Integrated thin film photovoltaic module and manufacturing method thereof

1. An integrated thin-film photovoltaic module, comprising:

a first cell and a second cell, the first cell and the second cell each comprising a lower electrode, a photoelectric conversion layer, and an upper electrode disposed on a substrate,

a separation groove comprising a lower electrode separation groove separating the lower electrode of the first cell and the second cell;

through holes penetrating the upper electrode and the photoelectric conversion layer in each of the first cell and the second cell, the through holes being spaced apart from each other in each of the first cell and the second cell; and

a conductive material filling the through holes and connecting the upper electrode of the second cell and the lower electrode of the first cell.

2. The integrated thin-film photovoltaic module of claim 1 , wherein the photoelectric conversion layer comprises a first unit cell layer, a second unit cell layer, and an intermediate reflector disposed between the first unit cell layer and the second unit cell layer.

3. The integrated thin-film photovoltaic module of claim 2 , wherein a side wall of each through holes is coated with an insulating layer.

4. The integrated thin-film photovoltaic module of claim 3 , wherein:

the separation groove comprises an upper separation groove separating the photoelectric conversion layer and the upper electrode of the first cell from the photoelectric conversion layer and the upper electrode of the second cell; and

a first portion of the upper separation groove overlaps the lower electrode separation groove.

5. The integrated thin-film photovoltaic module of claim 4 , wherein one of the lower electrode separation groove and the upper separation groove is disposed along a straight line extending in a direction parallel to the substrate.

6. The integrated thin-film photovoltaic module of claim 5 , wherein a ratio of the length of the first portion of the upper separation groove overlapping the lower electrode separation groove to the length of the separation groove formed along the straight line extending parallel to the substrate is in the range of 0.70 to 0.96.

7. The integrated thin-film photovoltaic module of claim 5 , wherein, in a second portion of the separation groove where the upper separation groove and the lower electrode separation groove do not overlap, one of the lower electrode separation groove and the upper separation groove has a partial circular shape or a partial elliptical shape.

8. The integrated thin-film photovoltaic module of claim 7 , wherein, at a branch point from which the upper separation groove and the lower electrode separation groove diverge from each other, an angle formed by the straight line and a tangent line of the partial circular shape or the partial elliptical shape is in the range of 90° to 135° .

9. The integrated thin-film photovoltaic module of claim 5 , wherein, in a second portion of the separation groove where the upper separation groove and the lower electrode separation groove do not overlap, one of the lower electrode separation groove and the upper separation groove has a partial polygonal shape.

10. The integrated thin-film photovoltaic module of claim 9 , wherein:

at a branch point from which the upper separation groove and the lower electrode separation groove diverge from each other,

an external angle of the partial polygonal shape is in the range of 90° to 135° ; and

all of the interior angles of the partial polygonal shape are less than 180°.

11. The integrated thin-film photovoltaic module of claim 5 , wherein, each through hole is disposed in a second portion of the separation groove where the upper separation groove and the lower electrode separation groove do not overlap and is located at the center of a line connecting an outermost point of the separation groove with respect to the straight line of each cell and a foot of perpendicular from the outermost point.

12. The integrated thin-film photovoltaic module of claim 5 , wherein:

two adjacent through holes are spaced from each other; and

a ratio of a distance between a foot of perpendicular extending from the through hole to the straight line to a distance between the two adjacent through holes is in the range of 4×10 −3 to 300×10 −3 .

13. The integrated thin-film photovoltaic module of claim 4 , wherein widths of the first cell and the second cell are in the range of 6 mm to 15 mm, respectively.

14. The integrated thin-film photovoltaic module of claim 4 , wherein a distance between two adjacent through holes among the through holes is in the range of 1 mm to 5 cm.

15. The integrated thin-film photovoltaic module of claim 4 , wherein, a ratio of an area surrounded by the lower electrode separation groove and the upper separation groove including the through hole therebetween is in the range of 0.007% to 1.5% of an area of the integrated thin-film photovoltaic module.

16. The integrated thin-film photovoltaic module of claim 4 , wherein each of the through holes has a circular shape, an elliptical shape, or a polygonal shape.

17. The integrated thin-film photovoltaic module of claim 4 , wherein at least one of the lower electrode separation groove, the through holes, and the upper separation groove is patterned to have a curved edge so that a ratio of level difference of the curved edge to a width of a pattern is in the range of 5% to 10%.