A transparent solar cell device and a method for manufacturing the same

Abstract

This invention relates to a transparent solar cell device and its fabrication method. The device includes a substrate, a transparent or semi-transparent anode layer, an anode auxiliary electrode layer, a PV photovoltaic layer, a transparent or semi-transparent cathode layer, a quantum dot absorption and emission layer, and an encapsulation layer, all stacked together. The quantum dot absorption and emission layer comprises quantum dot material, resin, and a photosensitizer. The quantum dot material is a nanostructured inorganic quantum material. The core diameter of the quantum dot material is 1-50 nm, and the thickness of the outer shell is 10-200 nm. The quantum dot material also includes an energy level transition layer between the core and the outer shell, which is one or more of sulfides, selenides, phosphides, or tellurides. Furthermore, a metal reflective layer is provided on the encapsulation surface. This solar cell device can fully utilize the high-energy photons in the short-wavelength band that are sacrificed in traditional solar cell devices.

Description

Technical Field

[0001] This invention relates to the field of product design and manufacturing of display and solar cell devices, specifically to a transparent solar cell device and its manufacturing method. Technical Background

[0002] Currently, common methods to improve the conversion efficiency of solar cells include adjusting the thickness of the light-absorbing layer, changing the system of the photoactive layer, adding an anti-reflection layer to the light incident surface, and changing different anode or cathode modification layer materials, i.e., adjusting the energy levels to make the energy level transition between the photoactive layer and HTL & ETL smoother, and to make the energy level matching between HTL and ETL and the anode and cathode closer to ohmic contact. Regarding improving the absorption and utilization of incident light, some types of cells, such as OPV and perovskite solar cells, are limited by the photoelectric conversion mechanism and cannot improve efficiency by increasing thickness. They can only improve efficiency by optimizing the energy levels of the materials so that the absorption wavelength of the light-absorbing layer matches as closely as possible to the 500nm-900nm region of the solar radiation spectrum under AM1.5. This sacrifices the high-energy short-wavelength band of solar radiation in the 300nm-500nm range under AM1.5. While it is possible to fully utilize this energy by vertically cascading multiple photovoltaic layers, this significantly increases the complexity and cost of the manufacturing process. Therefore, there is an urgent need for a solar cell device that can fully utilize the sacrificed high-energy photons in the short-wavelength band. Summary of the Invention

[0003] This invention discloses a transparent solar cell device and its fabrication method, aiming to solve the technical problems existing in the prior art.

[0004] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0005] On the one hand, a transparent solar cell device is proposed, including:

[0006] The substrate, transparent or semi-transparent anode layer, anode auxiliary electrode layer, PV photovoltaic layer, transparent or semi-transparent cathode layer, quantum dot absorption and emission layer, and encapsulation layer are stacked together; wherein, the quantum dot absorption and emission layer includes quantum dot material, resin and photosensitizer; the quantum dot material is an inorganic quantum material with a nanostructure.

[0007] As a preferred technical solution, the core diameter of the quantum dot material is 1-50nm, and the thickness of the outer shell is 10-200nm.

[0008] As a preferred technical solution, the quantum dot material further includes an energy level transition layer between the core and the shell, wherein the energy level transition layer is one or more of sulfides, selenides, phosphides or tellurides.

[0009] As a preferred technical solution, the thickness of the quantum dot absorption and emission layer is 0.1-10 μm.

[0010] As a preferred technical solution, a metal reflective layer is provided on the surface of the encapsulation layer; the metal reflective layer is made of a single metal or an alloy material, the thickness of the metal reflective layer is greater than 80nm, and the total light reflectivity is greater than 85%.

[0011] As a preferred technical solution, the encapsulation layer is made of glass, stainless steel, or a polymer material.

[0012] As a preferred technical solution, the surface of the encapsulation layer is provided with one or more water and oxygen barrier layers; the water and oxygen barrier layers are provided on one or both surfaces of the encapsulation layer.

[0013] On the other hand, the present invention also proposes a method for fabricating the above-mentioned transparent solar cell device, comprising:

[0014] A transparent or semi-transparent anodic layer is deposited on one surface of the substrate; the transparent or semi-transparent anodic layer is formed by physical vapor deposition, chemical vapor deposition or coating.

[0015] Auxiliary metal electrode coating is performed on a transparent or semi-transparent anode layer;

[0016] PV photovoltaic layer coating;

[0017] Transparent or semi-transparent cathode layer coating;

[0018] Quantum dot absorption and emission layer coating;

[0019] Encapsulation layer coating;

[0020] Sealing.

[0021] As a preferred technical solution, the quantum dot absorption and emission layer is directly coated on the surface of a transparent or semi-transparent cathode layer and cured into a film by means of light and heat.

[0022] As a preferred technical solution, the quantum dot absorption and emission layer is directly coated on the surface of the encapsulation layer, cured into a film by light and heat, and then assembled with the solar cell device.

[0023] The present invention achieves the following technical effects compared with the prior art: (1) On the one hand, in the solar cell device of the present invention, the quantum dot material absorbs the short-wavelength light that is not absorbed by the PV photovoltaic layer and excites visible light with a wavelength greater than the absorption wavelength, which is then incident and absorbed by the PV layer from the transparent or semi-transparent cathode layer and converted into electrical energy. After the quantum dot material absorbs the short-wavelength light, the quantum dot is then excited to excite the light with a wavelength greater than the absorption wavelength, and the external quantum efficiency of the absorption and conversion process can reach 50%-80%; (2) On the other hand, the quantum dot absorption and emission layer can present different transparent colors according to different quantum dot nanostructure components, which can compensate for the color of the PV photovoltaic layer itself, making the color of the PV photovoltaic area darker, and providing a certain adjustment space for the appearance of the product; (3) The encapsulation layer is made into a structure with a metal reflective layer, which can reflect all the light excited from the quantum dot material back into the solar cell device, so that the PV photovoltaic layer can fully absorb and utilize the short-wavelength excited quantum dot material that was not absorbed through the PV photovoltaic layer and convert it into light with a wavelength greater than 500nm. Attached image description:

[0024] Figure 1 A schematic diagram of a transparent solar cell device structure is provided in Embodiment 1 of the present invention;

[0025] Figure 2 Schematic diagrams of five encapsulation layer structures provided in Embodiment 1 of the present invention;

[0026] Explanation of reference numerals in the attached figures:

[0027] 1-Substrate; 2-Transparent or semi-transparent anode layer; 3-Anode auxiliary electrode layer; 4-PV photovoltaic layer; 5-Transparent or semi-transparent cathode layer; 6-Quantum dot absorption and emission layer; 7-Encapsulation layer; 71-Metal reflective layer; 72-Water and oxygen barrier layer; 8-Sealing layer. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings.

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0030] To address the problems existing in the prior art, this invention provides a transparent solar cell device and its fabrication method. The transparent solar cell device includes a substrate, a transparent or semi-transparent anode layer, an anode auxiliary electrode layer, a PV photovoltaic layer, a transparent or semi-transparent cathode layer, a quantum dot absorption and emission layer, and an encapsulation layer, all stacked together. The quantum dot absorption and emission layer comprises quantum dot material, resin, and a photosensitizer; the quantum dot material is a nanostructured inorganic quantum material. Furthermore, a metal reflective layer is provided on the surface of the encapsulation layer.

[0031] Example 1

[0032] like Figure 1 The diagram shown illustrates the structure of a transparent solar cell device proposed in this embodiment. This transparent solar cell device includes a substrate 1, a transparent or semi-transparent anode layer 2, an anode auxiliary electrode layer 3, a PV photovoltaic layer 4, a transparent or semi-transparent cathode layer 5, a quantum dot absorption and emission layer 6, and an encapsulation layer 7, all stacked together. The quantum dot absorption and emission layer 6 comprises quantum dot material, resin, and a photosensitizer. The quantum dot material is a nanostructured inorganic quantum material. Preferably, the resin can be an organic polymer material, such as acrylic resin or phenolic resin, or it can be an inorganic siloxane material.

[0033] Preferably, the solar cells include organic solar cells (OPV), perovskite solar cells, DSC (dye-sensitized) solar cells, antimony sulfide (Sb2S3), cadmium telluride (CdTe) solar cells, etc.

[0034] Preferably, the substrate 1 is made of inorganic materials such as colorless and transparent glass, or colorless and transparent organic polymer materials that have water and oxygen barrier properties, light resistance, and heat resistance, such as one or more composite materials of polymer films such as PEN, CPI, PET, COP, COC, PP, PE, PVC, and nylon.

[0035] Preferably, the transparent or semi-transparent anode layer 2 can be made of TCO (transparent conductive oxide), nano silver, carbon nanotubes, graphene, ultrathin metal layers such as magnesium-silver alloy layers, or directly using high-conductivity PEDOT:PSS materials, with a conductivity of ≥800S / cm.

[0036] Preferably, the anode auxiliary electrode is made of materials including but not limited to metals with excellent conductivity such as silver, aluminum, gold, copper, and platinum, either as single elements or alloys, in order to reduce the anode resistance and improve the photoelectric conversion efficiency of the device.

[0037] The PV photovoltaic layer 4 of OPV and perovskite solar cells includes a basic three-layer structure: HTL (hole transport layer), ACT-L (photovoltaic active layer), and ETL (electron transport layer).

[0038] The PV photovoltaic layer 4 of antimony sulfide (Sb2S3) and cadmium telluride (CdTe) type solar cells is composed of a heterostructure of P / N or N / P type.

[0039] The structure of a DSC-type solar cell consists of a photoanode, a liquid electrolyte, and a photocathode, with a quantum dot absorption and emission layer 6 located between the photocathode and the encapsulation layer 7.

[0040] Preferably, the transparent or semi-transparent cathode layer 5 can be made of TCO (transparent conductive oxide), nano-silver, carbon nanotubes, graphene, ultra-thin metal layers such as magnesium-silver alloy layers, or directly using high-conductivity PEDOT:PSS materials, with a conductivity of ≥800S / cm.

[0041] Preferably, the core diameter of the quantum dot material is 1-50 nm, and the thickness of the outer shell is 10-200 nm. The quantum dot absorption and emission layer 6 material is a photoresist material formed by mixing quantum dots, solvents (toluene, PGMEA, etc.), resins, photosensitizers, and additives in a certain proportion. Among them, quantum dots are inorganic quantum materials with nanostructures, mostly composed of elements from Group 2 and Group 6 of the periodic table, or elements from Group 3 and Group 5. The core is composed of nanoscale materials with low band gaps such as cadmium selenide (CdSe), indium phosphide (InP), and gallium arsenide (GaAs), while the outer shell is composed of materials with higher band gaps such as cadmium sulfide (CdS), zinc sulfide (ZnS), zinc selenide (ZnSe), and zinc telluride (ZnTe), forming microspheres, rods, stars, and other structures.

[0042] Preferably, the quantum dot material further includes an energy level transition layer between the core and the shell. The energy level transition layer is one or more of sulfides, selenides, phosphides or tellurides, combined in different component ratios, so that the energy levels of the core and the shell increase gradually and transition smoothly.

[0043] Preferably, quantum dot absorption and emission layers 6 of different thicknesses can be fabricated by adjusting the solid content of quantum dot nanomaterials in the photoresist solvent, or by optimizing the coating equipment or coating parameters. The thickness of the quantum dot absorption and emission layer 6 is 0.1-10 μm, and the film thickness is adjusted according to the absorption and conversion efficiency.

[0044] Quantum dot materials absorb short-wavelength light that is not absorbed by the PV photovoltaic layer 4 and excite visible light with a wavelength longer than the absorption wavelength. This visible light is then incident on the cathode surface of the PV layer, absorbed, and converted into electrical energy. By absorbing short-wavelength light and then exciting the quantum dots to re-excite light with a wavelength longer than the absorption wavelength, the external quantum efficiency of the absorption and conversion process can reach 50%-80%. The quantum dot absorption and emission layer 6 can exhibit different transparent colors depending on the different quantum dot nanostructure components, which can compensate for the color of the PV photovoltaic layer 4 itself, making the color of the PV photovoltaic area deeper and providing some adjustment space for the product's appearance.

[0045] Preferably, the encapsulation layer 7 is made of glass, stainless steel, or a polymer material. It is an organic polymer material with water and oxygen barrier properties, light resistance, and heat resistance, such as one or more composite materials of polymer films including PEN, PI, PET, COP, COC, PP, PE, PVC, and nylon.

[0046] like Figure 2 As shown, preferably, when the polymer material itself has poor water and oxygen barrier properties, one or more water and oxygen barrier layers 72 are provided on the surface of the encapsulation layer 7 to ensure the electrical performance and reliability of the device. The material of the water and oxygen barrier layer 72 includes, but is not limited to, aluminum, silicon nitride, silicon oxide, silicon oxynitride, organic resin coating, or a combination of the above.

[0047] The water and oxygen barrier layer 72 is disposed on one or both surfaces of the encapsulation layer 7.

[0048] Preferably, the surface of the encapsulation layer 7 is provided with a metal reflective layer 71. The metal reflective layer 71 is made of a single metal or an alloy material, and its thickness is greater than 80 nm, with a total light reflectivity greater than 85%. The function of the metal reflective layer 71 is to reflect all the light excited from the quantum dot material back into the device, so that the PV photovoltaic layer 4 can fully absorb and utilize the short-wavelength excitation of the quantum dot material that was previously transmitted through the PV but not absorbed, and convert it into light with a wavelength greater than 500 nm.

[0049] like Figure 2 As shown, the metal reflective layer 71 can be directly disposed on the surface of the encapsulation layer 7. When directly disposed on the surface of the encapsulation layer 7, the metal reflective layer 71 is made of aluminum. The aluminum reflective layer can serve as both the metal reflective layer 71 and the water and oxygen barrier layer 72. Alternatively, it can be disposed on the surface of the water and oxygen barrier layer 72. The metal reflective layer 71 disposed on the surface of the water and oxygen barrier layer 72 can be made of materials such as metal, silver, molybdenum, titanium, or platinum.

[0050] Preferably, the solar cell device further includes an adhesive material for bonding the substrate 1 and the encapsulation layer 7. The function of the adhesive material is to encapsulate the PV photovoltaic layer 4 and the quantum dot absorption and emission layer 6 inside the device, preventing the solar cell device from failing due to the absorption of water and oxygen, which would cause the PV photovoltaic material and quantum dot material to fail. The adhesive material can be a liquid glue that is cured by light or heat after coating and bonding; or it can be a sheet-like tape with a certain proportion of water and oxygen adsorption particles mixed inside the adhesive layer.

[0051] Example 2

[0052] This embodiment discloses a method for fabricating the transparent solar cell device described in Embodiment 1, the method comprising:

[0053] S1O: A transparent or semi-transparent anode layer 2 is deposited on one surface of substrate 1;

[0054] Preferably, the transparent or semi-transparent anode layer 2 is formed by physical vapor deposition, chemical vapor deposition or coating; TCO (transparent conductive oxide) is formed by physical vapor deposition or chemical vapor deposition; or nano silver solution or highly conductive PEDOT:PSS is uniformly coated on the surface of substrate 1 and the transparent or semi-transparent anode layer 2 pattern is formed by chemical etching or mechanical cutting.

[0055] S2O: Auxiliary metal electrode coating is performed on the transparent or semi-transparent anode layer 2;

[0056] S30: PV photovoltaic layer 4 film formation;

[0057] Among them, the PV photovoltaic layer 4 of OPV and perovskite solar cells includes a three-layer basic structure: HTL (hole transport layer), ACT-L (photovoltaic active layer), and ETL (electron transport layer). It is fabricated using a solution method, in which the solution-state material is coated onto the surface of the anode pattern and cured; the order of fabrication of each functional layer is as follows: first fabricate the HTL layer, then the ACT-L layer, and finally the ETL layer.

[0058] The PV photovoltaic layer 4 of antimony sulfide (Sb₂S₃) and cadmium telluride (CdTe) type solar cells is composed of a P / N or N / P heterostructure. Generally, n-type, moderately doped CdS (cadmium sulfide) is selected as the window layer, with a thickness of about 50-100 nm.

[0059] The structure of a DSC-type solar cell consists of a photoanode, a liquid electrolyte, and a photocathode, with a quantum dot absorption and emission layer 6 located between the photocathode and the encapsulation layer 7.

[0060] S40: Transparent or semi-transparent cathode layer 5 coating; manufactured by methods such as vapor deposition or spraying. When using vapor deposition, a metal shielding mold is required to create the cathode pattern; or IJP spraying can be used to directly form the desired transparent or semi-transparent cathode layer 5 pattern.

[0061] S50: Quantum dot absorption and emission layer 6 coating;

[0062] Preferably, the quantum dot absorption and emission layer 6 can be fabricated in two ways. In the first way, the quantum dot absorption and emission layer 6 is directly coated onto the surface of the transparent or translucent cathode layer 5 and cured into a film by means of light and heat;

[0063] In the second method, the quantum dot absorption and emission layer 6 is directly coated on the surface of the encapsulation layer 7, cured into a film by light and heat, and then assembled with the solar cell device.

[0064] S60: Encapsulation layer 7 coating;

[0065] Preferably, one or more layers of water and oxygen barrier layer 72 are deposited on one or both surfaces of the encapsulation layer 7; further, a metal reflective layer 71 is deposited on the surface of the water and oxygen barrier layer 72.

[0066] S70: Sealing adhesive; the adhesive material can be a liquid adhesive that is cured by light or heat after being coated and bonded; or it can be a sheet tape with a certain proportion of water and oxygen adsorption particles mixed inside the adhesive layer.

Claims

1. A transparent solar cell device, characterized by, It includes a colorless and transparent glass inorganic or organic polymer substrate, a transparent or semi-transparent anode layer, an anode auxiliary electrode layer, a PV photovoltaic layer, a transparent or semi-transparent cathode layer, a quantum dot absorption and emission layer, a metal reflective layer, and an encapsulation layer, all stacked together. The substrate material includes colorless and transparent glass inorganic material, or colorless and transparent organic polymer material with water and oxygen barrier properties, light resistance, and heat resistance, including one or more composite materials selected from PEN, CPI, PET, COP, COC, PP, PE, PVC, and nylon polymer films. The quantum dot absorption and emission layer comprises quantum dot material, phenolic resin or inorganic siloxane material and photosensitizer; the quantum dot material is a nanostructured inorganic quantum material; the core diameter of the quantum dot material is 1-50 nm; the thickness of the outer shell is 10-200 nm; the quantum dot material also includes an energy level transition layer between the core and the outer shell, the energy level transition layer being one or more of selenide, phosphide or telluride; The quantum dot material absorbs short-wavelength light that is not absorbed by the PV photovoltaic layer and excites visible light with a wavelength longer than the absorption wavelength; the quantum dot absorption and emission layer exhibits different transparent colors depending on the different quantum dot nanostructure components. The quantum dot absorption and emission layer is directly coated on the surface of the transparent or semi-transparent cathode layer and cured into a film by light and heat. The anode auxiliary electrode of the anode auxiliary electrode layer is made of metallic silver, aluminum, gold, copper, platinum or an alloy. The PV photovoltaic layer of the perovskite solar cell includes an HTL hole transport layer, an ACT-L photovoltaic active layer, and an ETL electron transport layer; The transparent or semi-transparent cathode layer includes TCO transparent conductive oxide, nano-silver, carbon nanotubes, graphene, ultrathin metal layer or high-conductivity PEDOT:PSS material with a conductivity of ≥800S / cm. The metal reflective layer is made of a single metal or an alloy material, and the thickness of the metal reflective layer is greater than 80 nm, with a total light reflectivity greater than 85%. The metal reflective layer reflects all the light excited from the quantum dot material back into the solar cell device, allowing the PV photovoltaic layer to fully absorb and utilize the short-wavelength excited quantum dot material that was not absorbed before passing through the PV photovoltaic layer and convert it into light with a wavelength greater than 500nm.

2. The transparent solar cell device according to claim 1, characterized in that, The thickness of the quantum dot absorption and emission layer is 0.1-10 μm.

3. A transparent solar cell device according to claim 1, characterized in that, The encapsulation layer is made of glass, stainless steel, or a polymer material.

4. A transparent solar cell device according to claim 3, characterized in that, The surface of the encapsulation layer is provided with one or more water and oxygen barrier layers; the water and oxygen barrier layers are provided on one or both surfaces of the encapsulation layer.

5. A method for fabricating the transparent solar cell device according to any one of claims 1-4, characterized in that, include: The transparent or semi-transparent anodic layer is deposited on one surface of the substrate; The transparent or semi-transparent anode layer coating is made by physical vapor deposition, chemical vapor deposition or coating method; An anode auxiliary electrode layer is deposited on the transparent or semi-transparent anode layer; The PV photovoltaic layer is coated; The transparent or semi-transparent cathode layer is coated; The quantum dot absorption and emission layer is coated; Encapsulation layer coating: one or more layers of water and oxygen barrier layer coating are applied to one or both surfaces of the encapsulation layer; a metal reflective layer coating is applied to the surface of the water and oxygen barrier layer. Sealing.

6. The method for fabricating a transparent solar cell device according to claim 5, characterized in that, The quantum dot absorption and emission layer is directly coated on the surface of the encapsulation layer, cured into a film by light and heat, and then assembled with the solar cell device.

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