Solar cell unit

Patent metadata

Field	Value
Publication number	US-10211358-B2
Application number	US-201514727328-A
Country	US
Kind code	B2
Filing date	Jun 1, 2015
Priority date	May 30, 2014
Publication date	Feb 19, 2019
Grant date	Feb 19, 2019

Abstract

A solar cell unit, comprising a solar cell with a light receiving surface, and a transparent optical element frictionally connected to the receiving surface. The optical element having a portion of surface formed substantially convex such that sunlight striking the receiving surface is bundled by the convex receiving surface. The light receiving surface is surrounded by a shoulder-shaped ledge that has a first rim surface and a second rim surface. A first alignment mark is provided in association with the first rim surface and a second alignment mark is provided in association with the second rim surface to position the optical element in regard to the receiving surface of the solar cell via the two alignment marks. The first alignment mark being spaced apart from the second alignment mark in order to guide the incident sunlight totally or at least largely to the receiving surface.

First claim

What is claimed is:

1. A solar cell unit, comprising
a solar cell with a light receiving surface;
a supporting substrate having a top side and a bottom side, the solar cell being connected electrically and frictionally to the top side of the supporting substrate; and
a transparent optical element including a shoulder-shaped ledge and frictionally connected to the light receiving surface, the optical element having a top surface and a bottom surface, a portion of the top surface being substantially convex with respect to the light receiving surface such that sunlight impinging on the light receiving surface is bundled via the convex receiving surface to guide the incident sunlight totally or at least largely to the light receiving surface, the shoulder-shaped ledge having a top rim surface, a normal vector of the top rim surface is formed substantially parallel to an optical axis of the optical element, the normal vectors pointing opposite to a direction of incident sunlight, the shoulder-shaped ledge being formed as a single piece with the optical element, the optical element and the shoulder-shaped ledge being made of the same material;
a first alignment mark associated with a first section of the top rim surface of the shoulder-shaped ledge; and
a second alignment mark associated with a second section of the top rim surface of the shoulder-shaped ledge, the first and second alignment mark facilitating a position and an orientation of the optical element with respect to the light receiving surface of the solar cell, the first alignment mark being spaced apart from the second alignment mark,
wherein an area of the bottom surface of the optical element is smaller than an area of the top side of the supporting substrate such that the first alignment mark and the second alignment mark are formed directly over the supporting substrate
wherein the entire bottom surface of the optical element is planar.

2. The solar cell unit according to claim 1 , further comprising a third alignment mark formed on the top rim surface of the shoulder-shaped ledge, wherein the third alignment mark is spaced apart from the first alignment mark and from the second alignment mark.

3. The solar cell unit according to claim 2 , wherein the first alignment mark and/or the second alignment mark and/or the third alignment mark comprise an elevation or a groove.

4. The solar cell unit according to claim 3 , wherein each alignment mark comprises precisely one groove.

5. The solar cell unit according to claim 3 , wherein the elevation or the groove is formed on the top rim surface of the shoulder-shaped ledge.

6. The solar cell unit according to claim 2 , wherein the first alignment mark, the optical axis, and the second alignment mark enclose a first angle, wherein the second alignment mark, the optical axis, and the third alignment mark enclose a second angle, and wherein the second angle is different from the first angle.

7. The solar cell unit according to claim 2 , wherein an angle of two directly adjacent alignment marks is 135° and 90°, and wherein the angle between alignment marks is measured in each case with respect to the optical axis.

8. The solar cell unit according claim 1 , wherein the first and second alignment marks have a structural height of at least 0.2 mm to enable a mechanical centering and orientation.

9. The solar cell unit according to claim 1 , wherein an angle between two directly adjacent alignment marks is 120° or 135°, and wherein the angle between alignment marks is determined in each case with respect to the optical axis.

10. The solar cell unit according to claim 1 , wherein the shoulder-shaped ledge comprises a plurality of ledge sections that are separated from each other with a gap, each ledge section including an alignment mark.

11. The solar cell unit according to claim 1 , wherein the shoulder-shaped ledge forms a circumferential rim and the circumferential rim completely surrounds the optical element in the shape of a ring.

12. The solar cell unit according to claim 1 , wherein the top rim surface forms a continuous planar surface in sections where the first and second alignment marks are not formed.

13. The solar cell unit according to claim 1 , wherein a UV-transparent adhesive layer is arranged between the optical element and the receiving surface of the solar cell.

14. A method for manufacturing a solar cell unit by a joining process according to claim 1 , the method comprising:
holding the optical element by a gripper unit;
determining the position and orientation of the optical element with respect to the gripper unit by a positive locking of the gripper unit with the alignment marks;
applying a connector to the receiving surface and/or to a bottom side of the optical element;
positioning the optical element with respect to the receiving surface; and
holding the optical element at a predetermined distance to the receiving surface during a curing of the connector in order to form a gap filled with the cured connector between the optical element and the receiving surface.

15. The method according to claim 14 , wherein, during the curing of connector, the optical element or the semiconductor body is kept at a temperature of at least 50° C.

16. The method according to claim 14 , wherein the position and orientation of the receiving surface on the supporting substrate are detected with an image recognition system before the positioning of the secondary optical element to the receiving surface.

17. The solar cell unit according to claim 1 , wherein the solar cell is a semiconductor.

18. The solar cell unit according to claim 1 , wherein a UV-transparent adhesive layer is arranged between the optical element and the receiving surface of the solar cell, and wherein the UV-transparent adhesive facilitates a positioning of the shoulder-shaped ledge that is fixedly and directly connected to the transparent optical element, and wherein during a positioning and alignment of the optical element, a height or width of the UV-transparent adhesive is altered about a circumference thereof based on the position and alignment of the optical element.

19. The solar cell unit according to claim 1 , wherein the optical element and shoulder-shaped ledge are made of quartz glass or a quart glass compound.

20. The solar cell unit according to claim 1 , further comprising:
a connector provided between the optical element and the supporting substrate, the connector contacting an entire bottom surface of the optical element, the light receiving surface and side surfaces of the solar cell, and the top side of the supporting substrate, the area of a top side of the connector being substantially equivalent to the area of the bottom surface of the optical element.

Assignees

• Azur Space Solar Power Gmbh

Inventors

• Loeckenhoff Ruediger

Classifications

• H01L31/0543 Primary

  Electricity · mapped topic

• H01L31/18

  Electricity · mapped topic

• Y02E10/52

  PV systems with concentrators · CPC title

• H10F71/00

  Manufacture or treatment of devices covered by this subclass (patterning processes to connect thin photovoltaic cells in integrated devices, or assemblies of multiple devices, having photovoltaic cells H10F19/33; manufacture or treatment of encapsulations or containers for integrated devices, or assemblies of multiple devices, having photovoltaic cells H10F19/80; manufacture or treatment of integrated devices, or assemblies of multiple devices, comprising at least one element in which radiation controls the flow of current H10F39/00) · CPC title

• H10F77/484 Primary

  Refractive light-concentrating means, e.g. lenses · CPC title