TWI505480B - 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 uneven heating of a thin film solar cell.

CIGS (copper indium gallium (di) selenide) in a thin film solar cell belongs to a compound semiconductor. 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.

2A is a schematic view showing the external structure of an annealing device of a conventional thin film solar cell. The annealing device 20 for a thin film solar cell includes five annealing chambers 21 to 25 and two cooling 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.

2B is a schematic view showing the internal structure of each annealing chamber of an annealing device of a conventional thin film solar cell. As shown in FIG. 2B, a bottom plate 26 is provided in the annealing chamber 21. The CIGS thin film solar cell 10 is placed on the bottom plate 26. A heater 50 heats the CIGS thin film solar cell 10 via a graphite plate 60.

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 40 is disposed in the bottom plate 26 of the annealing chambers 21 to 25 for transporting the CIGS thin film solar cell 10 (i.e., 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 plate 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 plate 26, and a small portion is exposed. The portion protrudes from the bottom plate 26 to make the glass substrate of the CIGS thin film solar cell 10. The back surface of the 11 is movable on the roller 41 without contacting the bottom plate 26.

In the conventional example of Fig. 3, two cylindrical push rods 42 are used, which are respectively located at the left and right halves of the bottom plate 26, and do not protrude substantially from the bottom plate 26. The abutment lever 43 is provided to the push lever 42. In the stationary state (not shown) of the conveyor 40, the abutment rod 43 is located in the recess 27 and is in a state of not protruding from the bottom plate 26. 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 plate 26. As the push rod 42 moves toward the next annealing chamber, the glass substrate 11 of the CIGS thin film solar cell 10 will abut against the abutment rod 43 and move with the push rod 42 on the roller 41. When 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 plate without protruding. In the state of 26, after the push rod 42 is retracted to the current annealing chamber, the transfer operation of the CIGS thin film solar cell 10 between the annealing chambers 21 to 25 is completed.

However, the CIGS thin film solar cell 10a formed by the conventional annealing device 20 reduces the quality and yield of the CIGS thin film solar cell 10a due to uneven heating. Therefore, the conventional annealing device 20 has room for further improvement.

An object of an embodiment of the present invention is to provide an annealing apparatus for a thin film solar cell which improves the uneven heating of a thin film solar cell.

According to an embodiment of the invention, a thin film solar cell annealing device includes at least one annealing chamber, a first heater, and a transfer device. The first heater is disposed in the annealing chamber for heating the thin film solar cell. The conveying device is disposed in the annealing chamber and includes a plurality of rollers, each of which is arranged along a first direction and rotates in the same direction. The back side of the thin film solar cell contacts the rollers, so that the thin film solar cell moves in the first direction on the rollers, so that the thin film solar cells in the annealing chamber move relative to the first heater.

In one embodiment, the first heater comprises a plurality of first heating tubes and a plurality of glass quartz sleeves (Robax), and the outer sides of each of the first heating tubes are respectively covered with a glass quartz sleeve to protect the first A heating tube. In an embodiment, the first heating tubes are located on the bottom sides of the rollers and do not protrude from the rollers. Preferably, the first heating tubes are located further on the bottom side of the gap between two adjacent rollers.

According to an embodiment of the invention, a thin film solar cell annealing apparatus includes at least one annealing chamber, a heater, and a transfer device. A heater is disposed within the annealing chamber and includes a plurality of heating tubes for heating the thin film solar cell. A conveyor is used to transport the thin film solar cell. In the operating state of the annealing chamber, the thin film solar cells are placed in the annealing chamber, and the heating tubes are continuously moved to move the heating tubes relative to the thin film solar cells. In one embodiment, the heating tubes reciprocate.

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 one embodiment, since the transport device 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 enhance 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

According to an embodiment of the invention, a thin film solar cell annealing device is provided, which comprises at least one annealing chamber, a heater and a conveying device. The heater is used to heat the thin film solar cell and is disposed in the annealing chamber. The transfer device is configured to transport the thin film solar cell and is disposed in the annealing chamber. When the heater heats the thin film solar cell, a relative movement is formed between the thin film solar cell in the annealing chamber and the heater. With this unique and novel design, it is possible to improve the uneven heating of the thin film solar cells generated by heating the thin film solar cells by the heater. Various embodiments of the invention are described in more detail below, but it should be understood that the invention is not limited to the embodiments.

4 is a schematic view showing a thin film solar cell annealing apparatus according to an embodiment of the present invention. Figure 5 is a schematic view showing a conveying apparatus of a thin film solar cell annealing apparatus according to an embodiment of the present invention. As shown in FIGS. 4 and 5, 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 21, a first heater 110, and a transfer device 120. In an embodiment, a second heater 130 may be further included. In the present embodiment, the thin film solar cell annealing apparatus 100 is provided with five annealing chambers 21 to 25 (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 plurality of rollers 121, each of which is arranged along a first direction 71 and rotates in the same direction, for example, both in a counterclockwise direction. The back surface of the thin film solar cell 10 contacts the rollers 121, so that the thin film solar cell 10 moves along the first direction 71 on the rollers 121, so that the thin film solar cell 10 in the annealing chamber 21 moves relative to the first heater 110. . In one embodiment, the thin film solar cell 10 is moved relative to the heating tube 111 of the first heater 110 (described later). The roller 121 is formed in an elongated shape and has a long axis extending in a second direction 72. Preferably, the second direction 72 is substantially perpendicular to the first direction 71.

In one embodiment, the first heater 110 is disposed within the annealing chamber 21. The heater 110 includes a plurality of first heating tubes 111 and a plurality of glass quartz sleeves (Robax) 112. The first heating tube 111 is elongated and has a long axis extending in a second direction 72, that is, substantially parallel to the rollers 121. The first heating tube 111 is located on the bottom side of the rollers 121 and does not protrude from the rollers 121. Preferably, the first heating tubes 111 are located on the bottom side of the gap between the two adjacent rollers 121. Further, since the CIGS thin film solar cell 10 contains selenium, it evaporates at a high temperature, and it is easy to corrode the device in the annealing chamber 21, for example, the first heating pipe 111 of the first heater 110 is damaged. Therefore, in the embodiment, a glass quartz sleeve 112 is respectively disposed on the outer side of each of the first heating tubes 111 to protect the first heating tube 111.

The inventors conducted experiments to collect data of a plurality of CIGS thin film solar cells 10a after annealing by using an annealing device 40 using a 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 plate 26 of the annealing chamber is made of graphite, and the material of the roller 41 and the push rod 42 are not made of graphite, and are not integrally formed with the bottom plate 26, and these components may cause CIGS thin film solar cells. 10a is heated unevenly, so that the portion of the corresponding roller 41 of the CIGS thin film solar cell 10a forms a dot-like spot 51, and the portion corresponding to the push rod 42 forms a strip-shaped spot 52.

In contrast, according to an embodiment of the present invention, since the CIGS thin film solar cell 10 can uniformly contact the roller 121 without the components, the first heater 110 can uniformly heat the CIGS thin film solar cell 10, thereby reducing the The production of some spots.

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. In the heating process of the heater to the thin film solar cell, the transfer device 40 is in a stationary state, and the CIGS thin film solar cell 10 is placed in the bottom plate 26 of the annealing chamber 21. 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.

In contrast, in an embodiment of the present invention, since the roller 121 can continuously drive the glass substrate 11 of the CIGS thin film solar cell 10 to continuously move in the first direction 71, the surface of the CIGS thin film solar cell 10 is The ability to receive heat more uniformly can improve the phenomenon of uneven heating and improve the quality and yield of the CIGS thin film solar cell 10a.

In addition, in an embodiment, the thin film solar cell annealing device 100 may further include a second heater 130 and a graphite plate 140. The second heater 130 includes a plurality of elongated second heating tubes 131. The graphite plate 140 is disposed between the second heater 130 and the transfer device 120. During the annealing process, since the second heating tubes 131 of the second heater 130 first heat the graphite plate 140, the graphite plate 140 can be uniformly homogenized. The heat of the tube 131 is heated to form a surface heat source, and the CIGS thin film solar cell 10 is heated. Therefore, the graphite plate 140 can further improve the phenomenon of uneven heating. In addition, since the second heating tube 131 of the second heater 130 is easily corroded by the selenium element in the annealing chamber 21, the second heater 130 and the CIGS thin film solar cell 10 are separated by the graphite plate 140, and There is protection for the second heater 130.

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. . . Thin film solar cell

100. . . Thin film solar cell annealing device

10a. . . CIGS thin film solar cell

11. . . glass substrate

111. . . First heating tube

112. . . Glass quartz sleeve

12. . . Molybdenum metal layer

120. . . Conveyor

121. . . roller

13. . . Copper gallium metal layer

130. . . Second heater

131. . . Second heating tube

14. . . Indium metal layer

140. . . Graphite plate

15. . . Selenium layer

16. . . CIGSe metal layer

20. . . Annealing device

21~25. . . Annealing chamber

26. . . Bottom plate

27. . . Groove

31~32. . . Cooling room

35. . . Entrance

36. . . Export

40. . . Conveyor

41. . . Wheel

42. . . Push rod

43. . . Abutting rod

50. . . Heater

51. . . Spotted spot

52. . . Strip spot

60. . . Graphite plate

71. . . First direction

72. . . Second direction

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.

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

2B is a schematic view showing the internal structure of each annealing chamber 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 thin film solar cell annealing apparatus according to an embodiment of the present invention.

Figure 5 is a schematic view showing a conveying apparatus of a thin film solar cell annealing apparatus according to 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.

10. . . CIGS thin film solar cell

100. . . Thin film solar cell annealing device

110. . . First heater

111. . . First heating tube

112. . . Glass quartz sleeve

121. . . roller

130. . . Second heater

131. . . Second heating tube

140. . . Graphite plate

twenty one. . . Annealing chamber

35. . . Entrance

Claims (4)

A thin film solar cell annealing device, which is suitable for annealing a thin film solar cell, comprising: at least one annealing chamber; a first heater disposed in the annealing chamber for heating the thin film solar cell, wherein the first The heater comprises a plurality of first heating tubes and a plurality of glass quartz sleeves (Robax), and the outer side of each of the first heating tubes is respectively sleeved with the glass quartz sleeve, thereby protecting the first heating tubes, and the The first heating tubes are located on the bottom sides of the rollers and do not protrude from the rollers; and a conveying device is disposed in the annealing chamber and includes a plurality of rollers, each of which is along a first direction Arranging and rotating in the same direction, wherein the back surface of the thin film solar cell contacts the rollers, so that the thin film solar cell moves along the first direction on the rollers, so that the thin film solar cell in the annealing chamber is opposite to the The first heater moves. The thin film solar cell annealing device of claim 1, wherein the first heating tubes are located at a bottom side of a gap between two adjacent rollers. The thin film solar cell annealing device of claim 1, further comprising a second heater and a graphite plate, wherein the graphite plate is disposed between the second heater and the thin film solar cell, the second heating Contains multiple The second heating tube is used to heat the thin film solar cell via the graphite plate. 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 rollers of the first annealing chamber cooperate with the rollers of the second annealing chamber to transfer the thin film solar cell from the first annealing chamber to the second annealing chamber.