Optical shield for photovoltaic cell and photovoltaic cell

Abstract

An optical shield for a photovoltaic cell and a photovoltaic cell are provided. The invention relates to an optical shield comprising a plurality of separate structural elements, each separate structural element comprising at least one carrier element (11) having at least one optically functional cavity embedded therein, the embedded optically functional cavities (51) are arranged in at least one predetermined optically engraved pattern (52), and wherein each separate structural element having at least one of the optically functional cavities embedded in the carrier element is positioned over and alignable with a separate surface structure (10), the invention relates to a photovoltaic cell (10) comprising a body (12) of the photovoltaic cell (10), a plurality of separate structural elements arranged on the body (12) of the photovoltaic cell (10) so as to prevent light from impacting the surface structure, the separate surface structures being arranged on the surface of the body (12) of the photovoltaic cell (10), each separate structural element not providing full coverage to the body (12) of the photovoltaic cell.

Description

[0001] This application is a divisional application of an invention patent application with an application date of February 22, 2018, application number "201880020190X" (PCT / FI2018 / 050132), and invention name "Optical shielding for photovoltaic cells". Technical Field

[0002] The present invention relates generally to optical components. In particular, the present invention relates to an optical shield for surface structures such as contacts, electrodes, fingers and busbars disposed on photovoltaic cells. Background Art

[0003] Typically, photovoltaic (PV) cells or PV materials, especially multicrystalline and monocrystalline silicon, have surface structures such as contacts, electrodes, fingers and / or busbars covering 5% to 10% of the PV surface. These surface contacts are typically silver electrodes produced by mask printing and have a reflectivity of 85%. Such contacts typically cause reflection and shadowing losses, which means that there will be optical losses of about 5% to 10% and, in general, a reduction in the output power of the same amount of cell used.

[0004] On the other hand, minimizing the amount and size of surface structures on the photovoltaic cell (top) surface will result in greater resistance and associated electrical losses to the overall cell power output. In this regard, conventional contact and / or electrode designs are a compromise design between these two parameters.

[0005] Additionally, the size, number, period and / or location of the PV cell structures described above have an impact on factors such as internal resistance, transmission current and high versus low area doping. These factors result in a reduction or increase in the overall power output of the PV cell.

[0006] Currently and expected in the future, the architecture, design and construction of PV cells are / will be based on providing contacts and / or electrodes on the surface of the cell. Figure 1A and Figure 1B ). Available contactless solutions combine higher manufacturing prices with lower yields; therefore, the dominance of such solutions in PV cell design and architecture is not a directly relevant topic. Summary of the invention

[0007] An object of the present invention is to at least alleviate the various problems caused by the limitations and disadvantages of the prior art. This object is achieved by various embodiments of an optical shield assembly for a photovoltaic cell according to what is defined in the embodiments of the present application.

[0008] In some embodiments, an optical shield for a photovoltaic cell is provided, wherein at least one carrier element includes a plurality of embedded optical functional cavities arranged into at least one predetermined optical engraving pattern, wherein each embedded optical functional cavity in the at least one carrier element is positioned and aligned on a separate surface structure, and the separate surface structure (such as an electrode, contact, finger or busbar) is disposed on a surface of the photovoltaic cell.

[0009] In some embodiments, the optical shield includes a plurality of separate structural elements, each of the separate structural elements includes at least one carrier element, the at least one carrier element having at least one optical functional cavity embedded in the carrier element, wherein the embedded optical functional cavities are arranged into at least one predetermined optical engraving pattern, and wherein each separate structural element having at least one optical functional cavity embedded in the carrier element is positioned above a separate surface structure and can be aligned with a separate surface structure to prevent light from striking the surface structure, the separate surface structure being disposed on the surface of the body of the photovoltaic cell, and each separate structural element does not provide full coverage of the body of the photovoltaic cell.

[0010] In some embodiments, the optical shield further comprises a flat planar base element disposed relative to at least one carrier element such that the optically functional cavity is located between a layer defined by the at least one carrier element and a layer defined by the base element.

[0011] In some embodiments, the optical function cavity is filled with an internal dielectric material having a refractive index different from the refractive index of the dielectric material surrounding the cavity. In other embodiments, in terms of the size, shape, dimensions and arrangement of the embedded optical function cavity, each embedded optical function cavity is configured to be used for at least one of a reflection function, a refraction function, a deflection function and a diffraction function.

[0012] In some embodiments, at least one of the carrier element and / or the base element is a plastic polymer, glass, or resin.

[0013] In some preferred embodiments, the embedded optical functional cavity is provided in the form of a V-shaped groove.

[0014] In some embodiments, the cavity is filled with an inner dielectric material provided in a fluid or solid form, which material may be selected from air, gas, and liquid.

[0015] In some further embodiments, each embedded optically functional cavity is at least partially coated by an optically functional coating, wherein the optical function of the coating comprises at least one of: specular reflection, diffuse reflection, and wavelength selective reflection.

[0016] In some embodiments, the embedded optically functional cavities each correspond to a surface structure disposed on the surface of a photovoltaic cell in terms of size parameters and arrangement within the optically engraved pattern.

[0017] In some further embodiments, the optical shield comprises at least two carrier elements, one carrier element being disposed on another carrier element, wherein each carrier element comprises a plurality of embedded optical functional cavities, the optical functional cavities being arranged into at least one predetermined optical engraving pattern, and wherein, for each carrier element, the size, shape and periodicity of the optical functional cavities in at least one optical engraving pattern are individually adjustable.

[0018] In some embodiments, the optical shield is configured to cover the entire surface of the photovoltaic cell. In some other embodiments, the optical shield is configured as a plurality of separate elements, wherein each separate element is positioned and aligned on a separate surface structure disposed on the surface of the photovoltaic cell. In other embodiments, the optical shield comprises separate elements arranged in a grid.

[0019] The optical shield may also be configured as a film, a sheet or a strip.

[0020] In another aspect, there is provided a photovoltaic cell according to what is defined in the embodiments of the present application and comprising an optical shield according to the previous aspects. In some embodiments, the photovoltaic cell comprises an optical shield disposed under its protective cover.

[0021] The utility of the present invention, according to various embodiments of the present invention, arises from various reasons. The primary standpoint is that the present invention is based on a fully integrated, embedded cavity optical element provided as a plurality of optically functional cavities forming at least one optical engraving pattern within a carrier element, the optical engraving pattern forming an optical shield for surface structures (such as contacts, electrodes, fingers and / or busbars) of a photovoltaic cell.

[0022] The embedded optical solution proposed thereby allows avoiding light reflection and shadow losses caused by contacts and / or electrodes on conventional PV cells (see Figure 1B , showing incident light 31, which is incident on the surface structure 10, and immediately reflected outside the PV cell 32). Embedded optical elements, such as optically functional cavities, are located near the individual surface structures mentioned above, thereby forming an optical shield that directs light onto the PV silicon surface, thereby preventing the light from hitting the individual surface structures and thereby being reflected out of the PV cell.

[0023] The invention also provides the flexibility to vary the size, shape and periodicity of the optically functional cavities within at least one optically engraved pattern, as well as their filling materials, whereby the pattern can be configured as a refractive, diffractive or hybrid optical element, the hybrid optical element combining reflective, deflective, refractive and / or diffractive functions. It is also possible to manufacture multi-layer solutions, in which a first layer forms an optical shield; while a second layer and / or further layers comprise integrated cavity optical elements in the same manner as the first layer, the second layer and / or further layers being endowed with additional optical functions, such as light guiding and redirection, diffusion, reflection, coupling, etc.

[0024] The term "surface structure" is generally used in this disclosure to refer to contacts, electrodes, fingers, busbars, etc., disposed on the surface of a photovoltaic cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Various embodiments of the present invention will become apparent by referring to the detailed description and the accompanying drawings, in which:

[0026] Figure 1A and Figure 1B A conventional solution of a photovoltaic cell 101 is shown, wherein Figure 1A A contact line 10 is shown on the surface of a solar (photovoltaic) cell, and Figure 1B A solar panel 101 is shown with one or more contacts 10 on the top surface of the solar panel 101, and incident light 31 is reflected away from the contacts (reflected light 32) so that no photon absorption occurs.

[0027] Figure 2 , Figure 3 , Figure 4 and Figure 5 Optical shielding solutions according to various embodiments of the invention are shown.

[0028] Figure 6 The optical shield is shown prior to lamination to the photovoltaic cell.

[0029] Figure 7 A separate optical shield solution is shown in accordance with some embodiments.

[0030] Fig. 8A and Figure 8B Various implementations of photovoltaic cells 201 , 201A are shown according to some aspects. DETAILED DESCRIPTION

[0031] Detailed embodiments of the present invention are disclosed herein with reference to the accompanying drawings. The same reference numerals are used throughout the drawings to represent the same components. The following references are used for the components:

[0032] 201, 201A-Photovoltaic cells,

[0033] 10-Surface structure on the surface of the PV cell,

[0034] 11. 11A-Carrier element with optical function,

[0035] 12-The body of the PV cell,

[0036] 13- adhesive layer,

[0037] 14- Top protective layer of PV cells,

[0038] 20, 20A-Optical shielding assembly,

[0039] 21- a base element of the carrier element 11,

[0040] 31, 32-corresponding incident light and reflected light,

[0041] 33-receive light,

[0042] 51, 51A-optical functional cavity,

[0043] 52, 52A-Optical engraving pattern.

[0044] Figure 2 The basic concept of various embodiments of an optical shield assembly (hereinafter referred to as an optical shield) is shown at 20, which is used for a photovoltaic cell indicated by reference numeral 201. The optical shield 20 thus comprises at least one flat planar carrier element 11 having a plurality of optically functional cavities 51 arranged in at least one predetermined optically engraved pattern 52 (referred to by Figure 2 The at least one carrier element 11 is preferably made of a plastic polymer, glass, resin or ceramic material.

[0045] In one embodiment, the carrier element 11 forming the optical shield 20 is advantageously arranged on the (top) surface of the body 12 of the photovoltaic cell.

[0046] Preferably, the optical shield is provided as a flat, planar, uniform element having smooth, uninterrupted uppermost and lowermost faces / sides. To achieve this, the optical shield is provided as 20A and at Figure 2The optical shield depicted in the dashed box also includes a base element 21, which is configured as a completely flat planar layer made of the same material as the carrier element 11, or made of an alternative material selected from the following: plastic polymer, glass, resin or ceramic material. For example, both layer 11 and layer 21 can be made of plastic polymer; alternatively, the carrier layer 11 can be a plastic polymer and the base element 21 can be glass. The optical shield assembly 20A can cover the entire surface of the PV cell body 12. Figure 6 Also shown in FIG. 2 is configuration 20A.

[0047] In some cases, the carrier element 11 is disposed between the body of the PV cell and a protective cover (such as cover glass or cover plastic) of the PV cell (not shown). Thus, the photovoltaic cell 201 may include a corresponding optical shield 20 disposed below the protective cover.

[0048] Alternatively, the optical shield 20 may be provided as a layer adhered to the lower surface (the surface facing the PV cells) of a protective cover (not shown), or be a part integrated on said protective cover.

[0049] Each optically functional cavity 51 is also positioned and aligned over an individual surface structure 10 provided on the surface of the PV cell 201. The individual surface structures 10 are non-exclusively provided as electrodes, contacts (contact pads or contact plates), fingers or busbars.

[0050] All of the above structures are electrical conductors that are configured to conduct direct current (DC) from the PV cells to the inverter(s). The fingers (also called finger contacts or finger electrodes) are thin metal wires that collect and transfer energy from the solar cells to the busbars. The busbars (also called busbar contacts or busbar electrodes) are typically made of aluminum or silver-plated copper and are arranged perpendicular to the fingers.

[0051] Thus, the optical cavity 51 forms a fully embedded optical pattern integrated at the interface between the carrier element 11 and the substrate 21 (configuration 20A) or between the carrier element 11 and the surface of the PV cell body 12 (configuration 20).

[0052] The height of the optically functional cavities 51 ranges in size from 10 to 1000 μm and is therefore consistent with the size and dimensions of the underlying PV cell surface structure 10. With regard to the configuration of the optical shield 20 provided, nanoscale substructures are however not excluded as far as the cavities 51 are concerned.

[0053] Therefore, the optical shield 20 is formed by at least one carrier element 11, which has a plurality of embedded optical functional cavities 51 (cavity optical elements) based on an internal dielectric material, such as a fluid (air, gas, liquid) or a solid, having an optimized refractive index compared to the surrounding material. Therefore, the cavity 51 is preferably filled with an internal dielectric material having a refractive index different from that of the dielectric material surrounding the cavity. Preferably, the refractive index of the medium is lower than that of the surrounding material. A preferred internal dielectric material (filling material) is air. Another preferred internal dielectric material is a substantially solid material with a low refractive index, such as silicone, which is capable of providing a total internal reflection (TIR) ​​function. "Low refractive index material" refers to a material whose refractive index is lower than that of the dielectric material surrounding the cavity (such as the material from which the carrier element 11 is made).

[0054] On the other hand, each embedded optical function cavity 51 can be at least partially coated with an optical function coating (not shown), wherein the optical function of the coating includes at least one of specular reflection, diffuse reflection and wavelength selective reflection. The coating can be partially applied to the cavity wall or fully applied to all cavity walls. A hybrid coating with nano-optical features constitutes another feasible solution. Therefore, the coating can include, for example, nanocrystals and be configured as an anti-reflection (AR) coating and / or a self-cleaning coating.

[0055] In a preferred embodiment, the cavities 51 are provided in the form of grooves or depressions extending in either direction of the carrier element 11. In some configurations, the grooves are arranged in substantially parallel rows. In other configurations, the grooves may be positioned transversely to form a grating.

[0056] In a preferred embodiment, the cavity (groove) 51 is configured as a V-shaped groove (V-groove), preferably an inverted V-groove (with an inverted V-shape). In practice, the pattern 52 including the cavity 51 depends on the size of the surface structure 10 accordingly in terms of size (such as size, width, height, length). In addition to the groove, the cavity 51 can also be provided as a different element, such as an element with a V-shaped depression (e.g., a prism). In addition, in addition to the V-shape, the cavity can be shaped into different shapes, such as an inclined triangular shape, a rectangular shape, a trapezoidal shape, a concave lens-like shape, etc. Therefore, the pattern 52 can be formed with a single profile (all cavities have the same shape) or multiple profiles (cavities have different shapes).

[0057] Preferably, the size, shape and periodicity of the optically functional cavities within each optically engraved pattern are individually adjustable for each carrier element.The term "adjustable" is used within the meaning of "variable" or "modifiable".

[0058] When a predetermined engraving pattern 52 (typically a V-groove solution) is positioned and aligned on top of a surface structure (e.g., contact and / or electrode), the incident light 31 is reflected by TIR to deviate from its original path ( Figure 2 ). Therefore, the incident light 31 is not reflected outside the PV cell or absorbed by the conductive structure 10 as usually happens in conventional solutions, but is coupled, directed towards the PV cell and collected at the silicon surface of the PV cell, thereby contributing to the generation of electricity. This coupled and contributing light to the generation of electricity is called "received light", which is indicated by reference numeral 33. The electrons generated in the PV cell can be considered as a function of the photon flux. According to equation 1, the generation rate G is proportional to the photon flux N0 per unit area per second.

[0059] Equation 1: G = αN0e -αx

[0060] All incident light 31 (such as sunlight) incident on / coupled at the solar panel is refracted at the top surface of the solar panel, which is usually made of glass or plastic; therefore, the angular distribution inside the solar cell stack is limited to a range of ±42° from the surface normal. In order for all incident light 31 to experience TIR at the surface of the V-groove 51, an opening angle of at least 12° (also called a prism angle or a V-groove angle α, Figure 4 ) groove profile. However, when considering the exposure from the sun over the entire annual period, the angular distribution is mainly concentrated within ±50° from the surface normal. Therefore, the V-groove angle profile can be designed with a larger opening and still provide good collection efficiency. The data in Table 1 below are simulation results with and without the V-groove solution (optical shield 20) in the solar panel using the accumulated annual sunlight exposure data from Morocco. The coverage area of ​​all surface structures 10 (such as surface contacts) in the model is about 10%.

[0061] Table 1: Comparative data obtained from solar panels with and without optical shield 20. The solution including optical shield 20 is called "ICS air cavity" with varying prism angles.

[0062] Normalized percentage increase in collected light energy compared to conventional panels

[0063]

[0064] It is clear from the above comparison that the surface contact design can be optimized with respect to minimizing electrical losses without taking into account reflection and / or shading losses. Electrical losses are defined by current multiplied by resistance. In principle, the total area occupied by the surface structures 10 relative to the entire solar cell or solar panel can be as high as 20-30% in order to be able to collect 95-98% of all available (incident) light by utilizing the contact shield assembly 20 optical element. This is an important feature when considering optimizing the design of surface structures 10 such as contact layers on the emitter (i.e., the top surface of the PV cell body 12). The fractional power loss can be recorded as a function of the distance S between structures 10 such as contact leads (see Equation 2), where the distance S is provided as the distance between the midpoints of the structures 10 ( Figure 3 ). It is worth noting that the distance S is provided as a power of 2 (S 2 ). Theoretically, a significant reduction in power losses can be achieved when the distance S is reduced by a factor of two or even three compared to conventional solutions.

[0065] Equation 22:

[0066]

[0067] Figure 5 A multilayer construction is also shown, wherein a PV cell 201A comprises an optical shield 20 having at least two carrier elements 11, 11A, wherein each carrier element comprises a plurality of embedded optical functional cavities 51, 51A arranged in at least one predetermined optical engraving pattern 52, 52A. Thus, the carrier element 11 forms a shielding structure for the PV cell surface 12 and the surface structure 10 located thereon, while the carrier element 11A has additional optical functions, including but not limited to: light guiding and redirecting, diffusion, reflection, coupling, etc.

[0068] For all configurations, it is preferred that the size, shape and periodicity of the cavities 51 , 51A within the pattern(s) 52 , 52A are adjustable for each individual carrier element 11 , 11A.

[0069] The optical shield 20 of the present invention can be manufactured by conventional manufacturing methods and integrated into the PV cells 201, 201A. The basic structure of the optical shield 20 is a film, preferably a thin film. During manufacturing, the film is arranged on each PV cell to align the cavity 51 on the surface structure 10. The optical shield film is preferably manufactured by a roll-to-roll or roll-to-sheet method, which provides punching according to the size of the photovoltaic cell. This method can manufacture large volumes at low cost. The film material can be an optical plastic, resin or ceramic material. A preferred material is an optical silicone resin, which is a high UV resistant and temperature resistant material, especially for use in long-term applications.

[0070] For example, after manufacturing the surface structures 10 (such as contacts) and the anti-reflection coating, the optical contact shield 20 arranged as a film can be applied directly on each PV cell by an in-line lamination unit. This is a very applicable solution with a minimized arrangement. Afterwards, each PV cell will be processed normally in the next processing stage. It is also possible to use a laminating adhesive 13 (selected from silicone, EVA, olefin-based layers, etc.) Figure 4 ).

[0071] In other embodiments, the optical shield 20 configured as a film may be applied to the underside of the top glass layer forming the protective cover for the PV cells. In this case, the alignment of the entire glass cover (with respect to the cavity 51) needs to match all PV cells in the module.

[0072] The distance d between the optical contact shield 20 and the PV cell surface ( Figure 4 ), the profile of the optical cavity, the top angle parameter (prism angle, α) and its relationship to the contact surface coverage (all area occupied by the surface structure 10) can be simulated and optimized. Figure 4 and Table 2 presents several simulated and optimized solutions along with the obtained gains.

[0073] Table 2: Simulated and optimized solutions for the optical contact shield 20 (configured as a film) according to the invention, and the gains obtained.

[0074]

[0075] therefore, Figure 6 An optical contact shield 20, 20A with a cavity 51 filled with a medium (eg air) is shown before lamination to a PV cell. The dashed line between layer 11 and layer 21 indicates that both constructions (with and without base layer 21) are possible.

[0076] Also refer to Figure 7, an optical shield 20, 20A is shown having a plurality of separate elements (indicated by boxes (i), (ii) and (iii)). Each separate element (i), (ii) and (iii) may be provided as a separate film, sheet or strip that is disposed on the PV cell body to align with the arranged surface structures (e.g., contacts) 10. In some embodiments (configuration 20), the separate element (iii) comprises at least one carrier element 11; in some other embodiments (configuration 21), the separate structures (i) and (ii) additionally comprise a base layer 21. Each separate structure may comprise a single cavity 51 or a plurality of cavities. The separate structures are distributed over the surface of the PV cell; however, no full coverage of the PV cell is provided.

[0077] In some other embodiments, the separated structures (i), (ii) and / or (iii) may be arranged in a grid form. The grid-like structure may be formed by a plurality of strip-shaped separated structures arranged laterally, or by a plurality of individual plate-shaped or film-shaped structures arranged row by row according to a predetermined order.

[0078] It is noteworthy that each of the separated structures (i), (ii) and / or (iii) comprises at least one cavity optical element 51, and the separated structures are aligned with the surface structures 10 distributed on the solar cell.

[0079] Fig. 8A and Figure 8B Different embodiments of photovoltaic cells 201, 201A are shown, including optical shields embodied as 20, 20A. Shields 20, 20A may be implemented as continuous film-like or plate-like structures that provide complete coverage of the entire PV cell surface, or as separate structures distributed over cavity optics 51.

[0080] The optical shield may be laminated by various methods and during different stages of manufacturing, such as: a) on the surface of the PV cell body 12, and b) between the PV cell body 12 and a protective layer 14, such as glass.

[0081] Therefore, the optical shielding member 20, 20A can be Fig. 8A ) or both sides (below and above, Figure 8B ) is provided with an adhesive layer 13.

[0082] The optical shield 20, 20A may also be mounted to the PV cell body 12 by automated manufacturing equipment, wherein the mounting is implemented as: a) precisely mounted on the surface of the PV cell body 12; b) mounted on the surface of the entire PV module; and / or c) forming "line contact" with the surface of the PV cell or PV module during installation.

[0083] The present invention effectively minimizes optical power losses, which are composed of losses caused by reflection, shadow losses and losses caused by incident light being absorbed into the contact structure. The optical shield assembly provided thereby is a simple and cost-effective solution that reduces the above losses and improves the efficiency of PV cell power output.

[0084] By utilizing the optical shielding assembly provided thereby, electrical losses can be minimized by 1) increasing the number of surface structures 10 and their size, and 2) minimizing the distance, gaps and period between the surface structures 10, thereby minimizing the current and resistance of each surface structure 10 (contact).

[0085] Additionally, the present invention supports the use of highly phosphorus doped (silicon) regions under larger surface structures 10 (such as contacts) to increase conductivity. This is beneficial when both highly doped regions and lowly doped regions are used, thus achieving high conductivity and low carrier charge.

[0086] It is obvious to those skilled in the art that, as technology advances, the basic idea of ​​the present invention is intended to cover various modifications included in its spirit and scope. Therefore, the present invention and its embodiments are not limited to the above examples; on the contrary, they can generally be changed within the scope of the attached claims.

Claims

1. An optical shield (20, 20A) for a photovoltaic cell, the optical shield comprising: - a plurality of separate structural elements, each separate structural element comprising: - at least one carrier element (11), the at least one carrier element having: - at least one optically functional cavity embedded in said carrier element, wherein the embedded optical functional cavity (51) is arranged into at least one predetermined optical engraving pattern (52), and Each separate structural element having at least one optical functional cavity embedded in the carrier element is positioned above a separate surface structure (10) and can be aligned with the separate surface structure (10) to prevent light from hitting the surface structure, and the separate surface structure is arranged on the surface of the body (12) of the photovoltaic cell, and each separate structural element does not provide full coverage of the body (12) of the photovoltaic cell.

2. The optical shielding member according to claim 1, wherein: The individual surface structures (10) arranged on the surface of the photovoltaic cell body are electrodes, contacts, fingers, busbars, or highly doped regions or lightly doped regions.

3. The optical shielding member according to claim 1, wherein: At least one of the separated structural elements further comprises a flat, planar base element (21), wherein the embedded optical functional cavity (51) in at least one of the separated structural elements is located between the base element (21) and the carrier element (11).

4. The optical shielding member according to claim 1, wherein: The embedded optical functional cavity (51) is filled with an internal dielectric material having a refractive index different from that of a dielectric material surrounding the cavity.

5. The optical shielding member according to claim 1, wherein: In terms of the size, shape, dimensions and arrangement of the embedded optical function cavity, each embedded optical function cavity (51) is configured to be used for at least one of a reflection function, a refraction function, a deflection function and a diffraction function.

6. The optical shielding member according to claim 1, wherein: The at least one carrier element (11) and / or the base element (21) is a plastic polymer, glass or a resin.

7. The optical shielding member according to claim 1, wherein: The embedded optical functional cavity (51) is arranged in the form of a V-shaped groove.

8. The optical shielding member according to claim 1, wherein: The embedded optical functional cavity (51) is filled with an internal dielectric material in a fluid form or a solid form.

9. The optical shielding member according to claim 8, wherein: The fluid internal medium material is selected from air, gas and liquid.

10. The optical shielding member according to claim 1, wherein: Each embedded optical function cavity (51) is at least partially coated by an optical function coating, wherein the optical function of the coating includes at least one of specular reflection, diffuse reflection and wavelength selective reflection.

11. The optical shielding member according to claim 1, wherein: In terms of the size parameters and arrangement of the embedded optical functional cavities (51) within the optical engraving pattern (52), the embedded optical functional cavities (51) each correspond to the surface structure (10) disposed on the surface of the photovoltaic cell.

12. The optical shielding member according to claim 1, wherein: Each separate structural element further comprises at least two carrier elements (11, 11A) arranged in a multilayer structure, wherein each carrier element comprises a plurality of embedded optical functional cavities (51, 51A), the embedded optical functional cavities being arranged into at least one predetermined optical engraving pattern (52, 52A), and wherein, for each carrier element, the size, shape and periodicity of the optical functional cavities in at least one of the optical engraving patterns are individually adjustable.

13. The optical shielding member according to claim 1, wherein: The separate structural elements are arranged to form a grid.

14. The optical shielding member according to claim 13, wherein: The grid is formed by a plurality of separate structural elements configured in strips and arranged transversely.

15. The optical shielding member according to claim 13, wherein: The grid is formed of a plurality of separate structural elements that are configured as a plate-like structure or a film-like structure and are arranged row by row according to a predetermined order.

16. A photovoltaic cell (201, 201A) comprising the optical shield (20, 20A) according to claim 1.

17. Photovoltaic cell according to claim 16, comprising an optical shield (20) arranged under its protective cover.

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