A solar cell device includes a supporting substrate, and an epitaxial active structure that is disposed on the supporting substrate. The epitaxial active structure has a bottom surface adjacent to the supporting substrate and a top surface opposite to the bottom surface, and is formed with an isolation section that extends from the top surface to the bottom surface. A method for producing the solar cell device is also disclosed.

Visibly transparent photovoltaic devices are disclosed, such as those are transparent to visible light but absorb near-infrared light and/or ultraviolet light. The photovoltaic devices make use of transparent electrodes and near-infrared absorbing visibly transparent photoactive compounds, optical materials, and/or buffer materials.

A tandem photovoltaic cell includes a top cell having a first absorber and a bottom cell having a second absorber. The top cell and the bottom cell are electrically coupled in series. The top cell is configured to receive solar radiation through a first surface of the top cell and to transmit photons through a second surface of the top cell to the bottom cell, and the bottom cell is configured to receive the photons from the top cell through a first surface of the bottom cell and to receive solar radiation through a second surface of the bottom cell. A photovoltaic module includes a multiplicity of the tandem photovoltaic cells.

A tandem photovoltaic cell includes a top cell having a first absorber and a bottom cell having a second absorber. The top cell and the bottom cell are electrically coupled in series. The top cell is configured to receive solar radiation through a first surface of the top cell and to transmit photons through a second surface of the top cell to the bottom cell, and the bottom cell is configured to receive the photons from the top cell through a first surface of the bottom cell and to receive solar radiation through a second surface of the bottom cell. A photovoltaic module includes a multiplicity of the tandem photovoltaic cells.

Disclosed are a solar cell including an upper cell includes an upper passivation layer disposed on an upper surface of a functional layer, a transparent electrode disposed on an upper surface of the upper passivation layer, an upper first charge transport layer disposed on an upper surface of the transparent electrode, an upper electrode disposed on the upper first of the transparent electrode to be adjacent to the upper surface charge transport layer, an upper second charge transport layer disposed on the upper surface of the functional layer to be spaced apart from the upper passivation layer, the transparent electrode, the upper first charge transport layer, and the upper electrode, and an upper absorption layer disposed on the upper passivation layer, the transparent electrode, the upper first charge transport layer, and the upper second charge transport layer.

A method for manufacturing a stacked thin film of an embodiment includes forming a p-electrode on a substrate, forming a film that mainly contains a cuprous oxide and/or a complex oxide of cuprous oxides on the p-electrode, and performing an oxidation treatment on the film that mainly contains the cuprous oxide and/or the complex oxide of cuprous oxides. An ozone partial pressure in the oxidation treatment is 5 [Pa] or more and 200 [Pa] or less, a treatment temperature in the oxidation treatment is 273 [K] or more and 323 [K] or less, and a treatment time in the oxidation treatment is 1 second or more and 60 minutes or less.

A compound-semiconductor photovoltaic cell includes a first photoelectric conversion cell made of a first compound-semiconductor material which lattice matches with GaAs or Ge; a first tunnel junction layer arranged on a deep side farther than the first photoelectric conversion cell in a light incident direction, and including a first p-type (Al.sub.x1Ga.sub.1-x1).sub.y1In.sub.1-y1As (0≤x1<1, 0<y1≤1) layer and a first n-type (Al.sub.x2Ga.sub.1-x2).sub.y2In.sub.1-y2P (0≤x2<1, 0<y2<1) layer; and a second photoelectric conversion cell arranged on a deep side farther than the first tunnel junction layer in the light incident direction, and made of a second compound-semiconductor material which is a GaAs-based semiconductor material. The first photoelectric conversion cell and the second photoelectric conversion cell are joined via the first tunnel junction layer, and a lattice constant of the first n-type (Al.sub.x2Ga.sub.1-x2).sub.y2In.sub.1-y2P layer is greater than a lattice constant of the first photoelectric conversion cell.

Tunnel junctions for multijunction solar cells are provided. According to an aspect of the invention, a tunnel junction includes a first layer including p-type AlGaAs, a second layer including n-type GaAs, wherein the second layer is a quantum well, and a third layer including n-type AlGaAs or n-type lattice matched AlGaInP. The quantum well can be GaAs or AlxGaAs with x being more than about 40%, and lattice matched GaInAsNSb in the Eg range of from about 0.8 to about 1.4 eV.

Tunnel junctions for multijunction solar cells are provided. According to an aspect of the invention, a tunnel junction includes a first layer including p-type AlGaAs, a second layer including n-type GaAs, wherein the second layer is a quantum well, and a third layer including n-type AlGaAs or n-type lattice matched AlGaInP. The quantum well can be GaAs or AlxGaAs with x being more than about 40%, and lattice matched GaInAsNSb in the Eg range of from about 0.8 to about 1.4 eV.

A multijunction solar cell including interconnected first and second discrete semiconductor regions disposed adjacent and parallel to each other including first top solar subcell, second (and possibly third) lattice matched middle solar subcells; a graded interlayer adjacent to the last middle solar subcell; and a bottom solar subcell adjacent to said graded interlayer being lattice mismatched with respect to the last middle solar subcell; wherein an opening is provided from the bottom side of the semiconductor body to one or more of the solar subcells so as to allow a discrete electrical connector to be made extending in free space and to electrically connect contact pads on one or more of the solar subcells.