Diffuse reflection space solar cell and preparation method thereof

Abstract

The invention discloses a diffuse reflection space solar cell and a preparation method thereof. The method comprises the following steps: step 1, mixing a light diffusion agent and matrix resin to form a light diffusion coating; step 2, spraying a light diffusion coating on the first surface of the glass cover plate to form a light diffusion coating; step 3, uniformly dispensing a layer of cover plate glue on the light absorption surface of the space solar cell; and 4, covering the second surface of the glass cover sheet on the surface of the cover sheet glue, and curing to obtain the diffuse reflection space solar cell. According to the diffuse reflection space solar cell, reflection loss can be reduced, the conversion efficiency can be improved, the overall brightness of a spacecraft can be reduced, the on-orbit target characteristics of the spacecraft can be changed, and the concealment of the spacecraft in military application can be improved.

Description

Technical Field

[0001] The invention relates to the field of photovoltaic cells, and in particular to a diffuse reflection space solar cell and a preparation method thereof. Background Art

[0002] As the main power generation unit of spacecraft, space solar cells play a vital role in the entire spacecraft system. The safe and stable operation of space solar cells is directly related to the ability of spacecraft to perform on-orbit missions. Usually, the area of ​​the solar wing of a spacecraft is much larger than the area of ​​its own body. Therefore, the solar wing becomes the main target feature of the spacecraft in the on-orbit state. The surface reflection of traditional space solar cells is mainly mirror reflection, which leads to the overall high brightness of the spacecraft and is easy to be observed.

[0003] The light diffusion coating composed of a light diffuser and a matrix resin disperses the incident light into transmission and scattering at different angles through the light diffuser, and has been widely used in the fields of LED lighting. However, since the space environment reliability (extreme temperature tolerance, radiation resistance, etc.) of conventional light diffusers and matrix resins cannot meet the requirements of extremely high conversion efficiency of space solar cells, and the low transmittance of conventional light diffusion coatings will affect the conversion efficiency of space solar cells, light diffusion coatings have not yet been used in the field of space solar cells. Summary of the invention

[0004] The purpose of the present invention is to provide a diffuse emission space solar cell and a preparation method thereof. The space solar cell has a surface diffuse reflection characteristic, which can not only improve the conversion efficiency of the cell, but also reduce the overall brightness of the spacecraft, realize the change of its on-orbit target characteristics, and improve its concealment in military applications.

[0005] In order to achieve the above object, the present invention provides a method for preparing a diffuse reflection space solar cell, the method comprising:

[0006] Step 1, mixing a light diffusing agent with a base resin to form a light diffusing coating;

[0007] Step 2, spraying the light diffusion coating onto the first surface of the glass cover to form a light diffusion coating;

[0008] Step 3, evenly apply a layer of cover glue on the light-absorbing surface of the space solar cell;

[0009] Step 4, covering the second side of the glass cover sheet on the surface of the cover sheet adhesive, and curing to obtain a diffuse reflection space solar cell.

[0010] Optionally, in step 1, the light diffuser is any one of SiO2 microspheres and silicone resin spherical micropowders; the matrix resin is any one of spatial silicone rubber and polymethylsiloxane ester; the mass ratio of the light diffuser to the matrix resin is (3-5): (95-97).

[0011] Optionally, after step 1 and before step 2, the method further comprises fixing the glass cover sheet on the platform, and the method of fixing the glass cover sheet comprises: any one of vacuum adsorption, concave fixing tooling, and tape fixing.

[0012] Optionally, in step 2, the thickness of the light diffusion coating is 8 μm-12 μm.

[0013] Optionally, in step 2, the method for forming the light diffusion coating further comprises: heating and curing, wherein the curing temperature is 60° C.-100° C., and the curing time is 1 h-2 h.

[0014] Optionally, in step 4, before curing, the glass cover sheet is further subjected to weight pressing, and the weight pressure is 4.7 g / cm 2 -5g / cm 2 .

[0015] The present invention also provides a diffuse reflection space solar cell obtained by using any one of the preparation methods described above.

[0016] Optionally, it comprises a plurality of diffuse reflection space solar cells connected in series, wherein the series connection refers to lead-out welding of interconnecting sheets and diodes of the diffuse reflection space solar cells.

[0017] Optionally, the interconnection sheet is made of any one of silver and kovar silver-plated; and the diode includes an output diode and a bypass diode.

[0018] Optionally, the output diode is a germanium diode with a forward voltage of 0.2V-0.3V; the bypass diode is a silicon diode with a forward voltage of 0.5V-0.6V.

[0019] Compared with the prior art, the technical solution of the present invention has at least the following beneficial effects:

[0020] 1) Spray light diffusion coating on the surface of the glass cover to obtain a glass cover with a light diffusion coating, and then bond the glass cover with the light diffusion coating to the space solar cell to obtain a space solar cell with surface diffuse reflection characteristics. When the incident light enters the light diffusion coating, it is scattered and transmitted by the light diffusion particles to form a disordered diffuse light. The diffuse light enters the space solar cell and is reflected at its interface. The disordered reflected light passes through the light diffusion coating twice and then emerges in a disordered diffuse reflection state. Ordinary space solar cells are mainly based on mirror reflection, and basically all reflected light is reflected in a certain direction, while the reflected light of the diffuse reflection space solar cell is reflected in all directions. Part of the reflected light may enter the cell after multiple reflections in the light diffusion coating, reducing reflection loss and increasing the amount of absorbed light, thereby improving the conversion efficiency of the cell. At the same time, the diffuse reflection space solar cell can reduce the overall brightness of the space vehicle, achieve the change of its on-orbit target characteristics, and improve its concealment in military applications.

[0021] 2) Furthermore, since the light diffuser and base resin in the light diffusion coating have high transmittance, high haze (strong light diffusion ability) and high space environment reliability, they can improve the tolerance of space solar cells under extreme temperatures without affecting the conversion efficiency of space solar cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The present invention is a flow chart of the method for preparing the diffuse emission space solar cell.

[0023] Figure 2 Schematic diagram of the light diffusion coating of the present invention.

[0024] Figure 3 It is a schematic diagram of the structure of fixing the glass cover of the present invention.

[0025] Figure 4 It is a structural schematic diagram of a glass cover sheet sprayed with a light diffusion coating according to the present invention.

[0026] Figure 5 It is a schematic structural diagram of the light diffusion coating of the present invention.

[0027] Figure 6 The schematic diagram of the structure of the space solar cell of the present invention is that a layer of cover film glue is evenly coated on the light-absorbing surface of the space solar cell.

[0028] Figure 7 It is a schematic diagram of the structure of the diffuse reflection space solar cell of the present invention.

[0029] Figure 8 The present invention is a schematic structural diagram of the interconnection sheet and diode lead welding of the diffuse reflection space solar cell.

[0030] Fig. 9It is a schematic diagram of the structure of generating diffused light of the present invention.

[0031] Fig.10 It is a schematic diagram of the structure of generating diffuse reflected light according to the present invention.

[0032] Figure symbols: light diffuser 1, base resin 2, light diffusion coating 3, glass cover 4, platform 5, adsorption hole 51, nozzle 6, light diffusion coating 41, space solar cell 7, diffuse reflection space solar cell 71, interconnection sheet 8, diode 9, cover glue 10. DETAILED DESCRIPTION

[0033] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] In the description of the present invention, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0035] As described in the background technology, the reliability of conventional light diffusers and matrix resins in space environments cannot meet the requirements of extremely high conversion efficiency of space solar cells, and the light diffusion coating formed by conventional light diffusers and matrix resins has a low transmittance, which will also affect the conversion efficiency of space solar cells. Therefore, light diffusion coatings have not yet been used in the field of space solar cells.

[0036] In order to expand the application of light diffusion coatings in the field of space solar cells, the present invention sprays light diffusion coating on the surface of a glass cover sheet to obtain a glass cover sheet with a light diffusion coating, and then bonds and laminates the glass cover sheet with the light diffusion coating and a space solar cell to obtain a space solar cell with surface diffuse reflection characteristics. The space solar cell can not only improve the conversion efficiency, but also reduce the overall brightness of the space vehicle, achieve changes in its on-orbit target characteristics, and improve its concealment in military applications. In addition, because the light diffuser and the matrix resin in the light diffusion coating both have high transmittance, high haze, and high space environment reliability, the tolerance of space solar cells to extreme temperatures can be improved without affecting the conversion efficiency of the space solar cells. Specifically, the present invention provides a method for preparing a diffuse reflection space solar cell, and its process is as follows: Figure 1 As shown:

[0037] Step S1, mixing a light diffusing agent with a base resin to form a light diffusing coating.

[0038] like Figure 2 As shown, the light diffuser 1 and the base resin 2 are mixed in a certain mass ratio to obtain the light diffusion coating 3. In some embodiments, the light diffuser 1 is any one of SiO2 microspheres and silicone resin spherical micropowders; the base resin 2 is any one of space silicone rubber and polymethylsiloxane ester. The light diffuser 1 and the base resin 2 have high transmittance, high haze and high space environment reliability, which improve the tolerance of space solar cells under extreme temperatures and do not affect the conversion efficiency of the cells after bonding and lamination. Preferably, the mass ratio of the light diffuser 1 to the base resin 2 is 5:95. This ratio can better meet the requirements of the subsequent spraying process. For situations with high fluidity requirements and thin coating requirements, a mass ratio of 4:96 or 3:97 can also be selected.

[0039] Step S2, fixing the glass cover on the platform.

[0040] like Figure 3 As shown, the glass cover sheet 4 is fixed on the platform 5 by vacuum adsorption, and the platform 5 has a plurality of evenly distributed adsorption holes 51, which are used to achieve even distribution of adsorption force on the platform 5. In some embodiments, the adsorption size of the platform 5 can be switched according to the shape and size of the battery, and the method of fixing the glass cover sheet 4 also includes any one of a concave fixing tool and a tape fixing.

[0041] Step S3, spraying a light diffusion coating on the first surface of the glass cover to form a light diffusion coating.

[0042] like Figure 4 As shown, the light diffusion coating 3 is uniformly sprayed on the first surface of the glass cover 4 through the nozzle 6 to form a light diffusion coating 41. Figure 5The number of spraying times can be set according to the required coating thickness, haze, transmittance and other requirements, generally need to reach 80 times to ensure that the coating has a high haze and transmittance, the maximum is not more than 120 times, the thickness of the light diffusion coating 41 is controlled at 8μm-12μm.

[0043] Step S4, heating and curing the glass cover.

[0044] The glass cover sheet 4 is heated and cured in an oven. The specific curing conditions are related to the type of the matrix resin 2. Since the curing temperature will affect the flatness of the glass cover sheet 4, the curing temperature is controlled at 60° C.-100° C. and the curing time is 1 h-2 h.

[0045] Step S5, evenly apply a layer of cover glue on the light-absorbing surface of the space solar cell.

[0046] like Figure 6 As shown, an automatic glue dispenser is used to evenly apply a layer of cover glue 10 on the light-absorbing surface of the space solar cell 7, the purpose of which is to resist the damage of high-energy particles and space rays to the space solar cell 7 and improve the reliability and efficiency of the space solar cell 7 in the harsh space environment. In this embodiment, the cover glue 10 is made of space silicone rubber, which has high transmittance, high haze and high reliability in the space environment, and does not affect the conversion efficiency and service life of the space solar cell 7 after lamination.

[0047] Step S6, covering the second side of the glass cover sheet on the surface of the cover sheet adhesive, and curing to obtain a diffuse reflection space solar cell.

[0048] like Figure 7 As shown, the second side of the glass cover sheet 4 is covered on the surface of the cover sheet glue 10 by a tool fixing method, so that the light diffusion coating 41 does not contact the cover sheet glue 10. After the covering is completed, the glass cover sheet 4 is subjected to counterweight extrusion to assist the cover sheet glue 10 to be evenly distributed on the surface of the space solar cell 7. According to the characteristics of the cover sheet glue 10 and the thickness requirements of the laminated battery, the light diffusion coating 41 can be 4.7g / cm 2 -5g / cm 2 The appropriate counterweight pressure is selected within the range. After the counterweight is extruded, it is solidified to obtain a space solar cell with surface diffuse reflection characteristics.

[0049] Step S7, lead-out welding is performed on the interconnection sheet and the diode of the diffuse reflection space solar cell.

[0050] like Figure 8As shown, an automatic welding device is used to weld the interconnection sheet 8 at the positive and negative electrodes of the diffuse reflection space solar cell 71, and to weld the diode 9 at the negative electrode. The main function of the interconnection sheet 8 is to connect multiple solar cells by welding to achieve series connection between cells, thereby forming a solar cell array. Through precise welding, the effective transmission of current can be ensured and the efficiency of the battery array can be improved. The main function of the diode 9 is unidirectional conduction, which is used to prevent the battery cell from burning. In some embodiments, the material of the interconnection sheet 8 is any one of silver and kovar silver-plated; the diode 9 includes an output diode and a bypass diode, the output diode is a germanium diode, and the forward opening voltage is 0.2V-0.3V; the bypass diode is a silicon diode, and the forward opening voltage is 0.5V-0.6V.

[0051] The diffuse reflection principle of the space solar cell is: when light passes through the light diffusion coating 41, due to the different refractive indices of the light diffuser 1 and the matrix resin 2, optical phenomena such as reflection, refraction and scattering occur, thereby achieving the effect of light diffusion. Fig. 9 The diffuse light enters the diffuse reflection space solar cell 71 and is reflected at its interface. The disordered reflected light passes through the light diffusion coating 41 twice and then is emitted in a disordered diffuse reflection state, thus realizing the surface diffuse reflection of the diffuse reflection space solar cell 71. Fig.10 shown.

[0052] The following SiO2 microspheres were purchased from Shin-Etsu Co., Ltd., Japan, and the space silicone rubber was purchased from the Institute of Chemistry, Chinese Academy of Sciences.

[0053] Example

[0054] Step 1: Mix SiO2 microspheres with a particle size of 1 μm and spatial silicone rubber in a mass ratio of 5:95, and stir and disperse them at a speed of 600 r / min for 20 minutes to obtain a light diffusion coating.

[0055] Step 2: Fix a 4 cm×6 cm glass cover sheet on the platform by vacuum adsorption.

[0056] Step 3: spray the light diffusion coating onto the first surface of the glass cover plate through a nozzle using a spraying process to form a light diffusion coating. The thickness of the light diffusion coating is 10 μm.

[0057] Step 4, using an oven to heat and cure the glass cover sheet, the curing temperature is 60° C., and the curing time is 2 hours.

[0058] Step 5, use an automatic dispensing machine to evenly apply a layer of space silicone rubber on the light-absorbing surface of the space solar cell.

[0059] Step 6: Use a tooling fixation method to cover the second side of the glass cover on the surface of the space silicone rubber, and perform weight extrusion on the glass cover with a weight pressure of 4.8 g / cm 2After the weight extrusion is completed, it is cured at a temperature of 60°C and a curing time of 1 hour. After the curing is completed, a diffuse reflection space solar cell is obtained.

[0060] Step 7, use automatic welding equipment to weld silver interconnects at the positive and negative electrodes of the diffuse reflection space solar cell, and weld germanium diodes and silicon diodes at the negative electrode. The forward opening voltage of the germanium diode is 0.2V; the forward opening voltage of the silicon diode is 0.5V.

[0061] In summary, the present invention bonds and laminates a glass cover sheet with a light diffusion coating with a space solar cell to obtain a space solar cell with surface diffuse reflection characteristics. When the incident light enters the light diffusion coating, it is scattered and transmitted by the light diffusion particles to form a disordered diffuse light. The diffuse light enters the space solar cell and is reflected at its interface. The disordered reflected light passes through the light diffusion coating twice and then emerges in a disordered diffuse reflection state. Ordinary space solar cells mainly use mirror reflection, and basically all reflected light is reflected in a certain direction, while the reflected light of the diffuse reflection space solar cell is reflected in all directions. Part of the reflected light may enter the cell after multiple reflections in the light diffusion coating, thereby reducing reflection losses and increasing the amount of absorbed light, thereby improving the conversion efficiency of the cell. At the same time, the diffuse reflection space solar cell can reduce the overall brightness of the space vehicle, realize the change of its on-orbit target characteristics, and improve its concealment in military applications. In addition, since the light diffuser and the base resin in the light diffusion coating have high transmittance, high haze and high space environment reliability, the tolerance under extreme temperatures is improved without affecting the conversion efficiency of the space solar cell.

[0062] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. A method for preparing a diffuse reflection space solar cell, characterized in that: The method includes: Step 1, mixing a light diffusing agent with a base resin to form a light diffusing coating; Step 2, spraying the light diffusion coating onto the first surface of the glass cover to form a light diffusion coating; Step 3, evenly apply a layer of cover glue on the light-absorbing surface of the space solar cell; Step 4, covering the second side of the glass cover sheet on the surface of the cover sheet adhesive, and curing to obtain a diffuse reflection space solar cell.

2. The method for preparing a diffuse reflection space solar cell according to claim 1, characterized in that: In step 1, the light diffuser is any one of SiO2 microspheres and silicone resin spherical micropowders; the matrix resin is any one of spatial silicone rubber and polymethylsiloxane ester; the mass ratio of the light diffuser to the matrix resin is (3-5): (95-97).

3. The method for preparing a diffuse reflection space solar cell according to claim 1, characterized in that: After step 1 and before step 2, the glass cover sheet is further fixed on the platform, and the method of fixing the glass cover sheet includes: any one of vacuum adsorption, concave fixing tooling, and tape fixing.

4. The method for preparing a diffuse reflection space solar cell according to claim 1, characterized in that: In the step 2, the thickness of the light diffusion coating is 8 μm-12 μm.

5. The method for preparing a diffuse reflection space solar cell according to claim 1, characterized in that: In the step 2, the method for forming the light diffusion coating further comprises: heating and curing, wherein the curing temperature is 60° C.-100° C. and the curing time is 1 h-2 h.

6. The method for preparing a diffuse reflection space solar cell according to claim 1, characterized in that: In the step 4, before the curing, the glass cover sheet is further subjected to weight pressing, and the weight pressure is 4.7 g / cm 2 -5g / cm 2 .

7. A diffuse reflection space solar cell obtained according to the preparation method according to any one of claims 1 to 6.

8. A diffuse reflection space solar array, characterized in that: The invention comprises a plurality of diffuse reflection space solar cells as claimed in claim 7 connected in series, wherein the series connection refers to the lead-out welding of the interconnecting pieces and the diodes of the diffuse reflection space solar cells.

9. The diffuse reflection space solar cell array according to claim 8, characterized in that: The interconnection sheet is made of any one of silver and kovar silver-plated; the diode includes an output diode and a bypass diode.

10. The diffuse reflection space solar cell array according to claim 9, characterized in that: The output diode is a germanium diode with a forward opening voltage of 0.2V-0.3V; the bypass diode is a silicon diode with a forward opening voltage of 0.5V-0.6V.

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