TW201214716A - Back contact structure for solar cell and fabrication method thereof - Google Patents

Abstract

A back contact structure for solar cell applications disclosed. The solar cell device sequentially includes a first transparent conducting oxide (TCO) layer, a solar cell unit and a back contact structure. The first transparent conducting oxide layer is disposed on one side of the solar cell unit, and the back contact structure is disposed on the other side of the solar cell unit. The back contact structure includes a granular structure, a transparent conductive oxide and an electrode. The granular structure is disposed on the surface of the first TCO layer, and the transparent conductive oxide layer is then disposed on said surface. The electrode is eventually fabricated on the granular structure and the transparent conductive oxide. The feature is that the height of the transparent conductive oxide is equal to or smaller than the diameter of the granular structure, so the granular structure is at the interface between the transparent conductive oxide and the electrode.

Description

201214716 VI. Description of the Invention: [Technical Field] The present invention relates to a back electrode structure, and more particularly to a back electrode structure for use in a solar cell and a method of fabricating the same, which can improve optical use by improving the structure of the back electrode Efficiency to improve the photoelectric conversion efficiency of solar cells. [Prior Art] As for commercialization, too much 1% of this production απ' has been used for texture (((3) Plus; *ed)

The Transparent Conductive Oxide (TCO) glass serves as the light incident surface of the battery. The transparent conductive layer has a textured transparent conductive layer, which can effectively increase the incident efficiency of sunlight and increase the sunlight. The light-trapping effect in a battery. However, as the solar cell is improved in processing, its thickness is also increased, so that the rough surface of the film on the uppermost layer of the solar cell is also lowered. According to the research, in addition to the textured transparent conductive layer as the light incident surface, the light capturing effect of sunlight on the solar cell towel can be effectively increased, and the light ship effect of the back electrode portion can also improve the photoelectric conversion efficiency of the solar cell. Therefore, by increasing the roughness of the surface of the back electrode, it is also possible to increase the scattering effect of the unabsorbed light, thereby increasing the path of the light for resorption, and the conversion efficiency can even reduce the thickness of the absorption layer and reduce the cost. And reduce photocracking. Rong, the second structure to make the back electrode includes 1 insect engraving method, embossing method on the pool is also 二 二 = = = and pollution, in a large area of solar cell solar cell photoelectric conversion efficiency =: effective structure, to enhance the sun 201214716 The rate is an issue that the technical field is eager to solve. SUMMARY OF THE INVENTION The process also has a lower production cost structure as a method to improve the advantages of the back electrode. Other objects and advantages of the present invention are obtained from the features. The technology of the present invention is disclosed in Wei (4). The solar battery of the present invention comprises a -first-turning-electrode structure, wherein the side of the solar transparent conductive layer and the back electrode junction battery unit, the second transparent conductive The solar cell is disposed on the first transparent conductive layer of the first transparent conductive granular structure in the solar cell unit; the surface is electrically connected to the surface of the solar cell; The method includes: - an opaque material, - a third transparent conductive layer / ... the granular structure is on the conductive layer, an electrode is disposed on the granular and the first transparent feature is a high-surface conductive layer of the third transparent conductive layer; It allows the granular structure to have a diameter of _=== and a thickness ranging from 0 to 2000 nm. - The upper 3 is composed of dopants, and belongs to: genus: the material of the structure is composed of a polymer material and a gold material, and the granular structure or the particles containing the dopant have a diameter of 10 to 1000. 【 201214716 Nano. Electroacoustic fr New Zealand tree, green knotting wire, the material three transparent guides have a plurality of air bubbles, the electrode material can fill the hole, up to the above - or the wire part is the purpose, the invention = example The method for applying the back electrode structure in the solar cell is to form a remnant structure on the first transparent conductive layer; the peach layer is formed on the granular structure and the first transparent conductive layer, and the height of the transparent conductive layer is equal to Or the secret junction electrode is on this structure. After the formation - the other - for one or part or all of the purpose or other purposes, the present invention: 匕 includes: forming a first metal layer in a first: to make the first metal layer aggregate - the first - Shape-like structure; shape: the eyebrows layer on the first-granular structure; performing annealing treatment to convert the second two-layer layer into an H-like structure; forming a third-transparent-granular structure, a second granular structure and The third layer of transparent conductive sound on your monthly conductive layer, the third and third-shaped stove structure of the material - _ turn and the second layer. 1, and forming the first pole in the granular structure and the third transparent conductive [embodiment] with the above-mentioned and other technical contents, features and effects of the fri invention, in the implementation of the direction language mentioned in the current 1: For example, on the right, after shouting, etc., only refer to the direction of the additional assignment. Therefore, the use of 2012方 201214716 is used to illustrate and limit the invention. Referring to the first figure, a first embodiment of the present invention is applied to a back electrode structure 2 of a tantalum battery. The solar cell 1 is provided with a transparent transparent conductive layer ι〇1, a solar cell unit 102 and a second element I!: 203 transparent conductive layer 101 is disposed on the side of the solar cell unit 102, and the second transparent conductive layer 103 is disposed. The side of the solar cell is incident on the light side with respect to one of the sides, and the back electrode structure 200 is disposed on the side. : & transparent conductive layer ι 〇 1 relative to solar cell unit 102 - solar cell (10) can be squam or microcrystalline solar cell Mingdao:, pin, carbon stone single layer or multi-junction solar cell The second dielectric layer 1〇3 is a lan substrate or a plastic substrate having a total thickness of about 3 to 4 cm. The moon electrode structure 200 includes a plurality of granular structures 2, a third reading day 2, and an electrode 2〇3. The material of the first transparent conductive layer 101 and the third alternating impurity layer 2G2 is composed of a metal oxide, a ferulide or the like containing yttrium to t ,, such as a chamber or F:Sn0, and the thickness thereof is rnn 'The material of the electrode 2〇3 may be a metal material such as zinc (Zn), Zhentao, Hua), g), copper (Cu), nickel (Ni) or the above alloy. , the complex structure 2 () 1 is disposed on the surface of the first transparent conductive layer and the plurality of granular structures are opaque materials, and the third transparent conductive layer is in the plural granular structure 201 and the first transparent The conductive layer 101±, the second preparation one=pole 203 is disposed on the granular structure 2〇1 and the third transparent conductive sound plus:· t is characterized by the height h of the third transparent conductive layer 202, and the diameter R of 2〇1, so that These granular structures are added to the interface of the structure _203. Located in the second transparent conductive layer 201214716 In a preferred embodiment, the particles of the granular structure 201 have a diameter ranging from 10 nm to i 〇〇〇 nm ' and the material thereof is composed of a southern molecular material, a metal, a metal alloy, a metal oxide, The tantalum oxide or the like contains a dopant, such as a conductive nanosphere or a metal nanosphere, such that the surface of the back cell structure 200 is coarse. Therefore, the light of the sunlight is as shown by the broken line in the figure. When the sunlight enters the back battery structure 200 of the solar cell 100, the granular structure 201 can effectively reflect the sunlight light back to the solar cell of the solar cell. The unit 102 increases the scattering effect of the unabsorbed sunlight, thereby increasing the path of the sunlight to facilitate re-absorption, thereby improving the light capturing effect of the solar fb battery and effectively improving the solar energy. The photoelectric conversion efficiency of the battery. As shown in the second figure, it is a manufacturing process of the back electrode structure 200 applied to the solar cell 100 in the first embodiment of the present invention. First, a solar cell 100 is prepared. The solar cell 1A includes a first transparent conductive layer 1G1, a solar cell unit 1G2, and a second transparent conductive layer 1〇3. The first transparent conductive layer 101 is disposed on the solar cell. Unit 1〇2 : one side, the second transparent conductive layer 103 1m is placed on the human light side of the solar cell unit 102 opposite to the side, and the back electrode structure is finely disposed on the first conductive layer 101 -side. Next, a method of depositing a plurality of particles is applied to the first transparent conductive layer 1〇1, for example, a coating method, a spin method, and a broadcast 1 is equal to the rise of the transparent conductive layer 101 to form a uniformly distributed granular knot. 01 'eg conductive nanosphere or metal nanosphere; redeposited - third transparent conductive layer 2〇2 is taken on the granular structure 2〇1 and the first transparent conductive layer' and the third transparent conductive layer 2〇 The height h of 2 is equal to or less than that of the grain layer 201214716 layer 202 and the electrode plate 203 of the second plate structure 2〇1 is located at the third transparent conductive _ and the third transparent guide =: shape f, 203 on the table of the granular knot = / The performance of the completed back electrode structure described above. It can further enhance the solar cell 100 month month > According to the second picture, it is the invention of the solar cell _ brother a 4 cases - application

The first transparent conductive layer: =:: : _ The electrical layer 1G1 is disposed on the solar cell, and the transparent conductive layer 103 is disposed on the solar cell 102. The solar cell unit 102 is read: the human light side, and the back electrode structure 21G is disposed. The first crystal bite day: two 3 - side. Wherein, the solar cell (10) may be a non-"back electrode structure 210 comprising a plurality of granular structures 2?la, a third transparent guide = 1[deg.] 2 and an electrode 203. Wherein the materials of the first transparent conductive layer 101 and the third electrical layer 202 are selected from the group consisting of metal oxides, stone oxides, and dopants, for example, Α1:Ζη〇 or F:Sn〇 And it is: 1 & 0 to 2_nm ' and the electrode 2〇3 is zinc (four), magnesium strontium), Ming 1) silver (Ag), steel (cu), nickel (four) or the above-mentioned alloys and other metal materials. ♦ The plurality of granular structures 2〇1a are disposed on the surface of the first transparent conductive layer 1〇1. The third transparent conductive layer 2〇2 is disposed on the granular structure 2Q1a and the first transparent conductive layer 1〇1, and the electrode 203 Provided on the granular structure 2〇1a and the third, monthly conductive layer 202; characterized in that the height h of the third transparent conductive layer 2〇2 is equal to or smaller than the R of the granular structure 2Gla, such that the granular structure 2〇ia 201214716 is located at the interface between the third transparent conductive layer 202 and the electrode 203, and the granular structure 201a can be removed in the second embodiment, so that the metal material of the electrode 2〇3 will fill the removed granular structure 201a. Void. Among them, the particles of the granular structure 2〇1& have a diameter ranging from 10 to 1000 nm. Since the granular structure 2〇la is located at the interface between the third transparent conductive layer 202 and the electrode 203, the light of the sunlight is shown by a broken line in the figure, and when the sunlight enters the back battery structure 21 of the solar cell 100, these The metal material filled with the gap can effectively reflect the sunlight light back to the solar cell unit 102 of the solar cell, increasing the scattering effect of the unabsorbed sunlight, thereby increasing the path of the sunlight light to facilitate Absorption, and improve the light-trapping effect of the solar cell, thus effectively improving the photoelectric conversion efficiency of the solar cell. As shown in the fourth figure, the port is a manufacturing process for applying the back electrode structure 21 in the battery 100 in the second embodiment of the present invention. First, a prepared solar cell 100 is provided. The solar cell cartridge (8) includes a first transparent conductive layer 101, a solar cell unit and a second transparent conductive layer 〇3. The first transparent conductive layer 〇1 is disposed on On the side of the solar cell unit 102, the second transparent conductive layer 103 is disposed on the human light side of the solar cell unit 102 opposite to the side, and the back electrode structure is disposed on the other side of the first KU. Then, a plurality of granular structures may be deposited on the first transparent conductive layer 101 by different methods, such as a coating method, a spin-on method, a 2-ink method, etc., to form a uniformly distributed granular knot on the first transparent conductive layer. 1, for example, a polymer nanosphere or the like; a third transparent conductive layer 2 〇 2 is deposited on the granular structure 201 and the first transparent conductive layer 101, and the height of the first permeable s ϋ 2 is equal to or less than the particle size The height of the structure 201 (not labeled 201214716 two it!; the method of removing the recorded structure, such as the earthquake method, the method, etc.) causes the third transparent conductive layer to apply the electrode 2〇3 to have a plurality of granular structures鸠, and the granular structure 2〇ia is a void. = 'Formation-electrode 2〇3 is applied to the surface of the granular structure coffee and the third transparent conductive layer due to αΓ filling the void. The energy of the completed back electrode structure 210. The mouth is (4) thick chain, but can further improve the efficiency of solar cells

The fifth figure is the third embodiment of the invention. The fabrication process of the two-electrode structure. First, the solar cell contacts include a first transparent conductive layer 101, a cell unit and a second transparent conductive layer (10), and the solar conductive layer 1 m transparent conductive layer 103 is sequentially The first transparent conductive layer 1 is disposed on the first transparent conductive layer 1〇1]m side, and then a first metal layer is formed on the first transparent conductive layer or the first layer The layered ruthenium is integrated into the island scenting plant; 'the first granular structure 201b; a second metal layer is formed on the above-mentioned H-th transfer, and an annealing treatment is performed, so that the metal layer is aggregated into the island or the granular second The structure is laser-removed, and the first metal layer and the second metal layer are formed on the first transparent layer 1G1, and then the annealing treatment is performed to form the first particle. The step 201b and the second granular structure are employed, and the steps can be repeated. On the younger-transparent conductive layer 1 可, (10) can be made into gold granules of different sizes to correspond to political wavelengths of different wavelengths. The silk surface structure can enhance the sunlight 201214716 in solar power 100 towel light trapping effect. The first metal layer M and the second metal layer M are both low-melting metal films, and the first metal layer M and the second metal layer M are selected from the group consisting of zinc (Zn), town (Mg), and Ming (A1). ), a group of silver (Ag), copper (Cu), and nickel (Ni). Further, the first metal layer M has a thickness ranging from 5 to 1 nm-second metal layer M, and has a thickness ranging from $100 to 100 nm and a thickness of the metal layer of the second gold. Then, a third transparent conductive layer 202 is deposited on the first granular structure 2〇1b, the second granular structure 201b, and the first transparent conductive layer 101, and the height of the third transparent=electric layer 202 is equal to or less than The height of the first granular structure (not private) and the height of the second granular structure 2〇11?, (not shown); then, forming the electrode 203 in the first granular structure, the second granular The structure is on the third transparent conductive layer 202. The back electrode structures 200, 210, and 220 in the above embodiments are due to these grains, and. The arrangement of the structures 201, 2〇la and 201b makes the surface roughened, so that the scattering effect of the unabsorbed sunlight can be increased, thereby increasing the path of the sunlight to facilitate re-absorption to achieve solar energy enhancement. The light absorption efficiency of the battery 100 can further enhance the performance of the solar cell. In addition, the monthly pen structure 2〇〇, 210 and 22Θ can be compatible with the process of any original solar cell equipment of solar cells, and has the advantage of lower production cost. However, the above is only the preferred embodiment of the present invention, and it is not limited to the scope of the present invention, that is, the simple equivalent of the patent application scope and the 4 Changes and modifications are still within the scope of this issue = patent coverage. Further, any of the objects or singularities or features of the invention disclosed in the present invention. This 201214716 external 'summary section' and the standard's difficulty are intended to limit the scope of the invention. File search is not [simplified description]

One of the embodiments is applied to solar energy for solar energy

The second diagram is the fabrication flow of the back electrode structure in the battery in the first embodiment of the present invention. The fourth® is the second embodiment of the present invention, which is a manufacturing process for the back electrode structure in the solar cell. The fifth drawing is a manufacturing process for applying the back electrode structure in a solar cell according to a third embodiment of the present invention. [Description of main component symbols] Solar cell 100 First transparent conductive layer solar cell unit 102 Second transparent conductive layer 103 Back electrode structure 2〇〇, 210, 220 Granular structure 2〇1, 2〇la, 201b Third transparent conductive Layer 202 electrode 203 (the third transparent conductive layer) height h 201214716

(grain structure) diameter R

14

Claims (1)

201214716 VII. Patent application scope: • Applied to a solar cell #-第-伽(四)Γ^electrode structure, wherein the solar solar cell unit and a first battery comprise a first transparent conductive layer: a guide: disposed on the side A fine incident, the arrangement of the granular structure in the first structure comprises a structure which is impervious to the filament, and the granular layer is on the first transparent conductive layer, and the electrical layer is placed on the planar structure and the conductive layer. The feature is that the high transparent structure of the third transparent conductive layer allows the granular structure to be recorded on the interface of the transparent conductive layer and the electrode. Aav electricity 2. As described in the scope of the patent application The utility model relates to a north pole structure of a solar cell, wherein the second conductive layer and the third transparent conductive layer are selected from the group consisting of metal oxides, recording materials and social substances. It has a light-transmissive and conductive hiding, and its thickness = 2000 nm. n I 3. As described in the scope of the claim, it is applied to a drain structure of a solar cell, wherein the particle diameter of the granular structure is 1〇 to _ nano. 4. Applying the back electrode structure of the solar cell described in the above paragraph, wherein the material of the granular structure is selected from the group consisting of polymer materials, metals, metal alloys, metal oxides, 11 oxides and above The group is composed of the back electrode structure of the solar cell, wherein the granular structure can be removed. The method for manufacturing the back electrode structure of the solar cell towel is packaged. Providing a first transparent conductive layer; depositing a plurality of granular structures on the first transparent conductive layer; forming a second turned conductive layer on the filamentary structure and the first transparent The height of the third transparent conductive layer is equal to or smaller than the grain shape, the direct structure of the structure, and the formation of the electrode on the granular structure and the third transparent conductive layer. A method for fabricating a back electrode structure in a solar cell, comprising: providing a first transparent conductive layer; forming a first metal layer on the first transparent conductive layer; Performing an annealing process to cause the _th-metal layer to be integrated into a first-grained junction to form a second metal layer on the first granular structure; and performing an annealing treatment to integrate the second metal layer into a second a granular junction forming a third transparent conductive layer on the first granular structure, the first structure and the first transparent conductive layer, and the third transparent conductive layer is equal to or smaller than a diameter of the first granular structure And the second granular structure is formed; and an electrode is formed on the first granular structure, the second granular structure ^201214716. 8. The back electrode according to claim 7 of the invention, wherein the first metal layer is sequentially formed on the first transparent conductive 1; and an annealing treatment is performed, so that an annealing process is performed Disposing the first metal layer on the first granular structure to form the second metal layer on the first granular structure; performing an annealing process to cause the second metal layer to aggregate into the second granular structure, The above steps can be repeated. [9] The back electrode structure for solar cells according to claim 7, wherein the first metal layer has a thickness ranging from 5 to 1 nm, and the sea-metal layer has a thickness ranging from 5 to 1 nanometer, and the thickness of the second metal layer is less than the thickness of the first metal layer. 10. The back electrode structure used in a solar cell according to claim 7, wherein the first metal layer and the second metal layer are both low melting point materials and the first metal layer and the second layer The metal layers are selected from the group consisting of rhodium, magnesium, aluminum, silver, copper, nickel, and the above alloys.