TWI423340B - Annealing device for a thin-film solar cell - Google Patents

Description

Thin film solar cell annealing device

The present invention relates to an annealing apparatus for a thin film solar cell, and more particularly to an annealing apparatus for a thin film solar cell which improves the spot of a thin film solar cell.

CIGS (copper indium gallium (di) selenide) is a compound semiconductor in a material of a thin film solar cell. CIGS is in the form of a polycrystalline film, which is a group of three or five compound semiconductor materials composed of copper, indium, gallium and selenium. Figure 1A shows a schematic diagram of one of the steps in the fabrication of a CIGS thin film solar cell. Figure 1B shows a schematic diagram of one of the steps in the fabrication of a CIGS thin film solar cell. As shown in FIG. 1A, the CIGS thin film solar cell 10 includes a glass substrate 11. A molybdenum metal layer 12, a copper gallium metal layer 13, an indium metal layer 14, and a selenium layer 15 are sequentially deposited on the glass substrate 11. As shown in FIG. 1B, the CIGS thin film solar cell 10 of the step of FIG. 1A is subjected to an annealing treatment, and the annealing mainly refers to a process of exposing the material to a high temperature for a period of time and then slowly cooling, after annealing, The copper gallium metal layer 13, the indium metal layer 14, and the selenium layer 15 form a CIGSe metal layer 16.

2 is a schematic view showing the structure of an annealing device of a conventional thin film solar cell. A conventional thin film solar cell annealing apparatus 20 includes five annealing chambers 21 to 25 and two storage chambers 31 to 32 that communicate with each other. When the annealing treatment is performed, the CIGS thin film solar cell 10 of the step of FIG. 1A is sent from the inlet 35 of the annealing device 20 to the annealing chamber 21 for preheating, and then sent to the annealing chamber 22 for rapid heating by a transfer device (not shown). To a high temperature state, for example, 500 ° C ~ 600 ° C. The CIGS thin film solar cell 10 is maintained in a high temperature state for a while in the annealing chambers 23 and 24. The CIGS thin film solar cell 10 is previously cooled in the annealing chamber 25, and finally, the CIGS thin film solar cell 10 is gradually cooled to a low temperature state in the cooling chambers 31 to 32, and then sent out from the outlet 36.

Figure 3 shows a schematic view of a conventional transfer device for a thin film solar cell annealing apparatus. As shown in FIG. 3, a conventional thin film solar cell annealing apparatus transfer device 40 is disposed on the bottom surface 26 of the annealing chambers 21 to 25 for transporting the CIGS thin film solar cell 10 (or its glass substrate 11). The transfer device 40 of the conventional thin film solar cell annealing device includes at least one roller 41, at least one push rod 42 and at least one abutment rod 43. The roller 41 is disposed on the bottom surface 26 of each of the annealing chambers 21 to 25. Preferably, most of the rollers 41 are disposed on the back side of the bottom surface 26, and a small portion is exposed. The portion protrudes from the bottom surface 26 to make the glass substrate of the CIGS thin film solar cell 10. The back surface of the 11 is not in contact with the bottom surface 26, but is movable on the roller 41.

In the conventional example of Fig. 3, two cylindrical push rods 42 are used, which are respectively located on the left and right sides of the bottom surface 26, and do not protrude substantially from the bottom surface 26. The abutment lever 43 is provided to the push lever 42. In the stationary state (not shown) of the conveyor 40, the abutment lever 43 is located in the recess 27 and is in a state where the bottom surface 26 is not protruded. In the transport state of the transport device 40, as shown in FIG. 3, the push lever 42 is rotated counterclockwise by a predetermined angle, for example, 90 degrees, so that the abutment lever 43 protrudes from the bottom surface 26. When the push rod 42 moves toward the next annealing chamber, the glass substrate 11 of the CIGS thin film solar cell 10 abuts against the abutment rod 43 and moves on the roller 41 as the push rod 42 moves. After both the push rod 42 and the glass substrate 11 are moved to the next annealing chamber, the push rod 42 is rotated clockwise (not shown), so that the abutting rod 43 is in the other recess 27, and returns to the bottom surface without protruding. After the state of 26, the push rod 42 will be retracted to the current annealing chamber, thus completing the transfer operation of the CIGS thin film solar cell 10 between the annealing chambers 21-25.

However, when the CIGS thin film solar cell 10a formed by the conventional annealing device 20 is viewed by illumination, it is observed that the CIGS thin film solar cell 10a has a plurality of dot-like and elongated strips which affect the CIGS film. The quality and yield of the solar cell 10a. Therefore, there is still room for further improvement in the conventional transfer device 40.

It is an object of an embodiment of the present invention to provide an annealing apparatus for a thin film solar cell that improves the spot of a thin film solar cell.

According to an embodiment of the invention, a thin film solar cell annealing device is provided, which is suitable for performing an annealing process on a thin film solar cell. The thin film solar cell annealing device comprises at least one annealing chamber, a conveying device and a heater. The conveying device is disposed in the annealing chamber and includes a guiding rail and a fixing device. The guiding track extends in a first direction in the annealing chamber. The fixing device is movably disposed on the guiding track for fixing the thin film solar cell, thereby enabling the thin film solar cell to move along the guiding track. A heater is disposed in the annealing chamber for heating the thin film solar cell.

In one embodiment, the guiding track is disposed on the top side of the annealing chamber, and the fixing device vertically fixes the thin film solar cell. Preferably, the normal vector of the surface of the thin film solar cell is substantially perpendicular to the direction of gravity. In one embodiment, the at least one annealing chamber includes a first annealing chamber and a second annealing chamber, and the first annealing chamber and the second annealing chamber are in communication, and the guiding track extends from the first annealing chamber to the second annealing chamber. . In one embodiment, the guide track continuously moves the fixture along the guide track, preferably with the guide track continuously moving the fixture along the guide track at a fixed speed.

In one embodiment, the fixture is a clamp for holding the thin film solar cell. In one embodiment, the fixture is a hook for hooking a hole in the thin film solar cell to fix the thin film solar cell.

According to an embodiment of the present invention, the heater can uniformly heat the thin film solar cell, thereby reducing the generation of spots. In an embodiment, since the guiding track can continuously drive the thin film solar cell to continuously move in the first direction, the surface of the thin film solar cell can be heated more uniformly, which can improve the uneven heating phenomenon and improve the film. The quality and yield of solar cells.

Other objects and advantages of the present invention will become apparent from the technical features disclosed herein. The above and other objects, features, and advantages of the invention will be apparent from

4 is a schematic view showing a transfer device of a thin film solar cell annealing apparatus according to an embodiment of the present invention. As shown in FIG. 4, the thin film solar cell annealing apparatus 100 is used for annealing a CIGS thin film solar cell 10, which comprises at least one annealing chamber, a heater 110, and a transfer device 120. In the present embodiment, five annealing chambers 21 to 25 are provided (please refer to FIG. 2A). Hereinafter, the annealing chamber 21 will be described as an example, and the remaining annealing chambers 22 to 25 are the same as the annealing chamber 21, and thus the description thereof will be omitted. The transfer device 120 is disposed in the annealing chamber 21 for transferring the CIGS thin film solar cell 10 into the annealing chamber 21 or transferring it out of the annealing chamber 21. The transport device 120 includes a guide rail 121 and at least one fixture 122. The guide rail 121 is disposed on the top side of the annealing chamber 21 and extends along a first direction and extends from the current annealing chamber 21 to the next annealing chamber 22. The fixing device 122 is movably disposed on the guiding track 121 and is capable of vertically fixing the CIGS thin film solar cell 10 (or its glass substrate 11), that is, in such a manner that the normal vector of the surface of the CIGS thin film solar cell 10 is perpendicular to the direction of gravity. , the glass substrate 11 is fixed.

In one embodiment, the fixture 122 is a fixture for holding the glass substrate 11 of the CIGS thin film solar cell 10. Figure 5 is a schematic illustration of a thin film solar cell, and a fixture therewith, in accordance with an embodiment of the present invention. As shown in FIG. 5, in an embodiment, the fixing device 122 can be a hook, and the glass substrate 11 is formed with a hole 11a corresponding to the hook. When the hook hooks the hole 11a, the fixing device 122 can fix the glass substrate. 11.

The heater 110 is disposed in the annealing chamber 21 for heating the CIGS thin film solar cell 10 fixed to the fixture 122. In one embodiment, the heater 110 includes a plurality of heating tubes 111, and the longitudinal direction of each of the heating tubes 111 extends in the direction of gravity. In one embodiment, the guide track 121 drives the fixture 122 to continuously move in the first direction such that the glass substrate 11 secured to the fixture 122 also continuously moves in the first direction.

According to the conventional annealing apparatus 20 for a thin film solar cell, the transfer device 40 includes a stationary state and a transfer state, causing the CIGS thin film solar cell 10 to intermittently move in each annealing chamber of the annealing device 20. Since the heating tube 111 is elongated, and the glass substrate 11 of the CIGS thin film solar cell 10 is planar, the portion of the glass substrate 11 adjacent to the heating tube 111 is heated more, and the portion of the glass substrate 11 away from the heating tube 111 is far away. Less heat is generated, resulting in uneven heating, which in turn affects the physical characteristics such as crystallinity and concentration of each metal in the CIGSe metal layer 16. As a result, the quality and yield of the CIGS thin film solar cell 10a are lowered.

However, according to the present embodiment, since the guide rail 121 can continuously drive the glass substrate 11 to continuously move in the first direction, the surface of the glass substrate 11 can be uniformly heated, and the uneven heating phenomenon can be improved. Improve the quality and yield of CIGS thin film solar cell 10a.

In addition, in an embodiment, the thin film solar cell annealing apparatus 100 may further include a graphite plate 130 disposed between the heater 110 and the transfer device 120, that is, the path of the heater 110 and the CIGS thin film solar cell 10. between. During the annealing process, since the heating tubes 111 of the heater 110 first heat the graphite plate 130, the graphite plate 130 can uniformly homogenize the heat of the heating tubes 111 to form a surface heat source, and then heat the CIGS thin film solar cells 10. . Therefore, the graphite sheet 130 can further improve the phenomenon of uneven heating.

The inventors conducted experiments to collect a plurality of pieces of the CIGS thin film solar cell 10a after annealing using the annealing device 40 of the conventional thin film solar cell, and plotted the spots thereon on the graph to know the shape and position of the spots. . The inventors have summarized the reasons for the formation of spots as follows.

Figure 6 shows a schematic of a CIGS thin film solar cell after annealing using a conventional annealing device. As shown in FIG. 6, the conventionally annealed device 40 is used to complete the annealed CIGS thin film solar cell 10a, and the spots thereon can be roughly divided into a dot spot 51 and a strip spot 52. Referring again to FIG. 3, in general, the bottom surface 26 of the annealing chamber is made of graphite, and the material of the roller 41 and the push rod 42 are not graphite, and are not integrally formed with the bottom surface 26. These components may cause CIGS thin film solar cells. The phenomenon of uneven heating is caused by the fact that the portion of the corresponding roller 41 of the CIGS thin film solar cell 10a forms a spot-like spot 51, and the portion corresponding to the push rod 42 is formed with strip-like spots 52.

On the other hand, according to an embodiment of the present invention, since the heater 110 can uniformly heat the CIGS thin film solar cell 10 without these elements, the generation of the spots can be reduced. In one embodiment, since the guide rail 121 can continuously drive the glass substrate 11 to continuously move in the first direction, the surface of the glass substrate 11 can be heated more uniformly, and the uneven heating phenomenon can be improved. Improve the quality and yield of CIGS thin film solar cell 10a.

While the present invention has been described in its preferred embodiments, the present invention is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application. In addition, any of the objects or advantages or features of the present invention are not required to be achieved by any embodiment or application of the invention. In addition, the abstract sections and headings are only used to assist in the search of patent documents and are not intended to limit the scope of the invention.

10. . . CIGS thin film solar cell

100. . . Thin film solar cell annealing device

10a. . . CIGS thin film solar cell

11. . . glass substrate

110. . . Heater

111. . . Heating pipe

12. . . Molybdenum metal layer

120. . . Conveyor

121. . . Guide track

122. . . Fixtures

13. . . Copper gallium metal layer

14. . . Indium metal layer

15. . . Selenium layer

16. . . CIGSe metal layer

20. . . Annealing device

21~25. . . Annealing chamber

26. . . Bottom

27. . . Groove

31~32. . . Cooling room

35. . . Entrance

36. . . Export

40. . . Conveyor

41. . . Wheel

42. . . Push rod

43. . . Abutting rod

51. . . Spotted spot

52. . . Strip spot

Figure 1A shows a schematic diagram of one of the steps in the fabrication of a CIGS thin film solar cell.

Figure 1B shows a schematic diagram of one of the steps in the fabrication of a CIGS thin film solar cell.

2 is a schematic view showing the structure of an annealing device of a conventional thin film solar cell.

Figure 3 shows a schematic view of a conventional transfer device for a thin film solar cell annealing apparatus.

4 is a schematic view showing a transfer device of a thin film solar cell annealing apparatus according to an embodiment of the present invention.

Figure 5 is a schematic illustration of a thin film solar cell, and a fixture therewith, in accordance with an embodiment of the present invention.

Figure 6 shows a schematic view of a CIGS thin film solar cell after annealing has been completed using an annealing device for a thin film solar cell.

100. . . Thin film solar cell annealing device

10. . . CIGS thin film solar cell

110. . . Heater

111. . . Heating pipe

120. . . Conveyor

121. . . Guide track

122. . . Fixtures

twenty one. . . Annealing chamber

35. . . Entrance

Claims (7)

A thin film solar cell annealing device, which is suitable for annealing a CIGS thin film solar cell, comprising: at least one annealing chamber; a conveying device disposed in the annealing chamber, the conveying device comprising: a guiding track, along the annealing chamber a first direction extending; a fixing device movably disposed on the guiding track for fixing the CIGS thin film solar cell, thereby enabling the CIGS thin film solar cell to move along the guiding track; and a heater disposed on the The annealing chamber includes a plurality of elongated heating tubes for heating the CIGS thin film solar cells, and a longitudinal direction of each of the heating tubes extends in a gravity direction, wherein the guiding track is disposed at a top of the annealing chamber The side, and the fixing device vertically fixes the CIGS thin film solar cell such that the normal vector of the surface of the CIGS thin film solar cell is substantially perpendicular to the direction of gravity. The thin film solar cell annealing device of claim 1, wherein at least one annealing chamber comprises a first annealing chamber and a second annealing chamber, and the first annealing chamber and the second annealing chamber are in communication, and The guide track extends from the first annealing chamber to the second annealing chamber. The thin film solar cell annealing device of claim 1, wherein the guiding track continuously moves the fixing device along the guiding track move. The thin film solar cell annealing device of claim 1, wherein the guiding track continuously moves the fixing device along the guiding track at a fixed speed. The thin film solar cell annealing device according to claim 1, wherein the fixing device is a jig for clamping the CIGS thin film solar cell. The thin film solar cell annealing device according to claim 1, wherein the fixing device is a hook for hooking a hole in the CIGS thin film solar cell to fix the CIGS thin film solar cell. The thin film solar cell annealing device of claim 1, further comprising a graphite plate disposed between the heater and the transfer device, whereby the heater heats the thin film solar cell via the graphite plate.