Tandem type integrated photovoltaic module and manufacturing method thereof
Disclosed is a tandem type integrated photovoltaic module. The tandem type integrated photovoltaic module includes: a first cell and a second cell, all of which are formed respectively by stacking on a substrate a lower electrode, a photoelectric conversion layer including a plurality of unit cell layers, and an upper electrode, wherein the lower electrode of the first cell and the lower electrode of the second cell are separated by a lower electrode separation groove, and wherein a plurality of through holes are formed to be spaced from each other in the photoelectric conversion layer of the second cell in order to connect the upper electrode of the first cell with the lower electrode of the second cell.
1. A tandem type integrated photovoltaic module comprising:
a first cell and a second cell, all of which are formed respectively by stacking on a substrate a lower electrode, a photoelectric conversion layer including a plurality of unit cell layers, and an upper electrode,
wherein the lower electrode of the first cell and the lower electrode of the second cell are separated by a lower electrode separation groove, the lower electrode separation groove extending in a first direction, and
wherein a plurality of through holes are formed spaced from each other in the first direction and are disposed in the photoelectric conversion layer of the second cell in order to connect the upper electrode of the first cell with the lower electrode of the second cell,
wherein the photoelectric conversion layer and the upper electrode of the first cell are separated by an upper separation groove from the photoelectric conversion layer and the upper electrode of the second cell, wherein a portion of the upper separation passes over the lower electrode separation groove.
2. The tandem type integrated photovoltaic module of claim 1 , wherein further including a high resistance layer formed on a side surface of the through hole.
3. The tandem type integrated photovoltaic module of claim 2 , wherein the first cell and the second cell further comprise a transparent electrode layer between the photoelectric conversion layer and the upper electrode, and wherein the through hole is formed in the photoelectric conversion layer and the transparent electrode layer of the second cell.
4. The tandem type integrated photovoltaic module of claim 1 , wherein lower electrode separation groove has a straight line shape.
5. The tandem type integrated photovoltaic module of claim 1 , wherein the high resistance layer is formed on the side surface of the through hole where a p-n tunnel junction portion of the photoelectric conversion layer is exposed.
6. The tandem type integrated photovoltaic module of claim 4 , wherein a ratio of the length of the portion of the upper separation groove passing over the lower electrode separation groove to the length of the lower separation groove is equal to or greater than 0.70 and equal to or less than 0.96.
7. The tandem type integrated photovoltaic module of claim 4 , wherein, in another portion where the upper separation groove does not pass over the lower electrode separation groove, the upper separation groove has a partial circular shape or a partial elliptical shape.
8. The tandem type integrated photovoltaic module of claim 7 , wherein, at a branch point from which the upper separation groove having the partial circular shape or partial elliptical shape branches off the straight line shape, an angle formed by the straight line shape and a tangent line of the circular shape or the elliptical shape is equal to or greater than 90° and equal to or less than 135°.
9. The tandem type integrated photovoltaic module of claim 4 , wherein, in another portion where the upper separation groove does not pass over the lower electrode separation groove, the the upper separation groove has a partial polygonal shape.
10. The tandem type integrated photovoltaic module of claim 9 , wherein, at a branch point from which the upper separation groove having the partial polygonal shape branches off the straight line, an external angle of the partial polygonal shape is equal to or greater than 90° and equal to or less than 135° , and wherein all of the interior angles of the partial polygonal shape are less than 180°.
11. The tandem type integrated photovoltaic module of claim 4 , wherein, in another portion where the upper separation groove does not pass over the lower electrode separation groove, the through hole is located in the middle between a foot of perpendicular which extends from the through hole to the straight line shape and the outermost point of the upper separation groove within the another portion where the upper separation groove does not pass over the lower separation groove.
12. The tandem type integrated photovoltaic module of claim 1 , wherein the widths of the first cell and the second cell are equal to or greater than 6 mm and equal to or less than 15 mm respectively.
13. The tandem type integrated photovoltaic module of claim 1 , wherein a distance between two adjacent through holes among the through holes is equal to or greater than 1 mm and equal to or less than 5 cm.
14. The tandem type integrated photovoltaic module of claim 1 , wherein, in the tandem type integrated photovoltaic module, a ratio of an ineffective area by the lower electrode separation groove, the through hole and the upper separation groove to an effective area is equal to or greater than 0.007% and equal to or less than 1.5%.
15. The tandem type integrated photovoltaic module of claim 4 , wherein two adjacent through holes among the through holes are spaced from each other, and wherein a ratio of a distance between the foot of perpendicular which extends from the through hole to the straight line shape and the outermost point of the upper separation groove within the another portion where the upper separation groove does not pass over the lower separation groove to the predetermined distance is equal to or greater than 4×10 −3 and equal to or less than 300×10 −3 .
16. The tandem type integrated photovoltaic module of claim 1 , wherein a cross-section of the through hole has a circular shape, an elliptical shape or a polygonal shape.
17. The tandem type integrated photovoltaic module of claim 1 , wherein, in at least one of the lower electrode separation groove, the through hole and the upper separation groove, a ratio of level difference of the bottom surface to the width is equal to or greater than 5% and equal to or less than 10%.
18. The tandem type integrated photovoltaic module of claim 1 , wherein the photoelectric conversion layer further comprises at least one intermediate reflector between the unit cell layers, and wherein the high resistance layer is formed on the side surface of the through hole where the intermediate reflector is exposed.