Perovskite solar cell testing device

Abstract

The invention belongs to the technical field of solar cell performance testing, and discloses a perovskite solar cell testing device which comprises a glove box, one side of the glove box is connected with a solar simulator, a base is arranged in the glove box, a mask plate is arranged on the surface of the base, and probe assemblies are symmetrically arranged on the surface of the base. The glove box comprises a box body, water absorption silica gel is laid on the bottom face in the box body, the probe assembly comprises connecting blocks symmetrically connected to the two sides of the surface of a positioning plate, one side of each connecting block is slidably connected with an adjusting block, and the end, away from the corresponding connecting block, of each adjusting block is connected with a test probe. And the test probe is connected to the surface of the perovskite solar cell to be detected. According to the perovskite solar cell testing device, the water absorption silica gel is laid in the glove box, so that the problem that a traditional perovskite solar cell testing device is greatly interfered by water vapor and cannot meet the long-time characterization detection requirement is effectively solved, and the perovskite solar cell testing device which is replaceable and small in proportion is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of solar cell performance testing, and in particular to a perovskite solar cell testing device. Background Art

[0002] Perovskite solar cells are mainly composed of perovskite light-absorbing layer, electron transport material, electrode and conductive proton decoupling structure. Mesoporous perovskite solar cells are usually composed of FTO conductive glass, TiO2 dense layer, TiO2 mesoporous layer, perovskite layer, HTM layer (hole transport material layer) and metal electrode. On this basis, other types of structures can also be formed, such as removing the porous support layer n-type semiconductor TiO2 and replacing it with insulating material Al2O3 to form a mesoscopic superstructure heterojunction solar cell, or removing the insulating support layer to prepare a planar heterojunction cell with a pin-like structure.

[0003] The working principle of perovskite solar cells is mainly the photoelectric effect. When sunlight shines on the perovskite light-absorbing layer, it will stimulate the formation of hole-electron pairs (excitons). Under the action of the pn junction electric field, the excitons separate into electrons and holes, and transport them to the cathode and anode respectively. Photogenerated holes flow to the p region, and photogenerated electrons flow to the n region. When the circuit is connected, current is formed, thereby converting solar energy into electrical energy.

[0004] The rapid development of perovskite solar cells is due to their high photoelectric conversion efficiency and simple preparation process, which makes them stand out in the field of solar cells. This type of cell can not only significantly reduce the waste of materials in the production process, but also reduce production costs due to the diversity of material formulas and the simplification of production equipment. The construction of perovskite solar cell test equipment is crucial, which ensures the accurate evaluation and optimization of cell performance. The test device can simulate the actual use environment and verify the stability and reliability of the cell, thereby providing key data for further research and development and practical applications.

[0005] When the perovskite solar cell testing device in the prior art is in use, a large amount of water vapor will be generated inside the glove box, which will affect the stability of long-term measurement of the perovskite solar cell, and cannot accurately measure the photoelectric conversion efficiency and JV curve of the perovskite solar cell. In addition, the overall equipment operation is relatively complicated, and the perovskite solar cell to be measured cannot be simply fixed and connected. Summary of the invention

[0006] The purpose of the present invention is to provide a perovskite solar cell testing device to solve the problem that when the perovskite solar cell testing device in the prior art is used, a large amount of water vapor will be generated inside the glove box, which will affect the stability of long-term measurement of the perovskite solar cell, and the photoelectric conversion efficiency and JV curve of the perovskite solar cell cannot be accurately measured. In addition, the operation of the overall equipment is relatively complicated, and the perovskite solar cell to be measured cannot be simply fixed and connected.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A perovskite solar cell testing device comprises a glove box, one side of the glove box is connected to a solar simulator, a base is arranged inside the glove box, a mask is arranged on the surface of the base, and a probe assembly is symmetrically arranged on the surface of the base;

[0009] The glove box comprises a box body, the bottom surface of the box body is paved with water-absorbing silica gel, the water-absorbing silica gel and the side panels of the box body surround to form a mounting groove; a base is installed inside the mounting groove;

[0010] The base includes a mounting frame arranged inside the mounting groove, and the two ends of the top of the mounting frame are rotatably connected to a positioning plate by rotating a knob, and a receiving cavity is arranged at the center of the surface of the positioning plate, and a second light-transmitting groove is arranged through the center of the receiving cavity;

[0011] The mask is arranged inside the accommodating cavity, a first light-transmitting groove is arranged through the center of the mask surface, a perovskite solar cell to be tested is installed inside the first light-transmitting groove, and the center lines of the first light-transmitting groove and the second light-transmitting groove in the vertical direction are in the same straight line;

[0012] The probe assembly includes connecting blocks symmetrically connected to both sides of the positioning plate surface, one side of the connecting block is slidably connected to an adjustment block, one end of the adjustment block away from the connecting block is connected to a test probe, and the test probe is connected to the surface of the perovskite solar cell to be tested.

[0013] Further preferably, the water-absorbing silica gel is provided in a plurality of pieces, and the plurality of water-absorbing silica gels surround to form a U-shaped structure, and a mounting groove is provided inside the U-shaped structure formed by the plurality of water-absorbing silica gels.

[0014] Further preferably, the mounting frame is U-shaped as a whole, and rotating knobs are symmetrically arranged on both sides of the opening end of the U-shaped mounting frame, the rotating knobs pass through the side panels of the mounting frame and are connected to the mounting plate, the surface of the accommodating cavity on the surface of the mounting plate is provided with magnetic blocks at the four corners, and the surface of the accommodating cavity is also symmetrically provided with positioning grooves along the length direction of the mounting plate.

[0015] Further preferably, the accommodating cavity and the mask are detachably connected via a magnetic block.

[0016] Further preferably, the connecting block includes a magnetic seat connected to the surface of the mounting plate, a guide block is connected to one side of the top of the magnetic seat, an adjustment knob is connected through the surface of the guide block, and the adjustment knob passes through the end of the guide block and is movably connected to the surface of the adjustment block.

[0017] Further preferably, an adjustment cavity is provided on the side of the adjustment block away from the guide block, a threaded rod is provided inside the adjustment cavity along the length direction of the positioning plate, and the end of the threaded rod close to the guide block passes through the adjustment cavity and is fixedly connected to a rotating block, a test probe is provided through the rotating block, a tightening knob is also provided inside the adjustment cavity, the tightening knob is threadedly connected to the surface of the threaded rod, and a locking screw is also connected to the outer side of the rotating block away from the threaded rod.

[0018] Further preferably, a slide groove is provided at the connection between the magnetic seat and the adjustment block, and the adjustment block is slidably connected to the slide groove at the end close to the slide groove.

[0019] Further preferably, a through hole is provided through the rotating block in the vertical direction, the test probe is connected to the inside of the through hole, the axis of the locking screw is perpendicular to the axis of the through hole, and the locking screw passes through the side of the rotating block and is connected to the test probe, a reserved groove is also provided on the side surface of the rotating block close to the adjusting cavity, and the tightening knob passes through the adjusting cavity and is connected to the inside of the reserved groove.

[0020] Further preferably, probe grooves are symmetrically arranged on the surface of the mask along the length direction of the mask on both sides of the first light-transmitting groove.

[0021] Further preferably, the solar simulator includes a support base arranged on the outside of the box, an optical mixing channel is arranged on the top of the support base close to the side of the box, the optical mixing channel passes through the positioning hole on the side of the box and extends to the inside of the box, a light outlet is also arranged at one end of the optical mixing channel extending to the inside of the box, and the light outlet is vertically arranged directly above the first light-transmitting groove and the second light-transmitting groove.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] By laying a layer of absorbent silica gel in the glove box, the problem that traditional perovskite solar cell detection devices are greatly disturbed by water vapor and cannot meet the needs of long-term characterization and detection is effectively solved. In this way, a replaceable, small-sized perovskite solar cell test device is realized, which can stably test the JV characteristic curve and photoelectric conversion efficiency of the battery.

[0024] At the same time, the structure of the base, mask and probe assembly inside the entire device cooperates with each other, which not only facilitates the fixation of the perovskite solar cell to be tested, but also can adjust the test probe to contact various contact positions on the surface of the perovskite solar cell to be tested, thereby completing the measurement of the photoelectric conversion efficiency and JV curve of the perovskite solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0026] Figure 2 It is a schematic diagram of the structure of the solar simulator of the present invention;

[0027] Figure 3 It is a schematic diagram of the glove box structure of the present invention;

[0028] Figure 4 It is a schematic diagram of the overall structure of the probe assembly of the present invention;

[0029] Figure 5 It is a schematic diagram of the mask structure of the present invention;

[0030] Figure 6 It is a schematic diagram of the base structure of the present invention;

[0031] Figure 7 It is a front view schematic diagram of the overall structure of the probe assembly of the present invention;

[0032] In the figure: 100, solar simulator; 110, support base; 120, optical mixing channel; 130, light outlet; 200, glove box; 210, box body; 220, water-absorbing silica gel; 230, mounting groove; 240, positioning hole; 300, probe assembly; 310, adjustment knob; 320, magnetic base; 330, tightening knob; 340, locking screw; 350, test probe; 360, connection block; 37 0. Adjustment block; 380. Slide groove; 390. Adjustment cavity; 311. Rotation block; 312. Through hole; 313. Reserved groove; 314. Guide block; 315. Threaded rod; 400. Mask; 410. Probe groove; 420. First light-transmitting groove; 500. Base; 510. Magnetic block; 520. Accommodation cavity; 530. Second light-transmitting groove; 540. Positioning groove; 550. Rotation knob; 560. Mounting bracket. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] See also Figure 1-Figure 7 , the present invention provides a technical solution:

[0035] A perovskite solar cell testing device includes a glove box 200, a solar simulator 100 is connected to one side of the glove box 200, a base 500 is arranged inside the glove box 200, a mask 400 is arranged on the surface of the base 500, and a probe assembly 300 is symmetrically arranged on the surface of the base 500;

[0036] The glove box 200 includes a box body 210, the bottom surface of the box body 210 is paved with water-absorbing silica gel 220, and the water-absorbing silica gel 220 and the side panels of the box body 210 surround to form a mounting groove 230; a base 500 is installed inside the mounting groove 230;

[0037] The base 500 includes a mounting frame 560 disposed inside the mounting groove 230. The top ends of the mounting frame 560 are rotatably connected to a positioning plate through a rotating knob 550. A receiving cavity 520 is disposed at the center of the surface of the positioning plate. A second light-transmitting groove 530 is disposed through the center of the receiving cavity 520.

[0038] The mask 400 is arranged inside the accommodating cavity 520, a first light-transmitting groove 420 is arranged through the center of the surface of the mask 400, a perovskite solar cell to be tested is installed inside the first light-transmitting groove 420, and the center lines of the first light-transmitting groove 420 and the second light-transmitting groove 530 in the vertical direction are in the same straight line;

[0039] The probe assembly 300 includes a connecting block 360 symmetrically connected to both sides of the surface of the positioning plate, an adjusting block 370 is slidably connected to one side of the connecting block 360, and a test probe 350 is connected to the end of the adjusting block 370 away from the connecting block 360. The test probe 350 is connected to the surface of the perovskite solar cell to be tested.

[0040] In the present invention, a plurality of water-absorbing silica gel 220 are provided, and the plurality of water-absorbing silica gel 220 are surrounded to form a U-shaped structure, and a mounting groove 230 is provided inside the U-shaped structure formed by the plurality of water-absorbing silica gel 220. The water-absorbing silica gel 220 is used to absorb water molecules in the glove box 200 to reduce the influence of water vapor on the perovskite solar cell. The water-absorbing silica gel 220 will change color according to the amount of water absorbed, so that the staff can observe the color of the water-absorbing silica gel 220 and replace the water-absorbing silica gel 220 in time.

[0041] In the present invention, the mounting frame 560 is in a U-shaped structure as a whole, and the rotating knobs 550 are symmetrically arranged on both sides of the opening end of the mounting frame 560 of the U-shaped structure. The rotating knobs 550 penetrate the side plates of the mounting frame 560 and are connected to the mounting plate. The four corners of the surface of the accommodating cavity 520 on the surface of the mounting plate are provided with magnetic blocks 510, and the surface of the accommodating cavity 520 is also symmetrically provided with positioning grooves 540 along the length direction of the mounting plate. The accommodating cavity 520 is detachably connected to the mask 400 through the magnetic blocks 510. The base 500 is provided with an accommodating cavity 520 for placing the mask 400, and the second light-transmitting groove 530 can also be used as a light-transmitting hole, so that the external solar simulator 100 can be irradiated onto the perovskite solar cell through the light outlet 130. In addition, the rotating knob 550 is turned to rotate the mounting plate connected to the top of the mounting frame 560, so that the fixed perovskite solar cell is directly irradiated with simulated natural light after rotation.

[0042] In the present invention, the connection block 360 includes a magnetic seat 320 connected to the surface of the mounting plate, a guide block 314 is connected to one side of the top of the magnetic seat 320, an adjustment knob 310 is connected to the surface of the guide block 314, and the end of the adjustment knob 310 passes through the guide block 314 and is movably connected to the surface of the adjustment block 370. An adjustment cavity 390 is also provided on the side of the adjustment block 370 away from the guide block 314, a threaded rod 315 is provided inside the adjustment cavity 390 along the length direction of the positioning plate, and the end of the threaded rod 315 close to the guide block 314 passes through the adjustment cavity 390 and is fixedly connected to the rotating block 311, a test probe 350 is provided inside the rotating block 311, a tightening knob 330 is also provided inside the adjustment cavity 390, and the tightening knob 330 is screwed to the surface of the threaded rod 315, and a locking screw 340 is also connected to the side of the outer side of the rotating block 311 away from the threaded rod 315. A slide groove 380 is provided at the connection between the magnetic seat 320 and the adjustment block 370, and the end of the adjustment block 370 near the slide groove 380 is slidably connected to the slide groove 380. A through hole 312 is provided in the vertical direction of the rotating block 311, and a test probe 350 is connected inside the through hole 312. The axis of the locking screw 340 is perpendicular to the axis of the through hole 312, and the locking screw 340 passes through the side of the rotating block 311 and is connected to the test probe 350. A reserved groove 313 is also provided on the surface of one side of the rotating block 311 near the adjustment cavity 390, and the tightening knob 330 passes through the adjustment cavity 390 and is connected inside the reserved groove 313.

[0043] In the present invention, the surface of the mask 400 is symmetrically provided with probe grooves 410 on both sides of the first light-transmitting groove 420 along the length direction of the mask 400. In actual operation, the experimenter only needs to put the perovskite solar cell to be tested into the first light-transmitting groove 420 to achieve precise positioning. At this time, the test simulates the same natural light at the position of each contact on the perovskite solar cell, ensuring that each contact has the same irradiance, ensuring the accuracy of the test results, and when measuring multiple times, the previous test results can be reproduced, and the test repeatability is good.

[0044] In the present invention, the solar simulator 100 includes a support base 110 arranged on the outside of the box 210, and an optical mixing channel 120 is arranged on the top of the support base 110 close to the box 210. The optical mixing channel 120 passes through a positioning hole 240 on the side of the box 210 and extends to the inside of the box 210. A light outlet 130 is also arranged at one end of the optical mixing channel 120 extending to the inside of the box 210, and the light outlet 130 is vertically arranged directly above the first light-transmitting groove 420 and the second light-transmitting groove 530.

[0045] Example 1: When in use, first connect the solar simulator 100 to the outside of the box body 210 of the glove box 200 to ensure that the simulated natural light emitted by the solar simulator 100 can pass through the optical mixing channel 120 and the light outlet 130 to irradiate directly above the first light-transmitting groove 420 and the second light-transmitting groove 530.

[0046] Then, the mounting plate on the surface of the mounting frame 560 of the base 500 is rotated into a vertical state under the action of the rotating knobs 550 on both sides, and then the perovskite solar cell to be tested is placed in the first light-transmitting groove 420 on the surface of the mask 400, and the mask 400 is installed on the surface of the accommodating cavity 520 through the action of the magnetic suction block 510, so that precise positioning can be achieved. At this time, the test simulates the same natural light at the position of each contact on the perovskite solar cell, ensuring that each contact has the same irradiance and the accuracy of the test results. Then, the mounting plate with the mask 400 is rotated to a horizontal state by rotating the knob 550.

[0047] Then adjust the position of the test probe 350 to ensure that the end of the test probe 350 can be connected to the contact position on the surface of the perovskite solar cell to be tested. During adjustment, first fix the entire probe assembly 300 to an appropriate position on the surface of the mounting plate under the action of the magnetic seat 320. Then loosen the tightening knob 330 to adjust the angle of the rotating block 311 to ensure that the test probe 350 connected inside the rotating block 311 can be connected to the contact position on the surface of the perovskite solar cell to be tested, and then lock the tightening knob 330 to make the side of the rotating block 311 close to the outside of the adjustment cavity 390 to ensure that it does not rotate during the test. Then loosen the locking screw 340, adjust the length and height of the test probe 350 to ensure that it can contact the contact position on the surface of the perovskite solar cell to be tested. If the height of the entire probe assembly 300 is too high or too low, the adjustment knob 310 can be rotated to drive the adjustment block 370 to move up and down along the slide 380. A bearing or other movably connected connecting member is provided between the adjustment knob 310 and the adjustment block 370 to ensure that the adjustment knob 310 is fixedly connected to the adjustment block 370, and it can also ensure that the adjustment knob 310 will not drive the adjustment block 370 to rotate during the rotation process, but will only drive it to move up and down along the slide 380. After the test probe 350 contacts the contact point on the surface of the perovskite solar cell to be tested, the other end of the test probe 350 is connected to the external circuit to measure the photoelectric conversion efficiency and JV curve of the perovskite solar cell.

[0048] At this time, the test of each contact position on the perovskite solar cell simulates the same natural light, ensuring that each contact has the same irradiance, ensuring the accuracy of the test results, and when measured multiple times, the previous test results can be reproduced, and the test repeatability is good.

[0049] There are multiple water-absorbing silica gel 220, and the multiple water-absorbing silica gel 220 surrounds a U-shaped structure, and a mounting groove 230 is arranged inside the U-shaped structure formed by the multiple water-absorbing silica gel 220. The water-absorbing silica gel 220 is used to absorb water molecules in the glove box 200 to reduce the influence of water vapor on the perovskite solar cell. The water-absorbing silica gel 220 will change color according to the amount of water absorbed, so that the staff can observe the color of the water-absorbing silica gel 220 and replace the water-absorbing silica gel 220 in time.

[0050] It is obvious 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 present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-limiting from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention, and any reference numerals in the claims should not be regarded as limiting the claims involved.

[0051] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A perovskite solar cell testing device, comprising a glove box (200), characterized in that: A solar simulator (100) is connected to one side of the glove box (200), a base (500) is arranged inside the glove box (200), a mask (400) is arranged on the surface of the base (500), and a probe assembly (300) is also symmetrically arranged on the surface of the base (500); The glove box (200) comprises a box body (210), the bottom surface of the box body (210) is paved with water-absorbing silica gel (220), the water-absorbing silica gel (220) and the side panels of the box body (210) surround to form a mounting groove (230); a base (500) is installed inside the mounting groove (230); The base (500) comprises a mounting frame (560) arranged inside the mounting groove (230), the top ends of the mounting frame (560) are rotatably connected to a positioning plate via a rotating knob (550), a receiving cavity (520) is arranged at the center of the surface of the positioning plate, and a second light-transmitting groove (530) is arranged through the center of the receiving cavity (520); The mask (400) is arranged inside the accommodating cavity (520), a first light-transmitting groove (420) is provided through the center of the surface of the mask (400), a perovskite solar cell to be tested is installed inside the first light-transmitting groove (420), and the center lines of the first light-transmitting groove (420) and the second light-transmitting groove (530) in the vertical direction are in the same straight line; The probe assembly (300) comprises a connection block (360) symmetrically connected to both sides of the surface of the positioning plate, an adjustment block (370) is slidably connected to one side of the connection block (360), and a test probe (350) is connected to one end of the adjustment block (370) away from the connection block (360), and the test probe (350) is connected to the surface of the perovskite solar cell to be tested.

2. A perovskite solar cell testing device according to claim 1, characterized in that: The water-absorbing silica gel (220) is provided in a plurality of pieces, and the plurality of water-absorbing silica gel (220) surrounds and forms a U-shaped structure, and a mounting groove (230) is provided inside the U-shaped structure formed by the plurality of water-absorbing silica gel (220).

3. A perovskite solar cell testing device according to claim 1, characterized in that: The mounting frame (560) is in a U-shaped structure as a whole, and rotating knobs (550) are symmetrically arranged on both sides of the opening end of the mounting frame (560) of the U-shaped structure, and the rotating knobs (550) pass through the side plates of the mounting frame (560) and are connected to the mounting plate, and magnetic blocks (510) are arranged at the four corners of the surface of the accommodating cavity (520) on the surface of the mounting plate, and positioning grooves (540) are also symmetrically arranged on the surface of the accommodating cavity (520) along the length direction of the mounting plate.

4. A perovskite solar cell testing device according to claim 3, characterized in that: The accommodating cavity (520) and the mask plate (400) are detachably connected via a magnetic attraction block (510).

5. A perovskite solar cell testing device according to claim 1, characterized in that: The connecting block (360) comprises a magnetic seat (320) connected to the surface of the mounting plate, a guide block (314) is connected to one side of the top of the magnetic seat (320), an adjusting knob (310) is connected through the surface of the guide block (314), and the adjusting knob (310) passes through the end of the guide block (314) and is movably connected to the surface of the adjusting block (370).

6. A perovskite solar cell testing device according to claim 5, characterized in that: An adjusting cavity (390) is also provided on the side of the adjusting block (370) away from the guide block (314); a threaded rod (315) is provided inside the adjusting cavity (390) along the length direction of the positioning plate; and one end of the threaded rod (315) close to the guide block (314) passes through the adjusting cavity (390) and is fixedly connected to a rotating block (311); a test probe (350) is provided inside the rotating block (311); a tightening knob (330) is also provided inside the adjusting cavity (390); the tightening knob (330) is screwed to the surface of the threaded rod (315); and a locking screw (340) is also connected to the outer side of the rotating block (311) away from the threaded rod (315).

7. A perovskite solar cell testing device according to claim 5, characterized in that: A slide groove (380) is provided at the connection between the magnetic seat (320) and the adjustment block (370), and the adjustment block (370) is slidably connected to the slide groove (380) near the end of the slide groove (380).

8. A perovskite solar cell testing device according to claim 6, characterized in that: The rotating block (311) is provided with a through hole (312) in the vertical direction, the testing probe (350) is connected inside the through hole (312), the axis of the locking screw (340) is perpendicular to the axis of the through hole (312), and the locking screw (340) passes through the side of the rotating block (311) and is connected to the testing probe (350), and a reserved groove (313) is also provided on a side surface of the rotating block (311) close to the adjusting cavity (390), and the tightening knob (330) passes through the adjusting cavity (390) and is connected to the inside of the reserved groove (313).

9. A perovskite solar cell testing device according to claim 1, characterized in that: The surface of the mask (400) is symmetrically provided with probe grooves (410) on both sides of the first light-transmitting groove (420) along the length direction of the mask (400).

10. A perovskite solar cell testing device according to claim 1, characterized in that: The solar simulator (100) comprises a support base (110) arranged on the outside of the box (210); an optical mixing channel (120) is arranged on the top of the support base (110) close to the box (210); the optical mixing channel (120) passes through a positioning hole (240) on the side of the box (210) and extends into the interior of the box (210); a light outlet (130) is also arranged at one end of the optical mixing channel (120) extending into the interior of the box (210); and the light outlet (130) is vertically arranged directly above the first light-transmitting groove (420) and the second light-transmitting groove (530).

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