Crystalline silicon solar cell preparation method for inhibiting carrier injection attenuation
阅读说明：本技术 一种抑制载流子注入衰减的晶体硅太阳能电池制备方法 (Crystalline silicon solar cell preparation method for inhibiting carrier injection attenuation ) 是由 庞瑞卿 陈刚 于 2021-05-31 设计创作，主要内容包括：本发明公开了一种抑制载流子注入衰减的晶体硅太阳能电池制备方法,包括如下工艺步骤：(1)制绒、(2)高温气相扩散、(3)蚀刻清洗、(4)背面氧化铝镀膜、(5)氮化硅叠层薄膜钝化、(6)正面氮化硅薄膜钝化、(7)背面激光开槽、(8)丝网印刷背面铝电极和正面银电极浆料、(9)烘干烧结；其中,所述的(2)高温气相扩散过程中进行高温热处理后,采用梯度降温的方式对太阳能电池进行冷却处理。该制备方法可以有效降低晶体硅太阳能电池的LID和LeTID衰减,从而保证晶体硅太阳能电池的工作效率保持在较高的水平。(The invention discloses a crystalline silicon solar cell preparation method for inhibiting carrier injection attenuation, which comprises the following process steps: (1) texturing, (2) high-temperature gas phase diffusion, (3) etching and cleaning, (4) back side aluminum oxide coating, (5) passivation of a silicon nitride laminated film, (6) passivation of a front side silicon nitride film, (7) laser grooving of the back side, (8) screen printing of back side aluminum electrode and front side silver electrode slurry, and (9) drying and sintering; and (2) after high-temperature heat treatment is carried out in the high-temperature gas phase diffusion process, cooling the solar cell by adopting a gradient cooling mode. The preparation method can effectively reduce LID and LeTID attenuation of the crystalline silicon solar cell, thereby ensuring that the working efficiency of the crystalline silicon solar cell is kept at a higher level.)
1. A crystalline silicon solar cell preparation method for inhibiting carrier injection attenuation comprises the following process steps: (1) texturing, (2) high-temperature gas phase diffusion, (3) etching and cleaning, (4) back side aluminum oxide coating, (5) passivation of a silicon nitride laminated film, (6) passivation of a front side silicon nitride film, (7) laser grooving of the back side, (8) screen printing of back side aluminum electrode and front side silver electrode slurry, and (9) drying and sintering; the solar cell is characterized in that after high-temperature heat treatment is carried out in the high-temperature gas phase diffusion process in the step (2), the solar cell is cooled by adopting a gradient cooling mode.
2. The method for preparing a crystalline silicon solar cell for inhibiting carrier injection attenuation according to claim 1, wherein the (2) specific process of high-temperature gas phase diffusion is as follows:
s1: when a phosphorus source is deposited on the surface of a silicon wafer for the first time, after maintaining the state of constant pressure of 200 +/-20 mBar and diffusion constant temperature of 750 +/-10 ℃ in a quartz tube for at least 2min, introducing oxygen, wherein the flow rate of the oxygen is 300-1200 sccm; adjusting the pressure in the quartz tube to 50 +/-5 mBar after ventilating for 2-10 min, and then ventilating small nitrogen carrying phosphorus oxychloride with the flow of 140-600 sccm for 3-10 min;
s2: repeating the operation of the circulation S1, wherein the temperature gradient of each circulation is increased progressively, the gradient is 10-50 ℃, and the flow of the small nitrogen and the oxygen is not lower than the flow of the previous circulation;
s3: keeping the pressure in the furnace at 200 +/-20 mBar, closing the small nitrogen, keeping introducing oxygen at a flow rate of 200-2000 sccm, heating and keeping the heating rate at 7-20 ℃/min to 870 +/-10 ℃ for 3-10 min; controlling the propelling temperature to be 40-100 ℃ higher than the diffusion temperature of the last cycle in S2;
s4: stopping heating and oxygen introduction, maintaining the nitrogen flow at 1-2 SLM, keeping vacuum constant pressure in the furnace, performing gradient cooling at 20-60 ℃, and cooling to 820 +/-20 ℃;
s5: controlling the temperature of each zone in the furnace to be 820 +/-20 ℃ and the pressure to be 50 +/-5 mbar, introducing oxygen at the flow rate of 300-1200 sccm, maintaining for 2-10 min, and introducing small nitrogen carrying phosphorus oxychloride at the flow rate of 140-600 sccm for 3-10 min;
s6: repeating the operation of the circulation S5, wherein the temperature gradient of each circulation is reduced progressively, the gradient is 10-50 ℃, and the flow of the small nitrogen and the oxygen is not lower than the flow of the previous circulation;
s7: when the temperature in the furnace is reduced to below 770 ℃, the quartz boat is withdrawn, and the high-temperature gas phase diffusion is completed.
Preferably, S4 adopts multiple gradient platforms to realize gradient cooling, the first platform is set to 860 +/-20 ℃, the second platform is set to 840 +/-20 ℃, and the third platform is set to 800 +/-20 ℃.
3. The method for preparing a crystalline silicon solar cell for inhibiting carrier injection attenuation according to claim 2, wherein the step (9) of baking and sintering also comprises a gradient cooling process: the drying and sintering step (9) comprises four stages of drying, preheating, sintering and cooling, wherein the drying temperature in the drying stage is 100-250 ℃, and the drying time is not less than 12 s; the sintering stage is provided with a preheating section and a sintering section, the heating rate of the preheating section is set to be not lower than 50 ℃/s, and the residence time of the battery in the preheating section is not more than 20 s; the peak area of the sintering section is arranged at the position close to the front of the middle section, the retention time of the battery in the sintering section is not more than 5s, and the peak temperature is not higher than 760 +/-10 ℃; the temperature reduction speed of the temperature reduction stage is controlled to be not higher than 60 ℃/s.
4. The method for manufacturing a crystalline silicon solar cell for suppressing carrier injection decay according to claim 3, further comprising (10) front-side laser doping, (11) annealing, and (12-1) light injection or (12-2) electric injection.
5. The method of claim 4The preparation method of the crystalline silicon solar cell for inhibiting the carrier injection attenuation is characterized in that in the (12-1) light injection, a multi-module light injection heat treatment caterpillar furnace is used, and the maximum output power is 20000w/m2The total time of light injection is not less than 20 s;
the irradiation power of the first module is controlled to be 90 +/-10% of the maximum output power, the temperature is controlled to be 280 +/-30 ℃, and the duration time is 4-20 s;
the irradiation power of the second module is controlled to be 80 +/-10% of the maximum output power, the temperature is controlled to be 250 +/-30 ℃, and the duration time is 4-20 s;
the irradiation power of the third module is controlled to be less than 70% of the maximum output power, the temperature is controlled to be 230 +/-30 ℃, and the duration time is 4-20 s.
6. The method for preparing a crystalline silicon solar cell for suppressing carrier injection decay according to claim 4, wherein the (12-1) light injection is performed by using a light injection device integrated with a sintering furnace, the light injection device utilizes a residual temperature/set heating device in a sintering stage, the maximum output power of the heating device is more than 3000w, the maximum heating temperature is 450 ℃, the average temperature of the front module and the rear module is set to be reduced in a gradient manner, the gradient is 10-40 ℃, and the total time of light injection is not less than 20 s.
Technical Field
The invention belongs to the technical field of solar cell manufacturing, and particularly relates to a crystalline silicon solar cell preparation method for inhibiting carrier injection attenuation.
Background
Light Induced attenuation (LID) of a crystalline silicon solar cell is a very obvious attenuation phenomenon existing in a Czochralski monocrystalline silicon solar cell, and is caused by the capture of a metastable boron-oxygen pair complex (B-O pair for short) to minority carriers in monocrystalline silicon.
Generally, LID occurs in two stages: (1) a rapid phase occurring on the second time scale, with relatively weak temperature dependence; (2) the activation energy for the formation of attenuation-related defects is about 0.48eV, with a time scale of tens of hours in a gradual phase. The decay in the gradual phase is generally much more severe than in the rapid phase, and therefore defects formed in the gradual phase are believed to be the primary cause of the decay in the efficiency of boron-doped silicon solar cells after illumination.
On the other hand, in a backside Passivated high efficiency cell (PERC), there is a Light and elongated Temperature Induced Degradation (LeTID), and the mechanisms causing the LeTID Degradation include hydrogen Induced Degradation, passivation Degradation, metal impurities, and the like, and the structures of the PERC cells are all related to these mechanisms.
The main differences between LID attenuation and LeTID attenuation are: LID decay requires only a relatively short time (days or one or two months) to reach saturation at normal temperature, while LeTID is a decay that requires high temperature (75 ℃ or higher) and is saturated for a longer time (months to years); the attenuation of the LeTID is much greater than the LID.
In order to solve the attenuation problem of solar cells, the prior art has made various studies:
(1) researches show that after annealing of a boron-doped Czochralski silicon n + pp + diode 3 omega cm sample (Cz Si: B) at the temperature of 350-450 ℃, the peak value of a defect-related minority carrier lifetime spectrum (DLTS for short) generated by correlation of an H390 trap (representing that a minority carrier complex defect state appears at 390K) is remarkably increased; the DLTS peak size was significantly reduced after annealing above 600 ℃. Furthermore, the diode was irradiated at room temperature with about 1 solar intensity for 5, 20 and 70 hours, showing that the peak of the H390 trap decreased significantly with increasing light irradiation time. Thus, an almost perfect negative correlation is shown between the change in the concentration of the H390 trap and the change in the concentration of the complex active defect { [ BO ] } that leads to the degradation of the lifetime of the sample. This phenomenon exhibits excellent reproducibility over many sample cycles, and therefore the H390 trap appears to be most likely to be considered a precursor to complex active BO defects. In addition to showing a transition barrier compatible with cell decay/recovery kinetics, the model also explains the ability of gallium-doped materials to recover LID. BO degradation of boron-oxygen containing solar cell minority carrier lifetime is related to trap assisted auger recombination of carriers in the BsO2 complex.
(2) The results of the present study also show that the concentration of defects causing light-induced degradation of silicon solar cells depends on the square of the oxygen concentration and increases almost linearly with the increase in boron concentration in uncompensated boron doped silicon, and that the BO recombination process can be deactivated by dark annealing at around 200 ℃ for a few minutes, thus converting the defects into the "annealed state". However, after subsequent illumination, attenuation occurs again. Although it can be further eliminated by high temperature annealing under light to form a "steady state", this "steady state" is also only metastable and still undergoes significant degradation again under the influence of environmental factors, requiring a dark annealing operation at about 200 ℃ for 100min to return to the annealed state.
(3) For the attenuation of the lerd performance of PERC cells, the prior art has mainly used an electro-or photo-injection treatment after sintering. Although the attenuation phenomenon can be repaired to a certain extent so as to improve the performance of the solar cell, the regeneration or recovery degree of the cell performance is obviously influenced by the magnitude of light (electricity) injection energy, and the relationship with the heat treatment process of energy injection is very close. This approach is energy intensive on the one hand and requires upgrading of existing equipment to increase the injection energy on the other hand. Whether the photoelectric injection time is increased or the photoelectric injection energy is increased, the number and the occupied area of the photoelectric (electric) injection equipment are required to be increased, and huge burden is brought to a battery manufacturer.
Disclosure of Invention
The invention aims to provide a crystalline silicon solar cell preparation method for inhibiting carrier injection attenuation, which can effectively reduce LID and LeTID attenuation of the crystalline silicon solar cell so as to ensure that the working efficiency of the crystalline silicon solar cell is kept at a higher level.
The purpose of the invention is realized by the following technical scheme:
a crystalline silicon solar cell preparation method for inhibiting carrier injection attenuation comprises the following process steps: (1) texturing, (2) high-temperature gas phase diffusion, (3) etching and cleaning, (4) back side aluminum oxide coating, (5) passivation of a silicon nitride laminated film, (6) passivation of a front side silicon nitride film, (7) laser grooving of the back side, (8) screen printing of back side aluminum electrode and front side silver electrode slurry, and (9) drying and sintering; and (2) after high-temperature heat treatment is carried out in the high-temperature gas phase diffusion process, cooling the solar cell by adopting a gradient cooling mode.
As a specific embodiment of the invention, the (2) high-temperature gas phase diffusion comprises the following specific processes:
s1: when a phosphorus source is deposited on the surface of a silicon wafer for the first time, after maintaining the state of constant pressure of 200 +/-20 mBar and diffusion constant temperature of 750 +/-10 ℃ in a quartz tube for at least 2min, introducing oxygen, wherein the flow rate of the oxygen is 300-1200 sccm; adjusting the pressure in the quartz tube to 50 +/-5 mBar after ventilating for 2-10 min, and then ventilating small nitrogen carrying phosphorus oxychloride with the flow of 140-600 sccm for 3-10 min;
s2: repeating the operation of the circulation S1, wherein the temperature gradient of each circulation is increased progressively, the gradient is 10-50 ℃, and the flow of the small nitrogen and the oxygen is not lower than the flow of the previous circulation;
s3: keeping the pressure in the furnace at 200 +/-20 mBar, closing the small nitrogen, keeping introducing oxygen at a flow rate of 200-2000 sccm, heating and keeping the heating rate at 7-20 ℃/min to 870 +/-10 ℃ for 3-10 min; controlling the propelling temperature to be 40-100 ℃ higher than the diffusion temperature of the last cycle in S2;
s4: stopping heating and oxygen introduction, maintaining the nitrogen flow at 1-2 SLM, keeping vacuum constant pressure in the furnace, performing gradient cooling at 20-60 ℃, and cooling to 820 +/-20 ℃;
s5: controlling the temperature of each zone in the furnace to be 820 +/-20 ℃ and the pressure to be 50 +/-5 mbar, introducing oxygen at the flow rate of 300-1200 sccm, maintaining for 2-10 min, and introducing small nitrogen carrying phosphorus oxychloride at the flow rate of 140-600 sccm for 3-10 min;
s6: repeating the operation of the circulation S5, wherein the temperature gradient of each circulation is reduced progressively, the gradient is 10-50 ℃, and the flow of the small nitrogen and the oxygen is not lower than the flow of the previous circulation;
s7: when the temperature in the furnace is reduced to below 770 ℃, the quartz boat is withdrawn, and the high-temperature gas phase diffusion is completed.
Preferably, S4 adopts multiple gradient platforms to realize gradient cooling, the first platform is set to 860 +/-20 ℃, the second platform is set to 840 +/-20 ℃, and the third platform is set to 800 +/-20 ℃.
Long-term experiments show that in the process of preparing the crystalline silicon solar cell, after phosphorus oxychloride is diffused in high-temperature heat treatment (higher than 600 ℃), the cell is gradually cooled in a gradient cooling mode, and compared with the traditional solar cell prepared by one-step cooling, the boron-oxygen defect concentration is obviously reduced, so that the LID attenuation and the LeTID attenuation are obviously reduced.
Further, the drying and sintering (9) of the present invention also includes a gradient temperature reduction process:
the drying and sintering step (9) comprises four stages of drying, preheating, sintering and cooling, wherein the drying temperature in the drying stage is 100-250 ℃, and the drying time is not less than 12 s; the sintering stage is provided with a preheating section and a sintering section, the heating rate of the preheating section is set to be not lower than 50 ℃/s, and the residence time of the battery in the preheating section is not more than 20 s; the peak area of the sintering section is arranged at the position close to the front of the middle section, the retention time of the battery in the sintering section is not more than 5s, and the peak temperature is not higher than 760 +/-10 ℃; the temperature reduction speed of the temperature reduction stage is controlled to be not higher than 60 ℃/s. In this way, the rearrangement of impurities in the body can occur while the metallization of the cell is completed.
In order to further improve the conversion efficiency of the solar cell, the preparation method further comprises (10) front laser doping, (11) annealing, and (12-1) light-induced generation (LIR) or (12-2) Electric Injection (EIR).
As a specific embodiment of the invention, in the (12-1) light injection, a multi-module light injection heat treatment caterpillar furnace is used, and the maximum output power is 20000w/m2The total time of light injection is not less than 20 s;
the irradiation power of the first module is controlled to be 90 +/-10% of the maximum output power, the temperature is controlled to be 280 +/-30 ℃, and the duration time is 4-20 s;
the irradiation power of the second module is controlled to be 80 +/-10% of the maximum output power, the temperature is controlled to be 250 +/-30 ℃, and the duration time is 4-20 s;
the irradiation power of the third module is controlled to be less than 70% of the maximum output power, the temperature is controlled to be 230 +/-30 ℃, and the duration time is 4-20 s.
As another specific embodiment of the invention, in the (12-1) light injection, a light injection device integrated with a sintering furnace is used, the light injection device utilizes the residual heat/set heating device in the sintering stage, the maximum output power of the heating device is more than 3000w, the maximum heating temperature is 450 ℃, the average temperature of the front module and the rear module is set to be reduced in a gradient manner, the gradient is 10-40 ℃, and the total time of light injection is not less than 20 s.
Compared with the prior art, the invention has the following beneficial effects:
(1) according to the invention, the heat treatment in the solar cell manufacturing process is optimized, and a gradient cooling mode is adopted in the heat treatment, so that the defect concentration of a BO compound is reduced, and the activity of the BO compound is passivated, thereby realizing the inhibition of the LeTID attenuation and the LID attenuation of the single crystal PERC cell; after high radiation implantation, substitutional boron in siliconCombined with interstitial oxygen to form { [ BO]Complex, { [ BO }]Complex with large amount of H in silicon+The BO-H polymer is neutral, so that minority carriers are not captured any more, and the performance of the battery is not rapidly attenuated.
(2) According to the solar cell prepared by the method, the LID attenuation is reduced from 0.6% to below 0.1%, and the LeTID attenuation is reduced from 0.56% to 0.24%.
Detailed Description
The present invention will be further described with reference to the following specific examples.
The preparation method of the crystalline silicon solar cell comprises the following steps:
(1) and (5) making wool.
(2) High-temperature gas phase diffusion;
s1: when a phosphorus source is deposited on the surface of a silicon wafer for the first time, after maintaining the state of constant pressure of 200 +/-20 mBar and diffusion constant temperature of 750 +/-10 ℃ in a quartz tube for at least 2min, introducing oxygen, wherein the flow rate of the oxygen is 300-1200 sccm; adjusting the pressure in the quartz tube to 50 +/-5 mBar after ventilating for 2-10 min, and then ventilating small nitrogen carrying phosphorus oxychloride with the flow of 140-600 sccm for 3-10 min;
s2: repeating the operation of the circulation S1, wherein the temperature gradient of each circulation is increased progressively, the gradient is 10-50 ℃, and the flow of the small nitrogen and the oxygen is not lower than the flow of the previous circulation;
s3: keeping the pressure in the furnace at 200 +/-20 mBar, closing the small nitrogen, keeping introducing oxygen at a flow rate of 200-2000 sccm, heating and keeping the heating rate at 7-20 ℃/min to 870 +/-10 ℃ for 3-10 min; controlling the propelling temperature to be 40-100 ℃ higher than the diffusion temperature of the last cycle in S2;
s4: stopping heating and oxygen introduction, maintaining the nitrogen flow at 1-2 SLM, keeping vacuum constant pressure in the furnace, performing gradient cooling at 20-60 ℃, and cooling to 820 +/-20 ℃;
s5: controlling the temperature of each zone in the furnace to be 820 +/-20 ℃ and the pressure to be 50 +/-5 mbar, introducing oxygen at the flow rate of 300-1200 sccm, maintaining for 2-10 min, and introducing small nitrogen carrying phosphorus oxychloride at the flow rate of 140-600 sccm for 3-10 min;
s6: repeating the operation of the circulation S5 for multiple times, wherein the temperature gradient of each circulation is gradually reduced, the gradient is 10-50 ℃, and the flow of the small nitrogen and the oxygen is not lower than that of the previous circulation;
s7: when the temperature in the furnace is reduced to below 770 ℃, the quartz boat is withdrawn, and the concentration and distribution of phosphorus impurities and oxygen impurities in the silicon wafer are finished.
(3) And (5) etching and cleaning.
(4) Back side aluminum oxide coating.
(5) And passivating the silicon nitride laminated film.
(6) And passivating the front silicon nitride film.
(7) And laser grooving on the back.
(8) And screen printing back aluminum electrode and front silver electrode paste.
(9) Drying and sintering;
and the four stages of drying, preheating, sintering and cooling are performed in sequence, so that the impurities in the body are rearranged while the metallization of the battery is completed. The drying temperature in the drying stage is 100-250 ℃, and the drying time is not less than 12 s; the sintering stage is provided with a preheating section and a sintering section, the heating rate of the preheating section is set to be not lower than 50 ℃/s, and the residence time of the battery in the preheating section is not more than 20 s; the sintering section is composed of not less than 8 groups of infrared heating lamp tubes, each group of lamp tubes is symmetrically arranged right above and right below the sintering furnace zone, the output power of each group of lamp tubes can be independently controlled, the highest output temperature can reach 1000 ℃, the temperature precision is 0.1 ℃, the peak area of the sintering section is arranged at the position close to the front of the middle section, the retention time of the battery in the sintering section is not more than 5s, and the peak temperature is not higher than 760 +/-10 ℃ (different furnace temperature instruments and thermocouple test possible results are different, the peak temperature in the case of the invention corresponds to the battery piece and has the highest conversion efficiency); the temperature reduction speed of the temperature reduction stage is controlled to be not higher than 60 ℃/s. The setting range of the furnace belt transmission speed is 9000-15000mm/min, the sintering peak temperature is increased along with the increase of the furnace belt speed, for example, when the furnace belt speed is 10000mm/min, the corresponding peak temperature is properly increased to 770 +/-10 ℃, and the like.
(10) Laser doping on the front surface;
(11) annealing;
(12-1) light injection;
light injection in heat treatment caterpillar furnace, the light source is high power LED light source, the maximum output power density is 20000w/m2 (about equal to 20 solar radiation), the light source is preferably white light, and can be yellow light; the light injection is divided into N modules, each module consists of a plurality of sets of high-power LED light source lamp panels and a plurality of variable frequency fans (N is not less than 3), and the LED light intensity and the output power of the variable frequency fans are independent and continuously adjustable. Meanwhile, the back of the lamp panel of the light source is provided with a plurality of groups of copper cooling water pipes, the circulating cooling water pressure is 5kg, the temperature of the product outlet is 18 ℃, and the lamp panel is protected from being burnt due to overheating of the LED light source. The temperature of the battery plate is mainly controlled by a fan in the light injection process, the irradiation power of the first module is 90% + -10% of the maximum output power, the temperature is 280 +/-30 ℃, and the irradiation power lasts for 4-20 s; the irradiation power of the second module is 80% +/-10% of the maximum power, the temperature is 250 +/-30 ℃, and the irradiation power lasts for 4-20 s; the third module starts the irradiation power to be less than 70% of the maximum output power, the temperature is 230 +/-30 ℃, and the irradiation power lasts for 4-20 s; the LIR integrated with the sintering furnace utilizes the sintering residual temperature, and can also be not provided with a heating device, for example, a plurality of groups of infrared heating devices are arranged at the front end of an off-line LIR, the maximum output power of each group of heating lamp tubes is more than 3000w, and the maximum heating temperature is 450 ℃; the average temperature of the latter module is lower than that of the former module, and the temperature gradient between the former module and the latter module is 10-40 ℃. The total light injection time is not less than 20s according to the number of the light injection modules. The outlet of the light injection crawler furnace is provided with a plurality of fans for forced cooling, and the temperature of the battery piece is reduced to below 40 ℃, so that the requirement of a testing machine on the surface temperature of the battery piece is met.
The specific parameters and test result data of the embodiments of the present invention are as follows:
TABLE-1 high temperature vapor phase diffusion
Example 1
Example 2
Example 3
S2 temperature gradient/. degree.C
10
20
30
S3 furnace pressure/mBar
200
200
200
S3 heating rate/° C/min
7
15
20
S3 Final temperature/. degree.C
870
870
870
S3 duration/min
8
6
4
First platform temperature/. degree.C
850
840
860
Second platform temperature/. degree.C
830
820
840
Third plateau temperature/. degree.C
810
790
800
S5 furnace pressure/mBar
50
50
50
S5 furnace temperature/. degree C
810
790
800
S6 temperature gradient/deg.C
20
10
15
TABLE-2 baking sintering
Example 1
Example 2
Example 3
Drying temperature/. degree.C
180
200
220
Preheating zone temperature rise rate/° C/s
55
55
55
Residence time/s in preheating zone
4
4
4
Peak temperature/deg.C of sintering section
745
755
765
Residence time/s in the sintering zone
2
1.7
1.5
Cooling Rate/. degree.C/s
50
50
50
TABLE-3 light injection
Example 1
Example 2
Example 3
First module output power%
90
98
85
First module temperature/. degree.C
280
300
270
First module duration/s
7
7
7
Second module output power%
80
90
80
Second module temperature/. degree.C
250
260
250
Second module duration/s
6
6
6
Third module output power%
70
80
70
Third module temperature/. degree.C
230
245
230
Third module duration/s
6
6
6
Temperature gradient/. degree.C
20-30
15-40
15-20
TABLE-4
In the test, the LeTID test condition of the crystalline silicon battery is 110 ℃, 0.6A direct current is applied to two ends of the battery, and the attenuation of the LeTID and the LTD is obviously reduced under the condition of lasting 8H.
It should be noted that the above-mentioned embodiments are only illustrative and not restrictive, and any modifications or changes within the meaning and range of equivalents to the technical solutions of the present invention by those skilled in the art should be considered to be included in the protection scope of the present invention.
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