Patent ID: 11881532
Assignee: AZUR SPACE SOLAR POWER GMBH
Field: Semiconductors (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 18:
19. A stacked multi-junction solar cell comprising:
a solar cell stack with a front side, a rear side, and a through contact opening extending from the front side to the rear side of the solar cell stack;
a front terminal contact;
a rear terminal contact;
a dielectric insulating layer; and
a contact layer,
wherein the solar cell stack has a germanium substrate layer forming the rear side, a germanium subcell, and at least two III-V subcells, the germanium subcell being formed between the germanium substrate layer and the at least two III-V subcells,
wherein the through contact opening has a continuous lateral surface and an oval perimeter in cross section,
wherein the front terminal contact is arranged on the front side of the solar cell stack and is connected to the front side of the solar cell stack in an integral and electrically conductive manner,
wherein the dielectric insulating layer covers a region of the front side of the solar cell stack that is not covered by the front terminal contact, an edge region of a top surface of the front terminal contact, the lateral surface of the through contact opening, and a region of the rear side of the solar cell stack adjacent to the through contact opening,
wherein the contact layer extends on the dielectric insulating layer from the top of the front terminal contact that is not covered by the dielectric insulating layer through the through contact opening to the rear side of the solar cell stack, is connected to the top of the front terminal contact in an integral and electrically conductive manner, and is connected to the dielectric insulating layer in an integral manner,
wherein a central portion of the through contact opening is empty from a height of the front side of the solar cell stack to a height of the rear side of the solar cell stack,
wherein the rear terminal contact covers a region of the rear side of the solar cell stack that is not covered by the dielectric insulating layer, and is connected to the rear side of the solar cell stack in an integral and electrically conductive manner,
wherein the contact layer is a multilayer system comprising, in the stated order, a first layer that includes gold and germanium with a layer thickness of at least 2 nm and at most 50 nm, a second layer that includes titanium with a layer thickness of at least 10 nm and at most 300 nm, a third layer that includes palladium or nickel or platinum with a layer thickness of at least 5 nm and at most 300 nm, and at least one metallic fourth layer with a layer thickness of at least 2 μm, and
wherein the first layer is adjacent to the dielectric insulating layer and to the front terminal contact.