Abstract: A method for passing photovoltaic current between a subcell formed from a single crystal Group ll-VI semiconductor material and a subcell formed from a single crystal Group IV semiconductor material, includes the steps of forming a first subcell by an epitaxial growth process, the first subcell having a first upper surface; forming a tunnel heterojunction between the first subcell and the second subcell, and tunneling carriers formed by light incident on the first and second subcells through the tunnel heterojunction, thereby permitting a photoelectric series current to flow through the first and second subcells.

Abstract: A photovoltaic cell comprises a first subcell formed of a Group IV semiconductor material, a second subcell formed of a Group II-VI semiconductor material, and a tunnel heterojunction interposed between the first and second subcells. A first side of the tunnel heterojunction is formed by a first layer that is adjacent to a top surface of the first subcell. The first layer is of a first conductivity type, is comprised of a highly doped Group IV semiconductor material. The other side of the tunnel heterojunction is formed by a second layer that adjoins the lower surface of the second subcell. The second layer is of a second conductivity type opposite the first conductivity type, and is comprised of a highly doped Group II-VI semiconductor material. The tunnel heterojunction permits photoelectric series current to flow through the subcells.

Abstract: A photovoltaic cell comprises a first subcell formed of a Group IV semiconductor material, a second subcell formed of a Group II-VI semiconductor material, and a tunnel heterojunction interposed between the first and second subcells. A first side of the tunnel heterojunction is formed by a first layer that is adjacent to a top surface of the first subcell. The first layer is of a first conductivity type, is comprised of a highly doped Group IV semiconductor material. The other side of the tunnel heterojunction is formed by a second layer that adjoins the lower surface of the second subcell. The second layer is of a second conductivity type opposite the first conductivity type, and is comprised of a highly doped Group II-VI semiconductor material. The tunnel heterojunction permits photoelectric series current to flow through the subcells.

Abstract: A photovoltaic cell comprises a first subcell formed of a Group IV semiconductor material, a second subcell formed of a Group II-VI semiconductor material, and a tunnel homojunction interposed between the first and second subcells. A first side of the tunnel homojunction is formed by a first layer that is adjacent to a top surface of the first subcell. The first layer is of a first conductivity type and is comprised of a highly doped Group IV semiconductor material. The other side of the tunnel homojunction is formed by a second layer that adjoins the lower surface of the second subcell. The second layer is of a second conductivity type opposite the first conductivity type and also is comprised of a highly doped Group IV semiconductor material. The tunnel homojunction permits photoelectric series current to flow through the subcells.

Abstract: A photovoltaic cell comprises a first subcell formed of a Group IV semiconductor material, a second subcell formed of a Group II-VI semiconductor material, and a tunnel homojunction interposed between the first and second subcells. A first side of the tunnel homojunction is formed by a first layer that is adjacent to a top surface of the first subcell. The first layer is of a first conductivity type and is comprised of a highly doped Group IV semiconductor material. The other side of the tunnel homojunction is formed by a second layer that adjoins the lower surface of the second subcell. The second layer is of a second conductivity type opposite the first conductivity type and also is comprised of a highly doped Group IV semiconductor material. The tunnel homojunction permits photoelectric series current to flow through the subcells.

Abstract: A photovoltaic cell comprises a first subcell formed of a Group IV semiconductor material, a second subcell formed of a Group II-VI semiconductor material, and a tunnel heterojunction interposed between the first and second subcells. A first side of the tunnel heterojunction is formed by a first layer that is adjacent to a top surface of the first subcell. The first layer is of a first conductivity type, is comprised of a highly doped Group IV semiconductor material. The other side of the tunnel heterojunction is formed by a second layer that adjoins the lower surface of the second subcell. The second layer is of a second conductivity type opposite the first conductivity type, and is comprised of a highly doped Group II-VI semiconductor material. The tunnel heterojunction permits photoelectric series current to flow through the subcells.