Solar cell and preparation method thereof

Abstract

The invention relates to a solar cell and a preparation method thereof, and the method comprises the steps: preparing a first electrode layer on a substrate, forming a first groove in the first electrode layer, and enabling the first electrode layer to be a transparent layer; a photoelectric conversion unit is prepared on the first electrode layer, a second groove is formed in the photoelectric conversion unit, the first groove is filled with the photoelectric conversion unit, the photoelectric conversion unit comprises a first functional layer and a photoelectric conversion layer, and the first functional layer is located between the photoelectric conversion layer and the first electrode layer; preparing an isolation layer on the photoelectric conversion unit, and arranging a third groove on the isolation layer; a second electrode layer is prepared on the isolation layer, a fourth groove is formed in the second electrode layer, and the third groove is filled with the second electrode layer; according to the invention, after the second electrode layer is prepared, the second electrode layer and the photoelectric conversion layer are separated by the isolation layer, thereby effectively preventing the halogen element in the photoelectric conversion layer from corroding the second electrode layer, prolonging the service life of the solar cell, and improving the working performance of the solar cell.

Description

Technical Field

[0001] The invention belongs to the field of photovoltaic technology, and in particular relates to a solar cell and a method for preparing the solar cell. Background Art

[0002] As an emerging photovoltaic technology, perovskite solar cells have attracted widespread attention due to their high efficiency, low cost, adjustable band gap and good processability. Perovskite solar cells include a substrate, a first electrode layer, a first functional layer, a photoelectric conversion layer, a second functional layer and a second electrode layer stacked in sequence, wherein one of the first functional layer and the second functional layer is an electron transport layer and the other is a hole transport layer.

[0003] In order to divide the solar cell into multiple battery cells, during production, a first electrode layer is first prepared on the substrate, and then the first electrode layer is scribed P1 to form a first groove that cuts the first electrode layer; then a first functional layer is prepared on the first electrode layer, and a photoelectric conversion layer is prepared on the first functional layer, and then a second functional layer is prepared on the photoelectric conversion layer; then the second functional layer is scribed P2 to form a second groove that cuts the first functional layer, the photoelectric conversion layer and the second functional layer; then a second electrode layer is prepared on the second functional layer, wherein the second electrode layer contacts the first electrode layer in the second groove; then the second electrode layer is scribed P3 to form a third groove that cuts the second electrode layer.

[0004] However, in the solar cells prepared in this way, the second electrode layer will be in contact with the photoelectric conversion layer, and the halogen elements in the photoelectric conversion unit of the photoelectric conversion layer are prone to corrode the second electrode layer, thereby causing damage to the performance and life of the perovskite solar cell. Summary of the invention

[0005] The technical problem to be solved by the present invention is: in view of the problem that in the solar cell prepared by the prior art, the second electrode layer will contact the photoelectric conversion layer, and the halogen elements in the photoelectric conversion layer are easy to corrode the second electrode layer, thereby causing the performance and life of the solar cell to be damaged, a solar cell and a method for preparing the solar cell are provided.

[0006] In order to solve the above technical problems, on the one hand, an embodiment of the present invention provides a method for preparing a solar cell, comprising the following steps: preparing a first electrode layer on a substrate, and setting a first groove on the first electrode layer, wherein the first electrode layer is a transparent layer; preparing a photoelectric conversion unit on the first electrode layer, and setting a second groove on the photoelectric conversion unit, wherein the photoelectric conversion unit fills the first groove; the photoelectric conversion unit comprises a first functional layer and a photoelectric conversion layer, wherein the first functional layer is located between the photoelectric conversion layer and the first electrode layer; preparing an isolation layer on the photoelectric conversion unit, and setting a third groove on the isolation layer, wherein the isolation layer fills the second groove, and the third groove is located between the first electrode layer and the second functional layer; in the second groove; a second electrode layer is prepared on the isolation layer, and a fourth groove is set on the second electrode layer, and the second electrode layer fills the third groove; in the first direction and the second direction, the first groove penetrates the first electrode layer, the second groove penetrates the photoelectric conversion unit, the third groove penetrates the isolation layer, and the fourth groove penetrates the second electrode layer; in the third direction, the first groove, the second groove and the fourth groove are arranged at intervals, and the third groove is arranged at intervals with the side of the second groove; the first direction, the second direction and the third direction intersect each other; the first direction is the arrangement direction of the substrate and the first electrode layer.

[0007] Optionally, the isolation layer is a transparent layer, and the steps of preparing the isolation layer on the photoelectric conversion unit and setting the third groove on the isolation layer include: preparing a light-shielding layer on the first electrode layer, wherein the light-shielding layer is located in the second groove and is spaced apart from the photoelectric conversion unit; preparing an isolation layer on the photoelectric conversion unit, wherein the isolation layer covers the light-shielding layer; and etching the light-shielding layer using a laser to remove the light-shielding layer and the isolation layer on the light-shielding layer to obtain the third groove.

[0008] Optionally, in the first direction, the thickness of the light shielding layer is greater than the thickness of the isolation layer.

[0009] Optionally, the step of preparing a photoelectric conversion unit on the first electrode layer and setting a second groove on the photoelectric conversion unit includes: etching the photoelectric conversion unit using a laser to obtain the second groove; wherein the laser power when etching the photoelectric conversion unit using the laser is greater than the laser power when etching the light-shielding layer using the laser.

[0010] Optionally, the thickness of the light-shielding layer is greater than or equal to 150 nm and less than or equal to 300 nm; and / or the thickness of the isolation layer is greater than or equal to 5 nm and less than or equal to 20 nm.

[0011] Optionally, the step of preparing an isolation layer on the photoelectric conversion unit and setting a third groove on the isolation layer includes: setting a mask plate on the first electrode layer, the mask plate being located in the second groove and spaced apart from the photoelectric conversion unit; preparing an isolation layer on the photoelectric conversion unit, the isolation layer covering an area of ​​the first electrode layer that is located in the second groove and is not blocked by the mask plate; and removing the mask plate to form the third groove on the isolation layer.

[0012] Optionally, the steps of preparing a second electrode layer on the isolation layer and setting a fourth groove on the second electrode layer include: preparing a second electrode layer on the isolation layer; etching the second electrode layer using a laser to obtain the fourth groove; wherein, in the first direction, the depth of the fourth groove is greater than or equal to the thickness of the second electrode layer, and the depth of the fourth groove is less than or equal to the sum of the thicknesses of the second electrode layer and the photoelectric conversion unit.

[0013] Optionally, one of the isolation layer and the first functional layer is an electron transport layer, and the other of the isolation layer and the first functional layer is a hole transport layer.

[0014] In order to solve the above technical problems, on the other hand, an embodiment of the present invention provides a solar cell, comprising a substrate, a first electrode layer, a photoelectric conversion unit, an isolation layer and a second electrode layer; the first electrode layer is arranged on the substrate; the first electrode layer is a transparent layer; a first groove is arranged on the first electrode layer; the photoelectric conversion unit is arranged on the first electrode layer and fills the first groove; the photoelectric conversion unit is provided with a second groove; the photoelectric conversion unit comprises a first functional layer and a photoelectric conversion layer, the first functional layer is located between the photoelectric conversion layer and the first electrode layer; the isolation layer is arranged on the photoelectric conversion unit and fills the second groove; the isolation layer is provided with a third groove ; The third groove is located in the second groove; the second electrode layer is arranged on the isolation layer and fills the third groove; a fourth groove is arranged on the second electrode layer; in the first direction and the second direction, the first groove penetrates the first electrode layer, the second groove penetrates the photoelectric conversion unit, the third groove penetrates the isolation layer, and the fourth groove penetrates the second electrode layer; in the third direction, the first groove, the second groove and the fourth groove are arranged at intervals, and the third groove is arranged at intervals with the side of the second groove; the first direction, the second direction and the third direction intersect each other; the first direction is the arrangement direction of the substrate and the first electrode layer.

[0015] Optionally, in the first direction, the depth of the fourth groove is greater than or equal to the thickness of the second electrode layer, and the depth of the fourth groove is less than or equal to the sum of the thicknesses of the second electrode layer and the photoelectric conversion unit.

[0016] In the solar cell and the method for preparing the solar cell provided in the embodiments of the present invention, two P2 scribings are performed, wherein the first P2 scribing is to cut off the photoelectric conversion unit to form a second groove, and the second P2 scribing is to cut off the isolation layer to form a third groove. After the second electrode layer is subsequently prepared, the second electrode layer and the photoelectric conversion layer are separated by the isolation layer, which effectively prevents the halogen elements in the photoelectric conversion layer from corroding the second electrode layer, thereby improving the service life and working performance of the solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of a solar cell provided by an embodiment of the present invention; Figure 2 It is a schematic diagram of a solar cell preparation process provided by an embodiment of the present invention.

[0018] The reference numerals in the specification are as follows: 10. Solar cells; 1. Substrate; 2. first electrode layer; 21. first groove; 3. Photoelectric conversion unit; 31. Second groove; 32. First functional layer; 33. Photoelectric conversion layer; 4. Isolation layer; 41. Third slot; 5. second electrode layer; 51. fourth groove; 6. Protective layer; 7. Shading layer. DETAILED DESCRIPTION

[0019] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0020] like Figure 1 and Figure 2As shown, in one embodiment, the solar cell 10 includes a substrate 1, a first electrode layer 2, a photoelectric conversion unit 3, an isolation layer 4 and a second electrode layer 5; wherein the first electrode layer 2 is arranged on the substrate 1; the first electrode layer 2 is a transparent layer, and a first groove 21 is provided on the first electrode layer 2; the photoelectric conversion unit 3 is arranged on the first electrode layer 2 and fills the first groove 21; a second groove 31 is provided on the photoelectric conversion unit 3, and the photoelectric conversion unit 3 includes a first functional layer 32 and a photoelectric conversion layer 33, and the first functional layer 32 is located between the photoelectric conversion layer 33 and the first electrode layer 2; the isolation layer 4 is arranged on the photoelectric conversion unit 3 and fills the second groove 31; a third groove 41 is provided on the isolation layer 4; the third groove 41 is located in the second groove 31; the second electrode layer 5 is arranged on the isolation layer 4 and fills the third groove 41; the second electrode layer 5 is provided with a fourth groove 51.

[0021] In the first direction and the second direction, the first groove 21 penetrates the first electrode layer 2 , the second groove 31 penetrates the photoelectric conversion unit 3 , the third groove 41 penetrates the isolation layer 4 , and the fourth groove 51 penetrates the second electrode layer 5 .

[0022] That is, the first groove 21 penetrates the first electrode layer 2 in the first direction, and the first groove 21 penetrates the first electrode layer 2 in the second direction; the second groove 31 penetrates the photoelectric conversion unit 3 in the first direction, and the second groove 31 penetrates the photoelectric conversion unit 3 in the second direction; the third groove 41 penetrates the isolation layer 4 in the first direction, and the third groove 41 penetrates the isolation layer 4 in the second direction; the fourth groove 51 penetrates the second electrode layer 5 in the first direction, and the fourth groove 51 penetrates the second electrode layer 5 in the second direction.

[0023] In addition, in the third direction, the first groove 21, the second groove 31 and the fourth groove 51 are spaced apart, and the third groove 41 is spaced apart from the side of the second groove 31; the first direction, the second direction and the third direction intersect each other; the first direction is the arrangement direction of the substrate 1 and the first electrode layer 2.

[0024] Preferably, the first direction, the second direction and the third direction are perpendicular to each other. Figure 1 and Figure 2 In the example shown, the first direction is parallel to the Z axis, the second direction is parallel to the Y axis, and the third direction is parallel to the X axis.

[0025] In one scenario, the first direction may be the thickness direction of the solar cell 10, the second direction may be the width direction of the solar cell 10, and the third direction may be the length direction of the solar cell 10. The first direction is usually a vertical direction.

[0026] In addition, the first groove 21 is a groove formed after P1 scribing, the second groove 31 and the third groove 41 are both grooves formed after P2 scribing, and the fourth groove 51 is a groove formed after P3 scribing.

[0027] The first groove 21 cuts off the first electrode layer 2, the second groove 31 cuts off the photoelectric conversion unit 3, the third groove 41 cuts off the isolation layer 4, and the fourth groove 51 cuts off the second electrode layer 5. A first groove 21, a second groove 31, a third groove 41 and a fourth groove 51 form a partition structure, and a partition structure can separate the solar cell 10 into two battery cells. Among them, in a solar cell, the number of partition structures can be multiple, and each partition structure is arranged in sequence along the third direction. "Multiple" means greater than or equal to two, and the term "multiple" has the same meaning in each embodiment and will not be repeated in the following text.

[0028] In this embodiment, when preparing the solar cell 10, two P2 scribings are performed: the first P2 scribing is to cut off the photoelectric conversion unit 3 to form the second groove 31; the second P2 scribing is to cut off the isolation layer 4 to form the third groove 41. After the second electrode layer 5 is subsequently prepared, the second electrode layer 5 and the photoelectric conversion unit 3 are separated by the isolation layer 4. At this time, the second electrode layer 5 and the photoelectric conversion layer 33 are also separated by the isolation layer 4, thereby effectively avoiding the halogen elements in the photoelectric conversion layer 33 from corroding the second electrode layer 5, thereby improving the service life and working performance of the solar cell 10.

[0029] In addition, since the thickness of the photoelectric conversion unit 3 is relatively large, usually much greater than the first electrode layer 2, “the photoelectric conversion unit 3 fills the first groove 21” may mean that the photoelectric conversion unit 3 completely fills the first groove 21, and at this time, the bottom surface of the first groove 21 and the side surface of the first groove 21 are completely covered by the photoelectric conversion unit 3. Usually, the first groove 21 only penetrates the first electrode layer 2 and does not extend to the substrate 1.

[0030] The thickness of the photoelectric conversion unit 3 is also much greater than the thickness of the isolation layer 4. "The isolation layer 4 fills the second groove 31" generally means that the isolation layer 4 partially fills the second groove 31, and the isolation layer 4 covers the bottom and side surfaces of the second groove 31, wherein the bottom surface of the second groove 31 and the side surfaces of the second groove 31 may intersect. Since the second groove 31 runs through the photoelectric conversion unit 3, the bottom surface of the second groove 31 is the surface of the first electrode layer 2. Usually, the second groove 31 only runs through the photoelectric conversion unit 3 and does not extend to the first electrode layer 2, so the bottom surface of the second groove 31 is the upper surface of the first electrode layer 2.

[0031] In addition, the isolation layer 4 covering the bottom surface of the second groove 31 may mean that the isolation layer 4 partially covers the bottom surface of the second groove 31, and the area of ​​the bottom surface of the second groove 31 not covered by the isolation layer 4 is the bottom surface of the third groove 41, that is, when the third groove 41 is not provided on the isolation layer 4, the isolation layer 4 completely covers the bottom surface of the second groove 31; the isolation layer 4 covering the side surface of the second groove 31 may mean that the isolation layer 4 completely covers the side surface of the second groove 31. In the third direction, the second groove 31 has two side surfaces, and both of the side surfaces are covered by the isolation layer 4.

[0032] Of course, in other embodiments, the second groove 31 may also be completely filled with the isolation layer 4 .

[0033] “The second electrode layer 5 fills the third groove 41” may mean that the second electrode layer 5 completely fills the third groove 41, and at this time, the bottom surface of the third groove 41 and the side surface of the third groove 41 are completely covered by the second electrode layer 5. In addition, the third groove 41 only penetrates the photoelectric conversion unit 3 and does not extend to the first electrode layer 2. After the second electrode layer 5 fills the third groove 41, it can achieve electrical connection with the first electrode layer 2.

[0034] After penetrating the second electrode layer 5 , the fourth groove 51 may extend to the isolation layer 4 . Furthermore, the fourth groove 51 may also extend to the photoelectric conversion unit 3 .

[0035] In addition, the third groove 41 is located in the second groove 31 , and in the third direction, the third groove 41 and the side surfaces of the second groove 31 are spaced apart.

[0036] In one embodiment, the substrate 1 may be a transparent plate, such as any one of glass, PET, PI, etc.

[0037] The material of the first electrode layer 2 may be a transparent conductive oxide, such as any one of FTO, ITO, IZO, etc. The thickness of the first electrode layer 2 may be greater than or equal to 200 nm and less than or equal to 800 nm.

[0038] The material of the isolation layer 4 may be any one or a combination of C60, molybdenum oxide, tin oxide, aluminum oxide, etc. The thickness of the isolation layer 4 may be greater than or equal to 5 nm and less than or equal to 20 nm.

[0039] The second electrode layer 5 is made of metal, such as any one of gold, copper, silver, etc. The thickness of the second electrode layer 5 may be greater than or equal to 80 nm and less than or equal to 200 nm.

[0040] like Figure 1 As shown, in one embodiment, in the first direction, the first functional layer 32 is disposed on the first electrode layer 2 , the photoelectric conversion layer 33 is disposed on the first functional layer 32 , and the isolation layer 4 is disposed on the photoelectric conversion layer 33 .

[0041] The material of the first functional layer 32 may be any one or a combination of C60, molybdenum oxide, tin oxide, aluminum oxide, etc. The thickness of the isolation layer 4 may be greater than or equal to 5 nm and less than or equal to 20 nm.

[0042] In addition, the material of the photoelectric conversion layer 33 may be any one of perovskite, copper indium gallium selenide, cadmium telluride, etc. The thickness of the photoelectric conversion layer 33 may be greater than or equal to 200 nm and less than or equal to 3000 nm.

[0043] In one embodiment, the isolation layer 4 may be the second functional layer of the solar cell 10. In this case, one of the isolation layer 4 and the first functional layer 32 is an electron transport layer, and the other of the isolation layer and the first functional layer 32 is a hole transport layer. In addition, the electron transport layer and the hole transport layer may be arranged in the prior art.

[0044] like Figure 1 As shown, in one embodiment, the solar cell 10 further includes a protective layer 6 , which is disposed on the second electrode layer 5 and fills the fourth groove 51 .

[0045] Here, “the protective layer 6 fills the fourth groove 51” may mean that the protective layer 6 partially fills the fourth groove 51, and the protective layer 6 completely covers the bottom surface of the fourth groove 51 and completely covers the side surface of the fourth groove 51. Of course, the fourth groove 51 may also be completely filled with the protective layer 6.

[0046] Among the substrate 1, the first electrode layer 2, the photoelectric conversion unit 3, the isolation layer 4, the second electrode layer 5 and the protective layer 6, except for the parts filled in the corresponding grooves, the substrate 1, the first electrode layer 2, the photoelectric conversion unit 3, the isolation layer 4, the second electrode layer 5 and the protective layer 6 are stacked in sequence in the first direction.

[0047] like Figure 2 As shown, the embodiment of the present invention further provides a method for preparing a solar cell 10, which can be used to prepare the above-mentioned solar cell 10, and the method comprises the following steps: Step S1, preparing a first electrode layer 2 on a substrate 1, and setting a first groove 21 in the first electrode layer 2, wherein the first electrode layer 2 is a transparent layer.

[0048] Step S2, preparing a photoelectric conversion unit 3 on the first electrode layer 2, and setting a second groove 31 on the photoelectric conversion unit 3, the photoelectric conversion unit 3 fills the first groove 21, the photoelectric conversion unit 3 includes a first functional layer 32 and a photoelectric conversion layer 33, and the first functional layer 32 is located between the photoelectric conversion layer 33 and the first electrode layer 2.

[0049] Step S3 , preparing an isolation layer 4 on the photoelectric conversion unit 3 , and setting a third groove 41 on the isolation layer 4 , the isolation layer 4 fills the second groove 31 , the isolation layer 4 is a transparent layer, and the third groove 41 is located in the second groove 31 .

[0050] Step S4 , preparing a second electrode layer 5 on the isolation layer 4 , and setting a fourth groove 51 on the second electrode layer 5 , so that the second electrode layer 5 fills the third groove 41 .

[0051] In the first direction and the second direction, the first groove 21 penetrates the first electrode layer 2, the second groove 31 penetrates the photoelectric conversion unit 3, the third groove 41 penetrates the isolation layer 4, and the fourth groove 51 penetrates the second electrode layer 5; in the third direction, the first groove 21, the second groove 31 and the fourth groove 51 are arranged at intervals, and the third groove 41 is arranged at intervals from the side of the second groove 31. In addition, the first groove 21, the second groove 31, the third groove 41 and the fourth groove 51 can all be rectangular grooves.

[0052] In step S1, the first electrode layer 2 may be prepared on the substrate 1. Then, the first electrode layer 2 may be etched by laser to obtain the first groove 21; or, the first electrode layer 2 may be etched by etching liquid to obtain the first groove 21. In this method, exposure and development operations are required, and these operations may be prior arts. Among them, the first electrode layer 2 may be prepared by magnetron sputtering or the like.

[0053] In addition, in step S1, the first electrode layer 2 is prepared on the upper surface of the substrate 1. The upper surface of the substrate 1 may be a plane.

[0054] In addition, before the first groove 21 is provided, the first electrode layer 2 may completely cover the upper surface of the substrate 1 .

[0055] In step S2, the photoelectric conversion unit 3 may be prepared on the first electrode layer 2. Then, the photoelectric conversion unit 3 may be etched by laser to obtain the second groove 31; or, the photoelectric conversion unit 3 may be mechanically scratched to obtain the second groove 31. The photoelectric conversion unit 3 may be prepared by a solution coating method, a magnetron sputtering method, or a vacuum evaporation method.

[0056] In addition, in step S2, the photoelectric conversion unit 3 is formed on the upper surface of the first electrode layer 2, and the upper surface of the first electrode layer 2 can be a plane. In the first direction, the upper surface of the first electrode layer 2 is the surface of the first electrode layer 2 facing away from the substrate 1.

[0057] In addition, before the second groove 31 is provided, the photoelectric conversion unit 3 may completely cover the upper surface of the first electrode layer 2 .

[0058] In step S3, an isolation layer 4 may be prepared on the photoelectric conversion unit 3. Then, the isolation layer 4 may be etched by laser to obtain the third groove 41; or, the isolation layer 4 may be mechanically scratched to obtain the third groove 41. The isolation layer 4 may be prepared by chemical deposition, solution coating, vacuum evaporation, or atomic layer deposition.

[0059] In addition, in step S3, the isolation layer 4 is formed on the upper surface of the photoelectric conversion unit 3, and the upper surface of the photoelectric conversion unit 3 can be a plane. In the first direction, the upper surface of the photoelectric conversion unit 3 is the surface of the photoelectric conversion unit 3 away from the substrate 1.

[0060] In addition, the isolation layer 4 may completely cover the upper surface of the photoelectric conversion unit 3. At the same time, the isolation layer 4 completely covers the side surface of the photoelectric conversion unit 3 located in the second groove 31. Moreover, when the third groove 41 is not provided on the isolation layer 4, the isolation layer 4 completely covers the bottom surface of the second groove 31 and the side surface of the second groove 31.

[0061] In step S4, the second electrode layer 5 may be first prepared on the isolation layer 4. Then, the second electrode layer 5 may be etched by laser to obtain the fourth groove 51; or, the second electrode layer 5 may be mechanically scratched to obtain the fourth groove 51. The second electrode layer 5 may be prepared by magnetron sputtering or vacuum evaporation.

[0062] In addition, in step S4, the second electrode layer 5 is prepared on the upper surface of the isolation layer 4. The upper surface of the isolation layer 4 may be a plane.

[0063] In addition, before the fourth groove 51 is provided, the second electrode layer 5 may completely cover the upper surface of the isolation layer 4 .

[0064] In actual scenarios, the thickness of the isolation layer 4 is very thin, and the isolation layer 4 is a transparent layer with high light transmittance. In the process of using laser to etch the isolation layer 4 to prepare the third groove 41, when the laser acts on the isolation layer 4, most of the light will pass through the isolation layer 4, and only part of the light may be absorbed by the isolation layer 4, so as to achieve local heating and ablation of the isolation layer 4. Since both the isolation layer 4 and the first electrode layer 2 have high light transmittance (the light transmittance of the isolation layer 4 and the first electrode layer 2 can be the same or different), a relatively high laser power is required to etch the isolation layer 4 above the first electrode layer 2, so it is easy for the laser to damage the first electrode layer 2, thereby increasing the ohmic resistance of the first electrode layer 2 and even causing damage to the solar cell 10.

[0065] In this regard, in one embodiment, step S3 includes: step S31, preparing a light-shielding layer 7 on the first electrode layer 2, the light-shielding layer 7 is located in the second groove 31, and is spaced apart from the photoelectric conversion unit 3; step S32, preparing an isolation layer 4 on the photoelectric conversion unit 3, the isolation layer 4 covers the light-shielding layer 7; step S33, etching the light-shielding layer 7 with a laser to remove the light-shielding layer 7 and the isolation layer 4 on the light-shielding layer 7 to obtain a third groove 41.

[0066] That is, in this embodiment, before preparing the isolation layer 4, the light shielding layer 7 is first prepared in the area for forming the third groove 41 on the first electrode layer 2; after the isolation layer 4 is prepared, the light shielding layer 7 is ablated by laser. Since the light shielding layer 7 is opaque, it can avoid (or reduce) laser irradiation of the first electrode layer 2, thereby reducing damage to the first electrode layer 2. Since the isolation layer 4 is relatively thin, when the light shielding layer 7 is ablated by the laser, the part of the isolation layer 4 located thereon is also removed due to lack of support.

[0067] In addition, compared with the isolation layer 4, the shading layer 7 has better heat absorption capacity, so that only a lower power laser is needed to etch away the shading layer 7. That is, through the setting of this embodiment, a lower power laser can be used to remove the corresponding area of ​​the isolation layer 4 to obtain the third groove 41, which is more conducive to avoiding ablation damage to the first electrode layer 2.

[0068] It should be noted that step S32 needs to be performed after the light shielding layer 7 is solidified.

[0069] In one embodiment, the light shielding layer 7 may be an ink layer, and the color of the ink layer may be dark, such as a black ink layer, etc. The ink layer may also be prepared by inkjet printing or laser printing, etc. In addition, the light shielding layer 7 may be a rectangular parallelepiped structure.

[0070] The isolation layer 4 covering the light shielding layer 7 may mean that in the third direction, the isolation layer 4 covers two opposite side surfaces of the light shielding layer 7 , and in the first direction, the isolation layer 4 covers the surface of the light shielding layer 7 away from the first electrode layer 2 .

[0071] In one embodiment, in the third direction, the light shielding layer 7 and the photoelectric conversion unit 3 are spaced apart from each other, which means that the light shielding layer 7 and the side of the second groove 31 are spaced apart from each other, so that after the light shielding layer 7 is removed, the isolation layer 4 cannot completely cover the part of the photoelectric conversion unit 3 on the side of the second groove 31, which is more conducive to preventing the second electrode layer 5 prepared subsequently from contacting the photoelectric conversion unit 3. In the third direction, the second groove 31 has two side surfaces, and the light shielding layer 7 is located between the two side surfaces and spaced apart from both side surfaces.

[0072] In one embodiment, in the first direction, the thickness of the light shielding layer 7 is greater than the thickness of the isolation layer 4 , so that after the light shielding layer 7 is removed by ablation, it is easier for the isolation layer 4 on the light shielding layer 7 to be removed together with the light shielding layer 7 .

[0073] The thickness of the isolation layer 4 refers to the thickness of the portion located on the upper surface of the light shielding layer 7, and may also refer to the thickness of the portion located on the upper surface of the photoelectric conversion unit 3. In addition, the upper surface of the photoelectric conversion unit 3 is the upper surface of the photoelectric conversion layer 33.

[0074] In one embodiment, the thickness of the light shielding layer 7 is greater than or equal to 150 nm and less than or equal to 300 nm. This ensures that after the light shielding layer 7 is etched, the isolation layer 4 on its upper surface can be removed together, and the processing speed can be increased to avoid excessive heat on the light shielding layer 7 being transferred to the first electrode layer 2 due to long laser irradiation time, thereby effectively preventing the first electrode layer 2 from being ablated.

[0075] In one embodiment, when the photoelectric conversion unit 3 is laser etched to prepare the second groove 31 and the light shielding layer 7 is laser etched to prepare the third groove 41, the laser power when the photoelectric conversion unit 3 is laser etched is greater than the laser power when the light shielding layer 7 is laser etched.

[0076] The photoelectric conversion unit 3 also has good laser absorption capability, so the second groove 31 can be prepared by processing the photoelectric conversion unit 3 with a relatively low power laser. Normally, the laser power when etching the photoelectric conversion unit 3 is equal to the power when etching the light shielding layer 7, and the preparation of the second groove 31 and the third groove 41 can be completed. In this embodiment, the laser power when etching the photoelectric conversion unit 3 is set to be greater than the laser power when etching the light shielding layer 7, which can ensure the laser processing efficiency and reduce energy consumption.

[0077] In one embodiment, the laser power when etching the photoelectric conversion unit 3 may be 4W, and the laser power when etching the light shielding layer 7 may be 0.8W.

[0078] In one embodiment, the laser frequency when etching the photoelectric conversion unit 3 may be equal to the laser frequency when etching the light shielding layer 7, and the frequency may be 40KHZ, etc. In addition, the defocus of the laser when etching the photoelectric conversion unit 3 may also be greater than the defocus of the laser when etching the light shielding layer 7, for example, the defocus of the laser when etching the photoelectric conversion unit 3 is 3mm, and the defocus of the laser when etching the light shielding layer 7 is 2mm.

[0079] In one embodiment, step S4 includes: preparing the second electrode layer 5 on the isolation layer 4; etching the second electrode layer 5 by laser to obtain the fourth groove 51; wherein, in the first direction, the depth of the fourth groove 51 is greater than or equal to the thickness of the second electrode layer 5, and the depth of the fourth groove 51 is less than or equal to the sum of the thicknesses of the second electrode layer 5, the isolation layer 4 and the photoelectric conversion unit 3. That is, when the second electrode layer 5 is laser-etched, only the second electrode layer 5 may be cut off; or, in addition to cutting off the second electrode layer 5, the laser may also etch the isolation layer 4, or even the photoelectric conversion unit 3 in this process, and such a setting increases the fault tolerance of laser etching to prepare the fourth groove 51.

[0080] In one embodiment, after step S4, a protective layer 6 is further prepared on the second electrode layer 5, and the protective layer 6 fills the fourth groove 51, wherein the protective layer 6 can completely cover the side and bottom of the fourth groove 51. In addition, the material of the protective layer 6 can be silicon dioxide or aluminum oxide.

[0081] In one embodiment, since the photoelectric conversion unit 3 includes the first functional layer 32 and the photoelectric conversion layer 33, the step of preparing the photoelectric conversion unit 3 on the first electrode layer 2 includes: preparing the first functional layer 32 on the first electrode layer 2; and preparing the photoelectric conversion layer 33 on the surface of the first functional layer 32 away from the first electrode layer 2. When the second groove 31 is subsequently prepared, the corresponding areas of the photoelectric conversion layer 33 and the first functional layer 32 can be etched by laser to form the second groove 31.

[0082] In addition, the first functional layer 32 may completely fill the first groove. In the first direction, the surface of the first functional layer 32 away from the first electrode (i.e., the upper surface of the first functional layer 32) may be a plane, the surface of the photoelectric conversion layer 33 away from the first functional layer 32 (i.e., the upper surface of the photoelectric conversion layer 33) may be a plane, and the isolation layer 4 may be disposed on the surface of the photoelectric conversion layer 33 away from the first functional layer 32.

[0083] In addition, before the second groove is prepared, the first functional layer 32 may completely cover the upper surface of the first electrode layer 2 , and the photoelectric conversion layer 33 may completely cover the upper surface of the first functional layer 32 .

[0084] Of course, the above-mentioned related designs can also be replaced by other methods, such as: In other embodiments, the isolation layer 4 may not be the second functional layer. In this case, the photoelectric conversion unit 3 has a second functional layer in addition to the first functional layer 32 and the photoelectric conversion layer 33, and the photoelectric conversion layer 33 is located between the first functional layer 32 and the second functional layer. In addition, in this case, the material of the isolation layer 4 may also be any one of C60, molybdenum oxide, tin oxide, aluminum oxide, etc., and the material of the second functional layer may be any one of C60, molybdenum oxide, tin oxide, aluminum oxide, etc., but the material of the isolation layer 4 is different from the material of the second functional layer.

[0085] In other embodiments, in order to avoid damaging the first electrode layer 2 when the isolation layer 4 is laser-etched, the third groove 41 may be prepared by the following method, in which case step S3 includes: step S31', setting a mask plate on the first electrode layer 2, the mask plate is located in the second groove 31, and is spaced apart from the photoelectric conversion unit 3; step S32', preparing the isolation layer 4 on the photoelectric conversion unit 3, the isolation layer 4 covers the area of ​​the first electrode layer 2 located in the second groove 31 and not blocked by the mask plate; step S33', removing the mask plate to form the third groove 41 on the isolation layer 4. In this embodiment, the placement and removal of the mask plate can be achieved by a robot, or can be achieved manually.

[0086] In this embodiment, when preparing the isolation layer 4, the isolation layer 4 is not formed in the area of ​​the first electrode layer 2 blocked by the mask plate, so after the mask plate is removed, the third groove 41 is formed in the area where the mask plate is located.

[0087] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0088] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a solar cell, characterized in that: The following steps are involved: A first electrode layer is prepared on a substrate, and a first groove is provided on the first electrode layer, wherein the first electrode layer is a transparent layer; A photoelectric conversion unit is prepared on the first electrode layer, and a second groove is set on the photoelectric conversion unit, wherein the photoelectric conversion unit fills the first groove; the photoelectric conversion unit includes a first functional layer and a photoelectric conversion layer, wherein the first functional layer is located between the photoelectric conversion layer and the first electrode layer; preparing an isolation layer on the photoelectric conversion unit, and setting a third groove on the isolation layer, wherein the isolation layer fills the second groove, and the third groove is located in the second groove; preparing a second electrode layer on the isolation layer, and providing a fourth groove on the second electrode layer, wherein the second electrode layer fills the third groove; In the first direction and the second direction, the first grooves all penetrate the first electrode layer, the second grooves all penetrate the photoelectric conversion unit, the third grooves all penetrate the isolation layer, and the fourth grooves all penetrate the second electrode layer; In the third direction, the first groove, the second groove and the fourth groove are arranged at intervals, and the third groove is arranged at intervals from the side surface of the second groove; The first direction, the second direction and the third direction intersect each other; The first direction is an arrangement direction of the substrate and the first electrode layer.

2. The method for preparing a solar cell according to claim 1, characterized in that: The isolation layer is a transparent layer, and the steps of preparing the isolation layer on the photoelectric conversion unit and providing a third groove on the isolation layer include: preparing a light shielding layer on the first electrode layer, wherein the light shielding layer is located in the second groove and is spaced apart from the photoelectric conversion unit; Preparing an isolation layer on the photoelectric conversion unit, wherein the isolation layer covers the light shielding layer; The light shielding layer is etched by laser to remove the light shielding layer and the isolation layer on the light shielding layer to obtain the third groove.

3. The method for preparing a solar cell according to claim 2, characterized in that: In the first direction, the thickness of the light shielding layer is greater than the thickness of the isolation layer.

4. The method for preparing a solar cell according to claim 2, characterized in that: The step of preparing a photoelectric conversion unit on the first electrode layer and providing a second groove on the photoelectric conversion unit comprises: etching the photoelectric conversion unit by laser to obtain the second groove; The laser power when the photoelectric conversion unit is etched by laser is greater than the laser power when the light shielding layer is etched by laser.

5. The method for preparing a solar cell according to claim 2, characterized in that: The thickness of the light shielding layer is greater than or equal to 150 nm and less than or equal to 300 nm; and / or the thickness of the isolation layer is greater than or equal to 5 nm and less than or equal to 20 nm.

6. The method for preparing a solar cell according to claim 1, characterized in that: The step of preparing an isolation layer on the photoelectric conversion unit and providing a third groove on the isolation layer comprises: Disposing a mask plate on the first electrode layer, wherein the mask plate is located in the second groove and is spaced apart from the photoelectric conversion unit; preparing an isolation layer on the photoelectric conversion unit, wherein the isolation layer covers an area of ​​the first electrode layer that is located in the second groove and is not blocked by the mask plate; The mask plate is removed to form the third groove on the isolation layer.

7. The method for preparing a solar cell according to claim 1, characterized in that: The steps of preparing a second electrode layer on the isolation layer and providing a fourth groove on the second electrode layer include: preparing a second electrode layer on the isolation layer; The second electrode layer is etched by laser to obtain the fourth groove; wherein, in the first direction, the depth of the fourth groove is greater than or equal to the thickness of the second electrode layer, and the depth of the fourth groove is less than or equal to the sum of the thickness of the second electrode layer and the photoelectric conversion unit.

8. The method for preparing a solar cell according to any one of claims 1 to 7, characterized in that: One of the isolation layer and the first functional layer is an electron transport layer, and the other of the isolation layer and the first functional layer is a hole transport layer.

9. A solar cell, characterized in that: It includes a substrate, a first electrode layer, a photoelectric conversion unit, an isolation layer and a second electrode layer; The first electrode layer is disposed on the substrate; the first electrode layer is a transparent layer; A first groove is provided on the first electrode layer; The photoelectric conversion unit is disposed on the first electrode layer and fills the first groove; The photoelectric conversion unit is provided with a second groove; the photoelectric conversion unit comprises a first functional layer and a photoelectric conversion layer, wherein the first functional layer is located between the photoelectric conversion layer and the first electrode layer; The isolation layer is disposed on the photoelectric conversion unit and fills the second groove; A third groove is provided on the isolation layer, and the third groove is located in the second groove; The second electrode layer is disposed on the isolation layer and fills the third groove; A fourth groove is provided on the second electrode layer; In the first direction and the second direction, the first grooves all penetrate the first electrode layer, the second grooves all penetrate the photoelectric conversion unit, the third grooves all penetrate the isolation layer, and the fourth grooves all penetrate the second electrode layer; In the third direction, the first groove, the second groove and the fourth groove are arranged at intervals, and the third groove is arranged at intervals from the side surface of the second groove; The first direction, the second direction and the third direction intersect each other; The first direction is an arrangement direction of the substrate and the first electrode layer.

10. The solar cell according to claim 9, characterized in that: In the first direction, a depth of the fourth groove is greater than or equal to a thickness of the second electrode layer, and a depth of the fourth groove is less than or equal to a sum of thicknesses of the second electrode layer and the photoelectric conversion unit.

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