CN103343323B - Preparation method of copper indium gallium selenide thin film - Google Patents

Abstract

A method for preparing a copper indium gallium selenide thin film, comprising the following steps: preparing a copper indium gallium selenide prefabricated layer on a substrate by magnetron sputtering using a copper target, an indium target, and a gallium target, and the gallium target is composed of three Made of gallium selenide material; the gallium target starts magnetron sputtering later than the indium target, and the gallium target stops magnetron sputtering later than the indium target; the copper indium gallium selenide preset The layer is selenized and annealed to obtain a copper indium gallium selenide thin film. In the above-mentioned copper indium gallium selenium film preparation method, during the magnetron sputtering process, the gallium target starts magnetron sputtering later than the indium target, and the gallium target stops magnetron sputtering later than the indium target, thereby effectively reducing the gallium group. The component is enriched at the bottom of the final CIGS thin film, increasing the content of gallium components on the top of the CIGS thin film to achieve the purpose of increasing the open circuit voltage. In addition, solar cells using the CIGS thin film high photoelectric conversion efficiency.

Description

Preparation method of copper indium gallium selenide thin film

technical field

The invention relates to photovoltaic technology, in particular to a method for preparing a copper indium gallium selenium thin film.

Background technique

Thin-film solar cells are low in cost and light in weight, can be fabricated into devices on a variety of cheap substrates, and are convenient for mass production, which is an important direction for the development of solar cells in the future. Copper indium gallium selenide (CIGS) thin films are often used as light absorbing layers in thin film solar cells.

Sputtering selenization, as a common method for preparing copper indium gallium selenide thin films, has been widely used in industrial production. The sputtering selenization method is to first sputter-deposit a metal pre-layer of copper indium or copper indium gallium on the substrate, and then anneal the pre-preparation layer in an atmosphere containing hydrogen selenide or selenium vapor to make copper, indium, The four elements gallium and selenium react with each other and crystallize to obtain a stoichiometric copper indium gallium selenide thin film.

In the traditional process of preparing copper indium gallium selenide thin films, since the reactivity of indium with other elements is much stronger than that of gallium during the annealing process, the copper indium gallium selenide solar thin films prepared by sputtering Both have the problem that the gallium component gathers at the bottom of the film and the indium component gathers at the top of the film. In the copper indium gallium selenide film, the distribution of the molar ratio of indium to gallium in space affects the spatial distribution of the conduction band, and the open circuit voltage of the battery is affected by the forbidden band width. Therefore, the absence of the gallium component at the top of the film severely reduces the open-circuit voltage of CIGS thin-film solar cells.

Contents of the invention

Based on this, it is necessary to adjust the distribution of the gallium component in the light absorbing layer, and provide a method for preparing a copper indium gallium selenide thin film that can increase the open circuit voltage of a solar cell.

A method for preparing a copper indium gallium selenide thin film, comprising the following steps:

A copper indium gallium selenide prefabricated layer is prepared on the substrate by magnetron sputtering using a copper target, an indium target and a gallium target, and the gallium target is made of gallium triselenide material;

the gallium target starts magnetron sputtering later than the indium target, and the gallium target stops magnetron sputtering later than the indium target; and

Selenization and annealing are performed on the CIGS pre-set layer to prepare a CIGS thin film.

In one of the embodiments, the start or stop of magnetron sputtering on the copper target, indium target or gallium target is controlled by opening or closing the baffle above the copper target, indium target or gallium target.

In one of the embodiments, the start or stop of depositing the coating film on the substrate is controlled by opening or closing the baffle above the sample holder.

In one embodiment, the sputtering power of the indium target is greater than that of the gallium target, the gallium target starts magnetron sputtering 3 to 5 minutes later than the indium target, and the gallium The target stops magnetron sputtering 3-5 minutes later than the indium target.

In one of the embodiments, the step of preparing a copper indium gallium selenide prefabricated layer on the substrate by using magnetron sputtering of a copper target, an indium target and a gallium target further includes:

The copper target, the indium target and the gallium target were pre-sputtered by magnetron sputtering, and the copper target, the indium target and the gallium target were glowed for 10 minutes.

In one of the embodiments, the step of selenizing and annealing the CIGS pre-set layer to prepare CIGS thin film specifically includes the following steps:

Evaporating a selenium layer on the CIGS pre-set layer; and

Under a protective gas atmosphere, anneal the copper indium gallium selenide preset layer evaporated with the selenium layer, and react the copper indium gallium selenide preset layer with the selenium layer to prepare a copper indium gallium selenide thin film .

In one of the embodiments, the step of evaporating a selenium layer on the CIGS pre-layer is specifically:

placing the CIGS pre-layer and the evaporation boat equipped with selenium particles in the selenium evaporation chamber, and evacuating the selenium evaporation chamber; and

The selenium particles are heated to vapor-deposit a selenium layer on the CIGS pre-set layer.

In one of the embodiments, under the protective gas atmosphere, the copper indium gallium selenide preset layer evaporated with the selenium layer is annealed, so that the copper indium gallium selenide preset layer and the selenium layer The steps for preparing the copper indium gallium selenide thin film by reaction are as follows:

placing the pre-set layer of copper indium gallium selenide evaporated with the selenium layer in an annealing furnace, vacuuming the annealing furnace, and passing in a protective gas;

Heating the copper indium gallium selenide preset layer on which the selenium layer was evaporated, first gradually raised the temperature to 200°C at a heating rate of 17.5°C/min, and then gradually raised the temperature to 580°C within 3 minutes and then heated at 580°C held at 550°C for 3 minutes, then cooled to 550°C within 3 minutes and held at 550°C for 10 minutes; and

Heating was stopped, cooled naturally to 200°C, and vacuumed again, and then cooled naturally to room temperature to prepare a copper indium gallium selenide thin film.

In one of the embodiments, the indium target material is simple indium or diindium triselenide.

In one of the embodiments, the sputtering power of magnetron sputtering on copper target is 120W, the sputtering power of magnetron sputtering on indium target is 200W, and the sputtering power of magnetron sputtering on gallium target is 120W.

In the above copper indium gallium selenium thin film preparation method, through the magnetron sputtering process, the gallium target starts magnetron sputtering later than the indium target, and at the end, the gallium target stops the magnetron sputtering later than the indium target, thereby effectively The enrichment degree of the gallium component at the bottom of the final CIGS thin film is reduced, and the content of the gallium component at the top of the CIGS thin film is increased to achieve the purpose of increasing the open circuit voltage. In addition, in the final CIGS thin film, starting from the bottom of the CIGS thin film, the molar ratio of gallium to selenium presents a trend of decreasing first and then rising, so that starting from the bottom of the CIGS thin film, The bandgap width shows a trend of decreasing first and then rising, and then forms a potential difference, which drives the photogenerated carriers away from the high recombination region, avoids the recombination between the photogenerated carriers, prolongs the life of the photogenerated carriers, and produces The potential difference is beneficial to increase the diffusion length of photogenerated carriers, improve the collection efficiency of photogenerated carriers, and then improve the photoelectric conversion efficiency of solar cells using the copper indium gallium selenide thin film, and improve the current and voltage of solar cells.

Description of drawings

Fig. 1 is the flow chart of the copper indium gallium selenium film preparation method in the preferred embodiment of the present invention;

Fig. 2 is the relationship diagram of heating temperature and time during annealing in the copper indium gallium selenide film preparation method shown in Fig. 1;

Fig. 3 is the relationship figure of sputtering time among copper target, indium target and gallium target in embodiment 1;

Fig. 4 is the change diagram of the molar ratio of gallium in the total composition of gallium and indium in the copper indium gallium selenide pre-layer prepared in embodiment 1 with thickness;

5 is a diagram showing the change of the molar ratio of gallium in the total composition of gallium and indium in the copper indium gallium selenide thin film finally prepared in Example 1 with thickness.

Detailed ways

The preparation method of the copper indium gallium selenide thin film will be further described below in conjunction with the accompanying drawings and specific examples. Please refer to Fig. 1, the copper indium gallium selenide film preparation method in the preferred embodiment of the present invention, comprises the following steps:

In step S110, a copper indium gallium selenide prefabricated layer is prepared on the substrate by magnetron sputtering using a copper target, an indium target and a gallium target, and the gallium target is made of gallium triselenide material.

Put the substrate into the magnetron sputtering chamber, and the molybdenum film layer is coated on the substrate. Vacuumize the magnetron sputtering chamber, and open the argon gas control valve, so as to pass the argon gas required for magnetron sputtering into the magnetron sputtering chamber. A copper target, an indium target, a gallium target and a sample holder are arranged in the magnetron sputtering chamber, and a substrate is placed on the sample holder. The copper indium gallium selenide prefabricated layer is prepared on the substrate by using the magnetron sputtering of the copper target, the indium target and the gallium target. Wherein, the indium target is made of simple indium or diindium triselenide, and the gallium target is made of digallium triselenide.

Specifically in this embodiment, the process of evacuating the magnetron sputtering chamber and introducing argon gas is as follows: first use a mechanical pump to evacuate the magnetron sputtering chamber until the reading of the resistance gauge is 50 Pa, and then use a molecular The pump is evacuated from 50Pa until the reading of the ionization gauge is 2×10 ^-3 Pa, at this time the system enters the working pressure. Open the argon control valve, use the D08-1F flowmeter to pass 99.999% high-purity argon into the sputtering chamber, and control the rate at 12.5 ml per minute, observe the ionization gauge, and adjust the opening and closing of the molecular pump plug valve Level, so that the air pressure in the magnetron sputtering chamber is maintained at 0.11Pa.

In the magnetron sputtering chamber, there are baffles above the target materials such as copper target, indium target and gallium target and the sample holder. The start or stop of the magnetron sputtering of the copper target, the indium target or the gallium target is controlled by opening or closing the baffle plate above the copper target, the indium target or the gallium target. The start or stop of depositing the coating film on the substrate is controlled by opening or closing the baffle above the sample holder. The baffle above the target can block the particles lased from the target so that they cannot fly to the substrate. The baffle on the substrate can block the particles flying from the target to the substrate. Only when the above baffles are opened can sputtering coating be realized. When depositing the coating, first close the baffles on each target and the sample holder, turn on the RF magnetron sputtering power supply of each target, and adjust the output power and reflection power of the power supply to make the target glow. Open the shutters to allow deposition of coatings on the substrate. Wherein, the baffle above the gallium target is opened later than the baffle above the indium target.

In addition, before preparing the copper indium gallium selenium prefabricated layer on the substrate by magnetron sputtering using copper targets, indium targets and gallium targets, it may also include magnetron sputtering of copper targets, indium targets and gallium The targets were pre-sputtered to ignite the copper, indium and gallium targets in steps of 10 minutes. After evacuation and argon gas flow, pre-sputtering is performed on the copper target, indium target and gallium target to remove impurity particles adsorbed on the target surface. During the pre-sputtering process, the copper target, indium target, gallium target or the baffle above the sample holder can be closed to prevent sputtered particles mixed with impurity particles from depositing on the substrate.

It can be understood that when the surface of the target is relatively clean, the above step of pre-sputtering can also be omitted.

In step S120, the gallium target starts magnetron sputtering later than the indium target, and the gallium target stops magnetron sputtering later than the indium target.

After performing magnetron sputtering on each target for a preset time, turn off the radio frequency magnetron sputtering power supply corresponding to each target to stop the deposition and coating on the substrate, and make a copper indium gallium selenide preset on the substrate. layer.

The gallium target starts magnetron sputtering later than the indium target, and the shutdown time of the radio frequency magnetron sputtering power supply corresponding to the gallium target is later than the radio frequency magnetron sputtering power supply corresponding to the indium target, so that the magnetron sputtering of the gallium target is later than the indium target. controlled sputtering. Specifically, the sputtering power of the indium target is higher than that of the gallium target, the gallium target starts magnetron sputtering 3 to 5 minutes later than the indium target, and the gallium target stops magnetron sputtering 3 to 5 minutes later than the indium target . Finally, in the CIGS preset layer prepared on the substrate, the gallium component is distributed along the longitudinal gradient, and the content on the contact surface between the preset layer and the molybdenum thin film layer is extremely small.

Step S130, performing selenization and annealing on the CIGS pre-set layer to prepare a CIGS thin film. Wherein, step S130 may specifically include the following steps:

In step S132, a selenium layer is evaporated on the CIGS pre-set layer.

The steps of evaporating a layer of selenium on the CIGS preset layer are as follows: placing the CIGS preset layer and the evaporation boat equipped with selenium particles in the selenium evaporation chamber, and facing the selenium evaporation chamber Vacuum. The selenium particles are heated to vapor-deposit the formed selenium layer on the CIGS pre-set layer.

Specifically, in this embodiment, the purity of the selenium particles is 99.999%. An appropriate amount of selenium particles is weighed with an analytical balance, loaded into an evaporation boat, and placed in the selenium evaporation chamber. Vacuum the selenium evaporation chamber with a mechanical pump until the reading of the resistance gauge is 5×10 ¹ Pa. Close the angle valve of the mechanical pump, open the plug valve of the molecular pump, turn on the switch of the molecular pump, use the molecular pump to evacuate from 5×10 ¹ Pa until the reading of the ionization gauge is 5×10 ^-3 Pa, at this time the system enters the working pressure. Turn on the selenium steaming power supply, adjust the current to 60A until all the selenium particles are steamed, and then turn off the selenium steaming power supply. After cooling for 15 minutes, the CIGS preset layer is taken out, and finally the selenium layer formed by evaporation on the CIGS preset layer is about 1.5-3 microns.

Step S134 , annealing the CIGS pre-deposited layer deposited with the selenium layer in a protective gas atmosphere, so that the CIGS pre-deposited layer reacts with the selenium layer to obtain a CIGS thin film.

Firstly, the pre-set layer of CIGS deposited with a selenium layer is placed in an annealing furnace, the annealing furnace is evacuated, and a protective gas is introduced into the annealing furnace. The protective gas is specifically nitrogen. Specifically, in this embodiment, a mechanical pump is used to evacuate from 1×10 ⁵ Pa to 0 Pa. Close the angle valve of the mechanical pump, pass 99.999% high-purity nitrogen into the annealing furnace to 5×10 ⁴ Pa to stop the ventilation, open the angle valve of the mechanical pump to evacuate the annealing furnace to 0 Pa, and repeat the above steps three times. When it reaches 0Pa for the third time, continue to pump for another 5 minutes to ensure that the annealing furnace is clean. Close the angle valve of the mechanical pump, and feed 99.999% high-purity nitrogen into the annealing furnace to 4×10 ⁴ Pa.

Then, please refer to FIG. 2 together, heat the CIGS pre-deposited layer with the selenium layer, and gradually raise the temperature to 200° C. at a heating rate of 17.5° C./min. Then gradually increase the temperature to 580°C within 3 minutes, at a rate of about 126.7°C per minute, and maintain at 580°C for 3 minutes. Then the temperature is lowered to 550°C within 3 minutes, the temperature is lowered by about 10°C per minute, and maintained at 550°C for 10 minutes. The substrate temperature was monitored by armored K-type thermocouples throughout the heating process.

Finally, the heating was stopped, cooled naturally to 200° C., and vacuumed again, and then cooled naturally to room temperature to prepare a copper indium gallium selenide thin film. After the substrate temperature was cooled to room temperature, 99.999% high-purity nitrogen gas was passed through the annealing furnace until the pressure in the annealing furnace was 1×10 ⁵ Pa, and the chamber of the annealing furnace was opened to take out the samples.

It should be pointed out that during the annealing process, a certain amount of hydrogen sulfide gas can be introduced into the annealing chamber to sulfide the CIGS thin film. In the above-mentioned steps of selenizing and annealing the CIGS preset layer, it is also possible to directly feed hydrogen selenide gas during the annealing process, or to evaporate selenium particles in an annealing furnace, so that the CIGS preset layer The layer is selenized during the annealing process, which saves the step of evaporating a selenium layer on the CIGS pre-set layer.

After selenization and annealing, in the final CIGS film, starting from the bottom of the CIGS film, that is, the contact surface with the molybdenum film layer, the molar ratio of gallium to selenium first decreases and then increases. the trend of. The change of the molar ratio of gallium to selenium in this material makes the bandgap width decrease first and then increase from the bottom of the CuInGaSe thin film, and then form a potential difference, so that the photogenerated carriers flow from the high recombination region Drive away, avoid the recombination between photogenerated carriers, prolong the life of photogenerated carriers, and the generated potential difference is conducive to increasing the diffusion length of photogenerated carriers, improving the collection efficiency of photogenerated carriers, and thus improving The photoelectric conversion efficiency of the solar cell using the copper indium gallium selenide thin film.

In the above copper indium gallium selenium thin film preparation method, through the magnetron sputtering process, the gallium target starts magnetron sputtering later than the indium target, and at the end, the gallium target stops the magnetron sputtering later than the indium target, thereby effectively The enrichment degree of the gallium component at the bottom of the CIGS thin film is reduced, and the content of the gallium component at the top of the CIGS thin film is increased to achieve the purpose of increasing the open circuit voltage. In addition, in the final CIGS thin film, starting from the bottom of the CIGS thin film, the molar ratio of gallium to selenium presents a trend of decreasing first and then rising, so that starting from the bottom of the CIGS thin film, The bandgap width shows a trend of decreasing first and then rising, and then forms a potential difference, which drives the photogenerated carriers away from the high recombination region, avoids the recombination between the photogenerated carriers, prolongs the life of the photogenerated carriers, and produces The potential difference is beneficial to increase the diffusion length of photogenerated carriers, improve the collection efficiency of photogenerated carriers, and then improve the photoelectric conversion efficiency of solar cells using the copper indium gallium selenide thin film, and improve the current and voltage of solar cells.

At the same time, the copper indium gallium selenide pre-layer is prepared by sputtering copper target, indium target and gallium target, which can accurately control the component distribution ratio of copper, indium and gallium in the copper indium gallium selenide pre-layer When copper-gallium mixed targets are used in traditional processes, the copper and gallium content cannot be independently adjusted.

In addition, the gallium target is made of gallium triselenide material, which can shorten the formation time difference of the two ternary phases of copper indium selenide and copper gallium selenide in the whole preparation process, thereby overcoming the difficulty of sputtering of copper indium selenide and copper gallium selenide The problem of phase separation occurs in selenization.

The following is the specific embodiment part:

Example 1

Place the substrate coated with an 800-nm thick Mo film on the sample holder of the sputtering chamber. The length and width of the substrate is about 10mm×10mm, and it is made of glass material. Vacuum until the reading of the ionization gauge is less than 2×10 ^-3 Pa, and pass through argon. Turn on the RF magnetron sputtering power supply of the copper target, indium target and gallium target, and adjust the RF magnetron sputtering power supply of the copper target, indium target and gallium target to 120W, 200W, and 120W respectively for pre-sputtering. The indium target is made of indium triselenide material. Please refer to Figure 3. After 10 minutes of pre-sputtering, open the copper target, indium target and the baffle above the sample holder to deposit a coating on the substrate. After sputtering for 3 minutes, open the baffle above the gallium target. After a total of 22 minutes of sputtering, turn off the power of the copper target and the indium target. After sputtering the gallium target for another 3 minutes, turn off the power of the gallium target and cool for 30 minutes Take out the CIGS preset layer. Finally, after selenization and annealing, a copper indium gallium selenide thin film is obtained.

Figure 4 is a graph showing the molar ratio of gallium (Ga) in the total composition of gallium and indium (In+Ga) in the copper indium gallium selenide pre-layer prepared in Example 1 as a function of thickness. The content of the gallium component in the CIGS pre-preparation layer is basically zero at the bottom of the CIGS pre-preparation layer.

Figure 5 is a graph showing the molar ratio of gallium (Ga) in the total composition of gallium and indium (In+Ga) in the copper indium gallium selenide film finally prepared in Example 1 as a function of the thickness. In the copper indium gallium selenide thin film, starting from the bottom of the copper indium gallium selenide thin film, that is, the contact surface with the molybdenum thin film layer, the content of gallium presents a trend of first decreasing and then increasing, which helps to improve the use of the copper indium gallium selenide thin film. The current and voltage of the solar cell.

Example 2:

Place the substrate coated with an 800-nm thick Mo film on the sample holder of the sputtering chamber. The length and width of the substrate is about 10mm×10mm, and it is made of glass material. Vacuum until the reading of the ionization gauge is less than 2×10 ^-3 Pa, and pass through argon. Turn on the RF magnetron sputtering power supply of the copper target, indium target and gallium target, and adjust the RF magnetron sputtering power supply of the copper target, indium target and gallium target to 120W, 200W, and 120W respectively for pre-sputtering. The indium target is made of indium triselenide material. After 10 minutes of pre-sputtering, the copper target, the indium target and the baffle above the sample holder were opened to deposit a coating on the substrate. After sputtering for 5 minutes, open the baffle above the gallium target. After a total of 20 minutes of sputtering, turn off the power of the copper target and the indium target. Take out the CIGS preset layer. Finally, after selenization and annealing, a copper indium gallium selenide thin film is obtained.

Example 3

Place the substrate coated with an 800-nm thick Mo film on the sample holder of the sputtering chamber. The length and width of the substrate is about 10mm×10mm, and it is made of glass material. Vacuum until the reading of the ionization gauge is less than 2×10 ^-3 Pa, and pass through argon. Turn on the RF magnetron sputtering power supply of the copper target, indium target and gallium target, and adjust the RF magnetron sputtering power supply of the copper target, indium target and gallium target to 120W, 200W, and 120W respectively for pre-sputtering. The indium target is made of indium triselenide material. After 10 minutes of pre-sputtering, open the indium target and the baffle above the sample holder. After sputtering for 3 minutes, open the baffles above the copper target and the gallium target. After continuing sputtering for another 22 minutes, turn off the power of the indium target, and after continuing to sputter the copper and gallium targets for 3 minutes, turn off the power of the copper and gallium targets, cool down for 30 minutes, and take out the CIGS preset layer. Finally, after selenization and annealing, a copper indium gallium selenide thin film is obtained.

Example 4:

Place the substrate coated with an 800-nm thick Mo film on the sample holder of the sputtering chamber. The length and width of the substrate is about 10mm×10mm, and it is made of glass material. Vacuum until the reading of the ionization gauge is less than 2×10 ^-3 Pa, and pass through argon. Turn on the RF magnetron sputtering power supply of the copper target, indium target and gallium target, and adjust the RF magnetron sputtering power supply of the copper target, indium target and gallium target to 120W, 200W, and 120W respectively for pre-sputtering. The indium target is made of indium triselenide material. After 10 minutes of pre-sputtering, open the baffle above the indium target and the sample holder. After sputtering for 5 minutes, open the baffles above the copper target and the gallium target. After continuing sputtering for another 22 minutes, turn off the power of the indium target, and after continuing to sputter the copper and gallium targets for 5 minutes, turn off the power of the copper and gallium targets, and take out the CIGS preset layer after cooling for 30 minutes. Finally, after selenization and annealing, a copper indium gallium selenide thin film is obtained.

Example 5:

Place the substrate coated with an 800-nm thick Mo film on the sample holder of the sputtering chamber. The length and width of the substrate is about 10mm×10mm, and it is made of glass material. Vacuum until the reading of the ionization gauge is less than 2×10 ^-3 Pa, and pass through argon. Turn on the radio frequency magnetron sputtering power supply of the copper target, indium target and gallium target, and adjust the radio frequency magnetron sputtering power supply of the copper target, indium target and gallium target to 200W, 200W and 120W respectively for pre-sputtering. The indium target is made of indium triselenide material. After 10 minutes of pre-sputtering, open the copper target, indium target and the baffles above the sample holder. After sputtering for 3 minutes, open the baffle above the gallium target. After the three targets were sputtered for 7 minutes, the power of the copper target was turned off. After the indium target was co-sputtered with the gallium target for 15 minutes, the power to the indium target was turned off. Then, after continuing to sputter the gallium target for 3 minutes, turn off the power of the gallium target, and take out the CIGS pre-set layer after cooling for 30 minutes. Finally, after selenization and annealing, a copper indium gallium selenide thin film is obtained.

The above-mentioned embodiments only express several implementation modes of the present invention, and the description thereof is relatively specific and detailed, but should not be construed as limiting the patent scope of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (10)

1. A method for preparing a copper indium gallium selenide thin film, comprising the following steps: A copper indium gallium selenide prefabricated layer is prepared on the substrate by magnetron sputtering using a copper target, an indium target and a gallium target, and the gallium target is made of gallium triselenide material; The gallium target starts magnetron sputtering later than the indium target, and the gallium target stops magnetron sputtering later than the indium target; wherein, the gallium target starts magnetron sputtering 3 to 5 minutes later than the indium target , and the gallium target stops magnetron sputtering 3 to 5 minutes later than the indium target; and Selenization and annealing are performed on the CIGS pre-set layer to prepare a CIGS thin film. 2. the copper indium gallium selenide film preparation method according to claim 1, is characterized in that, magnetron sputtering is carried out in magnetron sputtering chamber, and described magnetron sputtering chamber is provided with described copper target, The indium target, the gallium target and the sample holder, the substrate is placed on the sample holder; the control of the copper target, the indium target or the gallium target by opening or closing the baffle above the target Start or stop of copper, indium or gallium magnetron sputtering. 3. The method for preparing a copper indium gallium selenide thin film according to claim 2, wherein the start or stop of depositing a coating on the substrate is controlled by opening or closing the baffle above the sample holder. 4. The method for preparing a copper indium gallium selenide thin film according to claim 1, wherein the sputtering power of the indium target is greater than that of the gallium target, and the gallium target is later than the indium target The magnetron sputtering starts in 3-5 minutes, and the magnetron sputtering of the gallium target is stopped 3-5 minutes later than the indium target. 5. The copper indium gallium selenide thin film preparation method according to claim 1, characterized in that, the copper indium gallium selenide is prepared on the substrate by magnetron sputtering using a copper target, an indium target and a gallium target. The steps to prefab layers also include: The copper target, the indium target and the gallium target were pre-sputtered by magnetron sputtering, and the copper target, the indium target and the gallium target were glowed for 10 minutes. 6. The method for preparing a copper indium gallium selenide thin film according to claim 1, wherein the step of performing selenization and annealing on the copper indium gallium selenide preset layer to obtain a copper indium gallium selenide thin film specifically comprises The following steps: Evaporating a selenium layer on the CIGS pre-set layer; and Under a protective gas atmosphere, anneal the copper indium gallium selenide preset layer evaporated with the selenium layer, and react the copper indium gallium selenide preset layer with the selenium layer to prepare a copper indium gallium selenide thin film . 7. The method for preparing a copper indium gallium selenide thin film according to claim 6, wherein the step of evaporating a layer of selenium on the copper indium gallium selenide preset layer is specifically: placing the CIGS pre-layer and the evaporation boat equipped with selenium particles in the selenium evaporation chamber, and evacuating the selenium evaporation chamber; and The selenium particles are heated to vapor-deposit a selenium layer on the CIGS pre-set layer. 8. The method for preparing a copper indium gallium selenide thin film according to claim 7, wherein the copper indium gallium selenide pre-set layer on which the selenium layer is vapor-deposited is annealed under the protective gas atmosphere, so that the The steps for preparing the CIGS thin film by reacting the CIGS preset layer with the selenium layer are as follows: placing the pre-set layer of copper indium gallium selenide evaporated with the selenium layer in an annealing furnace, vacuuming the annealing furnace, and passing in a protective gas; Heating the copper indium gallium selenide preset layer on which the selenium layer was evaporated, first gradually raised the temperature to 200°C at a heating rate of 17.5°C/min, and then gradually raised the temperature to 580°C within 3 minutes and then heated at 580°C held at 550°C for 3 minutes, then cooled to 550°C within 3 minutes and held at 550°C for 10 minutes; and Heating was stopped, cooled naturally to 200°C, and vacuumed again, and then cooled naturally to room temperature to prepare a copper indium gallium selenide thin film. 9 . The method for preparing a copper indium gallium selenide thin film according to claim 1 , wherein the indium target material is simple indium or diindium triselenide. 10. The method for preparing copper indium gallium selenide thin film according to claim 9, characterized in that, the sputtering power of magnetron sputtering on copper target is 120W, and the sputtering power of magnetron sputtering on indium target is 200W , the sputtering power of magnetron sputtering on the gallium target is 120W.