A HIT battery annealing apparatus and annealing method

Abstract

This invention relates to an annealing apparatus and method for HIT (High-Intensity Interval) solar cells. The apparatus includes: a furnace body with an internal cavity capable of accommodating solar cells coated with silver paste; a light source connected to the furnace body for irradiating the silver-painted solar cells to anneal them; wherein the wavelength range of the light source is between 300-750 nm; and an exhaust system including an inlet, a supply outlet, and an outlet; the inlet is located within the furnace body and is connected to the supply outlet, which is located inside the furnace body; the outlet is located on the furnace body to exhaust gases from the furnace. This invention adds a 300-750 nm spectral light source to irradiate the top (or bottom) of the HIT cell, which helps to anneal H (high-intensity interval) cells present in the silicon and interface layer. + Convert to H 0 This achieves the effects of enhanced annealing and hydrogen passivation.

Description

Technical Field

[0001] This invention relates to the field of solar cell technology, and in particular to a HIT cell annealing apparatus and annealing method. Background Technology

[0002] HIT (Heterojunction with Intrinsic Thin-layer) films are 5–10 nm thick. HIT solar cells are constructed by sandwiching a single-crystal Si wafer between a p / i-type a-Si film on the light-illuminated side and an i / n-type a-Si film on the back side. The substrate for HIT solar photovoltaic cells is primarily silicon; a high-bandgap silicon nanofilm is deposited on the silicon substrate, followed by a transparent conductive film on the surface, resulting in a back surface electric field. By optimizing the surface texture of the silicon, the optical absorption loss of the transparent conductive oxide (TCO) layer and the a-Si layer can be reduced.

[0003] Due to the low temperature, high conversion efficiency, short processing time, and good high-temperature performance of HIT battery manufacturing processes, the materials used in HIT batteries necessitate the use of low-temperature silver paste for the printed electrodes. After the conductive silver paste is printed on the battery surface, it needs to be dried and then cured at a temperature not exceeding 250°C to effectively connect the silver paste with the conductive layer (such as TCO, ITO, IWO, IMO, IC-H, ZnO, etc.). Traditional industry methods for curing low-temperature silver paste primarily employ hot air drying ovens. These ovens mainly use hot air circulation during curing, and the drying and curing process begins on the surface of the paste. This causes residual organic gases to escape from the contact area between the silver paste and the solar cell surface. Completely removing these organic gases requires a long processing time and can lead to voids at the contact points, resulting in long processing times, low tensile strength of the silver grid lines after curing, and low photoelectric conversion efficiency. Summary of the Invention

[0004] This invention provides an annealing apparatus and method for HIT batteries, overcoming the shortcomings of existing technologies. The specific technical solution is as follows:

[0005] A HIT battery annealing apparatus, comprising:

[0006] The furnace body has an internal cavity that can accommodate solar cells coated with silver paste.

[0007] A light source, connected to the furnace body, is used to irradiate the solar cells coated with silver paste for annealing; wherein the wavelength range of the light source is between 300-750nm.

[0008] The exhaust device includes an air inlet, an air supply outlet, and an exhaust outlet; the air inlet is located in the furnace body; the air inlet is connected to the air supply outlet, the air supply outlet is located inside the furnace body, and the exhaust outlet is located on the furnace body, capable of discharging the gas inside the furnace body.

[0009] The HIT battery annealing equipment of the present invention preferably uses a light source selected from at least one of LED lamps, xenon lamps, tungsten lamps, and lasers.

[0010] Preferably, the light intensity of the light source is not less than 10 standard suns, and the light intensity of 1 standard sun is 1000 W / h·m. 2 .

[0011] The HIT battery annealing equipment of the present invention preferably further includes: a heating device;

[0012] The heating device is installed inside the furnace and is capable of heating the solar cells coated with silver paste.

[0013] Preferably, the heating device is an infrared light source with a wavelength in the range of 750nm to 4000nm;

[0014] More preferably, the infrared light source is selected from at least one of quartz infrared lamps, ceramic infrared lamps, and LED infrared lamps.

[0015] The HIT battery annealing equipment of the present invention preferably further includes: a lamp cooling device, which is arranged corresponding to the light source and is capable of cooling the light source;

[0016] And / or,

[0017] It also includes: a heat-insulating and light-transmitting plate, which is disposed corresponding to the light source and can be located between the light source and the solar cell.

[0018] The HIT battery annealing equipment of the present invention preferably has a furnace body with a first opening and a second opening opposite each other in a first direction;

[0019] The HIT battery annealing equipment further includes: a conveying device; the conveying device includes at least a conveyor belt, which extends along the first direction and passes through the first opening and the second opening to penetrate the receiving cavity; the conveyor belt is used to carry the solar cell coated with silver paste and can drive the solar cell coated with silver paste to move along the first direction, so that the solar cell coated with silver paste can enter the receiving cavity through the first opening and leave the receiving cavity through the second opening.

[0020] In the HIT battery annealing equipment of the present invention, preferably, the furnace body is composed of a first furnace body part and a second furnace body part, and the first opening and the second opening are located between the first furnace body part and the second furnace body part.

[0021] The HIT battery annealing equipment of the present invention preferably further includes: a clean chamber, the clean chamber being located within the receiving cavity and having a third opening and a fourth opening opposite each other in a first direction, the third opening being connected to the first opening and the fourth opening being connected to the second opening; and a conveyor belt passing through the third opening and the fourth opening to penetrate the clean chamber, the conveyor belt being able to drive the solar cell coated with silver paste to move along the first direction, so that the solar cell coated with silver paste can enter the clean chamber through the third opening and leave the clean chamber through the fourth opening.

[0022] The HIT battery annealing equipment of the present invention preferably further includes: a support and a driving device;

[0023] The conveying device further includes a drive roller, a transmission roller, and a transmission belt. The drive roller and the transmission roller are rotatably connected to the support via a rotating shaft. The transmission belt is annular and sleeved on the outside of the drive roller and the transmission roller. The drive roller can rotate relative to the support with the rotating shaft as the center to drive the transmission belt to operate.

[0024] The driving device includes a drive motor, a drive belt, and a drive roller. The axis of the drive motor is parallel to the rotating shaft. The drive roller is connected to the output end of the drive motor. The drive belt is annular and sleeved on the outside of the drive roller and the drive roller. The drive motor can drive the drive roller to rotate relative to the bracket about the axis of the drive motor to drive the drive belt to rotate, thereby driving the drive roller to rotate relative to the bracket about the rotating shaft.

[0025] Preferably, in the HIT battery annealing equipment of the present invention, the conveyor belt is made of a material with a specific heat capacity of less than 900 J / (kg·℃) (data for specific heat capacity at 20℃);

[0026] Preferably, the conveyor belt is selected from at least one of PEEK, PTFE, CTFE, PVDF, PVDC, POM, PA, PS, PE, ABS, PMMA, PVF, nylon, polysulfone, PPO, epoxy materials, modified materials, synthetic materials, ceramics, carbon fiber, and tungsten alloy wire.

[0027] The HIT battery annealing equipment of the present invention further includes: a solar cell cooling device, which is disposed outside the furnace body and is capable of cooling the annealed solar cells coated with silver paste.

[0028] This invention also provides a method for annealing HIT batteries, comprising:

[0029] Irradiate the solar cell coated with silver paste with a light source with a wavelength between 300-750nm for 0.1-10 minutes.

[0030] In the HIT battery annealing method of the present invention, preferably, the light intensity of the light source is not less than 10 standard suns, and the light intensity of 1 standard sun is 1000 W / h·m. 2 ;

[0031] Preferably, the light intensity of the light source is 50-60 standard solar masses, and the light source irradiates the solar cell coated with silver paste for 0.1-2 minutes.

[0032] The HIT battery annealing method of the present invention preferably further includes: curing the solar cell coated with silver paste at a temperature of 70-300°C.

[0033] Preferably, heating is performed using an infrared light source with a wavelength in the range of 750nm to 4000nm.

[0034] The HIT battery annealing method of the present invention preferably includes a curing process divided into three stages: a first stage, a second stage, and a third stage. The curing temperature of the first stage is lower than that of the second stage, and the curing temperature of the third stage is higher than that of the second stage.

[0035] The HIT battery annealing method of the present invention preferably adjusts the temperature of the solar cell coated with silver paste to between 70-300°C before curing the solar cell coated with silver paste, so as to ensure that the solar cell coated with silver paste can maintain a good process temperature.

[0036] Those skilled in the art will understand that the methods of adjusting the temperature include, but are not limited to, cooling and heating. The cooling method can be any method acceptable in the art, preferably air cooling, tray contact water cooling, etc.; the heating method can be light heating or other methods acceptable in the art.

[0037] Preferably, the curing process includes:

[0038] (1) First stage: Curing the solar cell coated with silver paste at 120-220℃.

[0039] (2) Second stage: Curing the solar cell coated with silver paste at 140-220℃.

[0040] (3) Third stage: Curing the solar cell coated with silver paste at 70-220℃.

[0041] The HIT battery annealing method of the present invention is preferably carried out in an atmospheric gas environment during annealing.

[0042] Preferably, the atmospheric gas is selected from either compressed air or nitrogen.

[0043] The HIT battery annealing method of the present invention preferably uses the HIT battery annealing equipment described in any of the above technical solutions;

[0044] Preferably, the process includes the following steps: irradiating the solar cell coated with silver paste with the light source; receiving atmospheric gas through the air inlet and delivering it to the furnace body through the air outlet, and completing the annealing step under the atmospheric gas.

[0045] The HIT battery annealing method of the present invention, preferably,

[0046] The solar cells coated with silver paste are heated by the heating device and / or cooled by the exhaust device.

[0047] Preferably, the solar cell is cured in the first stage through a first temperature zone formed by the heating device and / or the exhaust device;

[0048] After heating the solar cell in the first temperature zone, a second temperature zone is formed by the heating device and / or the exhaust device to perform the second stage of curing on the solar cell heated in the first temperature zone;

[0049] After the solar cell in the second temperature zone is cured, the solar cell cured in the second temperature zone is cured in the third stage through the third temperature zone formed by the heating device and / or the exhaust device.

[0050] This invention increases the spectral intensity by adding a 300-750nm light source, such as an additional LED lamp, xenon lamp, tungsten lamp, or laser, to the top (or bottom) of the solar cell. After increasing the spectrum, the overall light intensity typically exceeds 10 standard solar masses, and the higher the intensity, the better the effect. Tests have shown that this invention achieves extremely high results with light intensities exceeding 60 standard solar masses, while maintaining an illumination time of over 0.2 minutes. This method helps to address H+ ions present in silicon and the interface layer. + Convert to H0 This achieves the effects of enhanced annealing and hydrogen passivation.

[0051] Furthermore, this invention, by using a heating device (infrared IR lamp) in conjunction with a light source (such as an LED lamp, xenon lamp, tungsten lamp, or laser) to irradiate the top (or bottom) of the solar cell, can simultaneously achieve the functions of low-temperature silver paste curing, annealing, and hydrogen passivation of heterojunction solar cells. It should be noted that: if an IR lamp with an infrared spectrum wavelength in the range of 750nm to 4000nm is used alone, the functions of low-temperature silver paste curing and partial annealing of heterojunction solar cells can be achieved. If an LED lamp, xenon lamp, tungsten lamp, or laser is used alone to irradiate the top (or bottom) of the solar cell with a spectrum wavelength in the range of 300nm to 4000nm and a light intensity of more than 10 standard solar masses, the functions of annealing and hydrogen passivation of heterojunction solar cells can be achieved. By simultaneously irradiating the top (or bottom) of the solar cell with an infrared IR lamp, LED lamp, xenon lamp, tungsten lamp, or laser, the functions of low-temperature silver paste curing, annealing, and hydrogen passivation can be achieved in an integrated manner.

[0052] Of course, implementing any product or method of the present invention does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0053] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0054] Figure 1 This is a schematic diagram of the structure of the HIT battery annealing equipment provided by the present invention.

[0055] The attached figures are labeled as follows:

[0056] A: Solar cells coated with silver paste;

[0057] 101: Furnace body;

[0058] 102: Light source;

[0059] 103: Exhaust device;

[0060] 104: Air intake;

[0061] 105: Air inlet;

[0062] 106: Exhaust vent;

[0063] 107: Heating device;

[0064] 108: Lamp cooling device;

[0065] 109: Heat-insulating and light-transmitting panel;

[0066] 110: Conveying device;

[0067] 111: First furnace body section;

[0068] 112: Second furnace body section;

[0069] 113: Clean chamber;

[0070] 114: Bracket;

[0071] 115: Drive unit;

[0072] 116: Drive roller;

[0073] 117: Drive roller;

[0074] 118: Conveyor belt;

[0075] 119: Drive motor;

[0076] 120: Drive belt;

[0077] 121: Drive roller;

[0078] 122: Solar cell cooling device. Detailed Implementation

[0079] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0080] Example 1

[0081] Combined with appendix Figure 1 This embodiment provides a HIT battery annealing apparatus, including:

[0082] The furnace body 101 has an internal cavity that can accommodate solar cells coated with silver paste.

[0083] A light source 102 is connected to the furnace body 101 and is capable of irradiating the solar cell coated with silver paste for annealing; wherein the wavelength range of the light source 102 is between 300-750nm.

[0084] The exhaust device 103 includes an air inlet 104, an air supply port 105, and an exhaust port 106; the air inlet 104 is disposed on the furnace body 101; the air inlet 104 is connected to the air supply port 105, the air supply port 105 is disposed inside the furnace body 101, and the exhaust port 106 is disposed on the furnace body 101 and is capable of discharging the gas inside the furnace body 101.

[0085] In this embodiment, the furnace body 101 has an internal cavity, which can accommodate the solar cells coated with silver paste in any form, such as by placing, suspending or conveyor belt transport, all of which are within the protection scope of this embodiment.

[0086] The solar cell coated with silver paste can have a preset thickness. To explain, the preset thickness is set according to the conductivity of the silver paste and the performance of the HIT cell to be prepared. The preset thickness allows the silver paste to achieve the required conductivity after curing. The silver paste is generally composed of different forms of flake silver powder prepared under different conditions, different types of resin, surface dispersants and organic matter.

[0087] As will be understood by those skilled in the art, the HIT battery annealing equipment also includes a gas distribution pipe. The air inlet 104 is typically equipped with an air inlet pipe, one end of which is located outside the furnace body 101, and the other end of which passes through the furnace body 101 wall and connects to one end of the gas distribution pipe. The other end of the gas distribution pipe is connected to the air outlet 105, which is located inside the furnace body 101. The atmospheric gas in the gas distribution pipe discharges the organic gases generated by the solar cells. The atmospheric gas is then delivered to the gas distribution pipe through the air inlet 104 / air inlet pipe, and then distributed into the furnace body 101 through the air outlet 105. This atmospheric gas facilitates the removal of organic gases volatilized from the silver paste and also carries away some heat, achieving the purpose of cooling the solar cells. Subsequently, the atmospheric gas carrying the organic gases is discharged through the exhaust port 106. The exhaust port 106 can be equipped with a fan or any exhaust device acceptable in the art to discharge the gas inside the furnace body 101. Furthermore, in this embodiment, there may be one or at least two air inlets 104, air outlets 105, and air outlets 106, and any arrangement acceptable in the art (such as arranged in a straight line or staggered arrangement) should be within the protection scope of this embodiment.

[0088] The light source 102 described herein is connected to the furnace body 101, encompassing any connection method where the light source 102 is inside, outside, or otherwise acceptable within the furnace body 101, as long as the light source 102 can irradiate the solar cells coated with silver paste for annealing. Those skilled in the art should understand the scope of the above technical solution and its ability to achieve the aforementioned functions. Furthermore, the light source 102 described in this embodiment can be one or at least two, without any particular limitation.

[0089] Therefore, the cavity of the furnace body 101 contains solar cells coated with silver paste to be annealed, and the annealing is completed under the illumination of the light source 102; annealing using the equipment of this embodiment helps to remove H present in silicon and the interface layer. + Convert to H 0 This achieves the effects of enhanced annealing and hydrogen passivation. Furthermore, verification has shown that the cell efficiency (Eff) is further improved, with an increase of at least 0.1%. Additionally, during the annealing process, the exhaust device 103 introduces atmospheric gas into the furnace body 101 to assist in the removal of organic gases from the solar cells during annealing.

[0090] Furthermore, the exhaust device 103 can effectively cool the solar cells while providing atmospheric gas.

[0091] In the HIT battery annealing equipment described in this embodiment, preferably, the light source 102 is selected from at least one of LED lamps, xenon lamps, tungsten lamps, and lasers;

[0092] Preferably, the light intensity of the light source 102 is not less than 10 standard suns, and the light intensity of 1 standard sun is 1000 W / h·m. 2 More preferably, the light intensity of the light source 102 is 50-60 standard suns.

[0093] The intensity of the aforementioned light source 102 has been verified to significantly improve the efficiency of the solar cells. In particular, the Eff efficiency can be improved to over 0.15%.

[0094] The HIT battery annealing equipment described in this embodiment preferably further includes: a heating device 107;

[0095] The heating device 107 is installed inside the furnace body 101 and is capable of heating the solar cell coated with silver paste.

[0096] Heating the solar cells coated with silver paste inside the furnace body 101 using the heating device 107 facilitates uniform heating of the solar cells. Furthermore, the heating area of ​​the heating device 107 can be divided into several heating temperature zones to achieve gradient heating and other processes. Combined with the cooling function of the exhaust device 103, this effectively ensures that the solar cells are cured at a suitable process temperature.

[0097] Preferably, the heating device 107 is an infrared light source with a wavelength in the range of 750nm to 4000nm.

[0098] Verification has shown that infrared light within the aforementioned specific wavelength range is far more conducive to the curing of the solar cell, thereby enabling the HIT battery annealing equipment described in this embodiment to perform simultaneous annealing and curing.

[0099] More preferably, the infrared light source is selected from at least one of quartz infrared lamps, ceramic infrared lamps, LED infrared lamps, etc.

[0100] The HIT battery annealing equipment described in this embodiment preferably further includes: a lamp cooling device 108, which is correspondingly arranged with the light source 102 and is capable of cooling the light source 102.

[0101] As an explanation, the corresponding arrangement of the lamp cooling device 108 and the light source 102 means that the lamp cooling device 108 is positioned to cool the light source 102.

[0102] Therefore, during the operation of the HIT battery annealing equipment described in this embodiment, the light source 102 may generate heat when turned on, thereby affecting the preset temperature of the heating device 107. Therefore, the lamp cooling device 108 is added to avoid the temperature generated by the light source 102 from affecting the annealing or curing of the solar cell as much as possible.

[0103] The HIT battery annealing equipment described in this embodiment preferably further includes: a heat-insulating and light-transmitting plate 109, which is disposed corresponding to the light source 102 and can be located between the light source 102 and the solar cell coated with silver paste.

[0104] The heat-insulating and light-transmitting plate 109 can be positioned arbitrarily, as long as it prevents the light source 102 from shining on the solar cell coated with silver paste, and the light from the light source 102 must pass through the heat-insulating and light-transmitting plate 109 before shining on the solar cell coated with silver paste.

[0105] In the HIT battery annealing equipment described in this embodiment, preferably, the furnace body 101 is provided with a first opening and a second opening opposite to each other in a first direction;

[0106] The HIT battery annealing equipment further includes: a conveying device 110; the conveying device 110 includes at least a conveyor belt, which extends along the first direction and passes through the first opening and the second opening to penetrate the receiving cavity; the conveyor belt is used to carry the solar cell coated with silver paste and can drive the solar cell coated with silver paste to move along the first direction, so that the solar cell coated with silver paste can enter the receiving cavity through the first opening and leave the receiving cavity through the second opening.

[0107] This allows for the efficient and automated curing and annealing of HIT batteries.

[0108] In the HIT battery annealing equipment described in this embodiment, preferably, the furnace body 101 is formed by splicing a first furnace body part 111 and a second furnace body part 112, and the first opening and the second opening are located between the first furnace body part 111 and the second furnace body part 112.

[0109] The HIT battery annealing equipment described in this embodiment preferably further includes: a clean chamber 113, which is located within the receiving cavity and has a third opening and a fourth opening opposite each other in a first direction. The third opening is connected to the first opening, and the fourth opening is connected to the second opening. A conveyor belt passes through the third opening and the fourth opening to penetrate the clean chamber 113. The conveyor belt can drive the solar cell coated with silver paste to move along the first direction, so that the solar cell coated with silver paste can enter the clean chamber 113 through the third opening and leave the clean chamber 113 through the fourth opening.

[0110] Therefore, a clean chamber 113 is provided to improve the environment for annealing and curing the HIT battery and reduce the generation of impurities.

[0111] The HIT battery annealing equipment described in this embodiment preferably further includes: a bracket 114 and a driving device 115;

[0112] The conveying device 110 also includes a drive roller 116, a transmission roller 117, and a transmission belt 118. The drive roller 116 and the transmission roller 117 are rotatably connected to the bracket 114 via a rotating shaft. The transmission belt 118 is annular and sleeved on the outside of the drive roller 116 and the transmission roller 117. The drive roller 116 can rotate relative to the bracket 114 with the rotating shaft as the center to drive the transmission belt 118 to operate.

[0113] The driving device 115 includes a drive motor 119, a drive belt 120, and a drive roller 121. The axis of the drive motor 119 is parallel to the rotating shaft. The drive roller 121 is connected to the output end of the drive motor 119. The drive belt 120 is annular and sleeved on the outside of the drive roller 121 and the drive roller 116. The drive motor 119 can drive the drive roller 121 to rotate relative to the bracket 114 with the axis of the drive motor 119 as the center, thereby driving the drive belt 120 to rotate, and thus driving the drive roller 116 to rotate relative to the bracket 114 with the rotating shaft as the center.

[0114] The conveying device 110 further includes at least: a conveying unit support 114, a first transmission roller, a sliding bearing seat, a spring, and a limiting screw.

[0115] The conveying unit support 114 has a limiting groove, and the sliding bearing seat is at least partially disposed in the limiting groove. The roller head of the first transmission roller is located in the limiting groove and abuts against the bearing surface of the sliding bearing seat.

[0116] The limiting screw penetrates the conveying unit bracket 114 and is installed on the sliding bearing seat. The spring is sleeved on the limiting screw. The direction of the limiting screw is perpendicular to the direction of the first transmission roller. The bearing surface of the sliding bearing seat is equal to the groove surface of the limiting groove. The groove surface of the limiting groove is larger than the contact surface between the roller head of the first transmission roller and the sliding bearing seat.

[0117] The two working states of the conveyor 110 include: the spring is in its original length state, and there is a gap between the sliding bearing seat and the limiting groove. At this time, the conveyor belt is in a slack state, and the slack conveyor belt 118 is easy to install.

[0118] When the limit screw rotates, the spring is in a compressed state. Through the bearing located between the bearing surface and the roller head of the first transmission roller, the first transmission roller moves the length of the gap towards the center of gravity of the transmission unit bracket 114. The sliding bearing seat is in contact with the limit groove. At this time, the transmission belt 118 is in a tensioned state. The tensioned transmission belt 118 is conducive to the normal transmission of the belt.

[0119] In the HIT battery annealing equipment described in this embodiment, preferably, the conveyor belt is made of a material with a specific heat capacity of less than 900 J / (kg·℃) (data for specific heat capacity at 20℃);

[0120] Preferably, the conveyor belt is selected from PEEK (Polyetheretherketone), PTFE (Polytetrafluoroethylene), CTFE (Chlorotrifluorethene), PVDF (polyvinylidene fluoride), PVDC (Polyvinylidene chloride), POM (Polyoxymethylene), PA (polyamide), PS (Polystyrene), PE (Polyethylene), ABS (Acrylonitrile Butadiene Styrene), PMMA (Polymethylmethacrylate), PVF (Polyvinylformal), nylon, polysulfone, and PPO (Polyphenylene oxide). The material of the conveyor belt can be one or more of the following: oxyethylene (polyphenylene ether), epoxy materials, modified materials, synthetic materials, ceramics, carbon fiber, and tungsten alloy wire. Epoxy materials can be epoxy resins, etc., and synthetic materials can be plastics, glass, steel, etc. The material of the conveyor belt can also include various modified materials, such as modified PA (polyamide), modified PP (polypropylene), modified PC (polycarbonate), modified ABS (acrylonitrile butadiene styrene copolymer), modified PBT (polybutylene terephthalate), etc. In this embodiment, all materials that meet the requirements of temperature resistance exceeding the process temperature, cleanliness, and low heat capacity are within the scope of protection of this embodiment, and will not be listed individually here. Among these features, the cleanliness will not cause contamination to the contact surface of the solar cell that affects its electrical performance or appearance, and the low heat capacity will not affect the temperature rise, temperature drop, or temperature gradient of the solar cell. This allows for more stable curing and annealing of HIT cells.

[0121] The HIT battery annealing equipment described in this embodiment also includes a solar cell cooling device 122, which is located outside the furnace body 101 and can cool the annealed solar cells coated with silver paste.

[0122] The solar cell cooling device 122 may employ air cooling, water cooling, or any other form of cooling device acceptable in the art. No particular limitation is made in this regard.

[0123] Therefore, cooling the solar cells after the curing process facilitates the next step of the process.

[0124] This embodiment adds a 300-750nm spectral light source 102, such as an additional LED lamp, xenon lamp, tungsten lamp, or laser, to illuminate the top (or bottom) of the solar cell. After increasing the spectrum, the overall light intensity is typically above 10 standard solar masses, and the higher the light intensity, the better the effect. Tests of this invention have shown that light intensities exceeding 60 standard solar masses achieve extremely high standards, with the illumination time controlled to be above 0.2 minutes. This method helps to address H+ present in silicon and the interface layer. + Convert to H 0 This achieves the effects of enhanced annealing and hydrogen passivation.

[0125] In this embodiment, by using a heating device 107 (infrared IR lamp) and a light source 102 (such as an LED lamp, xenon lamp, tungsten lamp, or laser) to irradiate the top (or bottom) of the solar cell, the functions of low-temperature silver paste curing, annealing, and hydrogen passivation of heterojunction solar cells can be achieved simultaneously. It should be noted that: if an IR lamp with an infrared spectrum wavelength in the range of 750nm to 4000nm is used alone, the functions of low-temperature silver paste curing and partial annealing of heterojunction solar cells can be achieved. If an LED lamp, xenon lamp, tungsten lamp, or laser is used alone to irradiate the top (or bottom) of the solar cell with a spectrum wavelength in the range of 300nm to 4000nm and a light intensity of more than 10 standard solar masses, the functions of annealing and hydrogen passivation of heterojunction solar cells can be achieved. By simultaneously irradiating the top (or bottom) of the solar cell with an infrared IR lamp, LED lamp, xenon lamp, tungsten lamp, or laser, the functions of low-temperature silver paste curing, annealing, and hydrogen passivation can be achieved in an integrated manner.

[0126] Example 2

[0127] This embodiment provides a method for annealing HIT batteries, including the following steps:

[0128] The solar cells coated with silver paste were irradiated with a light source with a wavelength between 300-750nm for 10 minutes;

[0129] Furthermore, the light intensity of the light source is equivalent to 10 standard suns, and the light intensity of one standard sun is 1000 W / h·m. 2 .

[0130] Example 3

[0131] This embodiment provides a method for annealing HIT batteries, including the following steps:

[0132] A solar cell coated with silver paste was irradiated with a light source with a wavelength between 300-750 nm for 0.2 min.

[0133] Furthermore, the light intensity of the light source is 60 standard suns, and the light intensity of one standard sun is 1000 W / h·m. 2 .

[0134] Example 4

[0135] This embodiment provides a method for annealing HIT batteries, including the following steps:

[0136] A solar cell coated with silver paste was irradiated for 0.2 minutes with a light source having a wavelength between 300-750 nm; and the light intensity of the light source was equivalent to 60 standard suns, with one standard sun having a light intensity of 1000 W / h·m. 2 ;

[0137] Meanwhile, the solar cells coated with silver paste are heated in the furnace at a temperature of 70-220°C (changed to 70-300°C) for 0.2 minutes.

[0138] Example 5

[0139] This embodiment provides a HIT battery annealing method, which uses the HIT battery annealing equipment described in Embodiment 1, and includes the following steps:

[0140] The solar cell coated with silver paste is irradiated by the light source; atmospheric gas is received through the air inlet and delivered into the furnace through the air outlet, where the annealing is completed under atmospheric gas conditions.

[0141] Preferably, it further includes:

[0142] The solar cells coated with silver paste are heated by the heating device and cooled by the exhaust device to maintain the set process temperature.

[0143] Specifically, the set process temperature is in the range of 70-300℃.

[0144] Example 6

[0145] This embodiment provides a HIT battery annealing method. Compared with Embodiment 5, the difference lies in that, when heating the solar cell coated with silver paste using the heating device, a gradient heating method is adopted. The specific method is as follows:

[0146] The solar cell is cured in the first stage through the first temperature zone formed by the heating device and / or the exhaust device;

[0147] After heating the solar cell in the first temperature zone, a second temperature zone is formed by the heating device and / or the exhaust device to perform the second stage of curing on the solar cell heated in the first temperature zone;

[0148] After the solar cell in the second temperature zone is cured, the solar cell cured in the second temperature zone is cured in the third stage through the third temperature zone formed by the heating device and / or the exhaust device.

[0149] Specifically, the temperatures for the first, second, and third stages are as follows:

[0150] (1) First stage: Curing the solar cell coated with silver paste at 120-220℃;

[0151] (2) Second stage: Curing the solar cell coated with silver paste at 140-220℃;

[0152] (3) Third stage: Curing the solar cell coated with silver paste at 70-220℃.

[0153] The second temperature zone is the curing zone for solar cells coated with silver paste of a preset thickness. The temperature set for this second temperature zone is the curing temperature recommended by the low-temperature silver paste manufacturer. Different batches of paste produced by different silver paste manufacturers have different curing temperatures due to different formulations. Currently, the recommended curing temperature for low-temperature pastes on the market is usually in the range of 140℃ to 220℃. The set temperature is conducive to the rapid curing of the silver paste.

[0154] The second temperature zone is a cooling zone for solar cells coated with silver paste of a preset thickness. The second temperature zone is within a temperature range of 70°C to 220°C, and the set temperature is conducive to the curing of solar cells coated with silver paste of a preset thickness.

[0155] The temperature of each temperature zone can be controlled by PID temperature control, which detects the actual temperature through a temperature probe. The temperature control can be achieved by a temperature control instrument or by a programmable logic controller (PLC).

[0156] Preferably, it specifically includes:

[0157] First, the solar cell is heated in the first temperature zone formed by the infrared spectrum of the heating device. Here, the temperature of the solar cell is higher than that of the silver paste after heating. The temperature at the contact point between the solar cell and the silver paste is higher than that of the surface of the silver paste. The resin in the silver paste is in a semi-molten state, which is more conducive to the discharge of organic gases in the silver paste. At the same time, the temperature at the contact point between the solar cell and the silver paste is higher than that of the surface of the silver paste, which causes the organic gases inside the silver paste to escape from other locations besides the contact point between the solar cell and the silver paste.

[0158] Secondly, after heating the solar cell in the first temperature zone, the solar cell heated in the first temperature zone is cured in the second temperature zone formed by the infrared spectrum of the heating device. The temperature of the first temperature zone is lower than that of the second temperature zone, which is conducive to the volatilization of organic gases in the silver paste. Since most of the organic gases in the silver paste have been discharged after being heated in the first temperature zone, the second temperature zone is more conducive to the rapid curing of the silver paste, thereby covering the solar cell with the semi-molten resin in the silver paste to form an adhesive structure.

[0159] After the solar cell is cured in the second temperature zone, a third temperature zone formed by the infrared spectrum of the heating device is used to cool the solar cell cured in the second temperature zone. The temperature of the third temperature zone is lower than that of the first temperature zone, which is beneficial to the cooling of the silver paste and the solar cell.

[0160] Preferably, in the intrinsic thin-layer heterojunction (HIT) low-temperature silver paste curing method of this embodiment of the invention, the temperature of the heated solar cell is higher than the temperature of the silver paste, the temperature at the contact point between the solar cell and the silver paste is higher than the temperature of the silver paste surface, and the resin in the silver paste is in a semi-molten state, so that organic gases can escape from the interior of the silver paste from other locations besides the contact point, including:

[0161] When the solar cell is heated in the first temperature zone formed by the heating device, the temperature of the solar cell is higher than the temperature of the silver paste, the temperature of the contact point between the solar cell and the silver paste is higher than the temperature of the surface of the silver paste, and the resin in the silver paste is in a semi-molten state, so that the organic gas inside the silver paste can escape from other positions except the contact point. The first temperature zone is in the temperature range of 120°C to 220°C, and the set temperature is conducive to the volatilization of organic gas in the silver paste.

[0162] The solar cell, heated in the first temperature zone, is cured in a second temperature zone formed by the heating device. The resin in the silver paste, which is in a semi-molten state, covers the solar cell to form an adhesive structure. The second temperature zone is set in a temperature range of 140°C to 220°C, which is conducive to the rapid curing of the silver paste.

[0163] Preferably, in the intrinsic thin-layer heterojunction (HIT) low-temperature silver paste curing method of the present invention, cooling the bonding structure to obtain a solar cell with cured silver paste includes:

[0164] The third temperature zone formed by the heating device cools the bonded structure and the solar cell coated with silver paste of a preset thickness after the second temperature zone has been cured, resulting in a solar cell with cured silver paste. The third temperature zone is in the temperature range of 70°C to 220°C, and the set temperature is conducive to the cooling of the solar cell coated with silver paste of a preset thickness.

[0165] Comparative Example 1

[0166] Compared with Example 1, this comparative example differs in that the light source and other corresponding devices are not present; that is, infrared heating is used to cure the solar cell coated with silver paste.

[0167] Experimental Example 1

[0168] To better illustrate the application effect of the HIT battery annealing equipment and annealing method provided by the present invention, this experimental example provides data on HIT batteries obtained after actual-scale production according to the method described in Example 5, as shown in Table 1:

[0169] Table 1

[0170]

[0171] This experimental example also provides data on HIT batteries obtained after actual-scale production according to the method described in Example 6, as shown in Table 2:

[0172] Table 2

[0173]

[0174] As those skilled in the art can understand, when an experiment is repeated multiple times, even in the same manner (such as Comparative Example 1 in Tables 1 and 2), there will be slight differences in the data, which are experimental errors.

[0175] As can be seen from Tables 1 and 2, the HIT battery annealing method and / or HIT battery annealing equipment provided by this invention can increase battery efficiency by at least 0.15%.

[0176] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0177] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0178] Although the present invention has been described in detail above with general descriptions, specific embodiments, and experiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A HIT battery annealing apparatus, characterized in that, include: The furnace body has an internal cavity that can accommodate solar cells coated with silver paste. A light source, connected to the furnace body, is used to irradiate the solar cells coated with silver paste for annealing; wherein the wavelength range of the light source is between 300-750nm. An exhaust device includes an air inlet, an air supply outlet, and an exhaust outlet; the air inlet is located in the furnace body; the air inlet is connected to the air supply outlet, the air supply outlet is located inside the furnace body, and the exhaust outlet is located on the furnace body, capable of discharging gas from inside the furnace body; The light intensity of the light source is 50-60 standard suns, and the light intensity of 1 standard sun is 1000 W / h·m. 2 ; The HIT battery annealing equipment also includes: a heating device; The heating device is installed inside the furnace and is capable of heating the solar cells coated with silver paste. The heating device is an infrared light source with a wavelength in the range of 750nm to 4000nm; The infrared light source is selected from at least one of quartz infrared lamps, ceramic infrared lamps, and LED infrared lamps.

2. The HIT battery annealing equipment according to claim 1, characterized in that, The light source is selected from at least one of LED lamps, xenon lamps, tungsten lamps, and lasers.

3. The HIT battery annealing equipment according to claim 1, characterized in that, Also includes: A lamp cooling device is provided corresponding to the light source and is capable of cooling the light source; And / or, It also includes: a heat-insulating and light-transmitting plate, which is disposed corresponding to the light source and can be located between the light source and the solar cell coated with silver paste.

4. The HIT battery annealing apparatus according to any one of claims 1-3, characterized in that, The furnace body is provided with a first opening and a second opening opposite each other in a first direction; The HIT battery annealing equipment further includes: a conveying device; the conveying device includes at least a conveyor belt, which extends along the first direction and passes through the first opening and the second opening to penetrate the receiving cavity; the conveyor belt is used to carry the solar cell coated with silver paste and can drive the solar cell coated with silver paste to move along the first direction, so that the solar cell coated with silver paste can enter the receiving cavity through the first opening and leave the receiving cavity through the second opening.

5. The HIT battery annealing equipment according to claim 4, characterized in that, The conveyor belt is made of a material with a specific heat capacity of less than 900 J / (kg·℃); The conveyor belt is selected from at least one of the following: PEEK, PTFE, CTFE, PVDF, PVDC, POM, PA, PS, PE, ABS, PMMA, PVF, nylon, polysulfone, PPO, epoxy materials, modified materials, synthetic materials, ceramics, carbon fiber, and tungsten alloy wire.

6. A method for annealing HIT batteries, characterized in that, The HIT battery annealing apparatus according to any one of claims 1-5 comprises: Irradiate the silver-painted solar cell with a light source with a wavelength between 300-750nm for 0.1-10 minutes; The light intensity of the light source is 50-60 standard suns, and the light intensity of 1 standard sun is 1000 W / h·m. 2 .

7. The HIT battery annealing method according to claim 6, characterized in that, The light source illuminates the solar cell coated with silver paste for 0.1-2 minutes.

8. The HIT battery annealing method according to claim 6, characterized in that, Also includes: The solar cell coated with silver paste is cured at a temperature of 70-300℃. During curing, an infrared light source with a wavelength range of 750nm to 4000nm is used for heating.

9. The HIT battery annealing method according to claim 8, characterized in that, Before curing the solar cell coated with silver paste, the temperature of the solar cell coated with silver paste is adjusted to between 70-300°C. The curing process is divided into three stages: a first stage, a second stage, and a third stage. The temperature of the first stage is lower than that of the second stage, and the temperature of the third stage is higher than that of the second stage. The curing process is divided into: (1) First stage: Curing the solar cell coated with silver paste at 120-220℃; (2) Second stage: Curing the solar cell coated with silver paste at 140-220℃; (3) Third stage: Curing the solar cell coated with silver paste at 70-220℃.

10. The HIT battery annealing method according to claim 6, characterized in that, Annealing is performed in a specific atmospheric gas environment. The atmospheric gas is selected from either compressed air or nitrogen.

11. The HIT battery annealing method according to claim 6, characterized in that, The process includes the following steps: irradiating the solar cell coated with silver paste with the light source; receiving atmospheric gas through the air inlet and delivering it to the furnace through the air outlet, and completing the annealing step under the atmospheric gas.

12. The HIT battery annealing method according to claim 9, characterized in that, Also includes: The solar cells coated with silver paste are heated by the heating device and / or cooled by the exhaust device. The solar cell is cured in the first stage through the first temperature zone formed by the heating device and / or the exhaust device; After heating the solar cell in the first temperature zone, a second temperature zone is formed by the heating device and / or the exhaust device to perform the second stage of curing on the solar cell heated in the first temperature zone; After the solar cell in the second temperature zone is cured, the solar cell cured in the second temperature zone is cured in the third stage through the third temperature zone formed by the heating device and / or the exhaust device.

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