Test fixture for solar cells

Abstract

The application discloses a test fixture for solar cells, which comprises a fan, a bottom plate, a test plate and a pressing plate arranged in sequence above the fan, a ventilation groove is arranged through the bottom plate, a ventilation hole is arranged through the test plate, the ventilation hole is communicated with the ventilation groove, a sample groove is arranged on the pressing plate and communicated with the ventilation hole, the sample groove is used for placing the solar cell to be tested, and a groove is arranged on the side of the pressing plate facing the test plate and communicated with the sample groove and extending to at least one side of the pressing plate. The test fixture of the application is additionally provided with the fan and the ventilation channel arranged in the test fixture, and the temperature of the solar cell in the test process is effectively reduced by using the strong convection heat exchange.

Description

Technical Field

[0001] This invention belongs to the field of solar cell technology, specifically relating to a test fixture for solar cells. Background Technology

[0002] The testing process for solar cells is a crucial step in evaluating their photoelectric performance, and the accuracy of the test results directly affects the research and development progress and industrialization assessment of the cells.

[0003] In existing technologies, solar cell performance is often tested by simulating sunlight exposure under standard test conditions. The accuracy of this test is affected by numerous factors, the most prominent being the thermal effect. Because existing thin-film solar cells generally use glass or flexible polymer substrates, which have poor heat dissipation performance, they are prone to temperature accumulation under continuous sunlight, affecting the test results.

[0004] Furthermore, the thermal effects of sunlight not only interfere with the accuracy of real-time test data but can also cause irreversible damage to the battery structure. When a solar cell is exposed to sunlight, the portion of photon energy that is not converted into electrical energy is dissipated as heat. This energy conversion process causes the battery temperature to rise rapidly, thus affecting battery performance in multiple dimensions. In terms of carrier dynamics, increased temperature significantly increases the nonradiative recombination rate of electron-hole pairs in semiconductor materials. Taking amorphous silicon (a-Si) cells as an example, when the temperature exceeds a certain limit, its unique Staebler-Wronski effect is significantly aggravated, leading to a significant increase in the light-induced degradation rate. This effect directly reduces the short-circuit current density (J / L). SC This causes the test results to deviate from the true value. Regarding electrical characteristics, according to the detailed equilibrium theory of semiconductor physics, the open-circuit voltage (V...) OC The temperature coefficient (V) of copper indium gallium selenide (CIGS) cells shows a negative correlation with temperature. Most solar cells have a temperature coefficient between -0.2% / ℃ and -0.5% / ℃. When the cell temperature rises significantly, the V... OC A significant decrease occurs, with perovskite cells experiencing an even greater drop. This change significantly affects the fill factor (FF) and final conversion efficiency test results. Regarding material stability, high-temperature environments can induce degradation mechanisms in various solar cell materials. Organic photovoltaic materials exhibit phase separation at high temperatures; the migration rate of iodide ions in perovskite materials increases exponentially under thermal stress, potentially leading to irreversible degradation of the device structure during testing. For example, the efficiency of a MAPbI3 perovskite cell significantly decreases after one hour of continuous illumination at high temperatures.

[0005] Therefore, in order to address the aforementioned technical problems, it is necessary to provide a test fixture for solar cells. Summary of the Invention

[0006] The purpose of this invention is to provide a test fixture for solar cells that can obtain more stable test data and results.

[0007] To achieve the above objectives, an embodiment of the present invention provides the following technical solution:

[0008] A test fixture for solar cells includes a fan and a base plate, a test plate, and a pressure plate sequentially disposed above the fan. The base plate has a through-hole ventilation groove, and the test plate has a through-hole ventilation hole communicating with the ventilation groove. The pressure plate has a sample slot communicating with the ventilation hole, and the sample slot is used to place the solar cell to be tested. The side of the pressure plate facing the test plate has a groove communicating with the sample slot and extending to at least one side of the pressure plate.

[0009] In one embodiment, the cross-sectional area of ​​the ventilation slot on the upper surface of the base plate is smaller than the cross-sectional area of ​​the ventilation slot on the lower surface of the base plate.

[0010] In one embodiment, the ventilation slot includes a first slot and a second slot that are connected to each other. The first slot is connected to the ventilation hole, and the second slot is disposed toward the fan. The cross-sectional area of ​​the second slot gradually decreases from the fan toward the test plate.

[0011] In one embodiment, the fan includes an air outlet facing the ventilation slot, and the projection area of ​​the air outlet on the lower surface of the base plate is located within the opening of the ventilation slot on the lower surface of the base plate.

[0012] In one embodiment, the pressure plate has a first groove and a second groove on the side facing the test plate, the first groove and the second groove are respectively connected to the sample groove, and the first groove and the second groove extend to both sides of the pressure plate.

[0013] In one embodiment, the test fixture further includes a cover plate disposed on the pressure plate, the cover plate having an abutment disposed toward the pressure plate, the abutment extending into the sample slot to abut against the solar cell to be tested.

[0014] In one embodiment, the cover plate is provided with an observation window, and the projection area of ​​the observation window on the surface of the pressure plate is located within the sample slot.

[0015] In one embodiment, the cover plate is a stainless steel cover plate, the pressure plate is an acrylic pressure plate, and the base plate is an acrylic base plate.

[0016] In one embodiment, the cover plate is a stainless steel cover plate, the pressure plate is a stainless steel pressure plate, the bottom plate is a stainless steel bottom plate, and the pressure plate and the bottom plate are provided with an insulating varnish layer on at least one side surface that contacts the test plate.

[0017] In one embodiment, the test board is a circuit board, and the test board is provided with a probe holder arranged around the sample cell, the probe holder extending into the sample cell to contact the solar cell under test.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] This invention utilizes forced convection heat transfer to effectively reduce the temperature of the solar cell during testing, thereby improving the stability of the test. Attached Figure Description

[0020] 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 recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the test fixture in Embodiment 1 of the present invention;

[0022] Figure 2 This is an exploded view of the test fixture in Embodiment 1 of the present invention;

[0023] Figure 3 This is a cross-sectional schematic diagram of the test fixture in Embodiment 1 of the present invention;

[0024] Figure 4 The current-voltage characteristic curve of the perovskite solar cell obtained by testing using the test fixture in Comparative Example 1 of this invention;

[0025] Figure 5 The current-voltage characteristic curve of the perovskite solar cell obtained by testing using the test fixture in Example 1 of this invention.

[0026] Explanation of key figure labels:

[0027] 10-Fan, 101-Air outlet, 20-Base plate, 201-Ventilation slot, 2011-First slot, 2012-Second slot, 30-Test plate, 301-Ventilation hole, 40-Pressure plate, 401-Sample slot, 402-Groove, 4021-First groove, 4022-Second groove, 50-Cover plate, 501-Observation window, 502-Abutting part, 60-Solar cell under test. Detailed Implementation

[0028] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0029] The present invention discloses a test fixture for solar cells. The test fixture includes a fan, and a bottom plate, a test plate and a pressing plate sequentially arranged above the fan. The bottom plate is provided with a through ventilation groove, the test plate is provided with through ventilation holes, the ventilation holes are in communication with the ventilation groove, the pressing plate is provided with a sample groove in communication with the ventilation holes, the sample groove is used for placing a solar cell to be tested, and the side of the pressing plate facing the test plate is provided with a groove that is in communication with the sample groove and extends to at least one side of the pressing plate.

[0030] The present invention is further described below with reference to specific examples.

[0031] Embodiment 1:

[0032] Refe Figure 1 and in conjunction with Figure 2 as shown in the figure, the test fixture for solar cells in this embodiment includes a fan 10, and a bottom plate 20, a test plate 30 and a pressing plate 40 sequentially arranged above the fan 10. The bottom plate 20 is provided with a through ventilation groove 201, the test plate 30 is provided with through ventilation holes 301, the ventilation holes 301 are in communication with the ventilation groove 201, the pressing plate 40 is provided with a sample groove 401 in communication with the ventilation holes 301, the sample groove 401 is used for placing the solar cell 60 to be tested, and the side of the pressing plate 40 facing the test plate 30 is provided with a groove 402 that is in communication with the sample groove 401 and extends to at least one side of the pressing plate.

[0033] Among them, the fan 10 adopts a high-power fan, which includes an outer frame and an air outlet 101 arranged facing the ventilation groove 201. Four support rods are arranged near the four top corners of the surface of the outer frame on the side away from the bottom plate 20, which are used to stably place the test fixture on the workbench, and keep a certain distance between the bottom of the high-power fan and the workbench for air circulation.

[0034] in conjunction with Figure 3 as shown in the figure, the cross-sectional area of the ventilation groove 201 on the upper surface of the bottom plate 20 is smaller than the cross-sectional area of the ventilation groove 201 on the lower surface of the bottom plate 20, that is, a design with a large inlet and a small outlet is adopted to obtain a negative pressure difference and maintain the air flow in the ventilation groove 201.

[0035] Meanwhile, the projection area of ​​the air outlet 101 on the lower surface of the base plate 20 is located within the opening of the ventilation slot 201 on the lower surface of the base plate 20. That is, the inlet of the ventilation slot 201 should be greater than or equal to the air outlet 101 of the fan 10 in order to maintain sufficient air intake at the inlet.

[0036] Specifically, the ventilation slot 201 in this embodiment includes a first slot 2011 and a second slot 2012 that are connected to each other. The first slot 2011 is connected to the ventilation hole 301, and the second slot 2012 is arranged facing the fan 10. The cross-sectional area of ​​the second slot 2012 gradually decreases from the fan 10 toward the test plate 30.

[0037] More specifically, the size of the upper port of the second tank is the same as the size of the lower port of the first tank, reducing the resistance when the first airflow enters the first tank from the second tank. At the same time, the cross-sectional area of ​​the first tank remains unchanged in the direction from the test plate to the fan, so that the airflow is uniformly treated in the first tank before entering the ventilation holes of the test plate.

[0038] Furthermore, in this embodiment, the size of the ventilation hole 301 is less than or equal to the size of the first groove 2011.

[0039] In this embodiment, the test board 30 is a circuit board. The test board 30 is provided with a probe seat 302 surrounding the ventilation hole 301. The probe seat 302 extends into the sample cell 401 to contact the solar cell 60 under test. The test board 30 is electrically connected to an external detection device to realize the testing and data collection of the solar cell.

[0040] Furthermore, in this embodiment, the pressure plate 40 is provided with a first groove 4021 and a second groove 4022 on the side facing the test plate 30. The first groove 4021 and the second groove 4022 are respectively connected to the sample groove 401, and the first groove 4021 and the second groove 4022 extend to both sides of the pressure plate 40.

[0041] Specifically, in this embodiment, the first groove 4021 and the second groove 4022 are symmetrically arranged on both sides of the sample tank 401. The first groove 4021 and the second groove 4022 extend to the side wall of the pressure plate 40 and are connected to the outside. This allows the airflow to directly act on the surface of the solar cell in the sample tank 401 after passing through the ventilation slot 201 and ventilation hole 301 from the air outlet 101 of the fan during the test. The solar cell is cooled by forced convection heat exchange. Then, the hot airflow is quickly discharged through the first groove 4021 and the second groove 4022, thereby reducing the impact of temperature on the stability and reliability of the test results.

[0042] More specifically, the solar cell 60 under test is fixed in the sample cell 401, and the sample cell 401 passes through the pressure plate 40, so as to simulate sunlight irradiation on the solar cell 60 under test.

[0043] The test fixture in this embodiment also includes a cover plate 50 disposed on the pressure plate 40. The cover plate 50 is provided with an abutment 502 and an observation window 501. The abutment 502 is disposed towards the pressure plate 40 and extends into the sample groove 401 to abut against the solar cell 60 under test. The projection area of ​​the observation window 501 on the upper surface of the pressure plate 50 is located in the sample groove 401, that is, the abutment 502 is arranged around the observation window 501. The observation window 501 is used to simulate sunlight irradiation on the solar cell 60 under test.

[0044] Specifically, the sample cell 401 fixes the solar cell 60 under test in the horizontal direction, and the cover plate 50 with the abutment 502 fixes the solar cell 60 under test in the vertical direction. The combination of the two achieves better fixation of the solar cell 60 under test during the test.

[0045] In addition, in this embodiment, the cover plate 50 is a stainless steel cover plate, the pressure plate 40 is an acrylic pressure plate, and the base plate 20 is an acrylic base plate. The stainless steel cover plate 50 not only presses the solar cell 60 under test, but also increases the overall weight of the test fixture and improves the stability of the test fixture during the test.

[0046] It is worth noting that in other embodiments, the pressure plate 40 can also be made of stainless steel, and the base plate 20 can be made of stainless steel, which can further improve the stability of the test fixture. It is only necessary to add an insulating varnish layer to at least the surface of the pressure plate 40 and the base plate 20 that are in contact with the test plate 30.

[0047] The solar cell under test in this embodiment is a perovskite solar cell, which is tested using the test fixture described in this embodiment. The open-circuit voltage (V) of the perovskite solar cell under different illumination times is measured. OC ), short-circuit current density (J SC The fill factor (FF) and photoelectric conversion efficiency (PCE) are shown in Table 1. From Table 1 and combined with... Figure 3 As can be seen, during the measurement process, the airflow reaches the surface of the solar cell under test through the ventilation slots and ventilation holes along the direction of the arrow in the figure. Under the action of strong convection heat transfer, the solar cell is cooled down. Then the hot airflow is quickly discharged from the groove, which effectively solves the problem of the thermal effect generated by the light on the test. Therefore, the fluctuation range of the measured data is small under different light exposure times.

[0048] Table 1: Test data of perovskite solar cells under different illumination times

[0049] 1 1.181 26.41 84.4 26.33 2 1.179 26.41 84.5 26.34 3 1.179 26.39 84.6 26.31

[0050] Comparative Example 1:

[0051] The test fixture for solar cells in this comparative example is a test fixture with a conventional structure. Compared with the test fixture in Example 1, the test fixture with the conventional structure does not integrate a fan for cooling the solar cell to be tested, and no ventilation channel is formed inside, so the temperature of the solar cell to be tested cannot be reduced during the test process, which seriously affects the stability and reliability of the test results.

[0052] Specifically, under the same test conditions, this test fixture was used to test the open-circuit voltage, short-circuit current density, fill factor and photoelectric conversion efficiency of the solar cell to be tested under different illumination durations, as shown in Table 2. The solar cell to be tested in this comparative example is a perovskite solar cell that is completely identical to that in Example 1.

[0053] Compared with Example 1, when the perovskite solar cell is tested using the test fixture with the conventional structure, the measured fill factor and photoelectric conversion efficiency data decrease significantly with the extension of the illumination duration, indicating that the thermal effect generated by illumination seriously affects the test stability.

[0054] Table 2: Test data of perovskite solar cells under different illumination durations

[0055] 1 1.178 26.40 84.4 26.26 2 1.176 26.40 83.2 25.82 3 1.174 26.40 82.0 25.42

[0056] Reference Figure 4 and Figure 5 As shown, with the extension of the test duration, the performance of the solar cell tested using the test fixture in Comparative Example 1 decreases significantly, and there is a large difference between the current-voltage characteristic curves obtained under different illumination durations, while the current-voltage characteristic curves obtained using the test fixture in Example 1 under different illumination durations almost coincide.

[0057] It can be seen from the above technical solutions that the present solution has the following beneficial effects:

[0058] The present invention uses forced convection heat exchange to effectively reduce the temperature of the solar cell during the test process, and improves the test stability.

[0059] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0060] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A test fixture for solar cells, characterized in that, The test fixture includes a fan and a base plate, a test plate, and a pressure plate sequentially disposed above the fan. A ventilation slot is provided through the base plate, and a ventilation hole is provided through the test plate, the ventilation hole communicating with the ventilation slot. The pressure plate has a sample slot communicating with the ventilation hole, the sample slot being used to place the solar cell under test. The fan includes an air outlet facing the ventilation slot, the projection area of ​​which on the lower surface of the base plate is located within the opening of the ventilation slot on the lower surface of the base plate. The cross-sectional area of ​​the ventilation slot on the upper surface of the base plate is smaller than the cross-sectional area of ​​the ventilation slot on the lower surface of the base plate. The ventilation slot includes a first slot and a second slot communicating with each other, the first slot communicating with the ventilation hole, and the second slot facing the fan. The cross-sectional area of ​​the second tank gradually decreases from the fan toward the test plate. The upper port size of the second tank is the same as the lower port size of the first tank. The cross-sectional area of ​​the first tank remains unchanged from the test plate toward the fan. The size of the ventilation hole is less than or equal to the size of the first tank. The pressure plate has a first groove and a second groove on the side facing the test plate. The first groove and the second groove are respectively connected to the sample tank and extend to both sides of the pressure plate. The groove, the ventilation hole and the ventilation groove form a ventilation channel, forming a forced convection heat transfer path where the airflow reaches the surface of the solar cell under test from the fan through the ventilation groove and the ventilation hole, and then exits along the groove.

2. The test fixture for solar cells according to claim 1, characterized in that, The test fixture also includes a cover plate disposed on the pressure plate, the cover plate having an abutment disposed toward the pressure plate, the abutment extending into the sample slot to abut against the solar cell to be tested.

3. The test fixture for solar cells according to claim 2, characterized in that, The cover plate is provided with an observation window, and the projection area of ​​the observation window on the surface of the pressure plate is located in the sample slot.

4. The test fixture for solar cells according to claim 2, characterized in that, The cover plate is a stainless steel cover plate, the pressure plate is an acrylic pressure plate, and the base plate is an acrylic base plate.

5. The test fixture for solar cells according to claim 2, characterized in that, The cover plate is a stainless steel cover plate, the pressure plate is a stainless steel pressure plate, and the base plate is a stainless steel base plate. The pressure plate and the base plate have an insulating varnish layer on at least one side of their surfaces that are in contact with the test plate.

6. The test fixture for solar cells according to claim 1, characterized in that, The test board is a circuit board, and the test board is provided with a probe holder arranged around the sample cell. The probe holder extends into the sample cell to contact the solar cell under test.

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