Photoelectric energy conversion device and preparation method thereof

Abstract

The present invention discloses a photoelectric energy conversion device and a preparation method, comprising a cathode substrate and an anode substrate arranged in parallel; the cathode substrate comprises a transparent cathode substrate, a cathode electrode layer located on the cathode substrate, a cathode growth source film located on the cathode electrode layer, cathode nanowires located on the cathode growth source film, and a covering layer of thermoelectric material coated on the surface of the cathode nanowires; the anode substrate comprises a transparent anode substrate and an anode electrode layer located on the anode substrate; the cathode substrate and the anode substrate are separated and fixed by a high-voltage insulating separator so that a vacuum gap is left between the cathode substrate and the anode substrate. During operation, the nanowire cathode emits electrons under the combined action of external light and an external electric field applied by the anode. During the electron emission process, due to the action of Joule heat, a temperature gradient exists in the nanowire. The temperature gradient causes an axial potential to appear in the thermoelectric material, which increases the emission current, thereby improving the conversion efficiency.

Description

Technical Field

[0001] The present invention relates to the field of photoelectric energy conversion, and in particular to a photoelectric energy conversion device and a preparation method thereof. Background Art

[0002] Photon-enhanced thermionic emission (PETE) is a photovoltaic energy conversion mechanism that efficiently utilizes solar energy. Photons with energies greater than the band gap excite carriers, raising the cathode's quasi-Fermi level and lowering the effective barrier for electron emission. Photons with energies below the band gap convert to thermal energy, raising the cathode temperature and assisting electron emission, thereby achieving efficient solar energy utilization. Compared with traditional thin-film cathodes, nanowire cathodes offer advantages in anti-reflection and light-harvesting properties. Their high surface area enhances light absorption efficiency. Furthermore, electron transport in nanowires occurs in a single dimension, resulting in enhanced conductivity and favorable photoemission. Therefore, nanowire cathodes offer significant advantages in energy conversion using the PETE effect. However, the generation of Joule heating during electron emission increases the emitter's temperature, resulting in energy loss and potential melting. It is crucial to effectively utilize this energy, converting it into electrical energy to further improve energy conversion efficiency. Summary of the Invention

[0003] The purpose of the present invention is to provide a photoelectric energy conversion device and a preparation method to solve one or more technical problems existing in the prior art and at least provide a beneficial option or create conditions.

[0004] The technical solutions adopted to solve the above technical problems are:

[0005] First, the present invention provides a photoelectric energy conversion device, including a cathode substrate and an anode substrate arranged in parallel; the cathode substrate includes a transparent cathode substrate, a cathode electrode layer located on the cathode substrate, a cathode growth source film located on the cathode electrode layer, cathode nanowires located on the cathode growth source film, and a covering layer of thermoelectric material coated on the surface of the cathode nanowires; the anode substrate includes a transparent anode substrate and an anode electrode layer located on the anode substrate; the cathode substrate and the anode substrate are separated and fixed by a high-voltage insulating insulator so that a vacuum gap is left between the cathode substrate and the anode substrate.

[0006] The beneficial effects of the present invention are as follows: Joule heat is generated in the process of emitting electrons using cathode nanowires, resulting in a temperature gradient in the axial direction of the cathode nanowires. A covering layer of thermoelectric material is coated on the surface of the cathode nanowires. The axial temperature gradient of the cathode nanowires causes the thermoelectric material to have an axial potential, which increases the emission current and converts Joule heat into electrical energy. In addition, the thermoelectric material converts thermal energy into electrical energy, suppresses temperature rise, avoids vacuum breakdown, and increases the life of the cathode.

[0007] As a further improvement of the above technical solution, the anode electrode layer is connected to a high potential, and the cathode electrode layer is connected to a low potential.

[0008] As a further improvement of the above technical solution, the cathode electrode layer is a transparent conductive film, which includes an ITO conductive film.

[0009] As a further improvement of the above technical solution, the anode electrode layer is a conductive film, which includes a Cr, Ni, Ti metal film or an ITO conductive film.

[0010] As a further improvement of the above technical solution, the cathode nanowire is a semiconductor nanowire, which includes Si nanowire, copper oxide nanowire, zinc oxide nanowire, gallium arsenide nanowire or indium phosphide nanowire.

[0011] As a further improvement of the above technical solution, the thermoelectric material includes Bi 0.5 Sb 1.5 Te3.

[0012] As a further improvement of the above technical solution, the isolator is made of ceramic sheet or quartz sheet insulating material, and its height is 1 to 500 μm.

[0013] As a further improvement of the above technical solution, the vacuum degree of the vacuum gap is ~ Pa.

[0014] As a further improvement of the above technical solution, the cathode substrate and the anode substrate are both transparent glass plates, and an exhaust hole is provided on the anode substrate.

[0015] In addition, the present invention also provides a method for manufacturing the above-mentioned photoelectric energy conversion device, and the preparation process is as follows:

[0016] S1. Prepare a cathode substrate, manufacture a cathode substrate of a set size, clean the cathode substrate, wrap it with aluminum film, and use magnetron sputtering vacuum coating technology to coat a transparent conductive film on the cathode substrate as a cathode electrode layer, prepare a cathode growth source film on the cathode electrode layer, and prepare cathode nanowires on the cathode growth source film;

[0017] S2, preparing a covering layer of thermoelectric material on the surface of the cathode nanowire;

[0018] S3, preparing an anode substrate, manufacturing an anode substrate of a set size, cleaning the anode substrate, wrapping it with an aluminum film, and coating a conductive film on the anode substrate as an anode electrode layer using a magnetron sputtering vacuum coating technology;

[0019] S4. Fix the side of the anode substrate coated with the anode electrode layer and the side of the cathode substrate prepared with cathode nanowires to be insulated from each other through an insulator, and evacuate the vacuum gap between the anode substrate and the cathode substrate for packaging.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1) The covering layer of thermoelectric material coated on the surface of the cathode nanowires is used to convert part of the Joule heat generated during the cathode electron emission process into electrical energy, thereby improving energy utilization efficiency.

[0022] 2) Thermoelectric materials convert thermal energy into electrical energy, thereby suppressing temperature rise, avoiding vacuum breakdown, protecting the nanowire cathode from burning, and increasing its lifespan. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments;

[0024] Figure 1 Schematic diagram of a photoelectric energy conversion device in an embodiment of the present invention;

[0025] Figure 2 Schematic top view of an anode substrate of a photoelectric energy conversion device according to an embodiment of the present invention;

[0026] Figure 3 Schematic top view of a cathode substrate of a photoelectric energy conversion device according to an embodiment of the present invention;

[0027] Figure 4 This is a comparison diagram of the field emission characteristics of the CuO nanowire cathode before and after irradiation with an infrared light source in an embodiment of the present invention;

[0028] Figure 5 The surface morphology of the ZnO nanowire cathode and the Bi coating layer in the embodiment of the present invention are shown in FIG. 0.5 Sb 1.5 Surface morphology of Te3's ZnO nanowire cold cathode, and a comparison of the emission characteristics of the nanowires before and after coating. DETAILED DESCRIPTION

[0029] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it should not be understood as a limitation on the scope of protection of the present invention.

[0030] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0031] In the description of the present invention, if there are words such as "several", it means one or more, and "more" means more than two. Greater than, less than, and exceed are understood as not including the number itself, and above, below, and within are understood as including the number itself.

[0032] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0033] Reference Figures 1 to 5 The photoelectric energy conversion device of the present invention is implemented as follows:

[0034] Example 1:

[0035] like Figures 1 to 3 As shown, Figure 1 The number 10 in the figure is focused sunlight.

[0036] The photoelectric energy conversion device of this embodiment includes a cathode substrate and an anode substrate. The cathode substrate and the anode substrate are arranged parallel to each other. An insulator 4 is provided between the cathode substrate and the anode substrate. The insulator 4 is a high-voltage insulating component. The insulator 4 separates and fixes the cathode substrate and the anode substrate, thereby forming a vacuum gap between the cathode substrate and the anode substrate.

[0037] The insulator 4 in this embodiment is made of insulating materials such as ceramic sheets and quartz sheets. The height of the insulator 4 is in the range of 1 to 500 μm. In this embodiment, the height of the insulator 4 is 300 μm.

[0038] The vacuum degree in the vacuum gap is ~ Pa range, the vacuum degree of the vacuum gap in this embodiment is set to Pa.

[0039] The cathode substrate includes a cathode substrate 9, a cathode electrode layer 8, a cathode growth source film 7, and a cathode nanowire 6. The cathode substrate 9 is a transparent component. Specifically, the cathode substrate 9 of this embodiment adopts transparent glass. The cathode electrode layer 8 is arranged on the cathode substrate 9, the cathode growth source film 7 is arranged on the cathode electrode layer 8, and the cathode nanowire 6 is arranged on the cathode growth source film 7. The surface of the cathode nanowire 6 is coated with a covering layer 5, which is a thermoelectric material.

[0040] The cathode nanowire 6 is a semiconductor nanowire, which includes Si nanowire, copper oxide nanowire, zinc oxide nanowire, gallium arsenide nanowire or indium phosphide nanowire. In this embodiment, the cathode nanowire 6 is ZnO nanowire, and the thermoelectric material is Bi 0.5 Sb 1.5 Te3.

[0041] The cathode electrode layer 8 is made of a transparent conductive film, such as an ITO conductive film.

[0042] The anode substrate of this embodiment includes an anode substrate 1 and an anode electrode layer 3. The anode electrode layer 3 is provided on the anode substrate 1. The anode substrate 1 is a transparent component. In this embodiment, the anode substrate 1 is made of transparent glass.

[0043] The anode electrode layer 3 of this embodiment is a conductive film, such as a Cr, Ni, Ti metal film or an ITO conductive film.

[0044] Joule heat is generated in the process of emitting electrons using the cathode nanowire 6, which leads to a temperature gradient in the axial direction of the cathode nanowire 6. A covering layer 5 of thermoelectric material is coated on the surface of the cathode nanowire 6. The axial temperature gradient of the cathode nanowire 6 causes the thermoelectric material to have an axial potential. This potential increases the emission current and converts Joule heat into electrical energy. In addition, the thermoelectric material converts thermal energy into electrical energy, suppresses temperature rise, avoids vacuum breakdown, and improves the life of the cathode.

[0045] The steps of the preparation method of the photoelectric energy conversion device of this embodiment are as follows:

[0046] S1. Preparation of cathode substrate of ZnO nanowires: prepare a cathode substrate 9 of transparent glass with an area of ​​1.5 cm × 2 cm, ultrasonically clean it with acetone, ethanol and deionized water respectively, and finally blow it dry with a nitrogen gun; wrap it with aluminum film to expose an area of ​​about 1.2 cm × 1.5 cm, and use magnetron sputtering vacuum coating technology to coat ITO conductive film as cathode electrode layer 8 on the cathode substrate 9, wherein the ITO coating power is 1.27 kW, the coating time is 35 min, and the film thickness is 500 μm; use photolithography and electron beam evaporation technology to coat a cathode growth source film 7 of square Zn lattice on the ITO conductive film, and use thermal oxidation method to grow cathode nanowires 6 of ZnO nanowires on the cathode growth source film 7, the oxidation temperature is 470℃, the oxidation time is 3 h, and the distribution area of ​​cathode nanowires 6 is about 1 , the nanowire height is about 3 ~ 7μm, and the tip diameter is about 40 nm;

[0047] S2, using electron beam evaporation technology to coat a layer of Bi on the surface of ZnO nanowires 0.5 Sb 1.5 A capping layer 5 of Te3 thermoelectric material with a thickness of about 15 nm;

[0048] S3. Preparation of the anode substrate: prepare a glass anode substrate 1 with an area of ​​1.5 cm × 2 cm and a thickness of 3 mm. Prepare an exhaust hole 2 on the anode substrate 1 and clean it with acetone, ethanol and deionized water ultrasonically. Finally, blow it dry with a nitrogen gun and wrap it with aluminum film to expose an area of ​​approximately 1.2 cm × 1.5 cm. Use magnetron sputtering vacuum coating technology to coat an ITO conductive film on the anode substrate 1 as the anode electrode layer 3. The ITO coating power is 1.27 kW, the coating time is 35 minutes, and the film thickness is 500 μm.

[0049] S4. Prepare a photoelectric energy conversion device. Separate and fix the anode substrate with the ITO conductive film and the cathode substrate with the ZnO nanowires by an insulator 4. The insulator 4 is a ceramic sheet with a height of 300 μm. A vacuum gap is maintained between the anode substrate and the cathode substrate. Then, place the device in a vacuum chamber or perform vacuum packaging. The vacuum degree of the vacuum gap is Pa.

[0050] Example 2:

[0051] This embodiment uses a specific example to illustrate in detail that the temperature of the cathode nanowires 6 of the photoelectric energy conversion device of the present invention increases and the emission current increases after being irradiated with light.

[0052] The difference between this embodiment and embodiment 1 is that the cathode ZnO nanowires are replaced with CuO nanowires, and no thermoelectric material coating is performed.

[0053] The preparation process is as follows:

[0054] S1. Preparation of cathode substrate of CuO nanowires: prepare a cathode substrate 9 of transparent glass with an area of ​​1.5 cm × 2 cm, ultrasonically clean it with acetone, ethanol and deionized water respectively, and finally blow it dry with a nitrogen gun; wrap it with aluminum film to expose an area of ​​about 1.2 cm × 1.5 cm, and use magnetron sputtering vacuum coating technology to coat ITO conductive film as cathode electrode layer 8 on the cathode substrate 9, wherein the ITO coating power is 1.27 kW, the coating time is 35 min, and the film thickness is 500 μm; use photolithography and magnetron sputtering vacuum coating technology to coat a cathode growth source film 7 of square Cu lattice on the ITO conductive film, and use thermal oxidation method to grow cathode nanowires 6 of CuO nanowires on the cathode growth source film 7, the oxidation temperature is 430 ℃, the oxidation time is 6 h, and the distribution area of ​​cathode nanowires 6 is about 1 , the nanowire height is about 5 ~ 15 μm, and the tip diameter is about 30 nm;

[0055] S2. Preparation of the anode substrate: Prepare a glass anode substrate 1 with an area of ​​1.5 cm × 2 cm and a thickness of 3 mm. Prepare an exhaust hole 2 on the anode substrate 1, and ultrasonically clean it with acetone, ethanol, and deionized water. Finally, blow it dry with a nitrogen gun, wrap it with aluminum film, and expose an area of ​​approximately 1.2 cm × 1.5 cm. Use magnetron sputtering vacuum coating technology to coat an ITO conductive film on the anode substrate 1 as the anode electrode layer 3. The ITO coating power is 1.27 kW, the coating time is 35 minutes, and the film thickness is 500 μm.

[0056] S3. Prepare a photoelectric energy conversion device. Separate and fix the anode substrate with the ITO conductive film and the cathode substrate with the CuO nanowires by an insulator 4. The insulator 4 is a ceramic sheet with a height of 300 μm. A vacuum gap is maintained between the anode substrate and the cathode substrate. Then, place the device in a vacuum chamber or perform vacuum packaging. The vacuum degree of the vacuum gap is Pa.

[0057] S4. Connect the anode electrode layer 3 of the photoelectric energy conversion device to a high potential, and connect the cathode electrode layer 8 to a low potential.

[0058] In this embodiment, steps S1 to S4 are performed to obtain a comparison of the field emission characteristics of the CuO nanowire cathode before and after irradiation with infrared light, as shown in FIG. Figure 4The cathode temperature increased significantly under light irradiation, from room temperature 28 ℃ to 170 ℃, and the emission current of the nanowires was significantly improved, indicating that the CuO nanowires have a PETE effect.

[0059] Example 3

[0060] This embodiment uses a specific example to illustrate in detail that the present invention uses a covering layer 5 made of thermoelectric material, which can convert Joule heat energy in the emission process of the nanowire emitter into electrical energy, thereby improving the field emission characteristics.

[0061] The difference between this embodiment and embodiment 1 is that, in step S1 , only the emission characteristics of the cathode nanowires 6 before and after coating are tested.

[0062] The preparation process is as follows:

[0063] S1. Preparation of cathode substrate of ZnO nanowires: prepare a cathode substrate 9 of transparent glass with an area of ​​1.5 cm × 2 cm, ultrasonically clean it with acetone, ethanol and deionized water respectively, and finally blow it dry with a nitrogen gun; wrap it with aluminum film to expose an area of ​​about 1.2 cm × 1.5 cm, and use magnetron sputtering vacuum coating technology to coat ITO conductive film as cathode electrode layer 8 on the cathode substrate 9, wherein the ITO coating power is 1.27 kW, the coating time is 35 min, and the film thickness is 500 μm; use photolithography and electron beam evaporation technology to coat a cathode growth source film 7 of square Zn lattice on the ITO conductive film, and use thermal oxidation method to grow cathode nanowires 6 of ZnO nanowires on the cathode growth source film 7, the oxidation temperature is 470℃, the oxidation time is 3 h, and the distribution area of ​​cathode nanowires 6 is about 1 , the nanowire height is about 3 ~ 7μm, and the tip diameter is about 40 nm;

[0064] S2, placing the cathode nanowire 6 in a vacuum chamber, connecting the cathode substrate 9 to an ammeter, and the anode, a tungsten needle, to a voltage source;

[0065] S3, using electron beam evaporation technology to coat a layer of Bi on the surface of ZnO nanowires 0.5 Sb 1.5 A capping layer 5 of Te3 thermoelectric material with a thickness of about 15 nm;

[0066] S4, the Bi-plated 0.5 Sb 1.5 The cathode substrate of Te3 is placed in a vacuum chamber, the cathode substrate is connected to an ammeter, and the anode is a tungsten needle, which is connected to a voltage source.

[0067] In this embodiment, steps S1 to S4 are performed to obtain a ZnO nanowire cathode before coating. 0.5 Sb 1.5Comparison of field emission characteristics after Te3, such as Figure 5 The results show that the field emission characteristics of the cathode are significantly improved after coating, indicating that the coating of Bi 0.5 Sb 1.5 Te3 can improve the emission performance of nanowires.

[0068] The above specifically describes the preferred embodiments of the present invention, but the invention is not limited to the embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A photoelectric energy conversion device, characterized in that: comprising a cathode substrate and an anode substrate arranged in parallel; The cathode substrate comprises a transparent cathode substrate (9), a cathode electrode layer (8) located on the cathode substrate (9), a cathode growth source film (7) located on the cathode electrode layer (8), cathode nanowires (6) located on the cathode growth source film (7), and a covering layer (5) of thermoelectric material coated on the surface of the cathode nanowires (6); The anode substrate comprises a transparent anode substrate (1) and an anode electrode layer (3) located on the anode substrate (1); The cathode substrate and the anode substrate are separated and fixed by a high-voltage insulating separator (4) so ​​that a vacuum gap is left between the cathode substrate and the anode substrate; The cathode electrode layer (8) is a transparent conductive film, which includes an ITO conductive film; The cathode nanowire (6) is a semiconductor nanowire, which includes Si nanowire, copper oxide nanowire, zinc oxide nanowire, gallium arsenide nanowire or indium phosphide nanowire; The thermoelectric material includes Bi 0.5 Sb 1.5 Te3, thickness 15 nm; The Joule heat generated during the process of the cathode nanowire (6) emitting electrons causes a temperature gradient to exist in the axial direction of the cathode nanowire (6), causing the thermoelectric material to have an axial potential, thereby increasing the emission current and suppressing the temperature rise.

2. The photoelectric energy conversion device according to claim 1, characterized in that: The anode electrode layer (3) is connected to a high potential, and the cathode electrode layer (8) is connected to a low potential.

3. The photoelectric energy conversion device according to claim 1, characterized in that: The anode electrode layer (3) is a conductive film, which includes a Cr, Ni, Ti metal film or an ITO conductive film.

4. The photoelectric energy conversion device according to claim 1, characterized in that: The insulator (4) is made of a ceramic sheet or a quartz sheet insulating material, and has a height of 1 to 500 μm.

5. The photoelectric energy conversion device according to claim 1, characterized in that: The vacuum degree of the vacuum gap is ~ Pa.

6. The photoelectric energy conversion device according to claim 1, characterized in that: The cathode substrate (9) and the anode substrate (1) are both transparent glass plates, and an exhaust hole (2) is provided on the anode substrate (1).

7. A method for manufacturing the photoelectric energy conversion device according to any one of claims 1 to 6, characterized in that: The preparation process is as follows: S1. Prepare a cathode substrate, manufacture a cathode substrate (9) of a set size, clean the cathode substrate (9), wrap it with an aluminum film, and use magnetron sputtering vacuum coating technology to coat a transparent conductive film as a cathode electrode layer (8) on the cathode substrate (9), prepare a cathode growth source film (7) on the cathode electrode layer (8), and prepare cathode nanowires (6) on the cathode growth source film (7); S2: preparing a covering layer (5) of thermoelectric material on the surface of the cathode nanowire (6); S3, preparing an anode substrate, manufacturing an anode substrate (1) of a set size, cleaning the anode substrate (1), wrapping it with an aluminum film, and coating a conductive film on the anode substrate (1) as an anode electrode layer (3) using a magnetron sputtering vacuum coating technology; S4. The side of the anode substrate coated with the anode electrode layer (3) and the side of the cathode substrate prepared with the cathode nanowires (6) are fixed to each other by means of an insulator (4), and the vacuum gap between the anode substrate and the cathode substrate is evacuated and packaged.

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