KR20100075336A - Continuous downward thermal deposition equipment for large size cigs film layer of cigs solar cell - Google Patents

Abstract

According to the present invention, when manufacturing a large area CIGS thin film solar cell, in the production of a CIGS light absorption layer thin film which is very important for the efficiency of the solar cell, a plurality of top-down linear evaporation sources on a large area glass substrate coated with molybdenum thin film Copper gas, gallium gas, indium gas and selenium gas are sprayed downward to form a CIGS thin film, and at the same time, it is possible to convey a large area of glass substrate by roller conveyance, and at the same time, glass by surface heating device The present invention relates to a light-absorption layer continuous deposition apparatus of a large area CIGS solar cell having an effect of easily mass-producing a CIGS thin-film solar cell by forming a high-quality CIGS thin film by heating a substrate at a high temperature.

Description

Large-area copper, indium, gallium, selenium compound solar cell continuous absorption top-down deposition equipment for large size CIGS film layer of CIGS solar cell}

1 is a configuration diagram of a CIGS thin film solar cell

2 is a block diagram of a bottom-up CIGS thin film deposition method

3 is a conceptual diagram for manufacturing a top-down CIGS light absorption layer thin film

4 is a block diagram showing the arrangement of copper, gallium, indium, selenium evaporation source

5 is a block diagram of a top-down substrate transfer deposition equipment for continuously producing a large area CIGS thin film

6 is a bottom view of the cylindrical selenium evaporation source from below;

7 is a cross-sectional view of a tray for conveying a roller apparatus and a surface heating apparatus substrate;

8 is a perspective view of a substrate tray;

9 is a configuration in which a plurality of rollers are driven to rotate to transport the substrate tray

10 is a connection diagram of the continuous deposition chamber and the loading chamber, the unloading chamber for mass production

11 is a connection diagram of chambers for a continuous deposition process of a large-area substrate

12 is a connection diagram of chambers and tray circulation roller devices for a continuous deposition process of a large area substrate;

<Description of the symbols for the main parts of the drawings>

10: soda lime glass substrate 11: molybdenum electrode layer thin film

12: CIGS light absorbing layer thin film 13: CdS buffer layer thin film

14: ZnO window layer thin film 15: TCO transparent electrode layer thin film

16: EVA film 17: tempered glass

20: vacuum chamber 21: pumping port

22: glass substrate 23: CIGS thin film

24: heating device 25: selenium evaporation source

26: copper evaporation source 27: gallium point evaporation source

28: indium evaporation source 29: evaporation source device

30 glass substrate 31: tray

32: roller 33: surface heating device

34: copper top down linear evaporation source 35: gallium top down linear evaporation source

36: indium top-down linear evaporation source 37: selenium linear evaporation source

38: fixed shaft 39: evaporator housing

40: tube for selenium evaporation 41: tube for selenium gas transfer

42: nozzle for selenium gas injection 43: gas blowing nozzle of the top-down linear evaporation source

44: selenium cylindrical evaporation source 45: free-rotating roller

46: tray

50: mass production continuous deposition chamber 51: pumping port

52: substrate tray inlet port 53: substrate tray outlet port

54: shield for heating 55: cartridge heater for shield heating

60: roller rotation axis 61: bevel gear box

62: gear rotation shaft 63: drive unit

64: roller connecting shaft

70: loading chamber 71: inlet door

72: gate valve 73: unloading chamber

74: exit door 75: tray feed roller

76: up-down shaft unit 77: roller transfer roller unit

80: halogen lamp heater 81: cooling device

82: circulation roller 83: rotary circulation roller device

84: circulating roller device

90: substrate loading chamber 91: low vacuum heating chamber

92: high vacuum heating chamber 93: high vacuum atmospheric heating chamber

94: high vacuum atmospheric cooling chamber 95: high vacuum cooling chamber

96: low vacuum cooling chamber 97: substrate unloading chamber

The main culprit of global warming is the use of oil used in power plants to supply electricity developed by mankind. During the development of alternative energy to develop eco-friendly electricity generating device, there is a great need for a technology that can mass-produce solar cells for developing pollution-free power devices using solar light. Conventionally, solar cells based on silicon crystals have been developed and marketed, but supply of solar cells is not smooth due to the shortage of raw materials of silicon wafers, cost increase, and low efficiency. In order to overcome this problem, the world is spurring the development of thin-film solar cells, and its production technology holds the key to solving the future energy problems of the country and the earth. Figure 1 shows the structure of a CIGS solar cell known as one of the thin-film solar cell. The molybdenum electrode layer thin film 11 is formed on the soda-lime glass substrate 10, and the CIGS light absorbing layer thin film 12 is formed thereon. CIGS is a crystal thin film composed of four elements of copper, indium, gallum and selenium, and is known as an absorbing layer having excellent absorption of sunlight. The CdS buffer layer thin film 13 corresponds to the N layer of PN jnuction as a buffer layer that collects electrons generated in the absorption layer. The CIGS layer is a P layer. The ZnO window layer thin film 14 acts as another N layer and facilitates the collection of electrons, and also serves to protect the CIGS layer and the CdS layer during sputter deposition of the TCO layer. The TCO transparent electrode layer thin film 15 collects electrons collected in the N layer and flows well toward the bus bar to help collect electricity, transmit light, and collect electrons on the wire. Thin-film solar cells formed in multiple layers are covered with tempered glass 17 to protect them from hail after forming an EVA film 16 to ensure long life even when exposed to air, and as a result, the module of the thin-film CIGS solar cell is completed. Will be.

Figure 2 shows a conventional vacuum deposition method for manufacturing a CIGS light absorbing layer thin film, which is the main thin film of the CIGS solar cell. A heating device 24 is installed in the upper portion of the vacuum chamber 20 to heat the glass substrate 22 by heat by radiation. A pumping port 21 is attached to the lower part of the chamber to pump the chamber in a high vacuum, and five point evaporation sources are placed in the lower part of the chamber. Two selenium point evaporation sources 25 are installed on the left and right, and a copper evaporation source 26, a gallium evaporation source 27, and an indium evaporation source 28 are installed in the center, and copper gas, gallium gas, and indium gas are provided. As the selenium gas is simultaneously evaporated, the CIGS thin film 23 is formed on the glass substrate.

The above-mentioned bottom-up CIGS thin film manufacturing method is suitable for manufacturing a small thin-film CIGS solar cell, but is not suitable for producing a large-area CIGS thin film, and thus, it is very difficult to produce a large-area CIGS thin film solar cell. The temperature of the glass substrate should be heated to about 500 degrees, in this case, because the glass substrate is sagging, it becomes difficult to maintain the uniformity of the thin film even if a thin film is formed, it has a limit in supporting a large area of the substrate. In addition, since the capacity of the evaporation source is very small, it is impossible to deposit for a long time. In addition, it is very difficult to produce large area CIGS substrates at high speed.

In other words, it is urgent to develop a new concept of continuous deposition equipment of CIGS light absorbing layer thin film which can prevent sagging of the substrate even at high temperature, and can manufacture a large area CIGS light absorbing layer thin film.

As a method for solving the above problem, as shown in FIG. 3, a top-down deposition is performed by using a plurality of top-down evaporation sources, and the substrate is simultaneously linearly transferred. That is, the large glass substrate 30 is contained in the tray 31 to be transported.

At this time, the tray can be transported by a plurality of rollers (32). In other words, the rollers are rotated and the tray is linearly moved by friction with the lower portion of the tray placed on the roller. In addition, the surface heating device 33 is installed under the rollers, and the tray is heated by radiation radiated from the surface heating device, and the glass substrate of the large area in contact with the heated tray is heated. At this time, it is known that the heating temperature of the substrate is most suitable at about 550 degrees. In addition, a copper downward linear evaporation source 34, a gallium downward linear evaporation source 35, an indium downward linear evaporation source 36, and the like are connected to the evaporator housing 39 by a fixed shaft 38 on the upper portion of the vacuum chamber. do. In particular, the selenium linear evaporation source is selenium is injected downward by the tube selenium evaporation (40).

As shown in Figure 4, the selenium crucible 37 of the linear is connected to the selenium gas transfer tube 41, the selenium gas evaporated by heating is injected through the nozzle 42 for selenium gas injection, At this time, since the position of the nozzle is located downward toward the substrate, the top down injection of selenium gas is possible. As shown in FIG. 6, the selenium evaporation source may be manufactured in a cylindrical shape, and the selenium gas may be sprayed downward since the gas transfer tube 41 and the gas injection nozzle 42 have the same linear structure. In addition, copper, gallium, and indium gas may be sprayed downward by the gas ejection nozzle 43 formed at the bottom of the top-down linear evaporation source. In the case of downward deposition, in order to supply a sufficient amount of selenium, as shown in FIG. 3, four selenium evaporation tubes are placed on the left side of the copper evaporation source, and are placed between the copper and gallium evaporation sources and between the gallium and indium evaporation sources, respectively. It will improve the use rate of the material. For reference, selenium is highly volatile and has a characteristic of solidifying well on a metal surface. Therefore, great care should be taken when evaporating.

As shown in FIG. 5, a configuration diagram of a vacuum deposition apparatus capable of heating and top-down deposition while conveying a large-area glass substrate is shown. Mass production continuous deposition chamber 50 is a high vacuum vessel, in the form of a rectangular parallelepiped, a plurality of pump ports 51 are formed on the upper and lower sides, the substrate tray inlet port 52 is formed on the left side of the chamber, the substrate tray on the right side An outlet port 53 is formed. Since the heating shield 54 is formed in the upper portion of the chamber, the highly volatile selenium is solidified in the upper shield in the chamber, and then prevented from falling down to form particles on the glass substrate. Such a shield is equipped with a plurality of shield heating cartridge heaters 55 at the rear, thereby heating the shield at a heating temperature of about 100 to 300 degrees Celsius, thereby preventing selenium from solidifying.

One to three evaporation source devices are installed to enable high-speed deposition of CIGS thin films on large substrates, and a plurality of surface evaporation devices are placed in the lower part of the chamber, which helps to heat the substrate more effectively. In fact, it is difficult to manufacture a very large surface heating device 33 has a merit that it is easy to manufacture a large number.

7 shows a cross section of the surface heating apparatus 33, the roller 32, and the structure 31 of the substrate tray. That is, since the left and right edges of the tray are caught by the rollers, the trays are transferred by the rotational driving of the rollers, and the surface heating apparatus is placed between the rollers, so that the trays are closer to the trays, so that the tray heating by copying is more effective. When the substrate becomes large, the tray also becomes large and struck. A free rotating roller supporting the tray may be placed in the middle of the tray.

FIG. 8 shows a tray, which is dug to a certain depth so that the substrate can be inserted therein and has a stage so that the substrate does not fall out of the tray during substrate transfer.

As shown in FIG. 9, the tray on which the substrate is mounted is carried by a plurality of rollers, and the rollers 32 are connected to the roller rotation shaft 60 and driven, and the roller rotation shafts are all bevel gear boxes 61. Since it is connected to, the roller is driven by the rotational drive of the bevel gear. In particular, since all the bevel gear boxes are connected to the gear rotating shaft 62, the gear rotating shafts are driven to rotate at the same angular speed simultaneously with respect to the rotating motion of the rotating shaft. Gear rotation shaft 62 is installed on the left and right side is connected to the roller connecting shaft 64 to drive all the rollers using one drive device 63 has the effect that the control is very easy.

As shown in FIG. 10, the loading chamber 70 and the unloading chamber 73 of the substrate are connected to the left and right of the CIGS continuous deposition chamber 50, so that the substrate can be pulled in and output without breaking a high vacuum. This improves productivity. An inlet door 71 is formed on the left side of the loading chamber, and halogen lamp heaters 80 are placed therein to allow preheating of the substrate. In addition, roller devices can be placed to transfer the tray. A gate valve 72 is connected between the deposition chamber 50 and the loading chamber. An exit door 74 is formed at the right side of the unloading chamber to allow the tray to exit, and a cooling device 81 is formed at an upper portion of the inside of the unloading chamber to help cool the CIGS substrate on which the deposition is completed. In order to recycle the discharged tray, the tray transfer roller device 77 having the tray transfer rollers 75 attached thereon descends by the up-down shaft device 76, and the rollers are transferred to the loading chamber by roller transfer, and thus After being delivered to the door, the substrate is loaded and introduced into the vacuum chamber, thereby reusing the tray.

11 shows a loading chamber 90, a low vacuum heating chamber 91, a high vacuum heating chamber 92, and a high vacuum atmospheric heating chamber on the left and right sides of the mass production deposition chamber 50 as a method for further improving productivity. 93, the high vacuum atmospheric cooling chamber 94, the high vacuum cooling chamber 95, the low vacuum cooling chamber 96, and the substrate unloading chamber 97 are linearly connected as a gate valve. That is, in order to reduce the process time and the pumping time while drawing the substrate from atmospheric pressure without breaking the atmosphere of high vacuum, atmospheric pressure-> low vacuum substrate heating-> high vacuum substrate heating-> high vacuum substrate atmospheric and transfer time control-> deposition Scan-> High Vacuum Cooling Atmosphere and Time Control-> High Vacuum Cooling-> Low Vacuum Cooling-> Atmospheric Pressure Outlet

12 is connected to the rotary circulation roller device before and after the substrate loading chamber and the substrate unloading chamber in the linear chambers shown in FIG. 11, and the circulation roller device and the rotary circulation roller devices are connected between the rotary circulation roller devices. It shows the method to maximize the productivity by allowing the tray to cycle the infinite number of chambers and circulation roller devices configured in the form, the rotary roller device to change the conveying direction of the tray to 90 degrees and the circulation roller device is linear The trays are arranged regularly and transported on the listed rollers.

According to the present invention, when manufacturing a large area CIGS thin film solar cell, CIGS light absorbing layer thin film is very important for solar cell efficiency. High speed heating and high temperature heating of large-area glass substrate enables high-volume production of CIGS solar cells.

Claims (30)

As a rectangular parallelepiped vacuum container, a plurality of pumping ports are formed on the upper and lower parts, a high vacuum pump is mounted on the pumping ports, a substrate tray inlet / outlet port is formed on the left and right sides, and a heating shield is provided on the inner top of the vacuum container. And a plurality of top-down evaporation source devices are mounted under the heating shield, and a plurality of surface heating devices are mounted at the bottom of the vacuum vessel, and a plurality of rollers are mounted on the upper surface of the heating vessel, and a glass is provided on the upper portion of the roller. A tray containing a substrate is placed so that the roller can be rotated and the tray can be transported from side to side by a roller. The apparatus of claim 1, wherein the plurality of top-down evaporation source devices are constituted by one or more, the housing of the evaporation unit is on the upper side, and using the fixed shaft in the housing, the copper top-down linear evaporation source, gallium top-down linear evaporation source, indium top-down linear An evaporation source and a selenium top-down evaporation source are respectively fixed, and a plurality of top-down gas ejection nozzles are formed at the bottom of each evaporation source, and a large area of copper gas, gallium gas, indium gas, and selenium gas is respectively injected downward. Light absorption layer continuous top-down deposition equipment of CIGS solar cell. The selenium evaporation source of claim 2, wherein the selenium evaporation source is linear, and the selenium evaporation tube is connected, the selenium evaporation tube is connected to at least four at regular intervals, and the selenium evaporation tube is located below the line. A plurality of gas spray nozzles are formed at regular intervals, and the selenium gas is a light-absorbing layer continuous top-down deposition apparatus of the large-area CIGS solar cell, characterized in that it is easy to spray downward. The selenium evaporation source of claim 2, wherein the selenium evaporation source is cylindrical, selenium gas transfer tube is connected, the tube is connected to the selenium evaporation four or more at regular intervals, the selenium evaporation tube below the line of selenium A plurality of gas spray nozzles are formed at regular intervals, and the selenium gas is a light-absorbing layer continuous top-down deposition apparatus of the large-area CIGS solar cell, characterized in that it is easy to spray downward. The light absorption layer continuous top-down deposition apparatus of claim 1, wherein a plurality of shield heating cartridge heaters are mounted on the rear portion of the heating shield at a predetermined interval. 2. A glass substrate according to claim 1, wherein a large area glass substrate is placed on the tray, wherein the tray edge extends over the top of a plurality of rollers arranged in a row along both edges, and in the middle of the tray in a row along the tray conveying direction. A large area CIGS solar cell characterized by having a driving method in which a surface heating device is formed between the free rotating rollers arranged above, and a tray is linearly moved by rotation of the rollers. Light absorption layer continuous top down deposition equipment. The light absorption layer continuous top-down deposition apparatus of claim 6, wherein the free rotating roller comprises one to ten pieces in a direction perpendicular to the transfer direction of the substrate. The light absorption layer continuous top-down deposition apparatus of claim 1, wherein the tray has a rectangular parallelepiped larger and thinner than the glass substrate, and is cut at a predetermined depth to a thickness of the glass substrate. 4. The selenium evaporation tube according to claim 3, wherein one tube for selenium evaporation is placed on the left side of the copper top-down linear evaporation source, one between copper and gallium linear evaporation source, one between gallium and indium linear evaporation source, and indium top-down. Light absorption layer continuous top-down deposition equipment of large-area CIGS solar cell, characterized in that one is placed on the right side of the linear evaporation source The light absorption layer continuous top-down deposition apparatus of claim 1, wherein the size of the large-area substrate is determined between 10 cm X 10 cm and 1000 cm X 1000 cm. The bevel gear box of claim 6, wherein a plurality of rollers disposed on both sides along the edge of the substrate are connected to the bevel gear box by roller rotation shafts, and the plurality of bevel gear boxes are linearly connected by gear rotation shafts, and the top left and right bevels. The gearboxes are connected to each other by a roller connecting shaft, and are connected to one driving device, so that a plurality of rollers can be rotated by the driving of one driving device. Deposition equipment. The left and right sides of the rectangular parallelepiped vacuum container have gate valves interposed therebetween, and a loading chamber is connected to the left side, a halogen lamp heater is mounted on an upper portion of the loading chamber, and rollers are mounted on an inner lower portion of the loading chamber. The inlet door is mounted on the left side of the vacuum container, and the unloading chamber is connected to the right side of the vacuum container, and the cooling device is mounted on the upper part of the unloading chamber, and the rollers are mounted on the lower part of the unloading chamber. Continuous top-down deposition equipment for light absorption layer of large-area CIGS solar cell with exit door 13. The tray according to claim 12, wherein in the tray on which the glass substrate from the unloading chamber is loaded, the glass substrate is separated from the tray using a device such as a robot, and the remaining tray is placed on top of the tray transfer roller device, and the tray transfer roller An up-down shaft device is attached to the lower part of the device, and the tray transferred to the lower part is transported to the left by the tray feed roller, and is loaded on the upper part of the tray conveying roller device equipped with the up-down shaft device and transferred to the upper part of the tray feed roller. Light absorption layer continuous top-down deposition equipment of large-area CIGS solar cell with reusable configuration From the left side, the substrate loading chamber is sandwiched between the gate valve, the low vacuum heating chamber, the high vacuum heating chamber, the high vacuum atmospheric heating chamber, the continuous deposition chamber for mass production (the above-mentioned cuboid vacuum container), the high vacuum atmospheric cooling chamber, the high vacuum cooling chamber, Low vacuum cooling chamber, substrate unloading chambers are linearly connected to each other, the light absorption layer continuous top-down deposition equipment of a large area CIGS solar cell 15. The transfer of the substrate tray according to claim 14, wherein the substrate loading chamber, the low vacuum heating chamber, the high vacuum heating chamber, the high vacuum atmospheric heating chamber, the high vacuum atmospheric cooling chamber, the high vacuum cooling chamber, the low vacuum cooling chamber and the substrate unloading chamber are transported. Light absorption layer continuous top-down deposition equipment of large area CIGS solar cell, characterized in that the roller devices are configured 15. The large-area CIGS aspect according to claim 14, wherein the low vacuum heating chamber, the high vacuum heating chamber, and the high vacuum atmospheric heating chamber are mounted with a heater device for heating the substrate at the top and a surface heater is mounted at the bottom. Light-absorption layer continuous top-down deposition equipment of battery 15. The light absorption layer continuous top-down deposition apparatus of a large area CIGS solar cell according to claim 14, wherein cooling devices for cooling the substrate are configured in the high vacuum atmospheric cooling chamber, the high vacuum cooling chamber, and the low vacuum cooling chamber. Formation of CIGS thin film in continuous top-down deposition equipment of large-area CIGS solar cell, where copper, gallium, indium, selenium, sprayed downward from a plurality of top-down linear evaporation sources, are deposited on a large substrate with linear transfer to form a CIGS light absorption layer Way A glass substrate coated with a large molybdenum electrode thin film is loaded on the tray, and the tray is mounted on a plurality of rollers, and the tray is transported by friction between the upper part of the roller and the lower part of the tray by rotating the roller. Substrate transfer method of light absorption layer continuous top-down deposition equipment of large-area CIGS solar cell where large area substrate is linearly transferred left and right  Large area where the tray is heated by radiation radiated from the bottom surface heating device, the glass substrate is heated by radiation radiated from the heated tray, and the glass substrate is heated by heat conduction by contact with the heated tray. Substrate heating method of continuous top-down deposition equipment for light absorption layer of CIGS solar cell 21. The method of claim 20, wherein the heating temperature of the substrate is heated between 100 degrees Celsius and 800 degrees Celsius to produce a CIGS light absorbing layer. The method of claim 5, wherein the heating temperature of the heating shield is heated between 100 degrees Celsius and 300 degrees Celsius to produce a CIGS light absorbing layer. 15. The continuous top-down light absorbing layer of a large area CIGS solar cell according to claim 14, wherein the vacuum degree of the high vacuum chamber is operated in the range of 10-4torr to 10-8 Torr, and the low vacuum chamber is operated in the range of 1 Torr-10-3 Torr. Light absorption layer process method of deposition equipment CIGS thin film formation method of light absorption layer continuous top-down deposition equipment of large-area CIGS solar cells used in the range of 50mm ~ 500mm between top down linear evaporation source and glass substrate CIGS thin film of light absorption layer continuous top-down deposition equipment of large-area CIGS solar cell, where the linear transfer speed of the tray on which the large molybdenum thin film is coated is selected within the speed range of 1mm / s to 100mm / s Formation method The material of the tray is a continuous top-down deposition system of light absorption layer of large-area CIGS solar cell, which is composed of materials with high radiation emissivity such as graphite. A tray on which a molybdenum thin film-coated glass substrate is placed may produce a CIGS light absorbing layer within a thickness range of 1 μm to 2 μm by one transfer from left to right, and may be reciprocated several times without limiting the number of times of recovery from left to right. CIGS thin film processing method of light absorption layer continuous top-down deposition equipment of large-area CIGS solar cell in which CIGS light absorption layer is manufactured within 1um ~ 2um thickness by The method of claim 2, wherein when the substrate tray is deposited and transported, the top-down linear evaporation source is arranged in the order of copper evaporation source, gallium evaporation source, indium evaporation source, selenium evaporation source, continuous absorption top-down layer of a large area CIGS solar cell Deposition equipment 15. The method of claim 14, wherein the rotary circulation roller device for changing the tray transfer direction before the substrate loading chamber and after the substrate unloading chamber by 90 degrees is connected, the circulation roller devices and the rotary circulation roller devices are connected between the rotary circulation roller devices , Continuous absorption system of light absorption layer of large-area CIGS solar cell, characterized in that the equipment is connected in a rectangular shape 30. The apparatus of claim 29, wherein the substrate trays are arranged at regular intervals in the direction perpendicular to the substrate trays, the substrate trays are transported over the circulation rollers regularly arranged in the tray conveying direction, and circulated in an infinite number of times through the tray circulation roller devices. Continuous top-down deposition equipment for light absorption layer of area CIGS solar cell

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