SOLAR CELL UNIT

Abstract

A solar cell unit having a semiconductor body formed as a solar cell and having a front side and a back side, a carrier with a top side enclosed by at least four edges, a bottom side, and a first contact surface, formed on the top side and connected to the first terminal contact, and a second contact surface, connected to the second terminal contact and spaced apart from the first contact surface, and a secondary optical element. A back side of the semiconductor body is non-positively connected to a part of the top side of the carrier. The secondary optical element guides light to the front side of the semiconductor body and at least parts of the bottom side of the secondary optical element are non-positively connected to the front side of the semiconductor body and/or to the top side of the carrier by a polymer adhesive layer.

Claims

1. A solar cell unit comprising: a semiconductor body, formed as a solar cell and having a front side with a first terminal contact with a first polarity and a back side with a second terminal contact with a second polarity; a carrier with a top side, enclosed by at least four edges, a bottom side, a first contact surface, formed on the top side, and a second contact surface, formed on the top side and spaced apart from the first contact surface, the first contact surface is connected in an electrically conductive manner to the first electrical terminal contact of the semiconductor body, the second contact surface is connected in an electrically conductive manner to the second electrical terminal contact of the semiconductor body, and the back side of the semiconductor body is non-positively connected to a part of the top side of the carrier; a secondary optical element with a bottom side, the secondary optical element adapted to guide light to the front side of the semiconductor body and at least parts of the bottom side of the secondary optical element being non-positively connected to the front side of the semiconductor body and/or to the top side of the carrier solely by a polymer adhesive layer; and a carrier with a first contact surface formed on a top side of the carrier and with a second contact surface formed on the top side of the carrier, the second contact surface being spaced apart from the first contact surface, wherein the first contact surface and the second contact surface are arranged along the first edge, and wherein the first and/or second contact surface adjoin along at least 75% of the length of the first edge.

2. The solar cell unit according to claim 1, wherein the first contact surface and the second contact surface are arranged spaced apart from the bottom side of the secondary optical element.

3. The solar cell unit according to claim 1, wherein a distance of the bottom side of the secondary optical element from the first edge of the top side of the carrier, in a projection extending substantially perpendicular to the top side of the carrier, is at least 3 mm, wherein a distance of the bottom side of the secondary optical element from the second edge, from the third edge, and from the fourth edge in the projection, extending substantially perpendicular to the top side of the carrier, is at most 2 mm or at most 1 mm or is in a range between 0 mm and 0.2 mm.

4. The solar cell unit according to claim 1, wherein, in a projection extending substantially perpendicular to the top side of the carrier, the projection area of the optical element is at least 30% or at least 40% or at least 45% or at least 50% of the projection area of the carrier.

5. The solar cell unit according to claim 1, wherein, in a projection, extending substantially perpendicular to the top side of the carrier, the projection area of the semiconductor body is at least 6% or at least 8% or at least 10% or at least 12% of the projection area of the carrier.

6. The solar cell unit according to claim 1, wherein the secondary optical element is lens-shaped with a convex surface facing away from the semiconductor body or wherein the secondary optical element is funnel-shaped.

7. The solar cell unit according to claim 1, wherein the secondary optical element comprises a quartz glass compound and is made as a single piece.

8. The solar cell unit according to claim 1, wherein the polymer adhesive layer comprises a plastic compound.

9. The solar cell unit according to claim 1, wherein the carrier is formed as a ceramic printed circuit board or a printed circuit board with an insulated metal substrate.

10. The solar cell unit according to claim 1, wherein the first contact surfaces and the second contact surface are formed as traces.

11. The solar cell unit according to claim 1, wherein the semiconductor body has at least two photovoltaically active semiconductor junctions arranged one above the other.

12. The solar cell unit according to claim 1, wherein the first and/or second contact surface adjoin along at least 75% or at least 90% of the length of the first edge.

13. The solar cell unit according to claim 1, wherein the solar cell unit comprises a substantially rectangular base area of a maximum of 22 mm×28 mm or a maximum of 16 mm×22 mm edge length.

14. The solar cell unit according to claim 1, wherein the base area of the secondary optical element in the projection projects out over two or three edges of the carrier.

15. A solar cell module comprising: at least one first, second, and third solar cell unit according to claim 1; and at least one first and one second metallic connecting element, wherein the first, second, and third solar cell units are each arranged with the bottom side on a surface of a base plate, wherein the first metallic connecting element electrically connects the first contact surface of the first solar cell unit to the second contact surface of the second solar cell unit, wherein the second metallic connecting element electrically connects the second contact surface of the first solar cell unit to the first contact surface of the third solar cell unit, and wherein the first metallic connecting element in a first projection substantially perpendicular on the top side of the carrier covers completely or partially the second contact surface of the first solar cell unit.

16. The solar cell module according to claim 15, wherein the first metallic connecting element in a direction, extending substantially perpendicular to the surface of the base plate, is spaced apart from the second contact surface of the first solar cell unit and in the area of the second contact surface of the first solar cell unit from the second metallic connecting element.

17. The solar cell module according to claim 15, wherein the base plate comprises a metal or a nonmetal.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

[0035] FIG. 1 shows a schematic view of an embodiment of the invention of a solar cell unit;

[0036] FIG. 2 shows a schematic top view of an embodiment of the invention of a solar cell unit;

[0037] FIG. 3 shows a schematic top view of an embodiment of the invention of a solar cell module; and

[0038] FIG. 4 shows a schematic view of an embodiment of the invention of a solar cell module along section line A-A.

DETAILED DESCRIPTION

[0039] The illustration in FIG. 1 shows a side view of an exemplary embodiment of a solar cell unit 10, having a semiconductor body 20, a carrier 30, and a secondary optical element 50. The illustration of FIG. 2 shows a schematic top view of solar cell unit 10 illustrated in FIG. 1.

[0040] Semiconductor body 20 is non-positively connected with a back side 24 to a top side 32 of carrier 30. A front side 22 is completely covered by secondary optical element 50, whereby secondary optical element 50 is made as a convex lens and a planar bottom side 52 of secondary optical element 50 is non-positively connected by a polymer adhesive layer (not shown) at least partially to front side 22 of semiconductor body 20. Bottom side 52 of secondary optical element 50 in the illustrated exemplary embodiment furthermore covers a protection diode 38 disposed on top side 32 of carrier 30.

[0041] As can be seen in FIG. 2, carrier 30 has a rectangular top side 32, enclosed by four edges 34.1, 34.2, 34.3, 34.4. In the illustrated exemplary embodiment, a first and second contact surface 40, 45 are arranged next to secondary optical element 50 and along first edge 34.1 of carrier 30 on top side 32 of carrier 30. In an alternative embodiment (shown by the dashed line), the distance of the bottom side of secondary optical element 50 is in a range between 0 mm and 25 mm away from edges 34.2, 34.3, and 34.4, i.e., virtually flush. In a further embodiment (shown by the dot-dash line), the bottom side of the secondary optical element 50 overruns edges 34.2, 34.3, and 34.4; i.e., the base area of secondary optical element 50 is larger in diameter. An advantage is that the area of the carrier can be made smaller in this way and the costs decline. It is preferred that the secondary optical element is arranged eccentrically relative to the center of gravity of the carrier.

[0042] An exemplary embodiment of solar cell module 100 is shown schematically in the illustration of FIG. 3. FIG. 4 shows a section along the line A-A in FIG. 3.

[0043] The solar cell module has three solar cell units 10.1, 10.2, 10.3 of the above-described type, whereby solar cell units 10.0, 10.1, 10.2, 10.3 are each arranged with a bottom side 36.1, 36.2 on a surface 120 of a base plate 110.

[0044] A first contact surface 40.1 of first solar cell unit 10.1 is connected by a first metallic connecting element 70 to a second contact surface 45.2 of second solar cell unit 10.2, whereby first solar cell unit 10.1 and second solar cell unit 10.2 are arranged next to one another, so that in a projection extending perpendicular to surface 120 of base plate 110, both second contact surface 45.1 of first solar cell unit 10.1 and first contact surface 40.2 of second solar cell unit 10.2 are covered at least partially by first metallic connecting element 70.

[0045] To avoid short circuits, as can be seen in the section shown in FIG. 4, first metallic connecting element 70 in a direction extending perpendicular to surface 120 of base plate 110 has a distance from first contact surface 40.2 of second solar cell unit 10.2 and from second contact surface 45.1 of first solar cell unit 10.1.

[0046] Further, second contact surface 45.1 of first solar cell unit 10.1 is connected in an electrically conductive manner to a first contact surface 40.3 of third solar cell unit 10.3 by means of a second metallic connecting element 72. The distance of first metallic connecting element 70 from second contact surface 45.1 of first solar cell unit 10.1 is selected to be so large that second metallic connecting element 72 in the area of second contact surface 45.1 of first solar cell unit 10.1 in the direction extending perpendicular to surface 120 of base plate 110 also has a distance from first metallic connecting element 70.

[0047] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.