SOLAR CELL CONTACT ARRANGEMENT

Abstract

A solar cell contact arrangement, having a semiconductor body with a top and a bottom, wherein the semiconductor body has multiple solar cell stacks and includes a support substrate on the bottom, and each solar cell stack has at least two III-V subcells arranged on the support substrate and at least one through-contact extending from the top to the bottom of the semiconductor body with a continuous side wall, wherein the through-contact has a first edge region on the top and a second edge region on the bottom, and the first edge region has a first section and a second, metallic section, and the second edge region has a first section and a second section, wherein the respective second sections completely enclose the respective first sections, and an insulating layer.

Claims

1. A solar cell contact arrangement comprising: a semiconductor body with a top and a bottom, wherein the semiconductor body has at least one solar cell stack and includes a support substrate on the bottom, wherein, the at least one solar cell stack has at least two III-V subcells arranged on the support substrate, and at least one through-contact extending from the top to the bottom of the semiconductor body and having a continuous side wall, wherein the through-contact has a first edge region on the top and a second edge region on the bottom, wherein the first edge region has a first section and a second, metallic section, and the second edge region has a first section and a second section; an insulating layer with a thickness between 5 μm and 200 μm, wherein the insulating layer is formed on the first section in the case of the first edge region, on the side wall, and on the first section and the second section in the case of the second edge region; an electrically conductive layer formed as a heterogeneous layer with inclusions of gas, the electrically conductive layer having a thickness between 5 μm and 200 μm, and the electrically conductive layer being formed on the first section and at least partially on the second section in the case of the first edge region, at the side wall, and within the first section in the case of the second edge region, and the electrically conductive layer being arranged on the insulating layer.

2. The solar cell contact arrangement according to claim 1, wherein the electrically conductive layer forms a first contact region on the bottom of the support substrate.

3. The solar cell contact arrangement according to claim 1, wherein a second contact region is formed on the bottom of the support substrate, and wherein the support substrate is electrically connected at the bottom via the second contact region.

4. The solar cell contact arrangement according to claim 1, wherein the solar cell stack is electrically connected via the first contact region and via the second contact region.

5. The solar cell contact arrangement according to claim 1, wherein the two contact regions are planar and each have a size of at least 1.0 mm.sup.2.

6. The solar cell contact arrangement according to claim 2, wherein the two contact regions have at least partly the same height.

7. The solar cell contact arrangement according to claim 1, wherein, after the formation of the conductive layer, the through-opening is partially or completely closed or the through-opening still has a through hole.

8. The solar cell contact arrangement according to claim 1, wherein the first edge region has a smaller diameter than the second edge region.

9. The solar cell contact arrangement according to claim 1, wherein the first edge region and the second edge region are each implemented as an edge region completely surrounding the through-opening and wherein the respective edge region parallel to the semiconductor body has a diameter of at least 10 μm and at most 3.0 mm.

10. The solar cell contact arrangement according to claim 1, wherein the through-opening has a diameter between 25 μm and 1 mm prior to the formation of the insulating layer and the conductive layer.

11. The solar cell contact arrangement according to claim 1, wherein the respective second sections completely enclose the respective first sections.

12. The solar cell contact arrangement according to claim 1, wherein the proportion of the organic constituents in the electrical layer is between 0.1 and 5 volume percent or between 0.2 and 2 volume percent.

13. The solar cell contact arrangement according to claim 1, wherein the thickness of the part of the electrical layer directly at a corner of the first edge region to the through-opening is at least half the thickness of the part of the electrical layer resting on the second edge region.

14. The solar cell contact arrangement according to claim 1, wherein the through-opening is completely filled after the formation of the electrical layer.

15. The solar cell contact arrangement according to claim 1, wherein the insulating layer includes organic components in a range between 0.1 to 5 volume percent.

16. The solar cell contact arrangement according to claim 1, wherein the insulating layer has a thickness between 5 μm and 250 μm and/or the electrically conductive layer has a thickness between 5 μm and 500 μm.

17. The solar cell contact arrangement according to claim 1, wherein the electrically conductive layer has a metal volume fraction of less than 99% and more than 50%, and a maximum electrical conductivity between 30% and 90% of the metallic conductivity of a homogeneously formed metal layer with a material composition that is identical to a first approximation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0089] 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:

[0090] FIG. 1 is a cross-sectional view of a metallized through-opening in one embodiment,

[0091] FIG. 2 is a cross-sectional view of a metallized through-opening in another embodiment,

[0092] FIG. 3 is a cross-sectional view of a metallized through-opening in a different embodiment,

[0093] FIG. 4a is a top view of the top of the metallized through-opening corresponding to the embodiment shown in connection with the illustration in FIG. 3,

[0094] FIG. 4b is a top view of the bottom of the metallized through-opening corresponding to the embodiment shown in connection with the illustration in FIG. 3,

[0095] FIG. 5 is a cross-sectional view of a metallized through-opening with a first contact region and a second contact region,

[0096] FIG. 6 is a top view of a semiconductor body with two solar cell stacks.

DETAILED DESCRIPTION

[0097] The illustration in FIG. 1 shows a cross-sectional view of a metallized through-opening 22 of a semiconductor body 10.

[0098] A semiconductor body 10 with a top 10.1, a bottom 10.2, and a through-opening 22 extending from the top 10.1 to the bottom 10.2 with a continuous side wall 22.1 is provided.

[0099] The semiconductor body 10 includes multiple solar cell stacks 12 that have not yet been diced, each with a layer sequence composed of a support substrate 14 forming the bottom 10.2, a first III-V subcell 18, and a second III-V subcell 20 forming the top 10.1; only one solar cell stack 12 is shown in the present illustration.

[0100] A metal structure MV is formed on the top 10.1. The metal structure MV is implemented almost exclusively as a finger-shaped structure and has, in particular in the first edge region 11.1 of the through-opening 22, a continuous metal area formed completely around the through-opening 22.

[0101] Formed on the bottom 10.2 is a full-area rear-side metallization MR in order to connect the conductive support substrate 14. It is a matter of course that the respective solar cell stack 12 is electrically connected using the two metallizations MV and MR.

[0102] The through-opening 22 has a first edge region 11.1 on the top 10.1 and a second edge region 11.2 on the bottom 10.2. The first edge region 11.1 is formed directly on the metal structure MV and the second edge region 11.2 is formed directly on the rear-side metallization MR.

[0103] The first edge region 11.1 has a first section 12.1 and a second, metallic section 12.2. The second edge region 11.2 has a first section 13.1 and a second section 13.2. Hereinafter, the first section 12.1 of the first edge region 11.1 and the second section 12.2 of the first edge region 11.1 are also referred to as the first part or as the second part of the first edge region.

[0104] Accordingly, the first section 13.1 and the second section 13.2 of the second edge region 11.2 are also referred to as the first part or as the second part of the second edge region 11.2.

[0105] A part of the first edge region 11.1 formed directly around the through-opening 22, the entire second edge region 11.2, as well as the side wall 22.1 of the through-opening 22 are coated with an insulating layer 24, wherein the insulating layer 24 is formed with a first printing process. It is a matter of course that the side wall 22.1 in the through-opening 22 is completely covered by the insulating layer 24.

[0106] By means of a second printing process, a conductive layer 32 is applied to the entire area of the first edge region 11.1 and completely to the entire area of the side wall 22.1 and to a part of the second edge region 11.2 directly adjacent to the through-opening 22. In the present case, the through-opening 22 is still open, even after the conductive layer 32 has been formed.

[0107] Because the conductive layer 32 reaches over the insulating layer 24 on the top 10.1 and forms an integral connection with a part of the metal structure MV, but only covers the part of the second edge region 11.2 immediately adjacent to the through-opening 22 on the bottom 10.2, a contact region for a connection to the metal structure MV is formed on the bottom 10.2 by this means.

[0108] In the illustration in FIG. 2, another embodiment is shown. Only the differences from the illustration in FIG. 1 are explained below.

[0109] In the embodiment shown, the conductive layer 32 meets in the middle of the substrate 14 and forms a profile in the shape of an hourglass.

[0110] In the illustration in FIG. 3, a different embodiment is shown. Only the differences from the illustration in FIG. 1 are explained below.

[0111] In the embodiment shown, the through-opening 22 is completely filled by the conductive layer 32 and forms a bump projecting from the top 10.1 and one projecting from the bottom 10.2.

[0112] In the illustration in FIG. 4a, a top view of the top of the metallized through-opening 22 corresponding to the embodiment shown in connection with the illustration in FIG. 3 is illustrated.

[0113] The first edge region 11.1, as part of the metal structure MV, completely encloses the through-opening 22. The part of the first edge region 11.1 covered by the insulating layer 24 is drawn in dashed lines. It becomes apparent that the conductive layer 32 completely covers the insulating layer 24 on the top 10.1.

[0114] In the illustration in FIG. 4b, a top view of the bottom of the metallized through-opening 22 corresponding to the embodiment shown in connection with the illustration in FIG. 3 is illustrated.

[0115] The second edge region 11.2, as part of the rear-side metallization MR, completely encloses the through-opening 22. The part of the second edge region 11.2 covered by the insulating layer 24 is now larger than the part covered by the conductive layer 32. In other words, the conductive layer 32 only partially covers the insulating layer 24 on the bottom 10.2.

[0116] In the illustration in FIG. 5, another cross-sectional view of a metallized through-opening is shown. Only the differences from the illustration in FIG. 1 and the illustration in FIG. 4b are explained below.

[0117] On the bottom 10.2, the first section 13.1 of the second edge region 11.2 is widened at least on the right side of the through-opening 22 in order to form a first contact region K1. On the second section 13.2 of the second edge region 11.2, the bottom 10.2 is covered only by the insulating layer 24.

[0118] A second contact region K2 is formed on the bottom 10.2 adjacent to the second section 24 as part of the rear-side metallization MR.

[0119] The insulating layer 24 is likewise formed in a part of the second contact region K2 on the bottom 10.2 to adjust the height of the second contact region K2. In other words, the rear-side metallization MR is formed integrally on the insulating layer 24 in the second contact region K2.

[0120] By this means, the two surfaces of the first contact region K1 and the second contact region K2 can be adjusted so as to solder both contact regions K1 and K2 at the same time.

[0121] In the illustration in FIG. 6, a top view of a semiconductor body 10 with two solar cell stacks is shown. In the present case, the semiconductor body 10 has exactly two solar cell stacks 12. It is a matter of course that more than two solar cell stacks 12 can also be formed on the semiconductor body 10 in embodiments that are not shown.

[0122] 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.