Multifunctional intelligent photovoltaic window and preparation method thereof

Abstract

The application discloses a multifunctional intelligent photovoltaic window which is assembled by a multifunctional variable color unit and a silicon solar cell, and has the characteristics of wide wave adjustment, self-driving and self-cleaning. The laminated structure multifunctional variable color unit mainly comprises a vanadium dioxide / silicon dioxide / polyurethane nanocomposite film, a polymer stable liquid crystal with a near-crystal-cholesteric phase transition, an indium tin oxide and a silicon dioxide coating, which are respectively used as a near-infrared light adjusting layer, a visible light adjusting layer, an electrothermal layer and a super-hydrophobic layer. Based on the above design, the intelligent photovoltaic window can realize dynamic adjustment of the transmittance in the wavelength range of 380-2500 nm, so that the ideal energy-saving effect is achieved. In combination with the high output power of the silicon cell and the excellent direct current heating effect of the indium tin oxide, the self-driving characteristic of the intelligent photovoltaic window is realized, and the energy-saving effect is further improved. In addition, the silicon dioxide super-hydrophobic coating with a contact angle of 150-160 degrees effectively solves the environmental dependence of the intelligent photovoltaic window, and the intelligent photovoltaic window also has a good vision under complex weather conditions such as rain and snow. The application can widen the application of the intelligent photovoltaic window in the fields of energy-saving buildings, automobiles and flexible photoelectric devices.

Description

TECHNICAL FIELD

[0001] The present application relates to the intelligent window technology which can be applied to energy-saving buildings, automobiles and electronic optical devices, and relates to a multifunctional intelligent photovoltaic window and a preparation method thereof. BACKGROUND

[0002] The intelligent photovoltaic window is a new green technology which integrates privacy protection, energy saving and power generation and other functions. At present, the assembly of color-changing materials and photovoltaic cells has become a common strategy and means for constructing intelligent photovoltaic windows. According to the needs, different types of color-changing materials such as transition metal oxides, conductive polymers and color-changing gels can be combined with a series of photovoltaic cells including organic, dye-sensitized, perovskite and silicon-based solar cells to design and prepare intelligent photovoltaic windows. Photovoltaic cells can effectively collect solar energy and convert it into electrical energy to provide energy for energy-saving buildings, and drive the transmittance change of the intelligent photovoltaic window to provide energy-saving effect. Based on the electrical response characteristics of the intelligent photovoltaic window, it is also convenient to connect with computers and networks, which provides the possibility for the future construction of an integrated smart home system. However, in the face of the needs of practical application, the intelligent photovoltaic windows reported at present still have some difficulties and challenges: 1. How to achieve the characteristics of wide wave adjustment to achieve the ideal energy-saving effect; 2. How to make it more intelligent, and change the transparency according to the needs of the occupants; 3. How to reduce the water consumption caused by cleaning; 4. How to effectively overcome the dependence on environmental conditions, so that it still maintains a high transmittance under different weather conditions, providing a better view for the occupants. SUMMARY

[0003] In view of the deficiencies of the existing intelligent photovoltaic window, the present application designs and prepares a multifunctional intelligent photovoltaic window which can be applied to high-efficiency energy-saving buildings, automobiles and intelligent optoelectronic devices.

[0004] The preparation method comprises the following steps:

[0005] (1) Using ordinary glass and indium tin oxide glass with a square resistance of 3 ohm / square to 300 ohm / square as the substrate, the surface (non-conductive surface of the indium tin oxide glass) is grafted with an orientation agent dimethyl octadecyl [3-(trimethoxysilyl) propyl] ammonium chloride to prepare a liquid crystal cell that can induce vertical alignment of liquid crystals. After mixing the liquid crystal molecules (E8, 8CB, 8OCB, 10OCB and 5CT), the polymerizable monomer C6M, the chiral additive (R5011 or S5011) and the photoinitiator benzoin diethyl ether uniformly, they are filled into the prepared liquid crystal cell at 90℃. After cooling to room temperature, polymerization is carried out under ultraviolet light to obtain a vertically aligned polymer stabilized liquid crystal film as a visible light adjusting layer;

[0006] (2) Vanadium dioxide nanoparticles with a diameter of 20-100 nm are used as cores, and vanadium dioxide@silica core-shell structure nanoparticles are prepared through hydrolysis of tetraethyl orthosilicate. The vanadium dioxide@silica core-shell structure nanoparticles are doped into a polyurethane solution, and a vanadium dioxide@silica / polyurethane nanocomposite film is constructed on an indium tin oxide surface by solution casting, serving as a near-infrared light adjusting layer.

[0007] (3) Ethylene acrylic acid is dissolved in a mixed solution of tetrahydrofuran and butyl acetate, and hydrophobic fumed silica nanoparticles are dispersed in isopropyl alcohol. Then, the ethylene acrylic acid solution and the hydrophobic fumed silica nanoparticle dispersion are sprayed on the surface of a glass substrate in sequence, and an ultrahydrophobic coating is obtained after drying at room temperature.

[0008] (4) The multifunctional color-changing unit is assembled with a silicon solar cell, and a multifunctional intelligent photovoltaic window with wide-wave adjustable, self-driven and self-cleaning characteristics is constructed by connecting a DC-DC transformer in series.

[0009] The advantages of the characteristics of the present application are:

[0010] (1) The combination of polymer-stabilized liquid crystals and reversible phase transition of vanadium dioxide@silica core-shell structure nanoparticles realizes the wide-wave adjustable characteristic of the intelligent photovoltaic window Figure 1 , achieving good energy-saving effect Figure 2 .

[0011] (2) Benefiting from the high output voltage (7 V) of the silicon solar cell, the excellent direct current heating effect of indium tin oxide, and the suitable phase transition temperature (60℃) of polymer-stabilized liquid crystals and vanadium dioxide@silica core-shell structure nanoparticles, the designed and prepared intelligent photovoltaic window can realize the change of transmittance under low sunlight intensity (20 mW / cm 2 ) and is not affected by the ambient temperature Figure 3 .

[0012] (3) The ultrahydrophobic coating endows the intelligent photovoltaic window with self-cleaning characteristics, effectively saving water resources, and maintaining high transmittance under different weather adjustments, providing a better view for the occupants Figure 4 . BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 . The transmittance of the intelligent photovoltaic window at 25℃ and 70℃ as a function of wavelength;

[0014] Figure 2 . Energy-saving effect of the intelligent photovoltaic window;

[0015] Figure 3 . Outdoor working photo of the intelligent photovoltaic window;

[0016] Figure 4 .Superhydrophobic properties of smart photovoltaic windows. DETAILED DESCRIPTION

[0017] Example 1

[0018] (1) Ordinary glass and indium tin oxide glass with a sheet resistance of 7 ohms / □ were used as substrates. The surface (non-conductive surface of the indium tin oxide glass) was grafted with dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride, an orientation agent, to prepare a liquid crystal cell that can induce vertical liquid crystal alignment. Liquid crystal molecules with a phase transition point of 60°C (E8, 8CB, 8OCB, 10OCB, and 5CT accounted for 15%, 30%, 20%, 20%, and 15%, respectively), a polymerizable monomer C6M, a chiral additive (R5011 or S5011), and a photoinitiator benzoin diethyl ether were mixed uniformly and poured into the prepared liquid crystal cell at 90°C. After cooling to room temperature, polymerization was carried out under ultraviolet light to obtain a vertically aligned polymer-stabilized liquid crystal film as a visible light modulation layer.

[0019] (2) Using 50 nm diameter vanadium dioxide nanoparticles as the core, vanadium dioxide@silica core-shell nanoparticles were prepared by hydrolysis of tetraethyl orthosilicate. The vanadium dioxide@silica core-shell nanoparticles were incorporated into a polyurethane solution, and a vanadium dioxide@silica / polyurethane nanocomposite film was constructed on the surface of indium tin oxide by solution casting to serve as a near-infrared light modulation layer.

[0020] (3) Ethylene acrylic acid is dissolved in a mixture of tetrahydrofuran and butyl acetate, and hydrophobic fumed silica nanoparticles are dispersed in isopropyl alcohol. The ethylene acrylic acid solution and the hydrophobic fumed silica nanoparticle dispersion are then sprayed onto the surface of a glass substrate and dried at room temperature to obtain a superhydrophobic coating.

[0021] (4) The prepared multifunctional color-changing unit was assembled with a 6-watt silicon solar cell and connected in series with a DC-DC transformer to construct a multifunctional intelligent photovoltaic window with wide-band adjustable, self-driving and self-cleaning characteristics.

[0022] Example 2

[0023] (1) Using common glass and indium tin oxide glass with sheet resistance of 7 Ω / □ as substrate, the surface (non-conductive surface of indium tin oxide glass) was grafted with dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride as orienting agent to prepare a liquid crystal cell that can induce vertical alignment of liquid crystal. After mixing liquid crystal molecules (E8, 8CB, 8OCB, 10OCB and 5CT with a ratio of 35%, 15%, 15%, 20% and 15% respectively) with a phase transition point of 50℃, polymerizable monomer C6M, chiral additive (R5011 or S5011) and photoinitiator benzoin diethyl ether, the mixture was poured into the prepared liquid crystal cell at 90℃. After cooling to room temperature, polymerization was carried out under ultraviolet light to obtain a vertically aligned polymer stabilized liquid crystal film as a visible light adjusting layer.

[0024] (2) Using vanadium dioxide nanoparticles with a diameter of 100 nm as core, vanadium dioxide@silica core-shell structure nanoparticles were prepared by hydrolysis of tetraethyl orthosilicate. Vanadium dioxide@silica core-shell structure nanoparticles were incorporated into a polyurethane solution, and a vanadium dioxide@silica / polyurethane nanocomposite film was constructed on the surface of indium tin oxide using solution casting as a near-infrared light adjusting layer.

[0025] (3) Ethylene acrylic acid was dissolved in a mixed solution of tetrahydrofuran and butyl acetate, and hydrophobic fumed silica nanoparticles were dispersed in isopropyl alcohol. Then, the ethylene acrylic acid solution and the hydrophobic fumed silica nanoparticle dispersion were sprayed on the surface of the glass substrate in sequence, and a superhydrophobic coating was obtained after drying at room temperature.

[0026] (4) The prepared multifunctional color-changing unit was assembled with a 12-watt silicon solar cell, and a DC-DC transformer was connected in series to construct a multifunctional intelligent photovoltaic window with the characteristics of wide wave adjustment, self-driving and self-cleaning.

Claims

1. A multifunctional smart photovoltaic window, a super-hydrophobic layer, an electrothermal layer, a visible light adjusting layer and a near-infrared light adjusting layer are constructed by a hydrophobic fumed silica, an indium tin oxide glass, a polymer stabilized liquid crystal with a smectic-cholesteric phase transition and a vanadium dioxide / silica / polyurethane nanocomposite film, respectively, to form a laminated structure multifunctional color-changing unit, and the multifunctional color-changing unit is assembled with a silicon solar cell to form a smart photovoltaic window, and a preparation method thereof comprises the following steps: (1) Using common glass and indium tin oxide glass as substrate, the surface (non-conductive surface of indium tin oxide glass) is treated by using orienting agent to prepare liquid crystal cell which can induce vertical alignment of liquid crystal. After mixing liquid crystal molecules, polymerizable monomer, chiral additive and photoinitiator uniformly, the mixture is filled into the liquid crystal cell under 90 o C, and after cooling to room temperature, photopolymerization is carried out under ultraviolet light to obtain polymer stabilized liquid crystal film with vertical alignment as visible light adjusting layer; (2) a vanadium dioxide / silica / polyurethane nanocomposite film is constructed on the surface of an indium tin oxide by a solution casting method using a polyurethane solution containing vanadium dioxide / silica core-shell structure nanoparticles as a precursor, and the film is used as a near-infrared light adjusting layer; (3) a transparent super-hydrophobic silica coating is constructed on the surface of ordinary glass by a spraying method using ethylene acrylic acid as an adhesive and hydrophobic fumed silica as a substrate; (4) the multifunctional color-changing unit prepared is assembled with a monocrystalline silicon solar cell to form a multifunctional smart photovoltaic window with the characteristics of wide wave adjustment, self-driving and self-cleaning; wherein the electrothermal layer is an indium tin oxide glass with a transmittance > 90 % and a square resistance of 3 Ω / □-300 Ω / □.

2. The multi-functional smart photovoltaic window of claim 1, wherein, The visible light adjusting layer is a polymer stabilized liquid crystal with a smectic-cholesteric phase transition, and the phase transition temperature is in the range of 40 o C ~ 60 o C and is continuously adjustable in the temperature range.

3. The multi-functional smart photovoltaic window of claim 1, wherein, The near-infrared light adjusting layer is a vanadium dioxide / silica / polyurethane nanocomposite film, wherein the vanadium dioxide / silica core-shell structure nanoparticles have a particle size of 30 nm to 150 nm and a phase transition temperature of 60 o C, and the solid content of the polyurethane matrix is 20 wt % to 40 wt %.

4. The multi-functional smart photovoltaic window of claim 1, wherein, The super-hydrophobic layer is an ethylene acrylic acid and hydrophobic fumed silica coating, the hydrophobic fumed silica nanoparticles have a particle size of 10 nm-100 nm, and the content of acrylic acid is 5 wt %-20 wt %.

5. The multi-functional smart photovoltaic window of claim 1, wherein, The silicon solar cell is a polycrystalline silicon solar cell or a monocrystalline silicon solar cell, and the output power is > 4 W.

6. The multi-functional smart photovoltaic window of claim 1, wherein, The smart photovoltaic window is used as a door and window of an energy-saving building and a smart device such as a car.

Images