CN110878409A - Magnetron sputtering coating production line and method for preparing solar cell back electrode - Google Patents

Abstract

The invention relates to a magnetron sputtering coating production line for preparing a solar cell back electrode, which comprises a cylindrical cavity, wherein the cavity is sequentially divided into a sample wafer inlet section, a low-pressure vacuum chamber I, a main sputtering chamber, a low-pressure vacuum chamber II and a sample wafer outlet section by a high valve; the main sputtering chamber is provided with a target, a conveying device of the main sputtering chamber drives the sample wafer support to move back and forth relative to the target, and argon-oxygen mixed gas is introduced into the main sputtering chamber through an air inlet pipeline. The invention also discloses a method for using the magnetron sputtering coating production line for preparing the back electrode of the solar cell. The invention can effectively isolate external water vapor and oxygen from entering the perovskite battery and reduce the damage of the perovskite battery caused by the external water vapor and the oxygen.

Description

Magnetron sputtering coating production line and method for preparing solar cell back electrode

technical field

The invention relates to the technical field of solar cell manufacturing, in particular to a magnetron sputtering coating production line for preparing a solar cell back electrode and a method thereof.

Background technique

With the development of photovoltaic field in recent years, perovskite solar cell is a new type of cell with great potential to replace the dominant position of silicon-based solar cell. How to fabricate the back electrode of perovskite solar cells has always been a problem. Due to the decomposition of perovskite materials with water, the back electrode cannot be prepared by a low-cost solution method, nor can it be prepared by atomic layer deposition (ALD) and chemical vapor deposition (CVD), because the raw material contains water. In addition, perovskites are not resistant to high temperatures, so the screen printing technology widely used in crystalline silicon cells cannot be used in the preparation of perovskite back electrodes. The laboratory preparation of perovskite back electrodes generally adopts the evaporation method, but this method is difficult to achieve industrialized mass production.

At present, the preparation of the back electrode of perovskite batteries is generally carried out by the evaporation method. The evaporation method requires a high vacuum environment (<1e-5Pa), the temperature needs to reach above the boiling point of the metal to be evaporated (>2000K), and the coating speed is slow, and the evaporation time for a single electrode is generally more than half an hour, which is not conducive to industrial production. In addition, the adhesion of the film prepared by the evaporation method to other parts of the battery is not very good, it is easy to fall off, and the film density is not high, which cannot effectively block water molecules, thereby reducing the stability of the battery. .

Compared with evaporation coating, sputtering coating requires a slightly lower degree of vacuum, faster coating speed, and does not require a high temperature environment, making it more suitable for industrial production. In addition, the uniformity and density of the sputtered film are better than those of the vapor deposition, and the adhesion between the sputtered film and the battery is high. However, the high-energy plasma (glow) that needs to be excited during sputtering can damage the organic layers of perovskite cells, reducing cell efficiency. Therefore, reasonable control of sputtering parameters (power, gas pressure, target-to-base distance, etc.) is required to minimize the damage caused by sputtering to perovskite cells. Currently, there are no reports on sputtering equipment that can be used for industrial production of perovskite photovoltaic cell back electrodes.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a magnetron sputtering coating production line and method for preparing the back electrode of solar cells that can be used for industrial mass production, which can be used in perovskite solar cells and other products containing plasma-sensitive, or In the electrode preparation process of organic or nanomaterials that are not resistant to water or high temperature.

The present invention is realized in this way, and provides a magnetron sputtering coating production line for preparing the back electrode of a solar cell, which includes a cylindrical chamber, and the chamber is sequentially divided by a high valve into a sample entry section, a low-pressure vacuum chamber, The main sputtering chamber, the second low-pressure vacuum chamber and the sample discharge section are provided with a conveyor belt conveyor at the top of the chamber, and a plurality of sample racks are suspended at the lower part of the conveyor belt. The high valve automatically Open to allow the sample holder to pass through and automatically close after the sample holder passes; the sample holder includes a frame, a connecting column, a baffle, a rotating shaft and a sample slot, the frame is connected to the lower part of the conveyor belt through the connecting column, and the sample The card slot is set on the frame, and the sample of the back electrode to be sputtered is placed in the sample card slot. The baffle is set on the front side of the frame through the rotating shaft. Normally, the baffle covers the sample in the sample card slot. , when necessary, the rotating shaft drives the baffle to rotate to expose all the samples in the sample slot; a target is set in the main sputtering chamber, the target is located on the front side of the baffle, the main The conveying device of the sputtering chamber drives the sample holder to move back and forth relative to the target, and an air inlet pipe is also arranged in the main sputtering chamber, through which an argon-oxygen mixed gas is introduced into the main sputtering chamber.

Further, a high-vacuum transition chamber 1 separated by a high valve is set between the low-pressure vacuum chamber 1 and the main sputtering chamber, and a high-vacuum transition chamber is set between the main sputtering chamber and the low-pressure vacuum chamber 2. The separated high vacuum transition chamber 2 is separated by a high valve 1 between the sample entry section and the low pressure vacuum chamber 1, and is separated between the low pressure vacuum chamber 1 and the high vacuum transition chamber 1 by a high valve 2 , the high vacuum transition chamber 1 and the main sputtering chamber are separated by a high valve 3, and the main sputtering chamber and the high vacuum transition chamber 2 are separated by a high valve 4. In the high vacuum The transition chamber 2 and the low-pressure vacuum chamber 2 are separated by a high valve 5, and the low-pressure vacuum chamber 2 and the sample discharge section are separated by a high valve 6. The high-vacuum transition chamber 1 and the high-vacuum transition chamber The tops of the second chambers are respectively provided with conveying devices with conveying belts for conveying the sample holders.

Further, a vacuum pump is set outside the low-pressure vacuum chamber and is connected to it through a ventilation valve 1, and a vacuum pump 2 and a molecular pump are set outside the high-vacuum transition chamber 1 and are connected to it through the ventilation valve 2, A vacuum pump 3 and a molecular pump 2 are arranged outside the main sputtering chamber and are connected to them through a ventilation valve 3, and a vacuum pump 4 and a molecular pump 3 are arranged outside the high vacuum transition chamber 2 and are connected to them through the ventilation valve 4, A vacuum pump 5 is arranged outside the low-pressure vacuum chamber 2 and is connected to it through a ventilation valve 5 .

Further, the high valve includes a high valve motor, a high valve support and a moving door, the high valve motor is arranged on the high valve support, the high valve motor drives the moving door to move, and moving the moving door will open or close the phase. For two adjacent chambers, a sample channel is provided on the moving door, and when the moving door is in an open state, the sample holder reaches the next chamber through the sample channel on the moving door.

Further, the rotating shaft is driven to rotate by a stepping motor, and a laser position sensor is respectively provided at the front and rear positions of each of the high valves.

Further, the conveying device is any one of gear drive, sprocket drive and pulley drive, and correspondingly, the conveyor belt is any one of rack, chain and crawler.

Further, the proportion of oxygen in the argon-oxygen mixed gas is 0-20%, the distance between the sample and the target is 5-25 cm, and the conveying device of the main sputtering chamber drives the sample holder relative to the target. The reciprocating speed of the target is 10~30mm/s; the target is connected to the negative pole of the bias power supply and connected to a power supply with a bias voltage of 200~400V.

Further, the number of the baffles is 1 to 4, the number of the rotating shafts is set corresponding to the number of the baffles, and the shape of the baffles is any one of a quadrilateral, a circle and a triangle.

The present invention is achieved in this way, and provides a method for preparing a magnetron sputtering coating film of a solar cell back electrode, using the magnetron sputtering coating production line for preparing a solar cell back electrode as described above, comprising the following steps:

In the first step, the sample of the back electrode to be sputtered is placed in the sample slot of the sample holder, and the sample holder is placed in the sample entry section;

The second step is to close the ventilation valve 1, open the high valve 1, and then close the high valve 1 after the sample holder is transported into the low-pressure vacuum chamber 1 through the conveying device, open the vacuum pump 1 and the ventilation valve 1, and control the low-pressure vacuum chamber 1. internal pressure;

The third step is to close the ventilation valve 1, open the high valve 2, and then close the high valve 2 after the sample holder is transported to the high vacuum transition chamber 1 through the conveying device; open the vacuum pump 2, the molecular pump 1 and the ventilation valve 2, control the The internal pressure of the high vacuum transition chamber 1; at the same time, the next sample holder is in place in the sample entry section;

The fourth step is to open the high valve three, and then close the high valve three after the sample holder is transported into the main sputtering chamber through the conveying device; at the same time, the next sample holder starts to perform the second step;

In the fifth step, the argon-oxygen mixed gas is introduced into the main sputtering chamber through the air inlet pipe, and oxygen accounts for 0~20% in the argon-oxygen mixed gas, and the vacuum pump three, the molecular pump two and the ventilation valve three are turned on to control the main sputtering The internal pressure of the shooting chamber; connect the target to the negative pole of the bias power supply, the main sputtering chamber wall is grounded, and control the distance between the sample and the target in the sample holder to be 5~25cm. Before the target glows, the sample holder The baffle is closed, turn on the bias power supply on the target material to make it glow, wait for 5~15 seconds, then open the baffle to expose the sample to be sputtered in the sample card slot, and the glowing target material to the sample The surface is sputtered. During the sputtering process of the target material, the conveyor device drives the sample holder to move back and forth relative to the target material in the main sputtering chamber, and the bias power supply and baffle are turned off after the ignition time lasts for 1 to 15 minutes;

The sixth step is to open the high valve four, and then close the high valve four after the sample holder is transported to the high vacuum transition chamber two through the conveying device; open the vacuum pump four, the molecular pump three and the ventilation valve four, and control the high vacuum transition chamber two. the internal pressure; at the same time, the next sample holder starts to perform the third step and proceeds at intervals;

The seventh step, close the ventilation valve 4, open the high valve 5, and then close the high valve 5 after the sample holder is transported into the low-pressure vacuum chamber 2 through the conveying device; open the vacuum pump 5 and the ventilation valve 5, and control the low-vacuum transition chamber 2 the internal pressure;

The eighth step, open the high valve 6, and then close the high valve 6 after the sample holder is transported to the sample discharge section through the conveying device, and the sputtered samples in the sample holder are transported to the sample discharge section for subsequent processing. .

Further, by opening the vacuum pump and/or molecular pump of each chamber, and the ventilation valve, the internal pressures of the low-vacuum transition chamber 1 and the low-pressure vacuum chamber 2 are respectively controlled at 1-10Pa, and the high-vacuum transition chamber is The internal pressures of the first and high vacuum transition chambers are controlled at 10 ^-4 to 10 ^-5 Pa respectively, and the internal pressure of the main sputtering chamber is controlled at 0.1 to 2.0 Pa.

Compared with the prior art, the magnetron sputtering coating production line and the method for preparing the back electrode of the solar cell of the present invention have the following characteristics:

1. The production line has high cleanliness, which can improve the quality of electrodes;

2. Compared with the evaporation production line, this production line has higher production efficiency, which can speed up the mass production of the back electrode layer;

3. Compared with the traditional sputtering production line, this production line has a better protection effect on the sample, which can reduce the damage of the sputtering to the thin film layer of the perovskite battery and improve the efficiency of the finished battery;

4. The back electrode prepared by the production line and method can effectively improve the adhesion between the metal electrode and the electron transport layer;

5. When using the production line and method to prepare the back electrode, the outside water vapor and oxygen can be effectively isolated from entering the perovskite battery to reduce their damage to the perovskite battery.

Description of drawings

1 is a schematic plan view of a preferred embodiment of a magnetron sputtering coating production line for preparing a solar cell back electrode of the present invention;

Fig. 2a is a front view of the baffle of the sample holder in Fig. 1 in a closed state, Fig. 2b is a side view of Fig. 2a; Fig. 2c is a front view of the baffle of the sample holder of Fig. 2 in an open state, Fig. 2d is the side view of Figure 2c.

3a is a schematic diagram of the sample holder in FIG. 1 before passing through the high valve, FIG. 3b is a schematic diagram of the sample holder in FIG. 3a passing through the high valve, and FIG. 3c is a schematic diagram of the sample holder in FIG. 3a having passed the high valve.

Detailed ways

In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

1 and 2a, 2b, 2c, and 2d at the same time, a preferred embodiment of the magnetron sputtering coating production line for preparing the back electrode of a solar cell of the present invention includes a cylindrical chamber 1, and the Chamber 1 is divided by high valve 2 into sample entry section A, low pressure vacuum chamber 1 B, high vacuum transition chamber 1 C, main sputtering chamber D, high vacuum transition chamber 2 E, low pressure vacuum chamber 2 F and sample out. Warehouse section G. The sample entry section A is located at the front end of the coating production line, and the sample output section G is located at the rear end of the coating production line.

The sample entry section A and the low-pressure vacuum chamber 1B are separated by a high valve 1 21, and the low-pressure vacuum chamber 1B and the high vacuum transition chamber 1C are separated by a high valve 22. The high vacuum transition chamber 1 C and the main sputtering chamber D are separated by a high valve 3 23, and the main sputtering chamber D and the high vacuum transition chamber 2 E are separated by a high valve 4 24. The high-vacuum transition chamber 2E and the low-pressure vacuum chamber 2F are separated by a high valve 25 , and the low-pressure vacuum chamber 2F and the sample discharge section G are separated by a high-valve 626 .

On top of the chamber 1 is provided a conveyor 4 with a conveyor belt 3 . A plurality of sample holders 5 are suspended from the lower portion of the conveyor belt 3 . The conveying device 4 is driven in sections, and each chamber 1 is provided with a conveying device 4 with a conveyor belt 3 . The sample holders 5 are arranged at intervals. The transfer device 4 transfers the sample holder 5 from the front end of the coating production line to the rear end of the coating production line, and the sample M to be sputtered back electrode is placed up and down on the sample holder 5 and is entered from the sample entry section A by the transfer device 4. The coating production line then sends out the coating production line from the sample discharge section G, as shown by the three arrows in Figure 1.

The sample holder 5 includes a frame 51 , a connecting column 52 , a baffle plate 53 , a rotating shaft 54 and a sample card slot 55 . The frame 51 is connected to the lower part of the conveyor belt 3 through the connecting column 52 , the sample card slot 55 is arranged on the frame 51 , and the sample M to be sputtered on the back electrode is placed in the sample card slot 55 . The baffle 53 is provided on the front side of the frame 51 through the rotating shaft 54 . The rotating shaft 54 is driven to rotate by a stepping motor 56 . Normally, the baffle 53 covers the samples M in the sample slot 55 , and when necessary, the rotating shaft 54 drives the baffle 53 to rotate to expose all the samples M in the sample slot 55 .

A target 6 is installed in the main sputtering chamber D. The target 6 is located on the front side of the baffle 53 . The conveying device 4 of the main sputtering chamber D drives the sample holder 5 to move back and forth relative to the target 6 . When the shutter 53 is opened, the target material 6 sputters the target material onto the surface of the sample M to be sputtered in the sample card slot 55 . After the target substance is sputtered, the shutter 53 is automatically closed. The main sputtering chamber D is also provided with an air inlet pipe D1, and an argon-oxygen mixed gas is introduced into the main sputtering chamber D through the air inlet pipe D1. As shown by the single arrow in Figure 1. Before the sputtering of the target material 6, an argon-oxygen mixed gas is introduced into the main sputtering chamber D, so that the sputtering process of the target material 6 is always carried out in an argon-oxygen mixed gas environment.

Laser position sensors 7 are respectively arranged at the front and rear positions of each of the high valves 2 . The high valve 2 is in a normally closed state. Each of the high valves 2 can be automatically opened to allow the sample holder 5 to pass through and automatically closed after the sample holder 5 has passed through. When the laser position sensor 7 on the side of the high valve 2 senses the sample holder 1, it automatically opens to allow the sample holder 5 to pass. 2 and immediately automatically closes to restore the initial state of normally closed.

Referring to FIG. 1 and FIGS. 3 a , 3 b and 3 c simultaneously, the high valve 2 includes a high valve motor 201 , a high valve bracket 202 and a moving door 203 . The high valve motor 201 is disposed on the high valve bracket 202, and the high valve motor 201 drives the moving door 203 to move. Moving the moving door 203 will open or close two adjacent chambers. A sample channel 204 is provided on the moving door 203 . When the moving door 203 is in the open state, the sample holder 5 reaches the next chamber through the sample channel 204 on the moving door 203 . The process of the sample holder 5 passing through the high valve 2 is shown in Figs. 3a, 3b, and 3c, and the sample holder 5 passes through the high valve 2 in the direction indicated by the double arrow in the figure. The moving door 203 can move up and down, and can also move left and right. In this embodiment, the moving door 203 moves up and down.

Referring to FIG. 1, a vacuum pump-B1 is arranged outside the low-pressure vacuum chamber-B and is connected to it through a ventilation valve-B2. A vacuum pump 2 C1 and a molecular pump 1 C2 are arranged outside the high vacuum transition chamber 1 C and are connected to them through a ventilation valve 2 C3. Outside the main sputtering chamber D, a vacuum pump 3 D2 and a molecular pump 2 D3 are arranged and connected to them through a vent valve 3 D4. A vacuum pump 4 E1 and a molecular pump 3 E2 are arranged outside the high vacuum transition chamber 2 E and are connected to them through a ventilation valve 4 E3. A vacuum pump 5F1 is arranged outside the low-pressure vacuum chamber 2F and is connected to it through a ventilation valve 5F2.

The internal pressures of the low-vacuum transition chamber 1B and the low-pressure vacuum chamber 2F are respectively 1-10Pa. The internal pressures of the high vacuum transition chamber 1 C and the high vacuum transition chamber 2 E are respectively 10 ^-4 to 10 ^-5 Pa. The internal pressure of the main sputtering chamber D is 0.1-2.0 Pa. Oxygen accounts for 0-20% in the argon-oxygen mixed gas. The distance between the sample M and the target 6 is 5-25 cm. The speed at which the conveying device 4 of the main sputtering chamber D drives the reciprocating movement of the sample holder 5 relative to the target 6 is 10-30 mm/s.

The target 6 is connected to the negative electrode of the bias power supply and connected to a power supply with a bias voltage of 200-400V. Before the target 6 is ignited, the shutter 53 of the sample holder 5 is in a closed state. Turn on the bias power supply on the target 6 to make it glow, wait for 5 to 15 seconds, then open the baffle 53 to expose the sample M to be sputtered in the sample card slot 55, and the glowing target 6 faces the surface of the sample M Do sputtering. During the sputtering process of the target 6, the conveying device 4 drives the sample holder 5 to move back and forth at a constant speed relative to the target 6 in the main sputtering chamber D, and the bias power supply and the baffle 53 are turned off after the ignition time lasts for 1 to 15 minutes.

The number of the baffles 53 is 1 to 4, and the number of the rotating shafts 54 is set corresponding to the number of the baffles 53 . The shape of the baffle 53 is any one of quadrilateral, circular and triangular. In this embodiment, the number of baffles 53 is two, and the number of rotating shafts 54 is also two. The two rotating shafts 54 are respectively disposed on the diagonal lines of the frame 51, and each drives a baffle plate 53 to rotate. The baffle 53 is rectangular in shape. When the two shutters 53 are closed, they partially overlap at their closing positions, effectively covering the samples M placed in the sample card slot 55 and preventing them from being exposed to the outside of the shutters 53 .

The conveying device 4 is any one of gear drive, sprocket drive or pulley drive, and the conveyor belt 3 is any one of rack, chain or crawler. In this embodiment, the transmission device 4 is a sprocket drive, and the conveyor belt 3 is a chain.

The target material 6 is a square target material or a rotating target material, the number of the target material 6 is 1-6, and the number of the sample card slots 55 is 2-20. In this embodiment, the target material 6 is a rectangular target material, and the number of the target material 6 is two, which are arranged side by side on the left and right. The number of sample card slots 55 is six, which are arranged in two rows left and right, and three rows up and down. The number of sample card slots 55 can be set as required.

The invention also discloses a method for preparing the magnetron sputtering coating film of the back electrode of the solar cell, using the magnetron sputtering coating film production line for preparing the back electrode of the solar cell as described above, comprising the following steps:

In the first step, the sample M of the back electrode to be sputtered is placed in the sample slot 55 of the sample holder 5, and the sample holder 5 is placed in the sample entry section A.

In the second step, close the ventilation valve-B2, open the high valve-21, wait for the sample holder 5 to be transported into the low-pressure vacuum chamber-B through the conveying device 4, then close the high valve-21, open the vacuum pump-B1 and the ventilation valve-1 B2, the internal pressure of the low-pressure vacuum chamber 1B is controlled at 1~10Pa.

The third step is to close the ventilation valve one B2, open the high valve two 22, and then close the high valve two 22 after the sample holder 5 is transported to the high vacuum transition chamber one C through the conveying device 4. Turn on vacuum pump 2 C1, molecular pump 1 C2 and vent valve 2 C3, and control the internal pressure of high vacuum transition chamber 1 C at 10 ^-4 ~10 ^-5 Pa. At the same time, the next sample holder 5 is in place at the sample entry section A.

In the fourth step, the high valve three 23 is opened, and the high valve three 23 is closed after the sample holder 5 is transported into the main sputtering chamber D through the conveying device 4 . At the same time, the next sample holder 5 starts the second step.

In the fifth step, the argon-oxygen mixed gas is introduced into the main sputtering chamber D through the gas inlet pipe D1. Oxygen accounts for 0~20% in the argon-oxygen mixture. Turn on the vacuum pump 3 D2, the molecular pump 2 D3 and the vent valve 3 D4, and control the internal pressure of the main sputtering chamber D at 0.1~2.0Pa. The target 6 is connected to the negative electrode of the bias power supply, the outer wall of the main sputtering chamber 6 is grounded, and the distance between the sample M in the sample holder 5 and the target 6 is controlled to be 5-25 cm. Before the target 6 is ignited, the shutter 53 of the sample holder 5 is in a closed state. Turn on the bias power supply on the target 6 to make it glow, wait for 5 to 15 seconds, then open the baffle 53 to expose the sample M to be sputtered in the sample card slot 55, and the glowing target 6 faces the surface of the sample M Do sputtering. During the sputtering process of the target 6, the conveying device 4 drives the sample holder 5 to move back and forth at a constant speed relative to the target 6 in the main sputtering chamber D, and the bias power supply and the baffle 53 are turned off after the ignition time lasts for 1 to 15 minutes.

The sixth step is to open the high valve four 24, and then close the high valve four 24 after the sample holder 5 is transported into the high vacuum transition chamber 2E through the conveying device 4. Turn on the vacuum pump 4 E1, the molecular pump 3 E2 and the ventilation valve 4 E3, and control the internal pressure of the high vacuum transition chamber 2 E at 10 ^-4 ~10 ^-5 Pa. At the same time, the next sample holder 5 starts to perform the third step and proceeds sequentially at intervals.

In the seventh step, close the ventilation valve 4 E3, open the high valve 5 25, and close the high valve 5 25 after the sample holder 5 is transported into the low pressure vacuum chamber 2F through the conveying device 4. Open the vacuum pump 5F1 and the ventilation valve 5F2, and control the internal pressure of the low vacuum transition chamber 2F to 1~10Pa.

The eighth step is to open the high valve 6 26, and then close the high valve 6 26 after the sample holder 5 is transported to the sample discharge section G through the conveying device 4, and the sputtered sample M in the sample holder 5 is delivered to the sample holder 5. Subsequent processing is carried out in the sample outgoing section G.

The above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention shall be included in the protection of the present invention. within the range.

Claims (10)

1. A magnetron sputtering coating production line for preparing a solar cell back electrode comprises a cylindrical cavity and is characterized in that the cavity is sequentially divided into a sample wafer inlet section, a low-pressure vacuum chamber I, a main sputtering chamber, a low-pressure vacuum chamber II and a sample wafer outlet section by a high valve, a conveying device with a conveying belt is arranged at the top of the cavity, a plurality of sample wafer supports are hung at the lower part of the conveying belt, and the high valve is automatically opened to allow the sample wafer supports to pass through and is automatically closed after the sample wafer supports pass through; the sample wafer support comprises a frame, a connecting column, a baffle, a rotating shaft and a sample wafer clamping groove, wherein the frame is connected to the lower part of the conveying belt through the connecting column, the sample wafer clamping groove is formed in the frame, a sample wafer to be sputtered with a back electrode is placed in the sample wafer clamping groove, the baffle is arranged on the front side of the frame through the rotating shaft, the baffle covers the sample wafer in the sample wafer clamping groove normally, and the rotating shaft drives the baffle to rotate to expose all the sample wafers in the sample wafer clamping groove when necessary; the main sputtering chamber is provided with a target, the target is positioned on the front side of the baffle, a conveying device of the main sputtering chamber drives the sample wafer support to move in a reciprocating mode relative to the target, the main sputtering chamber is further provided with an air inlet pipeline, and argon-oxygen mixed gas is introduced into the main sputtering chamber through the air inlet pipeline.

2. The magnetron sputtering coating line for producing a back electrode of a solar cell according to claim 1, wherein a first high vacuum transition chamber separated by a high valve is provided between the first low pressure vacuum chamber and the main sputtering chamber, a second high vacuum transition chamber separated by a high valve is provided between the main sputtering chamber and the second low pressure vacuum chamber, the first sample entrance section and the first low pressure vacuum chamber are separated by a first high valve, the first low pressure vacuum chamber and the first high vacuum transition chamber are separated by a second high valve, the first high vacuum transition chamber and the main sputtering chamber are separated by a third high valve, the main sputtering chamber and the second high vacuum transition chamber are separated by a fourth high valve, the second high vacuum transition chamber and the second low pressure vacuum chamber are separated by a fifth high valve, and the second low pressure vacuum chamber and the sample exit section are separated by a sixth high valve, and conveying devices with conveying belts are respectively and similarly arranged on the tops of the first high-vacuum transition chamber and the second high-vacuum transition chamber and are used for conveying the sample wafer supports.

3. The magnetron sputtering coating line for manufacturing a back electrode of a solar cell according to claim 2, wherein a vacuum pump is disposed outside the first low-pressure vacuum chamber and connected thereto through a first vent valve, a vacuum pump II and a molecular pump are disposed outside the first high-vacuum transition chamber and connected thereto through a second vent valve, a vacuum pump III and a molecular pump II are disposed outside the main sputtering chamber and connected thereto through a third vent valve, a vacuum pump IV and a molecular pump III are disposed outside the high-vacuum transition chamber and connected thereto through a fourth vent valve, and a vacuum pump V is disposed outside the second low-pressure vacuum chamber and connected thereto through a fifth vent valve.

4. The magnetron sputtering coating production line for preparing the back electrode of the solar cell according to claim 2, wherein the high valve comprises a high valve motor, a high valve support and a movable door, the high valve motor is arranged on the high valve support, the high valve motor drives the movable door to move, the movable door opens or closes two adjacent chambers, a sample wafer channel is arranged on the movable door, and when the movable door is in an open state, the sample wafer support reaches the next chamber through the sample wafer channel on the movable door.

5. The magnetron sputtering coating line for manufacturing a back electrode of a solar cell according to claim 2, wherein the rotating shaft is driven to rotate by a stepping motor, and a laser position sensor is respectively arranged at the front and rear positions of each high valve.

6. The magnetron sputtering coating production line for manufacturing a back electrode of a solar cell according to claim 2, wherein the conveying device is any one of a gear transmission, a sprocket transmission and a pulley transmission, and correspondingly, the conveying belt is any one of a rack, a chain and a crawler belt.

7. The magnetron sputtering coating production line for manufacturing a back electrode of a solar cell according to claim 1, wherein the ratio of oxygen in the argon-oxygen mixed gas is 0 to 20%, the distance between the sample wafer and the target is 5 to 25cm, and the speed of the reciprocating movement of the sample wafer holder relative to the target driven by the conveying device of the main sputtering chamber is 10 to 30 mm/s; the target is connected with the negative electrode of the bias power supply and is connected with the power supply with the bias voltage of 200-400V.

8. The magnetron sputtering coating production line for preparing the back electrode of the solar cell as claimed in claim 1, wherein the number of the baffles is 1-4, the number of the rotating shafts is set corresponding to the number of the baffles, and the shape of the baffles is any one of quadrilateral, circular and triangular.

9. A method for preparing magnetron sputtering coating of solar cell back electrode, characterized in that, the magnetron sputtering coating production line for preparing solar cell back electrode as claimed in claim 3 is used, comprising the following steps:

the method comprises the following steps that firstly, a sample wafer to be sputtered with a back electrode is placed in a sample wafer clamping groove of a sample wafer support, and the sample wafer support is placed at a sample wafer entering section;

the second step, closing the first vent valve, opening the first high valve, closing the first high valve after the sample wafer support is conveyed into the first low-pressure vacuum chamber through the conveying device, opening the first vacuum pump and the first vent valve, and controlling the internal pressure of the first low-pressure vacuum chamber;

step three, closing the first vent valve, opening the second high valve, and closing the second high valve after the sample wafer support is conveyed into the first high vacuum transition chamber through the conveying device; opening a vacuum pump II, a molecular pump I and a vent valve II, and controlling the internal pressure of the high-vacuum transition chamber I; meanwhile, the next sample wafer bracket is in place at the sample wafer entering section;

step four, opening a high valve III, and closing the high valve III after the sample wafer support is conveyed into the main sputtering chamber through the conveying device; simultaneously, the next specimen holder starts to carry out the second step;

fifthly, introducing argon-oxygen mixed gas into the main sputtering chamber through a gas inlet pipeline, wherein the oxygen content in the argon-oxygen mixed gas is 0-20%, opening a third vacuum pump, a second molecular pump and a third vent valve, and controlling the internal pressure of the main sputtering chamber; connecting the target material with the negative electrode of a bias power supply, grounding the outer wall of the main sputtering chamber, and controlling the distance between the sample wafer in the sample wafer support and the target material to be 5-25 cm; before the target material is ignited, the baffle plate of the sample wafer support is in a closed state, the bias power supply on the target material is turned on to ignite, the time for waiting for 5-15 seconds is shortened, the baffle plate is turned on again to expose the sample wafer to be sputtered in the sample wafer clamping groove, the ignited target material sputters the surface of the sample wafer, the conveying device drives the sample wafer support to move back and forth in the main sputtering chamber in the sputtering process of the target material, and the bias power supply and the baffle plate are turned off after the ignition time lasts for 1-15 minutes;

a sixth step of opening a high valve IV and closing the high valve IV after the sample wafer support is conveyed into the high vacuum transition chamber II through the conveying device; opening a vacuum pump IV, a molecular pump III and a vent valve IV, and controlling the internal pressure of the high-vacuum transition chamber II; meanwhile, the next specimen holder starts to carry out the third step and sequentially carries out the third step at intervals;

a seventh step of closing the vent valve IV, opening the high valve V, and closing the high valve V after the sample wafer support is conveyed into the low-pressure vacuum chamber II through the conveying device; opening a vacuum pump V and a vent valve V, and controlling the internal pressure of the low-vacuum transition chamber II;

and step eight, opening the high valve six, closing the high valve six after the sample wafer support is conveyed to the sample wafer bin outlet section through the conveying device, and conveying the sample wafer subjected to sputtering processing in the sample wafer support to the sample wafer bin outlet section for subsequent processing.

10. The method according to claim 1, wherein the internal pressures of the first low-vacuum transition chamber and the second low-vacuum transition chamber are controlled to be 1 to 10Pa and the internal pressures of the first high-vacuum transition chamber and the second high-vacuum transition chamber are controlled to be 10Pa respectively by opening the vacuum pump and/or the molecular pump and the vent valve of each chamber^-4~10^-5Pa, and controlling the internal pressure of the main sputtering chamber to be 0.1-2.0 Pa.

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