations thereof;

[0030] The material of the transmission layer 2 is selected from ZnO, SnO 2 , PDINO, PDINN, PFN-Br and combinations thereof;

[0031] The transparent electrode layer 2 is made of a material selected from AgNWs, PH1000, AgNWs:HPMC, PH1000:AgNWs and combinations thereof.

[0032] The photochromic material is selected from BTE-CN and BTE units with different end groups of electron-withdrawing groups, wherein the different electron-withdrawing groups include -Cl, -F, -COOH, -SO 2 H, -CF 3 or-NO 2 .

[0033] According to one embodiment of the present invention,

[0034] The material of the transparent electrode layer 1 is indium tin oxide;

[0035] The material of the transmission layer 1 is poly (3,4-ethylenedioxythiophene): polystyrene sulfonate) PEDOT:PSS;

[0036] The photoactive layer material is PM6:Y6;

[0037] The material of the transmission layer 2 is ZnO;

[0038] The transparent electrode layer 2 is made of AgNWs:HPMC.

[0039] The photochromic component is made of BTE-CN.

[0040] According to another aspect of the present invention, a method for preparing a semi-transparent color-variable organic solar cell is provided, comprising:

[0041] One or more photovoltaic modules including or not including a color-changing module are sequentially prepared on a substrate, wherein the photovoltaic module including the color-changing module is prepared by one of the following methods a to d, and the photovoltaic module not including the color-changing module is prepared by the following method e:

[0042] Method a:

[0043] a1) preparing a transparent electrode layer 1;

[0044] a2) preparing a photovoltaic functional layer on the transparent electrode layer 1;

[0045] a3) preparing a photochromic layer above the photovoltaic functional layer;

[0046] a4) preparing a transparent electrode layer 2 on the photochromic layer,

[0047] Or, method b:

[0048] b1) preparing a transparent electrode layer 1;

[0049] b2) preparing a photochromic layer on the transparent electrode layer 1;

[0050] b3) preparing a photovoltaic functional layer above the photochromic layer;

[0051] b4) preparing a transparent electrode layer 2 on the photovoltaic functional layer,

[0052] Or, method c:

[0053] c1) preparing a transparent electrode layer 1;

[0054] c2) preparing a photovoltaic functional layer on the transparent electrode layer 1;

[0055] c3) preparing a transparent electrode layer 2 on the photovoltaic functional layer,

[0056] c4) preparing a photochromic layer on the transparent electrode layer 2,

[0057] Or, method d:

[0058] d1) preparing a photochromic layer;

[0059] d2) preparing a transparent electrode layer 1 on the photochromic layer;

[0060] d3) preparing a photovoltaic functional layer on the transparent electrode layer 1;

[0061] d4) preparing a transparent electrode layer 2 on the photovoltaic functional layer,

[0062] Method e:

[0063] e1) preparing a transparent electrode layer 1;

[0064] e2) preparing a photovoltaic functional layer on the transparent electrode layer 1;

[0065] e3) preparing a transparent electrode layer 2 on the photovoltaic functional layer.

[0066] According to one embodiment of the present invention,

[0067] In method a to method e, the preparation of the photovoltaic functional layer comprises:

[0068] m1) preparing a transmission layer 1,

[0069] m2) preparing a photoactive layer on the transmission layer 1;

[0070] Or include:

[0071] n1) preparing a transport layer 1,

[0072] n2) preparing a photoactive layer on the transmission layer 1;

[0073] n3) preparing a transmission layer 2 on the photoactive layer;

[0074] Or include:

[0075] p1) preparing a photoactive layer;

[0076] p2) Providing a transport layer 2 on the photoactive layer.

[0077] According to one embodiment of the present invention,

[0078] When a plurality of the photovoltaic modules are prepared on a substrate, the plurality of photovoltaic modules are stacked. According to one embodiment of the present invention,

[0079] The substrate is a flexible substrate, and the photovoltaic module with or without a color-changing module is a flexible module.

[0080] According to one embodiment of the present invention, the method comprises:

[0081] S1) preparing a transparent electrode layer 1 on a substrate;

[0082] S2) cleaning the transparent electrode layer 1 and performing oxygen plasma treatment;

[0083] The cleaning treatment includes ultrasonic cleaning with a surfactant and a detergent;

[0084] S3) diluting the transmission material 1 with a diluent, and spin coating the diluent on the transparent electrode layer 1 after the treatment in step S2), thereby forming a transmission layer 1 on the treated transparent electrode layer 1;

[0085] S4) diluting the photoactive material with a diluent and spin coating the diluent on the transport layer 1 in step S3) to prepare a photoactive layer;

[0086] S5) spin coating the transport material 2 on the product of step S4), thereby further preparing a transport layer 2 on the product of step S4);

[0087] S6) diluting the photochromic material with a diluent and spin coating the diluent on the transmission layer 2 in step S5) to prepare a photochromic layer;

[0088] S7) Spin-coating the transparent electrode material 2 on the photochromic layer in step S6) to obtain a transparent electrode layer 2; thereby finally obtaining a semi-transparent color-changing solar cell.

[0089] According to one embodiment of the present invention,

[0090] The oxygen plasma treatment in step S1) can be carried out by a conventional oxygen plasma treatment method. For example, the oxygen plasma treatment includes placing the sample in a Harrick plasma surface treatment chamber, evacuating the chamber for 1 to 2 minutes, then reducing the pressure to below 200 mbar, and selecting a mid-range power (10.5 W) for oxygen plasma treatment for 2 to 5 minutes.

[0091] According to one embodiment of the present invention,

[0092] The material of the transparent electrode layer 1 is selected from indium tin oxide, fluorine-doped tin oxide, aluminum-doped zinc oxide and a combination thereof;

[0093] The material of the transmission layer 1 is selected from poly (3,4-ethylenedioxythiophene:polystyrene sulfonate) (PEDOT:PSS), nickel oxide, tungsten oxide, molybdenum trioxide, titanium dioxide, vanadium pentoxide and combinations thereof;

[0094] The photoactive layer material is selected from PM6:ITIC, PM6:Y6, PM6:BTP-eC9, PCE10:IEICO-4F, D18:L8-BO and other donors and combinations thereof;

[0095] The material of the transmission layer 2 is selected from ZnO, SnO 2 , PDINO, PDINN, PFN-Br and combinations thereof;

[0096] The transparent electrode layer 2 is made of a material selected from AgNWs, PH1000, AgNWs:HPMC, PH1000:AgNWs and combinations thereof.

[0097] The photochromic component is made of BTE-CN.

[0098] According to one embodiment of the present invention,

[0099] The material of the transparent electrode layer 1 is indium tin oxide;

[0100] The material of the transmission layer 1 is poly (3,4-ethylenedioxythiophene): polystyrene sulfonate) PEDOT:PSS;

[0101] The photoactive layer material is PM6:Y6;

[0102] The material of the transmission layer 2 is ZnO;

[0103] The transparent electrode layer 2 is made of AgNWs:HPMC.

[0104] The photochromic component is made of BTE-CN.

[0105] Beneficial Effects

[0106] The preparation of all-solid-state, color-changing solar cells can be easily achieved through laboratory spin coating process. The semi-transparent color-changing solar cells based on the structure of glass / ITO / PEDOT:PSS / PM6:Y6 / ZnO / BTE-CN / AgNWs:HPMC / ZnO can maintain an average visible light transmittance of 56.6% while achieving an energy conversion efficiency of more than 5%, and the transmittance change after complete color change exceeds 6%. During the coloring-fading cycle, it can maintain better stability than standard devices, and the efficiency and color change degree can maintain more than 60% of the original device after more than 10 cycles. This invention can provide reference and reference for the simple preparation and application of all-solid-state, high-efficiency, color-changing semi-transparent solar cells, and can be used as a potential implementation method for the future development of smart windows.

[0107] 1. Compared with color-changing DSSCs, all-solid-state color-changing solar cells are realized, and the energy conversion efficiency is improved;

[0108] 2. Secondly, as a solid color-changing film, it has excellent stability. Based on the mature manufacturing process, it can ensure high repeatability of batches;

[0109] 3. Prior to the present invention, there has been no report on the use of the photochromic behavior of this type of molecules as a transport layer to prepare semi-transparent, all-solid-state organic solar cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0110] Figure 1 The schematic diagram of the structure of a typical semi-transparent, color-changeable organic solar cell of the present invention is shown.

[0111] Figure 2A schematic diagram of the structure of a semi-transparent, color-changeable organic solar cell comprising a plurality of photovoltaic modules arranged in a stacked manner is shown.

[0112] Figure 3 A schematic diagram showing the color change of the color change module.

[0113] Figure 4 Schematic diagram of the structure of a semi-transparent, color-changeable organic solar cell with a specific composition according to an embodiment of the present invention.

[0114] Figure 5 This is the JV curve of the semi-transparent full device after coloring prepared by the BTE-CN layer with a thickness of 13 nm in Example 1 of the present invention.

[0115] Figure 6 This is the A / T / R spectrum of the semi-transparent full device after coloring prepared with a BTE-CN layer with a thickness of 13 nm in Example 1 of the present invention.

[0116] Figure 7 This is the EQE curve of the semi-transparent full device after coloring, prepared with a BTE-CN layer with a thickness of 13 nm in Example 1 of the present invention.

[0117] Figure 8 This is the JV curve of the semi-transparent full device after fading prepared with a BTE-CN layer with a thickness of 13 nm in Example 1 of the present invention.

[0118] Fig. 9 This is the A / T / R spectrum of the semi-transparent full device after fading, prepared with a BTE-CN layer with a thickness of 13 nm in Example 1 of the present invention.

[0119] Fig.10 This is the EQE curve of the semi-transparent full device after fading, prepared with a BTE-CN layer with a thickness of 13 nm in Example 1 of the present invention.

[0120] Fig.11 These are the change values ​​of various device performance parameters during the coloring / fading process of the semi-transparent full device prepared with a BTE-CN layer with a thickness of 13 nm in Example 1 of the present invention.

[0121] Fig.12 The A / T / R spectral changes during the coloring / fading process of the semi-transparent full device prepared with a BTE-CN layer with a thickness of 13 nm in Example 1 of the present invention (A increases, T and R decrease).

[0122] Fig.13 This is the transmittance difference spectrum (the maximum value of the characteristic peak intensity observed) during the coloring / fading process of the semi-transparent full-device prepared with a BTE-CN layer with a film thickness of 13 nm in Example 1 of the present invention.

[0123] Fig.14The semi-transparent device prepared with a BTE-CN layer with a thickness of 13 nm in this embodiment was subjected to 10 coloring / fading cycles, and the change of the peak value at a wavelength of 460 nm was monitored.

[0124] Fig.15 The photovoltaic parameters V of the semi-transparent device prepared with a 13 nm thick BTE-CN layer in this example and the standard device during 10 coloring / fading cycles oc / J sc Changes to / FF / PCE.

[0125] Fig.16 These are the change values ​​of various device performance parameters during the coloring / fading process of the semi-transparent full device prepared with a BTE-CN layer with a thickness of 22 nm in this embodiment.

[0126] Fig.17 The A / T / R spectral changes during the coloring / fading process of the semi-transparent full-device prepared with a BTE-CN layer with a thickness of 22 nm in this embodiment (A increases, T and R decrease).

[0127] Fig.18 This is the EQE curve of the semi-transparent full-device after coloring prepared with a BTE-CN layer with a thickness of 22 nm in this embodiment.

[0128] Fig.19 This is the transmittance difference spectrum (the maximum value of the characteristic peak intensity is observed) during the coloring / fading process of the semi-transparent full-device prepared with a BTE-CN layer with a film thickness of 22 nm in this embodiment.

[0129] Fig. 20 The semi-transparent device prepared with a BTE-CN layer with a thickness of 22 nm in this embodiment was subjected to 10 coloring / fading cycles, and the change of the peak value at a wavelength of 460 nm was monitored.

[0130] Fig.21 The photovoltaic parameters V of the semi-transparent device prepared with a 22 nm thick BTE-CN layer in this example and the standard device during 10 coloring / fading cycles oc / J sc Changes to / FF / PCE. DETAILED DESCRIPTION

[0131] In order to enable persons with ordinary knowledge in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in the specification and the scope of the patent application. Unless otherwise specified, all technical and scientific words used in the text have the common meanings understood by those skilled in the art for the present invention. In case of conflict, the definitions in this specification shall prevail.

[0132] refer to Figure 1According to one embodiment of the present invention, there is provided a semi-transparent color-variable solar cell (10), characterized in that the cell comprises the following modules stacked in sequence:

[0133] A substrate (100), which is transparent and insulating, is configured as a support material, on one side of which the solar cell is deposited;

[0134] One or more photovoltaic modules 140 ( Figure 1 In the case of a photovoltaic module, each photovoltaic module comprises a transparent electrode layer 1 (110), a photovoltaic functional layer (120) and a transparent electrode layer 2 (130), which are located on one side of the substrate, wherein the photovoltaic functional layer (120) is configured to absorb light energy to generate carriers 1 and carriers 2 with different electrical properties, and to make the carriers 1 and the carriers 2 migrate to the transparent electrode layer 1 (110) and the transparent electrode layer 2 (120), respectively;

[0135] One or more color-changing modules ( Figure 1 Not shown), each color-changing module is composed of a photochromic layer and is located between photovoltaic modules and on one side of the photovoltaic module ( Figure 1 ① or ④ in the middle), or in the photovoltaic module ( Figure 1 ② or ③ in the figure), and is configured to absorb light energy to cause a change in the position or peak intensity of the spectral absorption peak.

[0136] According to one embodiment of the present invention, the color-changing module is located in the photovoltaic module ( Figure 1 When the color-changing module is at position ② or ③ in the middle), in addition to the original color-changing module function (absorbing light energy to cause a change in the position or peak intensity of the spectral absorption peak), the color-changing module can also transmit carriers from the photovoltaic functional layer (120).

[0137] like Figure 1 As shown, according to one embodiment of the present invention, the photovoltaic functional layer (120) may include a transmission layer 1 (121), a photoactive layer (122) and a transmission layer 2 (123).

[0138] The photovoltaic functional layer (120) may not include the transmission layer 1 (121), or may not include the transmission layer 2 (123), or may not include both.

[0139] like Figure 2 As shown, according to one embodiment of the present invention, the semi-transparent color-changing solar cell (20) comprises a plurality of photovoltaic modules (240a, 240b, ...) arranged in layers. In this case, the color-changing module can be located between the photovoltaic modules (as shown in the position ① in the figure), or can be located on one side of the photovoltaic module (as shown in the position ④ in the figure), or located in the photovoltaic module (as shown in the position ② or ③ in the figure). Other components in the photovoltaic module are Figure 1The situation is the same / similar to that in , and will not be described in detail here.

[0140] Without affecting the performance of the solar cell, the semi-transparent color-changing solar cell of the present invention may include a plurality of color-changing modules.

[0141] Figure 3 Schematic diagram showing the color change of the color change module of the present invention. Figure 3 As shown, the color-changing module 150 can change color in ultraviolet light / visible light and visible light / dark state. Specifically, the color-changing module 150 changes color (such as coloring) under light, and changes color again (such as fading) after being out of light. In other words, the color-changing module 150 can absorb light energy to cause a change in the position or peak intensity of the spectral absorption peak, and the change is reversible.

[0142] Preferred Embodiments

[0143] Preparation of semi-transparent organic photoluminescent materials

[0144] The high-transmittance and low-resistance ITO glass after etching is cleaned and the surface wettability is improved by oxygen plasma treatment;

[0145] The PEDOT:PSS stock solution was diluted with deionized water to a concentration range of 10% to 100%, and the hole transport layer was prepared at a spin coating speed of 2000-5000 r / min;

[0146] The organic semiconductor photoactive layer was prepared at a spin coating speed of 2000-5000 r / min, and the total concentration of the PM6:Y6 mixed solution was 3-30 mg / mL;

[0147] Preparation of PDINO, ZnO nanocrystals, ZnO nanoparticles, TiO 2 For dense thin films and other electron transport layers, a precursor solution such as ZnO is coated at a spin coating speed of 1000-5000 mm / min, and the solution concentration is 5-50 mg / mL;

[0148] Prepare a BTE-CN molecular solution with a concentration of 1-30 mg / mL and apply it at a spin coating speed of 1000-5000 mm / min;

[0149] Finally, the semi-transparent device uses a mixed solution of AgNWs and HPMC as the counter electrode. The total concentration of the solution is 0.5-10 mg / mL, and the mixing ratio of AgNWs and HPMC is 8:1-1.25:1. One to five layers of the mixed solution are coated at a spin coating speed of 500-5000 mm / min, and ZnO is coated on the electrode at a spin coating speed of 1000-5000 mm / min to complete the preparation of the semi-transparent device.

[0150] The energy conversion efficiency of the color-changing, semi-transparent organic solar cell device prepared based on the technology of the present invention and based on the device structure of glass / ITO / PEDOT:PSS / PM6:Y6 / ZnO / BTE-CN / AgNWs:HPMC / ZnO exceeds 5%, the average visible light transmittance exceeds 55%, and the light utilization rate exceeds 2.85%. More specifically, the energy conversion efficiency of the standard device made therefrom exceeds 6%, the average visible light transmittance exceeds 55%, and the light utilization rate is close to 3.4%.

[0151] After the color change is triggered by ultraviolet light, the transmittance of the device in the visible light region changes by more than 6%, the color coordinates are closer to AM1.5G (0.332, 0.344), the color temperature is reduced, and the efficiency is increased to 1.05 times the original. After 10 cycles in the coloring-fading process, it can maintain more than 60% of the original efficiency and color change degree.

[0152] The present invention will be further described below by way of examples, but the following examples are for illustrative purposes only and are not intended to limit the present invention.

[0153] Example

[0154] Example 1

[0155] (1) Synthesis of diarylethene derivatives BTE-CN

[0156] N 2 Under the conditions, 4,4-(cyclopentadiene-1-ene-1,2-foraminated)bis(5-methylthiophene-2-carboxaldehyde) (110.6 mg, 0.35 mmol) and malononitrile (369.6 mg, 5.6 mmol) were dissolved in 5 mL of anhydrous ethanol, and 0.1 mL of a saturated potassium carbonate solution was added at low temperature. After returning to room temperature, the mixture was stirred at 80°C for 4 hours. After the reaction solution cooled to room temperature, the crude product was filtered and rinsed with anhydrous ethanol several times to obtain a brown solid powder (90.6 mg, 62.8%).

[0157] 1. 1 H-NMR (500MHz, CDCl 3 )δ2.10-2.18(m,8H),2.82(t,d=7.51,4H),7.40(s,2H),7.63(s,2H).

[0158] 2.HRMS(MALDI-TOF)m / z:Calcd for C 23 H 16 N 4 S 2 (M+Na):435.08,Found:435.04.

[0159] 3. The LUMO energy level of BTE-CN in the fully open-ring state was measured by cyclic voltammetry (CV) to be -3.30eV, the HOMO energy level to be -5.90eV, and the corresponding electrochemical band gap to be 2.60eV; while the LUMO energy level of BTE-CN in the photostable state was -4.02eV, the HOMO energy level to be -5.43eV, and the corresponding electrochemical band gap to be 1.41eV. Using UV-visible absorption spectroscopy to test the film state, the characteristic absorption peak of BTE-CN in the fully open-ring state was located at 396nm, the absorption band edge was at 458nm, and the optical band gap was 2.70eV. The characteristic absorption peak of BTE-CN in the photostable state was located at 761nm, the absorption band edge was at 914nm, and the optical band gap was 1.36eV.

[0160] (2) Configuration of each functional layer solution

[0161] 1. Prepare a PEDOT:PSS (Al 4083) diluted solution (solid content of about 0.7-0.8 wt%) using deionized water as a hole transport layer material;

[0162] 2. Accurately weigh PM6:Y6 with a weight ratio of 1:1.2 and dissolve it in chloroform. The total concentration of the solution is 8.5 mg / mL. Place the mixed solution in a glove box and stir it at 55°C for 1 hour. Then add 0.5% CN additive and mix well for use as the photoactive layer material;

[0163] 3. ZnO nanoparticles were dispersed in n-butanol and a small amount of chloroform to prepare a mixed solution with a concentration of 10 mg / ml, and filtered through a 0.45 μm polytetrafluoroethylene membrane for use as an electron transport layer material;

[0164] 4. Prepare a 5 mg / mL BTE-CN acetonitrile solution. Before spin coating, the sample solution needs to be aged at 60°C for 10 min to ensure good dissolution and recovery to a fully open-ring state. The obtained film thickness is about 13 nm.

[0165] 5. The AgNWs stock solution (10 mg / mL) was dispersed in deionized water to prepare a 5 mg / mL aqueous suspension, and the cathode layer material was further prepared.

[0166] (3) Preparation of semi-transparent organic color-changing photovoltaics

[0167] After ITO was cleaned and dried, it was surface treated in an oxygen plasma environment. PEDOT:PSS (hole transport layer) was spin-coated at 4000r / min for 30s and annealed at 150°C for 5min. The device was then transferred into a glove box and a PM6:Y6 mixed solution (active layer) was spin-coated on the PEDOT:PSS layer at 3700r / min for 25s and annealed at 80°C for 5min. Next, a layer of ZnO (electron transport layer) was first coated on the active layer at 4000r / min, and then BTE-CN (photochromic layer) of different thicknesses was spin-coated at 3000r / min. The solution concentration of the BTE-CN layer was 5mg / mL, resulting in a thickness of about 13nm.

[0168] Semi-transparent device electrode: Four layers of AgNWs:HPMC were spin-coated on the BTE-CN layer (or ZnO layer) at a speed of 2500 r / min as the cathode, and then a layer of ZnO was coated on the top electrode at a speed of 4000 r / min to complete the preparation of the semi-transparent organic solar cell. The structure of the semi-transparent organic solar cell is as follows Figure 4 shown.

[0169] Embodiment 2-4

[0170] A semi-transparent organic solar cell was prepared in the same manner as in Example 1, except that in "4. Prepare a BTE-CN acetonitrile solution with a concentration of 5 mg / mL" in (2) the configuration of each functional layer solution, the concentration of 8, 10, and 15 mg / mL was used instead of 5 mg / mL, and the solution was used in (3) the preparation of a semi-transparent organic color-changing photovoltaic. The thickness of the BTE-CN layer showed a good linear relationship with the concentration of its solution, and when the concentration of the solution was adjusted to 8, 10, and 15 mg / mL, the thickness of about 22, 29, and 46 nm could be obtained.

[0171] Comparative Example 1

[0172] The semi-transparent organic solar cell of Comparative Example 1 was prepared in the same manner as described in Example 1, except that in the preparation of (3) semi-transparent organic color-changing photovoltaics, a layer of ZnO (electron transport layer) was first coated on the active layer at a rotation speed of 4000 r / min and then a layer of ZnO was continuously coated.

[0173] Experimental Example 1: Color change behavior and device characterization of semi-transparent organic solar cells

[0174] A solar simulator (Newport, M94043A) was used to simulate AM1.5G, 100 mW cm -2The photovoltaic performance of the cell was tested in the light environment with the help of Keithley 2400 digital source meter to obtain the JV curve of the cell. During the test, the test area was controlled to 0.03 cm using a mask. 2 , and then obtain an accurate JV curve. The external quantum efficiency (EQE) of the device in Example 1 was characterized using Newport's fully integrated quantum efficiency measurement instrument (Quantx-300). Before testing, the light spot of Quanx-300 was narrowed and calibrated using a standard silicon cell. A UV-vis-NIR spectrophotometer was used to characterize the A / T / R spectrum of the device or film, with a wavelength scanning range of 300 to 1100 nm.

[0175] 1. The wavelength is 365nm and the irradiation intensity is 136.94mW cm -2 The light triggers the closed-loop coloring of BTE-CN molecules. The irradiation height is 1 cm and the irradiation time is 240 s. The semi-transparent device is illuminated in a nitrogen atmosphere to achieve the maximum coloring of the device. The JV curve of the whole device of Example 1 is tested and the energy conversion efficiency PCE, A / T / R spectrum and external quantum efficiency EQE are calculated; the results are listed in Figure 5-7 middle.

[0176] 2. Place the colored device on a hot plate at 80°C for 2 minutes to accelerate fading or use a wavelength of 650nm and an irradiation intensity of 91.16mW cm -2 The light triggered the ring-opening and fading of BTE-CN molecules, the irradiation height was 1 cm, and the irradiation time was 30 min. The JV curve of the whole device of Example 1 after fading was tested again, and the energy conversion efficiency PCE, A / T / R spectrum and external quantum efficiency EQE were calculated; the results are listed in Figure 8-10 middle.

[0177] Summarize the results from step 1 / 2 into Figure 11-13 In the process of coloration / fading, the changes of various parameters of PCE and A / T / R spectrum of the whole device are observed.

[0178] from Figure 5-Figure 13 The results show that after the device is completely colored by UV irradiation, V oc Reduced, J sc The integrated current value calculated from the EQE curve can be well matched with the J obtained from the JV curve. sc The maximum change in the transmittance of the device in the visible light region before and after coloring reaches 6.10%.

[0179] Experimental Example 2: Characterization of fatigue resistance of semi-transparent organic color-changing photovoltaics

[0180] 1 / 2 of the steps in Example 1 of the experiment were repeated to draw a curve of the energy conversion efficiency PCE and the transmittance at a specific wavelength during the coloring / fading process of the semi-transparent device; the results are listed in Figure 14-15 middle.

[0181] from Figure 14-15 The results show that in the fatigue resistance test, the color change degree and photoelectric performance of the color-changing photovoltaic can maintain more than 60% of the initial state after 10 cycles, and it has stronger UV stability than standard devices.

[0182] This embodiment adopts the spin coating method to prepare a high-quality film layer on a hard or flexible substrate to obtain a semi-transparent device, such as Figure 4 The PCE of the semi-transparent device prepared with BTE-CN film as the photochromic layer after coloring reaches 5.24%, which is an improvement over the performance of the device after fading, which is 5.04%, as reflected in J sc and the rise of FF, such as Figure 5 , 8 and 11. After coloring, the semi-transparent device prepared with BTE-CN film as the photochromic layer has a lower AVT than that after fading, and the maximum ΔT reaches 6.10%, as shown in Figure 6 , 9 and 13. The EQE integrated current of the semi-transparent device prepared with BTE-CN film as the photochromic layer increased after coloring compared with that after fading, which is well matched with the JV test results, such as Figure 7 and 10 The semi-transparent device prepared with BTE-CN film as the photochromic layer can still maintain more than 60% of the color changing ability after 10 coloring / fading cycles. Fig.14 The semi-transparent device made of BTE-CN film as the photochromic layer still maintains a PCE of more than 60% after 10 coloring / fading cycles, and has better stability than the standard device. Fig.15 .

[0183] Experimental Example 3: Color change behavior and device characterization of semi-transparent organic solar cells

[0184] Referring to the method similar to that in Experimental Examples 1-2, the energy conversion efficiency PCE, A / T / R spectrum and external quantum efficiency EQE of the whole device of Example 2 (wherein the thickness of the BTE-CN layer is about 22 nm) before and after coloring / fading were tested; the results are listed in Figure 16-19 middle.

[0185] from Figure 16-Figure 19 The results show that after the device is completely colored by UV irradiation, V ocReduced, J sc The integrated current value calculated from the EQE curve can be well matched with the J obtained from the JV curve. sc The maximum change in the transmittance of the device in the visible light region before and after coloring reaches 6.81%.

[0186] Experimental Example 4: Characterization of fatigue resistance of semi-transparent organic color-changing photovoltaics

[0187] Plot the change curve of energy conversion efficiency PCE and transmittance at specific wavelength during the coloring / fading process of semi-transparent devices; the results are listed in Figure 20-21 middle.

[0188] from Figure 20-21 It can be seen from the results of the fatigue resistance test that the color change degree of the color-changing photovoltaic can maintain about 40% of the initial state after 10 cycles, and the photoelectric performance drops to about 60% of the initial state.

Claims

1. A semi-transparent color-changing solar cell, It is characterized in that The battery comprises the following modules stacked in sequence: a substrate, transparent and insulating, configured as a support material on one side of which the solar cell is deposited; One or more photovoltaic modules, each photovoltaic module comprising a transparent electrode layer 1, a photovoltaic functional layer and a transparent electrode layer 2, located on one side of the substrate, wherein the photovoltaic functional layer is configured to absorb light energy to generate carriers 1 and carriers 2 with different electrical properties, and to make the carriers 1 and the carriers 2 migrate to the transparent electrode layer 1 and the transparent electrode layer 2 respectively; One or more color-changing modules, each composed of a photochromic layer, are located between photovoltaic modules, on one side of a photovoltaic module, or in a photovoltaic module, and are configured to absorb light energy to cause a change in a spectral absorption peak position or peak intensity.

2. The semi-transparent color-changing solar cell according to claim 1, It is characterized in that When the color-changing module is located in a photovoltaic module, the photochromic layer is located between the transparent electrode layer 1 and the photovoltaic functional layer, or between the transparent electrode layer 2 and the photovoltaic functional layer, and the photochromic layer is configured to absorb light energy to cause a change in the position or peak intensity of the spectral absorption peak, while being able to transmit carriers from the photovoltaic functional layer.

3. The semi-transparent color-changing solar cell according to claim 1, It is characterized in that The photovoltaic functional layer comprises a photoactive layer and an optional transport layer, wherein the photoactive layer is configured to absorb light energy to generate carriers, and in the case where a transport layer is present, the transport layer comprises only the transport layer 1, or only the transport layer 2, or both the transport layer 1 and the transport layer 2. The transmission layer 1 and the transmission layer 2 are respectively located on both sides of the photoactive layer and are configured to transfer carriers 1 and carriers 2 respectively.

4. The semi-transparent color-changing solar cell according to claim 3, It is characterized in that The photoactive layer includes an organic semiconductor photoactive layer, a perovskite photoactive layer, a quantum dot photoactive layer, and a dye-sensitized cell sensitizing layer.

5. The semi-transparent color-changing solar cell according to claim 1, It is characterized in that When a plurality of the photovoltaic modules are included, the plurality of photovoltaic modules are stacked.

6. The semi-transparent color-variable solar cell according to claim 1, in, The solar cell is a flexible solar cell, wherein the flexible solar cell is made by stacking a flexible substrate, a photovoltaic module and a color-changing module in sequence.

7. The semi-transparent color-variable solar cell according to claim 2, It is characterized in that After the photochromic layer absorbs ultraviolet or visible light, the absorption peak position or peak intensity in the spectrum changes, resulting in a change in the CIE value of its color coordinate.

8. The method for preparing the semi-transparent color-changing solar cell according to claim 1, Features: One or more photovoltaic modules including or not including a color-changing module are sequentially prepared on a substrate, wherein the photovoltaic module including the color-changing module is prepared by one of the following methods a to d, and the photovoltaic module not including the color-changing module is prepared by the following method e: Method a: a1) preparing a transparent electrode layer 1; a2) preparing a photovoltaic functional layer on the transparent electrode layer 1; a3) preparing a photochromic layer above the photovoltaic functional layer; a4) preparing a transparent electrode layer 2 on the photochromic layer, Or, method b: b1) preparing a transparent electrode layer 1; b2) preparing a photochromic layer on the transparent electrode layer 1; b3) preparing a photovoltaic functional layer above the photochromic layer; b4) preparing a transparent electrode layer 2 on the photovoltaic functional layer, Or, method c: c1) preparing a transparent electrode layer 1; c2) preparing a photovoltaic functional layer on the transparent electrode layer 1; c3) preparing a transparent electrode layer 2 on the photovoltaic functional layer, c4) preparing a photochromic layer on the transparent electrode layer 2, Or, method d: d1) preparing a photochromic layer; d2) preparing a transparent electrode layer 1 on the photochromic layer; d3) preparing a photovoltaic functional layer on the transparent electrode layer 1; d4) preparing a transparent electrode layer 2 on the photovoltaic functional layer, Method e: e1) preparing a transparent electrode layer 1; e2) preparing a photovoltaic functional layer on the transparent electrode layer 1; e3) preparing a transparent electrode layer 2 on the photovoltaic functional layer.

9. The method for preparing the semi-transparent color-changing solar cell according to claim 7, Features In method a to method e, the preparation of the photovoltaic functional layer comprises: m1) preparing a transmission layer 1, m2) preparing a photoactive layer on the transmission layer 1; Or include: n1) preparing a transport layer 1, n2) preparing a photoactive layer on the transmission layer 1; n3) preparing a transmission layer 2 on the photoactive layer; Or include: p1) preparing a photoactive layer; p2) Providing a transport layer 2 on the photoactive layer.

10. The method for preparing the semi-transparent color-changing solar cell according to claim 7, Features: When a plurality of the photovoltaic modules are prepared on a substrate, the plurality of photovoltaic modules are stacked.

11. The method for preparing the semi-transparent color-changing solar cell according to claim 7, Features: The substrate is a flexible substrate, and the photovoltaic module with or without a color-changing module is a flexible module.

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