Lens, solar cell unit and joining method for a solar cell unit

1. A lens comprising:

a main body with a substantially planar base, a receiving surface opposite the base, a side surface area connecting the base and the receiving surface;

an optical axis extending substantially perpendicular to the base; and

at least one bulge arranged on the main body of the lens within the side surface area between the receiving surface and the planar base, the at least one bulge having a bottom spaced from the base of the main body in a direction of the optical axis,

wherein the at least one bulge covers an angular range of less than 130° of the circumference of the main body as measured from the optical axis,

wherein, in a projection along the optical axis, a shadow of the main body has a first diameter, and

wherein a shadow of the lens formed of the main body and the at least one bulge in a projection along the optical axis completely fits in a square having an edge length corresponding to the diameter.

2. The lens according to claim 1 , wherein the lens has exactly two bulges or exactly three bulges or exactly four bulges.

3. The lens according to claim 1 , wherein the lens has exactly four bulges, and

wherein the four bulges are evenly or not evenly distributed along a circumference of the main body of the lens extending parallel to the base.

4. The lens according to claim 1 , wherein the base of the main body has a diameter of at most 3 cm or at most 1.5 cm, and a height of the main body along the optical axis is at most 5 cm or at most 2 cm.

5. The lens according to claim 1 , wherein a portion of the lens aligned with the base tapers towards the base so that the projection of the base along the optical axis is a smaller subsurface of the projection of the main body along the optical axis.

6. The lens according to claim 1 , wherein the lens comprises a quartz glass compound and is formed integrally.

7. A lens comprising:

a main body with a substantially planar base, a receiving surface opposite the base, a side surface area connecting the base and the receiving surface;

an optical axis extending substantially perpendicular to the base; and

at least one bulge arranged on the main body of the lens at a first height on the base on the side surface area, the at least one bulge having a bottom spaced from the base of the main body in a direction of the optical axis,

wherein the at least one bulge covers an angular range of less than 130° of the circumference of the main body as measured from the optical axis,

wherein, in a projection along the optical axis, a shadow of the main body has a first diameter,

wherein a shadow of the lens formed of the main body and the at least one bulge in a projection along the optical axis completely fits in a square having an edge length corresponding to the diameter, and

wherein the base of the lens has a circular shape, the receiving surface of the lens is convex, and the side surface area of the lens has a circular circumference.

8. A solar cell unit comprising:

a lens according to claim 1 ;

a semiconductor body constructed as a solar cell with a receiving surface, a base and at least two electrical contacts; and

a support having a top and a bottom, wherein the base of the semiconductor body is electrically interconnected and frictionally connected to the top of the support,

wherein the base of the lens is frictionally connected with the receiving surface of the semiconductor body via a polymer adhesive layer or a silicone compound.

9. The solar cell unit according to claim 8 , wherein the top of the support is rectangular with four edges,

wherein the lens has four bulges, and

wherein the lens is arranged on the support such that a straight line connecting two opposing bulges case forms an angle between 35° and 55° towards edges of the support.

10. The lens according to claim 1 , wherein the base of the lens has a circular shape.

11. The lens according to claim 1 , wherein the receiving surface of the lens is convex.

12. The lens according to claim 1 , wherein the side surface area of the lens has a circular circumference.

13. A lens comprising:

a main body, comprising:

a base having a planar bottom surface;

a receiving surface opposite the base; and

a side surface area connecting the base and the receiving surface;

an optical axis extending perpendicular to the base; and

a bulge arranged within the side surface between the receiving surface and the base at a first height, the bulge having a bottom spaced from the base in a direction of the optical axis,

wherein the bulge covers an angular range of less than 130° of the circumference of the main body as measured from the optical axis,

wherein, in a projection along the optical axis, a shadow of the main body has a first diameter, and

wherein a shadow of the lens formed of the main body and the at least one bulge in a projection along the optical axis completely fits in a square having an edge length corresponding to the diameter.

14. The lens according to claim 1 , wherein the lens is a single lens.